Hydrogenaudio Knowledgebase - User contributions [en]

Lossless comparison

2008-06-13T17:09:18Z

Jarsonic: /* Oddball Formats */

The '''lossless comparison page''' aims to gather information about lossless codecs available so users can make an informed decision as to what lossless codec to choose for their needs.

== Introduction ==
Given the enormous amount of [[lossless]] audio compressor choices available, it is a very difficult task to choose the one most suited for each person's needs.

Several people only take into consideration compression performance when choosing a codec. But as the following table and article shows, there are several other features worth taking into consideration when making that choice.

For example, users wanting good multiplatform compatibility and robustness (E.G, people sharing live recordings) would favour [[WavPack]] or [[FLAC]]. Another user, looking for the very highest compression available, would go with [[OptimFROG]]. Someone wanting portable support would use [[FLAC]] or [[ALAC]], and so on.

En fin, this is not a matter worth getting too worked up about. If you later find out the codec you chose isn't the best for your needs, you can just transcompress to another format, without risk of losing quality.

'''Note:''' for latest comparison of lossless compression, scroll down to the [[Lossless comparison#External links|Links section of this page]].

== Comparison Table ==


{| cellspacing="2" style="text-align:center; border:1px solid blue;"
|width="120px"|'''Features'''
| width="95px" style="background: #00FFFF" | FLAC
| width="95px" style="background: #00FFFF" | WavPack
| width="95px" style="background: #00FFFF" | TAK
| width="95px" style="background: #00FFFF" | Monkey's
| width="95px" style="background: #00FFFF" | OptimFROG
| width="95px" style="background: #00FFFF" | ALAC
| width="95px" style="background: #00FFFF" | WMA
|-
|align="left" style="background: #FFFF99" | Encoding speed
| style="background: #CCFFCC" | fast
| style="background: #00FF00" | very fast
| style="background: #00FF00" | very fast
| style="background: #CCFFCC" | fast
| style="background: #FF9900" | slow
| style="background: #FFFFFF" | average
| style="background: #FFFFFF" | average
|-
|align="left" style="background: #FFFF99" | Decoding speed
| style="background: #00FF00" | very fast
| style="background: #00FF00" | very fast
| style="background: #00FF00" | very fast
| style="background: #FFFFFF" | average
| style="background: #FFFFFF" | average
| style="background: #CCFFCC" | fast
| style="background: #FFFFFF" | average
|-
|align="left" style="background: #FFFF99" | Compression*
| style="background: #CCFFCC" | 58.70%
| style="background: #CCFFCC" | 58.0%
| style="background: #CCFFCC" | 57.0%
| style="background: #00FF00" | 55.50%
| style="background: #00FF00" | 54.70%
| style="background: #CCFFCC" | 58.50%
| style="background: #00FF00" | 56.30%
|-
|align="left" style="background: #FFFF99" | Flexibility**
| style="background: #00FF00" | very good
| style="background: #00FF00" | very good
| style="background: #00FF00" | very good
| style="background: #00FF00" | very good
| style="background: #00FF00" | very good
| style="background: #FF9900" | bad
| style="background: #FF9900" | bad
|-
|style="background: #FFFFFF" |  
|-
|align="left" style="background: #FFFF99" | Error handling
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FFFFFF" |  
| style="background: #00FF00" | yes
|-
|align="left" style="background: #FFFF99" | Seeking
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
|-
|align="left" style="background: #FFFF99" | Tagging
| style="background: #00FF00" | Vorbis tags
| style="background: #00FF00" | ID3/APE
| style="background: #CCFFCC" | APEv2 (exp.)
| style="background: #00FF00" | ID3/APE
| style="background: #00FF00" | ID3/APE
| style="background: #CCFFCC" | Quicktime
| style="background: #CCFFCC" | ASF
|-
| align="left" style="background: #FFFF99" | Hardware support
| style="background: #00FF00" | very good
| style="background: #FF9900" | limited
| style="background: #FF9900" | no
| style="background: #FF9900" | limited
| style="background: #FF9900" | no
| style="background: #CCFFCC" | good
| style="background: #FF9900" | limited
|-
| align="left" style="background: #FFFF99" | Software support
| style="background: #00FF00" | very good
| style="background: #CCFFCC" | good
| style="background: #FFFFFF" | average
| style="background: #CCFFCC" | good
| style="background: #FFFFFF" | average
| style="background: #FF9900" | bad
| style="background: #CCFFCC" | good
|-
| align="left" style="background: #FFFF99" | Hybrid/lossy
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Replay Gain
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FFFFFF" | sort of
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | RIFF chunks
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FFFFFF" |  
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FFFFFF" |  
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Streaming
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
|-
| align="left" style="background: #FFFF99" | Pipe support
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
|-
| align="left" style="background: #FFFF99" | Open source
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #CCFFCC" | yes (decoding)
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Multichannel
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
|-
| align="left" style="background: #FFFF99" | High resolution
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
|-
| align="left" style="background: #FFFF99" | OS support
| style="background: #00FF00" | All
| style="background: #00FF00" | All
| style="background: #CCFFCC" | Win/Linux Wine
| style="background: #00FF00" | All
| style="background: #00FF00" | Win/Mac/Linux
| style="background: #CCFFCC" | Win/Mac
| style="background: #CCFFCC" | Win/Mac
|}

''(table continued below)''

{| cellspacing="2" style="text-align:center; border:1px solid blue;"
|width="120px"|'''Features'''
| width="95px" style="background: #00FFFF" | Shorten
| width="95px" style="background: #00FFFF" | LA
| width="95px" style="background: #00FFFF" | TTA
| width="95px" style="background: #00FFFF" | LPAC
| width="95px" style="background: #00FFFF" | MPEG-4 ALS
| width="95px" style="background: #00FFFF" | MPEG-4 SLS
| width="95px" style="background: #00FFFF" | Real Lossless
|-
| align="left" style="background: #FFFF99" | Encoding speed
| style="background: #00FF00" | very fast
| style="background: #FF9900" | slow
| style="background: #00FF00" | very fast
| style="background: #FFFFFF" | average
| style="background: #FFFFFF" | average
| style="background: #FF9900" | slow
| style="background: #FF9900" | slow
|-
| align="left" style="background: #FFFF99" | Decoding speed
| style="background: #00FF00" | very fast
| style="background: #FF9900" | slow
| style="background: #CCFFCC" | fast
| style="background: #CCFFCC" | fast
| style="background: #CCFFCC" | fast
| style="background: #FF9900" | slow
| style="background: #CCFFCC" | fast
|-
| align="left" style="background: #FFFF99" | Compression*
| style="background: #FF9900" | 63.50%
| style="background: #00FF00" | 53.50%
| style="background: #CCFFCC" | 57.10%
| style="background: #CCFFCC" | 57.20%
| style="background: #CCFFCC" | 57.10%
| style="background: #CCFFCC" | ?
| style="background: #CCFFCC" | 57.0%
|-
| align="left" style="background: #FFFF99" | Flexibility**
| style="background: #FF9900" | bad
| style="background: #FFFFFF" | average
| style="background: #FF9900" | bad
| style="background: #FF9900" | bad
| style="background: #00FF00" | very good
| style="background: #FF9900" | bad
| style="background: #FF9900" | bad
|-
|! style="background: #FFFFFF" |  
|-
| align="left" style="background: #FFFF99" | Error handling
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FFFFFF" |  
|-
| align="left" style="background: #FFFF99" | Seeking
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | slow
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
|-
| align="left" style="background: #FFFF99" | Tagging
| style="background: #FF9900" | no
| style="background: #CCFFCC" | ID3v1
| style="background: #CCFFCC" | ID3
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #CCFFCC" | Proprietary
|-
| align="left" style="background: #FFFF99" | Hardware support
| style="background: #FF9900" | limited
| style="background: #FF9900" | no
| style="background: #FF9900" | limited
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Software support
| style="background: #00FF00" | very good
| style="background: #FF9900" | bad
| style="background: #FFFFFF" | average
| style="background: #FFFFFF" | average
| style="background: #FF9900" | bad
| style="background: #FF9900" | bad
| style="background: #FF9900" | bad
|-
| align="left" style="background: #FFFF99" | Hybrid/lossy
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Replay Gain
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | RIFF chunks
| style="background: #FF9900" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FFFFFF" |  
| style="background: #FFFFFF" |  
| style="background: #FFFFFF" |  
|-
| align="left" style="background: #FFFF99" | Streaming
| style="background: #FF9900" | no
| style="background: #FFFFFF" |  
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
|-
| align="left" style="background: #FFFF99" | Pipe support
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #FFFFFF" |  
| style="background: #FFFFFF" |  
| style="background: #FFFFFF" |  
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Open source
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | Multichannel
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | High resolution
| style="background: #FF9900" | no
| style="background: #FF9900" | no
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #00FF00" | yes
| style="background: #FF9900" | no
|-
| align="left" style="background: #FFFF99" | OS support
| style="background: #00FF00" | All
| style="background: #CCFFCC" | Win/Linux
| style="background: #00FF00" | All
| style="background: #CCFFCC" | Win/Linux/Sol
| style="background: #00FF00" | All
| style="background: #00FF00" | All
| style="background: #00FF00" | Win/Mac/Linux
|}

<nowiki>*</nowiki> The Compression ratio is calculated with the division of compressed size by uncompressed size * 100. So, lower is better.

Encoding speed, Decoding speed and Compression ratio are based on each encoder's default settings.

<nowiki>**</nowiki> Flexibility refers to the amount of encoding choices offered to the users (Fast/low compression, Slow/high compression and everything inbetween)

These are the most popular lossless codecs, in alphabetical order:

== Apple Lossless Audio Codec (ALAC) ==
http://www.apple.com/itunes/import.html

[[ALAC]] is a codec developed by Apple for usage in [[Apple iPod|iPod]] and AirPort Express.

=== ALAC pros ===
* Very fast decoding
* [[Open source]] ([http://craz.net/programs/itunes/alac.html decoding only])
* Hardware support ([[Apple iPod|iPod]], AirPort Express)
* Streaming support
* Tagging support (QT tags)
* Excellent hardware-software-lossy format integration with [[iTunes]]/iPod.
* Supports [[multichannel]] audio and [[high resolution]]s

=== ALAC cons ===
* Closed source (encoding)
* Limited software support
* Compression efficiency not on par with other lossless codecs
* No hybrid/lossy mode

=== ALAC Other features ===
* Fits in the [[MP4]] container
* Can be used with the AirPort Express gadget

== Free Lossless Audio Codec (FLAC) ==
http://flac.sourceforge.net/

[[FLAC]] is a lossless codec developed by Josh Coalson. It's part of the Xiph multimedia portfolio, along with [[Ogg]], [[Vorbis]], [[Speex]] and [[Theora]].

=== FLAC pros ===
* [[Open source]]
* Very fast decoding
* Fast encoding
* Hardware support ([[Rio Karma|Karma]], Phatbox, etc.)
* Very good software support
* Error robustness
* Streaming support
* Supports [[multichannel]] audio and [[high resolution]]s
* Tagging support (FLAC tags)
* Supports [[RIFF]] chunks
* Pipe support
* [[Replay Gain]] compatible

=== FLAC cons ===
* No hybrid/lossy mode

=== FLAC Other features ===
* Supports embedded CUE sheets (with [http://flac.sourceforge.net/faq.html#general__no_cuesheet_tags limitations])
* Includes MD5 hashes for quick integrity checking
* Fits the [[Ogg]] and [[Matroska]] containers

== LosslessAudio (LA) ==
http://www.lossless-audio.com/

[[LA]] is a lossless codec developed by Michael Bevin.

=== LA pros ===
* Very high compression
* Tagging support ([[ID3v1]])
* Supports [[RIFF]] chunks
* Pipe support

=== LA cons ===
* Closed source
* Very slow encoding and decoding
* Doesn't support [[multichannel]] audio and [[high resolution]]s
* No hardware support
* No hybrid/lossy mode
* Bad software support
* Doesn't support [[Replay Gain]]

'''''It's important to mention that the LA foobar plugin is buggy and doesn't produce lossless streams!'''''

== Lossless Predictive Audio Coder (LPAC) ==
http://www.nue.tu-berlin.de/wer/liebchen/lpac.html

[[Lossless Predictive Audio Coder]] (LPAC) is a lossless codec developed by Tilman Liebchen. Development of it has been halted in favour of development of [[MPEG-4]] ALS.

=== LPAC pros ===
* Reasonable compression ratios
* [[High resolution]] audio support
* Supports [[RIFF]] chunks

=== LPAC cons ===
* Closed source
* No error robustness
* Slow seeking
* No tagging
* No [[multichannel]] support
* No hybrid/lossy mode
* No hardware support
* Doesn't support [[Replay Gain]]

== Monkey's Audio (APE) ==
http://www.monkeysaudio.com/

[[Monkey's Audio]] is a very efficient lossless compressor developed by Matt Ashland.

=== APE pros ===
* [[Open source]]
* High efficiency
* Good software support
* Simple and user friendly. Official GUI provided.
* Java version (multiplatform)
* Tagging support ([[ID3v1]], [[APE tags]])
* [[High resolution]] audio support
* Supports [[RIFF]] chunks (only in the GUI encoder)
* Pipe support (only in a [http://www.etree.org/shnutils/shntool/ special] version)

=== APE cons ===
* No [[multichannel]] support
* No error robustness
* No hybrid/lossy mode
* Limited hardware support ([http://www.engadget.com/2006/08/17/gemei-x-21-offers-ape-support/ Gemei X21])
* Doesn't support [[Replay Gain]]

=== APE Other features ===
* Includes MD5 hashes for quick integrity checking
* Supports APL image link files (similar to CUE sheets)

== MPEG-4 SLS ==
MPEG-4 SLS allows audio encoding from lossless scalable to [[AAC]].

=== SLS pros ===
* Transcoding to standard AAC or any higher lossy bitrate at the speed of copying a file
* Scalable decoding from lossless, to any bitrate down to the AAC core track
* Best lossless compression available when you count the AAC track (~5% gain over any other lossless compression + AAC)
* [[High resolution]] audio support
* Multi channel audio support
* [[Open source]] (MPEG-4 Reference code)
* Embedded in standard MP4 files, so supports same tagging and Replay Gain features as AAC does.

=== SLS cons ===
* No usable software available yet
* Pure lossless compression not the best there is
* Seems to be slow in encoding and decoding, but we have to wait for released software

=== SLS Other features ===
* Transform based lossless codec with optional LC AAC core track

== OptimFROG (OFR) ==
http://losslessaudiocompression.com/

[[OptimFROG]] is a lossless format developed by Florin Ghido to become the champion in audio compression.

=== OFR pros ===
* Very high compression
* Good software support
* Error robustness
* Streaming support
* Supports [[high resolution]]s
* Hybrid/lossy mode
* Tagging support ([[ID3]], [[APE tags]])
* Supports [[RIFF]] chunks
* [[Replay Gain]] compatible

=== OFR cons ===
* Closed source
* No [[multichannel]] audio support
* No hardware support
* Quite slow decoding

=== OFR Other features ===
* Supports 32bit float streams
* Includes MD5 hashes for quick integrity checking

== RealAudio Lossless (RAL) ==
http://www.realnetworks.com/products/codecs/realaudio.html

RealAudio lossless is the lossless codec developed by Real Networks for their multimedia portfolio

=== RAL pros ===
* Very fast decoding
* Streaming support
* Tagging support (proprietary)

=== RAL cons ===
* Closed source
* No [[multichannel]] and [[high resolution]] audio support
* Little software support (Real Player)
* No hardware support
* Compression efficiency not on par with other lossless codecs
* No hybrid/lossy mode
* No pipe support
* Doesn't support [[Replay Gain]]

== Shorten (SHN) ==
http://www.etree.org/shnutils/shorten/

[[Shorten]] is a very old and featureless lossless codec developed by Tony Robinson at SoftSound.

=== SHN pros ===
* [[Open source]]
* Fast decoding
* Very good software support
* Supports [[RIFF]] chunks
* Pipe support

=== SHN cons ===
* Quite inefficient
* No [[multichannel]] or [[high resolution]] audio support
* No hybrid/lossy mode
* No error robustness
* Not streamable
* No hardware support
* No native tagging
* Doesn't support [[Replay Gain]]

== True Audio (TTA) ==
http://www.true-audio.com/

[[TTA]] is a new lossless codec developed by a team of russian programmers.

=== TTA pros ===
* [[Open source]]
* Good efficiency
* Hardware support (obscure DVD player)
* Supports [[multichannel]] audio and [[high resolution]]s
* Tagging support ([[ID3]])
* [[Replay Gain]] compatible
* Error robustness

=== TTA cons ===
* No streaming support
* No hybrid/lossy mode
* Doesn't support [[RIFF]] chunks
* No pipe support

=== TTA Other features ===
* Fits the [[Matroska]] container

== WavPack (WV) ==
http://www.wavpack.com/

[[WavPack]] is a fast and featureful lossless codec developed by David Bryant.

=== WV pros ===
* [[Open source]]
* Very fast decoding
* Very fast encoding
* Good efficiency
* Error robustness
* Streaming support
* Hardware support ([http://www.rockbox.org/ RockBox])
* Supports [[multichannel]] audio and [[high resolution]]s
* Hybrid/lossy mode
* Tagging support ([[ID3v1]], [[APE tags]])
* Supports [[RIFF]] chunks
* Ability to create self extracting files for Win32 platform
* Pipe support
* Good software support
* [[Replay Gain]] compatible

=== WV cons ===
* Limited hardware player support

=== WV Other features ===
* Supports 32bit float streams
* Supports embedded CUE sheets
* Includes MD5 hashes for quick integrity checking
* Can encode in both symmetrical and assymmetrical modes.
* Fits the [[Matroska]] container

== Windows Media Audio Lossless (WMAL) ==
http://www.microsoft.com/windows/windowsmedia/9series/codecs/audio.aspx

WMA Lossless is the lossless codec developed by Microsoft to be featured in their Windows Media codec portfolio.

=== WMAL pros ===
* Streaming support
* Very good software support
* Supports [[multichannel]] audio and [[high resolution]]s.
* Tagging support (proprietary)
* Pipe support

=== WMAL cons ===
* Closed source
* No hybrid/lossy mode
* Limited hardware support ([http://en.wikipedia.org/wiki/Gigabeat Gigabeat V and S line from Toshiba])
* Doesn't support [[RIFF]] chunks
* Doesn't support [[Replay Gain]]

=== WMAL Other features ===
* Fits the [[ASF]] container

== Oddball Formats ==
There are several old lossless formats that aren't being featured in the article above. Reasons are: lack of widespread support, lack of features, bad efficiency and, most importantly, it seems no one is really interested in them.

Most of those would have disappeared by now, but they are being preserved for posterity at [[User:Rjamorim|rjamorim]]'s [http://www.rjamorim.com/rrw/ ReallyRareWares]

=== Advanced Digital Audio (ADA) ===
* http://www.rjamorim.com/rrw/ada.html

=== Bonk ===
* http://www.logarithmic.net/pfh/bonk

=== Marian's a-Pac ===
* http://www.marian.de/en/downloads#APAC
* http://www.rjamorim.com/rrw/apac.html

=== AudioZip ===
* http://www.rjamorim.com/rrw/audiozip.html

=== Dakx WAV ===
* http://www.dakx.com/
* http://www.rjamorim.com/rrw/daxwav.html

=== Entis Lab MIO ===
* http://www.entis.gr.jp/eri/frame.html
* http://www.rjamorim.com/rrw/mio.html

=== LiteWave ===
* http://www.clearjump.com/products/LiteWave.html
* http://www.rjamorim.com/rrw/litewave.html

=== Pegasus SPS ===
* http://www.krishnasoft.com/sps.htm
* http://www.rjamorim.com/rrw/pegasussps.html

=== RK Audio (RKAU) ===
* http://www.rjamorim.com/rrw/split2000.html

=== Sonarc ===
* http://www.rjamorim.com/rrw/sonarc.html

=== VocPack ===
* http://www.rjamorim.com/rrw/vocpack.html

=== WavArc ===
* http://www.rjamorim.com/rrw/wavarc.html

=== WaveZip/MUSICompress ===
* http://members.aol.com/_ht_a/sndspace/
* http://www.rjamorim.com/rrw/wavezip.html

== See also ==
* [[Lossless]]

== External links ==
=== Other lossless compressions comparisons ===
''Sorted based on last '''update''' date.''

* [http://uclc.info/LossLess.pdf Johan De Bock's speed oriented comparison] - best choices speedwise are indicated in green, mostly electronic music (last updated 2006-07-22)
* [http://web.inter.nl.net/users/hvdh/lossless/lossless.htm Hans Heijden's] -- used as reference to build the table (last updated 2006-07-07)
* [http://synthetic-soul.co.uk/comparison/lossless/ Synthetic Soul's comparison] (last update 2007-07-28)
* [http://synthetic-soul.co.uk/comparison/josef/ Josef Pohm's comparison, hosted by Synthetic Soul] (last update 2006-05-29)
* [http://www.bobulous.org.uk/misc/lossless_audio_2006.html Bobulous' lossless audio comparison] — a look at six lossless formats in terms of speed and file size (last updated 2006-05-22)
* [http://uclc.info/lossless_audio_compression_test.htm Johan De Bock's size oriented comparison] - aimed only at the maximum compression setting for each codec (based on a somewhat limited set of samples, however) (last updated 2006-05-19)
* [http://guruboolez.free.fr/lossless/ Guruboolez'] -- comparing only classical music (last updated 2005-02-27)
* [http://members.home.nl/w.speek/comparison.htm Speek's] (last updated 2005-02-07)

=== More on lossless compressions ===
* [http://losslessaudioblog.com/ The Lossless Audio Blog] - by windmiller, is a reliable and complete source of news about lossless compression.
* Go to the [http://www.hydrogenaudio.org/forums/index.php?showtopic=33226 Hydrogenaudio thread] to discuss this article.

[[Category:Guides]]

User:Jarsonic

2007-07-18T17:42:41Z

Jarsonic:

'''Jarsonic''' is the Internet moniker of '''Hunter Chorey'''. Hunter grew up in [[wikipedia:Atlanta, Georgia|Atlanta]], [[wikipedia:Georgia|Georgia]] and then went on to attend the [[wikipedia:University of Virginia|University of Virginia]] in [[wikipedia:Charlottesville, Virginia| Charlottesville]], [[wikipedia:Virginia|Virginia]] where he currently resides. Graduating from [[wikipedia:University of Virginia|UVA]] in 2005 with dual majors in Economics and Religious Studies, Hunter is a strategies analyst at an intellectual property consulting firm in Charlottesville.

Hunter is also an alumni of the 2005-2006 class of the [http://fellows.trinitycville.org Trinity Fellows Program] through [http://www.trinitycville.org Trinity Presbyterian Church] in Charlottesville.

== External links ==
=== Personal ===
*[http://thewildgoosechase.org/hunter/ Hunter's blog]
*[http://jarsonic.deviantart.com/ Hunter's DeviantArt gallery]

=== Frequented Forums ===
*[http://derekwebb.musiccitynetworks.com/index.htm?id=7017 the webboard] at [http://www.derekwebb.com/ derekwebb.com]
*[http://www.hydrogenaudio.org/ HydrogenAudio]

AAC encoders

2006-11-30T17:13:29Z

Jarsonic: /* iTunes AAC */

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietary AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found about Apple's AAC implementation on their [http://www.apple.com/quicktime/technologies/aac/ AAC Audio information page].

The current recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

The iTunes AAC encoder can be externally envoked via a command line tool created by Otto42 called [http://www.rarewares.org/files/aac/iTunesEncode46.zip iTunesEncode], which can be found at [http://www.rarewares.org/ RareWares] in the AAC section. This allows for the generation of iTunes AAC files from audio formats not inherently supported by iTunes using the format conversion functionality found in programs such as [[foobar2000]].

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding].

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares].

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T17:12:21Z

Jarsonic: /* iTunes AAC */

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietary AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found about Apple's AAC implementation on their [http://www.apple.com/quicktime/technologies/aac/ AAC Audio information page].

The current recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

The iTunes AAC encoder can be externally envoked via a command line tool created by Otto42 called [http://www.rarewares.org/files/aac/iTunesEncode46.zip iTunesEncode], which can be found at [http://www.rarewares.org/ RareWares] in the AAC section. This allows for the generation of iTunes AAC files from audio formats not inherently supported by iTunes using the conversion functions found in programs such as [[foobar2000]].

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding].

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares].

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

Hydrogenaudio Listening Tests

2006-11-30T17:09:21Z

Jarsonic: /* External Tests */

From time to time, various HydrogenAudio members have conducted listening tests, both private and public, to evaluate the merit of lossy encoding technologies '''at a point in time'''. These test results are provided for the explicit purpose of documenting the performance of various codecs in relation to one another, in turn providing useful data in gauging the best, most efficient encoder over certain bitrates at the time the test was conducted.

It should be noted that these tests '''may become obsolete''' over time as development of the tested codecs progress. With that in mind, please ensure that you consult the most recent test results before drawing conclusions.

When you read the test results, you may come across unfamiliar terminology, especially concerning ''artifacts''. [http://ff123.net/training/training.html ff123's Artifact Training Page] is the place to go to understand what these 'artifacts' are all about.

'''Note:''' There is no such thing as listening tests for [[Lossless]] compression, as recordings encoded using Lossless codecs are, by nature, bit-identical in their output to their respective original uncompressed recordings. When testing Lossless codecs, only performance characteristics are taken into account (e.g. compression ration, encode/decode speed, etc). If you are interested in these aspects of lossless encoding, take a look at the [[Lossless comparison|Lossless comparison page]], instead.

=Format-specific Tests=
All tests sorted by date, with older ones at top. All dates are in [http://www.cl.cam.ac.uk/~mgk25/iso-time.html ISO8601 format].

==[[AAC]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffaaaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2004-12-09
| style="width:174px" | Ahead vs Apple 128-kbps Classical
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | iTunes 4.1.052, 4.7.042; Nero 2.5.9.7, 2.9.998 CBR, 2.9.998 VBR
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924&view=findpost&p=258644 HA Thread]
|-
| 2005-09-05
| 48- & 64-kbps HE-AAC Classical
| Guruboolez
| Private
| CT aacPlus v.2 48- & 64-kbps Helix 11.0.0.1897, Nero 3.2.0.20 VBR
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=36868&view=findpost&p=325091 HA Thread]
|-
| 2006-02-05
| 48-kbps HE-AAC Classical
| Ivan Dimkovic
| Public
| Nero HE-AAC v1 & v2
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=41191&hl= HA Thread]
|-
| 2006-02-20
| 48-kbps HE-AAC General
| Gabriel
| Public
| 3gpp (v1), CT (v1 & v2), Nero (v1 & v2)
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=42679&hl= HA Thread] [http://www.mp3-tech.org/tests/aac_48/results.html Complete Result]
|}

==[[MP3]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaffaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2004-01-18
| style="width:174px" | Dithering Test (1) Special
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[MP3]] Decoders: MAD, [[LAME]], Fraunhofer, foobar2000
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=17728&view=findpost&p=174740 HA Thread]
|-
| 2004-11-15
| 130-kbps LAME rjamorim
| Guruboolez
| Private
| [[LAME]] 3.90.3 ABR, 3.96.1 ABR, 3.96.1 VBR
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=29422&view=findpost&p=253968 HA Thread]
|-
| 2005-01-11
| 128-kbps LAME ff123
| Guruboolez
| Private
| [[LAME]] 3.90.3, 3.96.1, 3.97a5
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=30547&view=findpost&p=264411 HA Thread]
|-
| 2005-10-17
| [[LAME]] 3.98 -V5 Classical
| Guruboolez
| Private
| [[LAME]] 3.98: -V5, -V5 --vbr-new, -V5 --vbr-new --athaa-sensitivity 1
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=37973&view=findpost&p=335086 HA Thread]
|}

'''''Notes:'''
(1) Performed under extreme listening conditions not reproducible on daily listening.''

==[[MPC]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaaaff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2005-06-18
| style="width:174px" | --standard Classical
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | 1.01j, 1.15u
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=34911&view=findpost&p=306910 HA Thread]
|}

==[[Vorbis]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffffaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-06-18
| style="width:174px" | 128-kbps ff123/rjamorim
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | GT2 & PCVS
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=10555&view=findpost&p=106189 HA Thread]
|-
| 2004-06-17
| 160-kbps Special
| Guruboolez
| Private
| CVS, GT3b2, [[aoTuV]]b2, [[aoTuV]]b2+QK
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=22495&view=findpost&p=218681 HA Thread]
|-
| 2004-02-05
| -q4 Transients
| Guruboolez
| Private
| RC3 2002-03, RC3 2002-04, 1.01, 1.01 QK2
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=18359&view=findpost&p=180697 HA Thread]
|}

==[[WMA]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffaaff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-06-18
| style="width:174px" | 128-kbps ff123/rjamorim
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[WMA]]9 Standard & Pro
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=10551&view=findpost&p=106158 HA Thread]
|}

=Multiformat Tests=

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaffff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-10-11
| style="width:174px" | 130-kbps Classical (Baroque)
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[AAC]] (FAAC, PsyTel, Nero, QuickTime) [[MP3]] [[LAME]] 3.90.3, [[MPC]] 1.14, [[Vorbis]] GT3b1, [[WMA]]9 Pro
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=14091&view=findpost&p=142684 HA Thread]
|-
| 2003-12-13
| 128-kbps Classical
| Guruboolez
| Private
| [[AAC]] (iTunes, Nero, FAAC), [[Vorbis]] 1.01, [[WMA]]9, [[MP3]] [[LAME]] 3.93.1
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=16395&view=findpost&p=163116 HA Thread]
|-
| 2004-07-12
| 175-kbps Classical
| Guruboolez
| Private
| [[Vorbis]] Megamix -q5,50, -q5,99 -q6,00 [[MP3]] [[LAME]] 3.97a3 -V3, -V2, [[MPC]] -q5
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=23355&view=findpost&p=225046 HA Thread]
|-
| 2004-12-09
| 130-kbps Classical
| Guruboolez
| Private
| [[AAC]] Nero 2.9.9.998 [[Vorbis]] aoTuVb3
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=29925&view=findpost&p=258645 HA Thread]
|-
| 2005-03-05
| 140-kbps VBR Classical
| Guruboolez
| Private
| [[AAC]] Nero 3.0.0.4, [[Vorbis]] 1.1, QK28
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=32080&view=findpost&p=279240 HA Thread]
|-
| 2005-03-17
| 256-kbps Transcode from MP3 subset of ff123
| Guruboolez
| Private
| [[AAC]] iTunes 4.7, [[MP3]] [[LAME]] 3.97a8 [[MPC]] 1.15u, [[Vorbis]] aoTuVb3, [[WavPack]] 4.2b3 Lossy
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=32440&view=findpost&p=282909 HA Thread]
|-
| 2005-07-11
| 80-kbps Various
| Guruboolez
| Private
| [[LAME]] [[MP3]], [[AAC]]-HE and -LC, [[Vorbis]] [[aoTuV]], [[WMA]] Std
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=35438&view=findpost&p=312296 HA Thread]
|-
| 2005-08-09
| 96-kbps Classical & Various
| Guruboolez
| Private
| [[LAME]] [[MP3]], [[AAC]],[[Vorbis]] [[aoTuV]] (Lancer), [[MPC]], [[WMA]]
| [http://forum.hardware.fr/hardwarefr/VideoSon/MP3-WMA-AAC-OGG-qualite-kbps-evaluation-sujet-84950-1.htm#t922011 Hardware.fr thread (in French)]
|-
| 2005-08-22
| 180-kbps Classical
| Guruboolez
| Private
| [[AAC]], [[MP3]], [[MPC]], [[Vorbis]] [[aoTuV]]b4
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=36465 HA Thread]
|-
| 2006-01-13
| 128-kbps General
| Sebastian Mares
| Public
| iTunes & Nero [[AAC]], [[LAME]] [[MP3]], [[Vorbis]] [[aoTuV]], [[WMA]] Pro
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=40607&view=findpost&p=357117 HA Thread] [http://www.maresweb.de/listening-tests/mf-128-1/results.htm Complete Result]
|-
| 2006-11-22
| 48-kbps General
| Sebastian Mares
| Public
| [[Vorbis]] [[aoTuV]], Nero [[AAC]], [[WMA]] Pro, [[WMA]] Standard
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=50408 HA Thread]
|}

=External Tests=
Other people have held listening tests in venues outside of Hydrogenaudio (although the organizers of the tests tend to be HA members :). The results of these tests are found below:

* [http://ff123.net/ ff123's site on audio testing and listening tests] (most recent test 2002-07-27)
* [http://www.rjamorim.com/test/index.html Roberto's Public Listening Tests] (most recent test 2004-07-11)
* [http://www.maresweb.de/listening-tests/ Sebastian Mares' Listening Tests] (most recent test updated 2006-11-22)
* [http://www.soundexpert.info/ SoundExpert Listening Tests] (continually updated)

[[Category:Listening Tests]]

Hydrogenaudio Listening Tests

2006-11-30T17:06:31Z

Jarsonic:

From time to time, various HydrogenAudio members have conducted listening tests, both private and public, to evaluate the merit of lossy encoding technologies '''at a point in time'''. These test results are provided for the explicit purpose of documenting the performance of various codecs in relation to one another, in turn providing useful data in gauging the best, most efficient encoder over certain bitrates at the time the test was conducted.

It should be noted that these tests '''may become obsolete''' over time as development of the tested codecs progress. With that in mind, please ensure that you consult the most recent test results before drawing conclusions.

When you read the test results, you may come across unfamiliar terminology, especially concerning ''artifacts''. [http://ff123.net/training/training.html ff123's Artifact Training Page] is the place to go to understand what these 'artifacts' are all about.

'''Note:''' There is no such thing as listening tests for [[Lossless]] compression, as recordings encoded using Lossless codecs are, by nature, bit-identical in their output to their respective original uncompressed recordings. When testing Lossless codecs, only performance characteristics are taken into account (e.g. compression ration, encode/decode speed, etc). If you are interested in these aspects of lossless encoding, take a look at the [[Lossless comparison|Lossless comparison page]], instead.

=Format-specific Tests=
All tests sorted by date, with older ones at top. All dates are in [http://www.cl.cam.ac.uk/~mgk25/iso-time.html ISO8601 format].

==[[AAC]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffaaaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2004-12-09
| style="width:174px" | Ahead vs Apple 128-kbps Classical
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | iTunes 4.1.052, 4.7.042; Nero 2.5.9.7, 2.9.998 CBR, 2.9.998 VBR
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924&view=findpost&p=258644 HA Thread]
|-
| 2005-09-05
| 48- & 64-kbps HE-AAC Classical
| Guruboolez
| Private
| CT aacPlus v.2 48- & 64-kbps Helix 11.0.0.1897, Nero 3.2.0.20 VBR
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=36868&view=findpost&p=325091 HA Thread]
|-
| 2006-02-05
| 48-kbps HE-AAC Classical
| Ivan Dimkovic
| Public
| Nero HE-AAC v1 & v2
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=41191&hl= HA Thread]
|-
| 2006-02-20
| 48-kbps HE-AAC General
| Gabriel
| Public
| 3gpp (v1), CT (v1 & v2), Nero (v1 & v2)
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=42679&hl= HA Thread] [http://www.mp3-tech.org/tests/aac_48/results.html Complete Result]
|}

==[[MP3]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaffaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2004-01-18
| style="width:174px" | Dithering Test (1) Special
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[MP3]] Decoders: MAD, [[LAME]], Fraunhofer, foobar2000
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=17728&view=findpost&p=174740 HA Thread]
|-
| 2004-11-15
| 130-kbps LAME rjamorim
| Guruboolez
| Private
| [[LAME]] 3.90.3 ABR, 3.96.1 ABR, 3.96.1 VBR
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=29422&view=findpost&p=253968 HA Thread]
|-
| 2005-01-11
| 128-kbps LAME ff123
| Guruboolez
| Private
| [[LAME]] 3.90.3, 3.96.1, 3.97a5
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=30547&view=findpost&p=264411 HA Thread]
|-
| 2005-10-17
| [[LAME]] 3.98 -V5 Classical
| Guruboolez
| Private
| [[LAME]] 3.98: -V5, -V5 --vbr-new, -V5 --vbr-new --athaa-sensitivity 1
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=37973&view=findpost&p=335086 HA Thread]
|}

'''''Notes:'''
(1) Performed under extreme listening conditions not reproducible on daily listening.''

==[[MPC]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaaaff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2005-06-18
| style="width:174px" | --standard Classical
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | 1.01j, 1.15u
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=34911&view=findpost&p=306910 HA Thread]
|}

==[[Vorbis]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffffaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-06-18
| style="width:174px" | 128-kbps ff123/rjamorim
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | GT2 & PCVS
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=10555&view=findpost&p=106189 HA Thread]
|-
| 2004-06-17
| 160-kbps Special
| Guruboolez
| Private
| CVS, GT3b2, [[aoTuV]]b2, [[aoTuV]]b2+QK
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=22495&view=findpost&p=218681 HA Thread]
|-
| 2004-02-05
| -q4 Transients
| Guruboolez
| Private
| RC3 2002-03, RC3 2002-04, 1.01, 1.01 QK2
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=18359&view=findpost&p=180697 HA Thread]
|}

==[[WMA]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffaaff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-06-18
| style="width:174px" | 128-kbps ff123/rjamorim
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[WMA]]9 Standard & Pro
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=10551&view=findpost&p=106158 HA Thread]
|}

=Multiformat Tests=

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaffff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-10-11
| style="width:174px" | 130-kbps Classical (Baroque)
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[AAC]] (FAAC, PsyTel, Nero, QuickTime) [[MP3]] [[LAME]] 3.90.3, [[MPC]] 1.14, [[Vorbis]] GT3b1, [[WMA]]9 Pro
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=14091&view=findpost&p=142684 HA Thread]
|-
| 2003-12-13
| 128-kbps Classical
| Guruboolez
| Private
| [[AAC]] (iTunes, Nero, FAAC), [[Vorbis]] 1.01, [[WMA]]9, [[MP3]] [[LAME]] 3.93.1
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=16395&view=findpost&p=163116 HA Thread]
|-
| 2004-07-12
| 175-kbps Classical
| Guruboolez
| Private
| [[Vorbis]] Megamix -q5,50, -q5,99 -q6,00 [[MP3]] [[LAME]] 3.97a3 -V3, -V2, [[MPC]] -q5
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=23355&view=findpost&p=225046 HA Thread]
|-
| 2004-12-09
| 130-kbps Classical
| Guruboolez
| Private
| [[AAC]] Nero 2.9.9.998 [[Vorbis]] aoTuVb3
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=29925&view=findpost&p=258645 HA Thread]
|-
| 2005-03-05
| 140-kbps VBR Classical
| Guruboolez
| Private
| [[AAC]] Nero 3.0.0.4, [[Vorbis]] 1.1, QK28
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=32080&view=findpost&p=279240 HA Thread]
|-
| 2005-03-17
| 256-kbps Transcode from MP3 subset of ff123
| Guruboolez
| Private
| [[AAC]] iTunes 4.7, [[MP3]] [[LAME]] 3.97a8 [[MPC]] 1.15u, [[Vorbis]] aoTuVb3, [[WavPack]] 4.2b3 Lossy
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=32440&view=findpost&p=282909 HA Thread]
|-
| 2005-07-11
| 80-kbps Various
| Guruboolez
| Private
| [[LAME]] [[MP3]], [[AAC]]-HE and -LC, [[Vorbis]] [[aoTuV]], [[WMA]] Std
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=35438&view=findpost&p=312296 HA Thread]
|-
| 2005-08-09
| 96-kbps Classical & Various
| Guruboolez
| Private
| [[LAME]] [[MP3]], [[AAC]],[[Vorbis]] [[aoTuV]] (Lancer), [[MPC]], [[WMA]]
| [http://forum.hardware.fr/hardwarefr/VideoSon/MP3-WMA-AAC-OGG-qualite-kbps-evaluation-sujet-84950-1.htm#t922011 Hardware.fr thread (in French)]
|-
| 2005-08-22
| 180-kbps Classical
| Guruboolez
| Private
| [[AAC]], [[MP3]], [[MPC]], [[Vorbis]] [[aoTuV]]b4
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=36465 HA Thread]
|-
| 2006-01-13
| 128-kbps General
| Sebastian Mares
| Public
| iTunes & Nero [[AAC]], [[LAME]] [[MP3]], [[Vorbis]] [[aoTuV]], [[WMA]] Pro
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=40607&view=findpost&p=357117 HA Thread] [http://www.maresweb.de/listening-tests/mf-128-1/results.htm Complete Result]
|-
| 2006-11-22
| 48-kbps General
| Sebastian Mares
| Public
| [[Vorbis]] [[aoTuV]], Nero [[AAC]], [[WMA]] Pro, [[WMA]] Standard
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=50408 HA Thread]
|}

=External Tests=
Other people also held listening tests outside of Hydrogenaudio (although the organizer of the tests are usually HA members :)

So, check out the following sites:
* [http://ff123.net/ ff123's site on audio testing and listening tests] (most recent test 2002-07-27)
* [http://www.rjamorim.com/test/index.html Roberto's Public Listening Tests] (most recent test 2004-07-11)
* [http://www.maresweb.de/listening-tests/ Sebastian Mares' Listening Tests] (most recent test updated 2006-11-22)
* [http://www.soundexpert.info/ SoundExpert Listening Tests] (continually updated)

[[Category:Listening Tests]]

Hydrogenaudio Listening Tests

2006-11-30T16:56:41Z

Jarsonic: cleanup

From time to time, various HydrogenAudio members have conducted listening tests, both private and public. These listening test should be valuable in gauging the performance of various digital audio techniques, e.g. compression, transcoding, etc., '''at a certain point in time'''.

It should be noted that these tests '''may become obsolete''' by newer enhancements in the techniques. So please ensure that there aren't newer tests before drawing conclusions.

When you read the test results, you may come across unfamiliar terminology, especially concerning ''artifacts''. [http://ff123.net/training/training.html ff123's Artifact Training Page] is the place to go to understand what these 'artifacts' are all about.

'''Note:''' There is no such thing as listening tests for [[Lossless]] compression, as recordings encoded using Lossless codecs are, by nature, bit-identical in their output to their respective original uncompressed recordings. When testing Lossless codecs, only performance characteristics are taken into account (e.g. compression ration, encode/decode speed, etc). If you are interested in these aspects of lossless encoding, take a look at the [[Lossless comparison|Lossless comparison page]], instead.

=Format-specific Tests=
All tests sorted by date, with older ones at top. All dates are in [http://www.cl.cam.ac.uk/~mgk25/iso-time.html ISO8601 format].

==[[AAC]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffaaaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2004-12-09
| style="width:174px" | Ahead vs Apple 128-kbps Classical
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | iTunes 4.1.052, 4.7.042; Nero 2.5.9.7, 2.9.998 CBR, 2.9.998 VBR
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924&view=findpost&p=258644 HA Thread]
|-
| 2005-09-05
| 48- & 64-kbps HE-AAC Classical
| Guruboolez
| Private
| CT aacPlus v.2 48- & 64-kbps Helix 11.0.0.1897, Nero 3.2.0.20 VBR
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=36868&view=findpost&p=325091 HA Thread]
|-
| 2006-02-05
| 48-kbps HE-AAC Classical
| Ivan Dimkovic
| Public
| Nero HE-AAC v1 & v2
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=41191&hl= HA Thread]
|-
| 2006-02-20
| 48-kbps HE-AAC General
| Gabriel
| Public
| 3gpp (v1), CT (v1 & v2), Nero (v1 & v2)
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=42679&hl= HA Thread] [http://www.mp3-tech.org/tests/aac_48/results.html Complete Result]
|}

==[[MP3]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaffaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2004-01-18
| style="width:174px" | Dithering Test (1) Special
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[MP3]] Decoders: MAD, [[LAME]], Fraunhofer, foobar2000
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=17728&view=findpost&p=174740 HA Thread]
|-
| 2004-11-15
| 130-kbps LAME rjamorim
| Guruboolez
| Private
| [[LAME]] 3.90.3 ABR, 3.96.1 ABR, 3.96.1 VBR
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=29422&view=findpost&p=253968 HA Thread]
|-
| 2005-01-11
| 128-kbps LAME ff123
| Guruboolez
| Private
| [[LAME]] 3.90.3, 3.96.1, 3.97a5
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=30547&view=findpost&p=264411 HA Thread]
|-
| 2005-10-17
| [[LAME]] 3.98 -V5 Classical
| Guruboolez
| Private
| [[LAME]] 3.98: -V5, -V5 --vbr-new, -V5 --vbr-new --athaa-sensitivity 1
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=37973&view=findpost&p=335086 HA Thread]
|}

'''''Notes:'''
(1) Performed under extreme listening conditions not reproducible on daily listening.''

==[[MPC]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaaaff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2005-06-18
| style="width:174px" | --standard Classical
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | 1.01j, 1.15u
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=34911&view=findpost&p=306910 HA Thread]
|}

==[[Vorbis]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffffaa"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-06-18
| style="width:174px" | 128-kbps ff123/rjamorim
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | GT2 & PCVS
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=10555&view=findpost&p=106189 HA Thread]
|-
| 2004-06-17
| 160-kbps Special
| Guruboolez
| Private
| CVS, GT3b2, [[aoTuV]]b2, [[aoTuV]]b2+QK
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=22495&view=findpost&p=218681 HA Thread]
|-
| 2004-02-05
| -q4 Transients
| Guruboolez
| Private
| RC3 2002-03, RC3 2002-04, 1.01, 1.01 QK2
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=18359&view=findpost&p=180697 HA Thread]
|}

==[[WMA]]==

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#ffaaff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-06-18
| style="width:174px" | 128-kbps ff123/rjamorim
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[WMA]]9 Standard & Pro
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=10551&view=findpost&p=106158 HA Thread]
|}

=Multiformat Tests=

{| border="1" cellpadding="2" cellspacing="0" style="text-align:center;"
|- style="background:#aaffff"
! Date !! Title Samples !! Performed by !! Type !! Codecs !! Links
|-
| style="width:064px" | 2003-10-11
| style="width:174px" | 130-kbps Classical (Baroque)
| style="width:101px" | Guruboolez
| style="width:045px" | Private
| style="width:299px" | [[AAC]] (FAAC, PsyTel, Nero, QuickTime) [[MP3]] [[LAME]] 3.90.3, [[MPC]] 1.14, [[Vorbis]] GT3b1, [[WMA]]9 Pro
| style="width:110px" | [http://www.hydrogenaudio.org/forums/index.php?showtopic=14091&view=findpost&p=142684 HA Thread]
|-
| 2003-12-13
| 128-kbps Classical
| Guruboolez
| Private
| [[AAC]] (iTunes, Nero, FAAC), [[Vorbis]] 1.01, [[WMA]]9, [[MP3]] [[LAME]] 3.93.1
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=16395&view=findpost&p=163116 HA Thread]
|-
| 2004-07-12
| 175-kbps Classical
| Guruboolez
| Private
| [[Vorbis]] Megamix -q5,50, -q5,99 -q6,00 [[MP3]] [[LAME]] 3.97a3 -V3, -V2, [[MPC]] -q5
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=23355&view=findpost&p=225046 HA Thread]
|-
| 2004-12-09
| 130-kbps Classical
| Guruboolez
| Private
| [[AAC]] Nero 2.9.9.998 [[Vorbis]] aoTuVb3
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=29925&view=findpost&p=258645 HA Thread]
|-
| 2005-03-05
| 140-kbps VBR Classical
| Guruboolez
| Private
| [[AAC]] Nero 3.0.0.4, [[Vorbis]] 1.1, QK28
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=32080&view=findpost&p=279240 HA Thread]
|-
| 2005-03-17
| 256-kbps Transcode from MP3 subset of ff123
| Guruboolez
| Private
| [[AAC]] iTunes 4.7, [[MP3]] [[LAME]] 3.97a8 [[MPC]] 1.15u, [[Vorbis]] aoTuVb3, [[WavPack]] 4.2b3 Lossy
|
[http://www.hydrogenaudio.org/forums/index.php?showtopic=32440&view=findpost&p=282909 HA Thread]
|-
| 2005-07-11
| 80-kbps Various
| Guruboolez
| Private
| [[LAME]] [[MP3]], [[AAC]]-HE and -LC, [[Vorbis]] [[aoTuV]], [[WMA]] Std
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=35438&view=findpost&p=312296 HA Thread]
|-
| 2005-08-09
| 96-kbps Classical & Various
| Guruboolez
| Private
| [[LAME]] [[MP3]], [[AAC]],[[Vorbis]] [[aoTuV]] (Lancer), [[MPC]], [[WMA]]
| [http://forum.hardware.fr/hardwarefr/VideoSon/MP3-WMA-AAC-OGG-qualite-kbps-evaluation-sujet-84950-1.htm#t922011 Hardware.fr thread (in French)]
|-
| 2005-08-22
| 180-kbps Classical
| Guruboolez
| Private
| [[AAC]], [[MP3]], [[MPC]], [[Vorbis]] [[aoTuV]]b4
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=36465 HA Thread]
|-
| 2006-01-13
| 128-kbps General
| Sebastian Mares
| Public
| iTunes & Nero [[AAC]], [[LAME]] [[MP3]], [[Vorbis]] [[aoTuV]], [[WMA]] Pro
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=40607&view=findpost&p=357117 HA Thread] [http://www.maresweb.de/listening-tests/mf-128-1/results.htm Complete Result]
|-
| 2006-11-22
| 48-kbps General
| Sebastian Mares
| Public
| [[Vorbis]] [[aoTuV]], Nero [[AAC]], [[WMA]] Pro, [[WMA]] Standard
| [http://www.hydrogenaudio.org/forums/index.php?showtopic=50408 HA Thread]
|}

=External Tests=
Other people also held listening tests outside of Hydrogenaudio (although the organizer of the tests are usually HA members :)

So, check out the following sites:
* [http://ff123.net/ ff123's site on audio testing and listening tests] (most recent test 2002-07-27)
* [http://www.rjamorim.com/test/index.html Roberto's Public Listening Tests] (most recent test 2004-07-11)
* [http://www.maresweb.de/listening-tests/ Sebastian Mares' Listening Tests] (most recent test updated 2006-11-22)
* [http://www.soundexpert.info/ SoundExpert Listening Tests] (continually updated)

[[Category:Listening Tests]]

EAC and Ogg Vorbis

2006-11-30T16:48:03Z

Jarsonic: /* Addtional Reading */

==Software Needed==
* [http://exactaudiocopy.org/eac6.html Exact Audio Copy]
* Oggenc2
** Download latest version from [http://www.rarewares.org/ogg.html RareWares Ogg page]
** Download accelerated [[Lancer]] version from [http://homepage3.nifty.com/blacksword/index_e.htm The Ogg Vorbis Acceleration Project]

==Installation==
'''Note:''' This guide assumes that EAC is has been configured for secure ripping, if not please follow [[EAC_Drive_Configuration | this guide]].
* Unzip the chosen Oggenc2 build into the same directory that EAC is in.

==Configuration==

* Open EAC and insert a CD into the drive.
* Click the '''EAC''' menu and select '''Compression Options'''.
* Click the '''External Compression''' Tab, and put a check box in '''use external program for compression'''.
* Change '''Parameter Passing Scheme''' to '''User Defined Encoder'''.
* Change '''Use file extension''' to '''.ogg'''.
* Click the '''Browse''' button and locate the '''OGGENC2.EXE''' that you unzipped earlier.
* Remove the ticks from '''Use CRC check''', '''Add ID3 tag''' and '''check for external programs return code'''.
* In the '''Additional command line options''' box, copy and paste one of the below strings based on the Tag you would prefer.
:'''No Tags:'''

<div style="margin-left:30px; margin-right:30px;">
'''-q 6''' %s %d
</div>

:'''Vorbis Comment:'''

<div style="margin-left:30px; margin-right:30px;">
'''-q 6''' -a "%a" -t "%t" -l "%g" -d "%y" -N "%n" -G "%m" %s -o %d
</div>

:'''Note:''' If you wanted to change the quality setting the green portion is what you would substitute with the new setting e.g. -q 10 or -q 2. For more information, see [[Recommended Ogg Vorbis#Recommended Encoder Settings|this page]].

* Do not worry what bit rate is shown in the bit rate drop down box, this will be ignored.

<center>[[Image:EAC_OGG.png|frame|center|Ogg configured with Vorbis Comment tagging]]</center>

==Additional Reading==
* [[Exact_Audio_Copy|Exact Audio Copy]]
* [[Ogg_Vorbis|Ogg Vorbis]]

[[Category:Guides]]
[[Category:EAC Guides|Ogg Vorbis & EAC]]

Ardour

2006-11-30T16:44:42Z

Jarsonic: /* Introduction */

{{Infobox Software
| name = Ardour
| screenshot =
| caption = Open-source multiplatform DAW
| maintainer = Paul Davis
| stable_release = 0.99
| preview_release = 2.00b8
| operating_system = Mac OS/X, Linux
| use = Digital Audio Workstation
| license = GPL
| website = http://www.ardour.org/
}}

=Introduction=
Ardour is a complete Digital Audio Workstation similar to Pro-Tools, Nuendo, and Logic.

==Features==
===Common===
* Designed to work with [[JACK]], [[ALSA]] on Linux and [[Core Audio]] on OS X.
* Soundcards supported are: M-Audio, Hammerfall, Echo, Creative, Terratec and Yamaha.
* Sample data is maintained internally in 32-bit floating point format
* Multichannel recording and mixing
* Partial support for VSTi's
* Support for over thirty different audio codecs
* Utilization of custom audio file database manager

===Mixing===
* Mixing realies directly on the hardware and automated plugins

===Editing===
* Timeline layout with trimming, crossfading, time-stretching, and splitting
===Mastering===
* Integration with JACK makes mastering with tools like JAMin possible
===Plug-ins===
* [[LADSPA]] support for over 100 DSP effects including, simple filters, analog flangers, and multiband EQ's.

===Compatibility===
* Open-source nature allows the DAW to be ported to multiple platforms including OS X.

==Screenshots==
* [http://ardour.org/files/main-screenshot-big.png Main window] this is a screenshot of Ardours main application window

=Development API=
==Getting Involved==
Ardour is written entirely in C++. The GUI is written using the ''gtkmm'' C++ wrapper. The application contains 160,000 lines of code, including 3rd party development efforts. Ardour makes heavy use of ''libsigc++'' as a way to provide anonymous coupling between various application components.

==MIDI Support==
There is major talk of developing and implementing MIDI timestamp codes, etc into Ardour for sequencing.

http://www.ardour.org/node/335

==External links==
* [http://www.ardour.org/ Ardour] official website of the new digital audio workstation

[[Category:MIDI Sequencers]]
[[Category:Audio Editors]]

Ableton Live

2006-11-30T16:43:59Z

Jarsonic: /* Introduction */ jsut fyi, this kinda reads like an advertising promotion ;) Maybe make this a little more neutral? (less "used worldwide," etc. Just a thought.

{{Infobox Software
| name = Ableton Live
| screenshot =
| caption = Fully featured MIDI sequencer
| maintainer = Ableton Team
| stable_release = 5.2.2
| preview_release = 6.0
| operating_system = Windows, Mac OS/X, Linux/BSD (Wine Emulation)
| use = MIDI Sequencing
| license = Propreitary
| website = http://www.ableton.com/
}}

=Introduction=
Ableton Live is a commercial music sequencer designed to be an instrument and a live performance tool for composing and arranging. Live was rewritten in C++ from a design in MAX/MSP a graphical editing enviroment and released under a commercial license in 2001. It is popular amongst the electronic music community circles and with DJ's worldwide.
==Features==
===Instruments===
===DSP Effects===
Ableton Live uses a post-processing rig designed with extensive Digital Signal Processing effects. The layout is designed so that electronic musicians and DJ's can drag and drop effects on the fly during a live performance, making it easy to manipulate samples and other elements.

* Audio Filter
* Auto Pan
* Beat Repeat
* Chorus
* Compressor I
* Compressor II
* Dynamic Tube
* EQ Three (Band)
* EQ Eight (Band)
* Erosion
* Filter Delay
* Flanger
* Gate
* Grain Delay
* Phaser
* Ping Pong Delay
* Saturator
* Simple Delay
* Redux (Quantizer)
* Resonators
* Reverb
* Utility

including MIDI only effects, arpeggiator, chord, scale, velocity, etc.

==Resources==
* [http://www.abletonlivedj.com/forum/ Ableton Live forum] an unofficial forum dedicated to tutorials and topics in reguard to using Ableton Live.

==External links==

{{stub}}

[[Category:MIDI Sequencers]]

User:Jarsonic

2006-11-30T16:38:30Z

Jarsonic:

'''Jarsonic''' is the Internet moniker of '''Hunter Chorey'''. Hunter grew up in [http://en.wikipedia.org/wiki/Atlanta%2C_Georgia Atlanta], [http://en.wikipedia.org/wiki/Georgia Georgia] and then went on to attend the [http://en.wikipedia.org/wiki/University_of_Virginia University of Virginia] in [http://en.wikipedia.org/wiki/Charlottesville%2C_Virginia Charlottesville], [http://en.wikipedia.org/wiki/Virginia Virginia] where he currently resides. Graduating from [http://en.wikipedia.org/wiki/University_of_Virginia UVA] in 2005 with dual majors in Economics and Religious Studies, Hunter is a strategies analyst at an intellectual property consulting firm in Charlottesville.

Hunter is also an alumni of the 2005-2006 class of the [http://fellows.trinitycville.org Trinity Fellows Program] through [http://www.trinitycville.org Trinity Presbyterian Church] in Charlottesville.

== External links ==
=== Personal ===
*[http://thewildgoosechase.org/hunter/ Hunter's blog]
*[http://jarsonic.deviantart.com/ Hunter's DeviantArt gallery]

=== Frequented Forums ===
*[http://derekwebb.musiccitynetworks.com/index.htm?id=7017 the webboard] at [[derekwebb.com]]
*[http://www.hydrogenaudio.org/ HydrogenAudio]

Advanced Audio Coding

2006-11-30T16:28:43Z

Jarsonic: /* Introduction */

=Introduction=
'''AAC''' or 'Advanced Audio Coding' forms part of the latest specifications from the MPEG committee, and is their official successor to the popular [[MP3]] format. As with MP3, the AAC format is an international standard, and is backed by several big-name companies, including Dolby, Sony and Nokia.

With the 13 years that had passed since the creation of the MP3 format, many improvements had been realised leading to a seemingly complex specification with several flavours of AAC available. To potentially add to the confusion, AAC is usually wrapped inside an [[MP4]] container to provide tagging, seeking and possibly other benefits?? For this reason, AAC can also be referred to as MP4 audio..

There are several AAC encoders to choose from, coming from large names such as Apple ([[iTunes]]) , Real Networks and Nero AG (Creators of Nero Burning Rom), or the open source [http://www.audiocoding.com FAAC] which is analogous to the [[LAME]] encoder. AAC is supported on some hardware players, most notably the [[Apple iPod]] and some cell phones, and is available in Apple's online store.

In terms of quality, the AAC format is on par with [[Ogg Vorbis]], [[LAME]] MP3, [[WMA]] Pro and other modern codecs, and with added SBR coding (HE AAC) it can provide quite high quality at low bitrates.

Recent developments have led to [[AACplus]] which is able to give subjectively good results at low bitrates. The website [http://www.tuner2.com Tuner2] has several Internet radio stations which are sending out streams at low rates - such as 40 kbps - and some of these are surprisingly good considering the bit rates used.

==Pros==

* An international standard approved by the [http://www.iso.ch ISO]
* Flexible: supports several [[sampling rate]]s (8000-96000 Hz), bit depths, and [[multichannel]] (up to 48 channels)
* Several implementations, including free and high quality ones ([http://www.itunes.com iTunes] or [http://www.nero.com/nerodigital/eng/Nero_Digital_Audio.html Nero Digital])
* Reaches transparency in most samples and for most users at around 150kbps
* Part of [[MPEG-4]] specs
* Anyone can create its own implementation (specifications and demo sources available)
* Some portable players support it (Philips Expanium, [[Apple iPod]], cell phones from Nokia, Sony Jukebox)

==Cons==

* Problem cases that trip out all transform codecs
* Heavily patented
* Increased complexity
* '''AAC''' comes in different "flavors" (object types: '''AAC LC''', '''AAC HE''', '''AAC PS''' etc.). Many (especially portable) players only support LC (at the moment) so you can have files that are valid but your player won't play them.

==Technical Information==
'''AAC''' stands for 'Advanced Audio Coding' and is part of the [[MPEG-4]] Systems Standard. Originally known as MPEG-2 Non-Backwards Compatible (As apposed to MPEG-2 Backwards Compatible) it is the succesor to MPEG-1/2 Layer III ([[MP3]]). It uses the [[MP4]] [[container]] (which is based on Apple's [[MOV]] container) to store metadata (i.e. tag information).

As part of the MPEG-4 Systems Standard, an '''AAC''' encoded file can include up to 48 full-bandwith audio channels (up to 96 kHz) and 15 Low Frequency Enhancement channels (limited to 120 Hz) plus 15 data streams.

'''AAC''' encoding methods are organised into Profiles (MPEG-2) or Object Types (MPEG-4). These different Object Types are not necessarily compatible with each other and may not be playable with various decoders. Some of the various Object Types are:

* MPEG-2 AAC LC / Low Complexity
* MPEG-2 AAC Main
* MPEG-2 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LC / Low Complexity
* MPEG-4 AAC Main
* MPEG-4 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LTP / Long Term Prediction
* MPEG-4 AAC HE / High Efficiency
* MPEG-4 AAC LD / Low Delay

Different Object Types vary in complexity. Some take longer to encode/decode as a result of the different complexities. Furthermore, the benefits of the more complex profiles are often not worth the CPU power required to encode/decode them. As a result the Low Complexity/LC Object Type has become the profile used by most encoders and supported by most decoders. However, the High Efficiency (HE) Object Type has become more popular recently with its addition to the Nero '''AAC''' encoder.

Currently all players support the LC Object Type, although some will work on only MPEG2 or MPEG4 streams. Players based on the FAAD2 decoder (eg. [[foobar2000]], [[Winamp]] plugins) support almost all Object Types including HE '''AAC'''. 3ivX also supports all Object Types except SSR.

==Technologies used for compression==

* [[Huffman coding]]
* [[Quantization]] and scaling
* [[Joint stereo|M/S matrixing]]
* [[Intensity stereo]]
* Channel coupling
* Backward adaptive prediction
* Temporal Noise Shaping (TNS)
* Modified Discrete Cosine Transform (I[[MDCT]])
* Gain control and hybrid filter bank (polyphase quadrature filter (IPQF)+IMDCT)
* Long Term Predictor (LTP) - MPEG4 '''AAC''' only
* Perceptual Noise Substitution (PNS) - MPEG4 '''AAC''' only
* Spectral Band Replication ([[SBR]]) - HE '''AAC'''
* Parametric Stereo (PS) - HE '''AAC'''

==Encoders / Decoders (Supported Platforms)==

* [[Nero AAC]] (Win32 and [[Linux_and_Nero_AAC|Linux under Wine]])
* [[QuickTime AAC]] (Win32/MacOS X)
* [[FAAC]] [[FAAD]] (Multiplatform)
* HHI/zPlane [[Compaact!]] (Win32)
* [[PsyTEL]] (Win32)

==External References==

* [[AAC FAQ]]
* Known [[AAC implementations]].
* Read the [[AAC guide]] to learn how to obtain '''AAC'''/[[MP4]] files out of WAV files and CDs.
* Detailed '''AAC''' comparisons can be found at [http://www.rjamorim.com/test/ Roberto's listening tests page].

[[Category:Codecs]]
[[Category:Lossy]]

Advanced Audio Coding

2006-11-30T16:28:17Z

Jarsonic: /* Introduction */

=Introduction=
'''AAC''' or 'Advanced Audio Coding' forms part of the latest specifications from the MPEG committee, and is their official successor to the popular [[MP3]] format. As with MP3, the AAC format is an international standard, and is backed by several big-name companies, including Dolby, Sony and Nokia.

With the 13 years that had passed since the creation of the MP3 format, many improvements had been realised leading to a seemingly complex specification with several flavours of AAC available. To potentially add to the confusion, AAC is usually wrapped inside an [[MP4]] container to provide tagging, seeking and possibly other benefits?? For this reason, AAC can also be referred to as MP4 audio..

There are several AAC encoders to choose from, coming from large names such as Apple ([[iTunes]]) , Real Networks and Nero AG (Creators of Nero Burning Rom), or the open source [http://www.audiocoding.com FAAC] which is analogous to the [[LAME]] encoder. AAC is supported on some hardware players, most notably the [[Apple iPod]] and some cell phones, and is available in Apple's online store.

In terms of quality, the AAC format is on par with [[Ogg Vorbis]], [[LAME]] MP3, [[WMA]] Pro and other modern codecs, and with added SBR coding (HE AAC) it can provide quite high quality at low bitrates.

Recent developments have led to [[AACplus]] which is able to give subjectively good results at low bitrates. The website [http://www.tuner2.com tuner2] has several Internet radio stations which are sending out streams at low rates - such as 40 kbps - and some of these are surprisingly good considering the bit rates used.

==Pros==

* An international standard approved by the [http://www.iso.ch ISO]
* Flexible: supports several [[sampling rate]]s (8000-96000 Hz), bit depths, and [[multichannel]] (up to 48 channels)
* Several implementations, including free and high quality ones ([http://www.itunes.com iTunes] or [http://www.nero.com/nerodigital/eng/Nero_Digital_Audio.html Nero Digital])
* Reaches transparency in most samples and for most users at around 150kbps
* Part of [[MPEG-4]] specs
* Anyone can create its own implementation (specifications and demo sources available)
* Some portable players support it (Philips Expanium, [[Apple iPod]], cell phones from Nokia, Sony Jukebox)

==Cons==

* Problem cases that trip out all transform codecs
* Heavily patented
* Increased complexity
* '''AAC''' comes in different "flavors" (object types: '''AAC LC''', '''AAC HE''', '''AAC PS''' etc.). Many (especially portable) players only support LC (at the moment) so you can have files that are valid but your player won't play them.

==Technical Information==
'''AAC''' stands for 'Advanced Audio Coding' and is part of the [[MPEG-4]] Systems Standard. Originally known as MPEG-2 Non-Backwards Compatible (As apposed to MPEG-2 Backwards Compatible) it is the succesor to MPEG-1/2 Layer III ([[MP3]]). It uses the [[MP4]] [[container]] (which is based on Apple's [[MOV]] container) to store metadata (i.e. tag information).

As part of the MPEG-4 Systems Standard, an '''AAC''' encoded file can include up to 48 full-bandwith audio channels (up to 96 kHz) and 15 Low Frequency Enhancement channels (limited to 120 Hz) plus 15 data streams.

'''AAC''' encoding methods are organised into Profiles (MPEG-2) or Object Types (MPEG-4). These different Object Types are not necessarily compatible with each other and may not be playable with various decoders. Some of the various Object Types are:

* MPEG-2 AAC LC / Low Complexity
* MPEG-2 AAC Main
* MPEG-2 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LC / Low Complexity
* MPEG-4 AAC Main
* MPEG-4 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LTP / Long Term Prediction
* MPEG-4 AAC HE / High Efficiency
* MPEG-4 AAC LD / Low Delay

Different Object Types vary in complexity. Some take longer to encode/decode as a result of the different complexities. Furthermore, the benefits of the more complex profiles are often not worth the CPU power required to encode/decode them. As a result the Low Complexity/LC Object Type has become the profile used by most encoders and supported by most decoders. However, the High Efficiency (HE) Object Type has become more popular recently with its addition to the Nero '''AAC''' encoder.

Currently all players support the LC Object Type, although some will work on only MPEG2 or MPEG4 streams. Players based on the FAAD2 decoder (eg. [[foobar2000]], [[Winamp]] plugins) support almost all Object Types including HE '''AAC'''. 3ivX also supports all Object Types except SSR.

==Technologies used for compression==

* [[Huffman coding]]
* [[Quantization]] and scaling
* [[Joint stereo|M/S matrixing]]
* [[Intensity stereo]]
* Channel coupling
* Backward adaptive prediction
* Temporal Noise Shaping (TNS)
* Modified Discrete Cosine Transform (I[[MDCT]])
* Gain control and hybrid filter bank (polyphase quadrature filter (IPQF)+IMDCT)
* Long Term Predictor (LTP) - MPEG4 '''AAC''' only
* Perceptual Noise Substitution (PNS) - MPEG4 '''AAC''' only
* Spectral Band Replication ([[SBR]]) - HE '''AAC'''
* Parametric Stereo (PS) - HE '''AAC'''

==Encoders / Decoders (Supported Platforms)==

* [[Nero AAC]] (Win32 and [[Linux_and_Nero_AAC|Linux under Wine]])
* [[QuickTime AAC]] (Win32/MacOS X)
* [[FAAC]] [[FAAD]] (Multiplatform)
* HHI/zPlane [[Compaact!]] (Win32)
* [[PsyTEL]] (Win32)

==External References==

* [[AAC FAQ]]
* Known [[AAC implementations]].
* Read the [[AAC guide]] to learn how to obtain '''AAC'''/[[MP4]] files out of WAV files and CDs.
* Detailed '''AAC''' comparisons can be found at [http://www.rjamorim.com/test/ Roberto's listening tests page].

[[Category:Codecs]]
[[Category:Lossy]]

Advanced Audio Coding

2006-11-30T16:27:41Z

Jarsonic: /* Introduction */ fixed link for tuner2

=Introduction=
'''AAC''' or 'Advanced Audio Coding' forms part of the latest specifications from the MPEG committee, and is their official successor to the popular [[MP3]] format. As with MP3, the AAC format is an international standard, and is backed by several big-name companies, including Dolby, Sony and Nokia.

With the 13 years that had passed since the creation of the MP3 format, many improvements had been realised leading to a seemingly complex specification with several flavours of AAC available. To potentially add to the confusion, AAC is usually wrapped inside an [[MP4]] container to provide tagging, seeking and possibly other benefits?? For this reason, AAC can also be referred to as MP4 audio..

There are several AAC encoders to choose from, coming from large names such as Apple ([[iTunes]]) , Real Networks and Nero AG (Creators of Nero Burning Rom), or the open source [http://www.audiocoding.com FAAC] which is analogous to the [[LAME]] encoder. AAC is supported on some hardware players, most notably the [[Apple iPod]] and some cell phones, and is available in Apple's online store.

In terms of quality, the AAC format is on par with [[Ogg Vorbis]], [[LAME]] MP3, [[WMA]] Pro and other modern codecs, and with added SBR coding (HE AAC) it can provide quite high quality at low bitrates.

Recent developments have led to [[AACplus]] which is able to give subjectively good results at low bitrates. The website [http://www.tuner2.com tuner2]] has several Internet radio stations which are sending out streams at low rates - such as 40 kbps - and some of these are surprisingly good considering the bit rates used.

==Pros==

* An international standard approved by the [http://www.iso.ch ISO]
* Flexible: supports several [[sampling rate]]s (8000-96000 Hz), bit depths, and [[multichannel]] (up to 48 channels)
* Several implementations, including free and high quality ones ([http://www.itunes.com iTunes] or [http://www.nero.com/nerodigital/eng/Nero_Digital_Audio.html Nero Digital])
* Reaches transparency in most samples and for most users at around 150kbps
* Part of [[MPEG-4]] specs
* Anyone can create its own implementation (specifications and demo sources available)
* Some portable players support it (Philips Expanium, [[Apple iPod]], cell phones from Nokia, Sony Jukebox)

==Cons==

* Problem cases that trip out all transform codecs
* Heavily patented
* Increased complexity
* '''AAC''' comes in different "flavors" (object types: '''AAC LC''', '''AAC HE''', '''AAC PS''' etc.). Many (especially portable) players only support LC (at the moment) so you can have files that are valid but your player won't play them.

==Technical Information==
'''AAC''' stands for 'Advanced Audio Coding' and is part of the [[MPEG-4]] Systems Standard. Originally known as MPEG-2 Non-Backwards Compatible (As apposed to MPEG-2 Backwards Compatible) it is the succesor to MPEG-1/2 Layer III ([[MP3]]). It uses the [[MP4]] [[container]] (which is based on Apple's [[MOV]] container) to store metadata (i.e. tag information).

As part of the MPEG-4 Systems Standard, an '''AAC''' encoded file can include up to 48 full-bandwith audio channels (up to 96 kHz) and 15 Low Frequency Enhancement channels (limited to 120 Hz) plus 15 data streams.

'''AAC''' encoding methods are organised into Profiles (MPEG-2) or Object Types (MPEG-4). These different Object Types are not necessarily compatible with each other and may not be playable with various decoders. Some of the various Object Types are:

* MPEG-2 AAC LC / Low Complexity
* MPEG-2 AAC Main
* MPEG-2 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LC / Low Complexity
* MPEG-4 AAC Main
* MPEG-4 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LTP / Long Term Prediction
* MPEG-4 AAC HE / High Efficiency
* MPEG-4 AAC LD / Low Delay

Different Object Types vary in complexity. Some take longer to encode/decode as a result of the different complexities. Furthermore, the benefits of the more complex profiles are often not worth the CPU power required to encode/decode them. As a result the Low Complexity/LC Object Type has become the profile used by most encoders and supported by most decoders. However, the High Efficiency (HE) Object Type has become more popular recently with its addition to the Nero '''AAC''' encoder.

Currently all players support the LC Object Type, although some will work on only MPEG2 or MPEG4 streams. Players based on the FAAD2 decoder (eg. [[foobar2000]], [[Winamp]] plugins) support almost all Object Types including HE '''AAC'''. 3ivX also supports all Object Types except SSR.

==Technologies used for compression==

* [[Huffman coding]]
* [[Quantization]] and scaling
* [[Joint stereo|M/S matrixing]]
* [[Intensity stereo]]
* Channel coupling
* Backward adaptive prediction
* Temporal Noise Shaping (TNS)
* Modified Discrete Cosine Transform (I[[MDCT]])
* Gain control and hybrid filter bank (polyphase quadrature filter (IPQF)+IMDCT)
* Long Term Predictor (LTP) - MPEG4 '''AAC''' only
* Perceptual Noise Substitution (PNS) - MPEG4 '''AAC''' only
* Spectral Band Replication ([[SBR]]) - HE '''AAC'''
* Parametric Stereo (PS) - HE '''AAC'''

==Encoders / Decoders (Supported Platforms)==

* [[Nero AAC]] (Win32 and [[Linux_and_Nero_AAC|Linux under Wine]])
* [[QuickTime AAC]] (Win32/MacOS X)
* [[FAAC]] [[FAAD]] (Multiplatform)
* HHI/zPlane [[Compaact!]] (Win32)
* [[PsyTEL]] (Win32)

==External References==

* [[AAC FAQ]]
* Known [[AAC implementations]].
* Read the [[AAC guide]] to learn how to obtain '''AAC'''/[[MP4]] files out of WAV files and CDs.
* Detailed '''AAC''' comparisons can be found at [http://www.rjamorim.com/test/ Roberto's listening tests page].

[[Category:Codecs]]
[[Category:Lossy]]

AAC encoders

2006-11-30T16:26:14Z

Jarsonic: /* FAAC */

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietary AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found about Apple's AAC implementation on their [http://www.apple.com/quicktime/technologies/aac/ AAC Audio information page].

The current recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

The iTunes AAC encoder can be externally envoked via a command line tool created by Otto42 called [http://www.rarewares.org/files/aac/iTunesEncode46.zip iTunesEncode], which can be found at [http://www.rarewares.org/ RareWares] in the AAC section. This allows for the generation of iTunes AAC files from audio formats not inherently supported by iTunes using the conversion functions found in programs such as [[Foobar2000]].

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding].

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares].

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T16:25:48Z

Jarsonic: /* PsyTEL */

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietary AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found about Apple's AAC implementation on their [http://www.apple.com/quicktime/technologies/aac/ AAC Audio information page].

The current recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

The iTunes AAC encoder can be externally envoked via a command line tool created by Otto42 called [http://www.rarewares.org/files/aac/iTunesEncode46.zip iTunesEncode], which can be found at [http://www.rarewares.org/ RareWares] in the AAC section. This allows for the generation of iTunes AAC files from audio formats not inherently supported by iTunes using the conversion functions found in programs such as [[Foobar2000]].

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding]

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares].

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T16:25:19Z

Jarsonic: /* iTunes AAC */

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietary AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found about Apple's AAC implementation on their [http://www.apple.com/quicktime/technologies/aac/ AAC Audio information page].

The current recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

The iTunes AAC encoder can be externally envoked via a command line tool created by Otto42 called [http://www.rarewares.org/files/aac/iTunesEncode46.zip iTunesEncode], which can be found at [http://www.rarewares.org/ RareWares] in the AAC section. This allows for the generation of iTunes AAC files from audio formats not inherently supported by iTunes using the conversion functions found in programs such as [[Foobar2000]].

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding]

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares]

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T16:24:47Z

Jarsonic: /* iTunes AAC */ reworking

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietary AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found about Apple's AAC implementation on their [http://www.apple.com/quicktime/technologies/aac/ AAC Audio information page].

The current recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

The iTunes AAC encoder can be externally envoked via a command line tool created by Otto42 called [http://www.rarewares.org/files/aac/iTunesEncode46.zip iTunesEncode] which can be found at [http://www.rarewares.org/ RareWares] in the AAC section. This allows for the generation of iTunes AAC files from audio formats not inherently supported by iTunes using the conversion functions found in programs such as [[Foobar2000]].

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding]

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares]

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T16:09:21Z

Jarsonic: /* Nero AAC */

These are some known [[AAC]] encoder implementations.

==[[Nero AAC]]==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietaryl AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found at the [http://www.apple.com/mpeg4/aac/ Apple Website]

The recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding]

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares]

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T16:07:28Z

Jarsonic: /* Nero AAC */

These are some known [[AAC]] encoder implementations.

==Nero AAC==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietaryl AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found at the [http://www.apple.com/mpeg4/aac/ Apple Website]

The recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding]

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares]

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

AAC encoders

2006-11-30T16:07:07Z

Jarsonic: updated info about nero commandline encoder.

These are some known [[AAC]] encoder implementations.

==Nero AAC==

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally precieved to have the highest quality VBR LC AAC implementation (although QuickTime bests it in CBR mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is availble for free as a command line tool called "Nero Digital Audio" [http://www.nero.com/nerodigital/eng/down-ndaudio.php here].

===Recommended Nero AAC Presets===

NOTE: Once a preset has been selected, the "Encoding Quality" option should be changed to the "Fast" mode. Despite the name implying worse quality then high, a test undertaken by guruboolez shows that the "Fast" mode offers significant quality advantages over the "High" (see the test [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 here]). In the forthcoming release of Nero AAC 3.0 (or a release soon afterwards), the "Fast" mode will become the default and the high quality mode will be removed.

====High Quality====

: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

====Portable====

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

====Small Filesize====

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

The High Quality preset is for the archival of music, while the Small Filesize preset is for internet/streaming purposes.

More information can be found in the [ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF] and on the [http://www.nerodigital.com/ Nero Digital Website].

==iTunes AAC==

Another proprietaryl AAC implementation, [[iTunes]] AAC is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.

The codec is available for free through the [[iTunes]] Digital Jukebox.

More information can be found at the [http://www.apple.com/mpeg4/aac/ Apple Website]

The recommended high quality encoding setting is 160kbps, or 128kbps for portable use.

==FAAC==

[[FAAC]] is a free LC AAC encoder under the Lesser GPL license. Its quality has improved drastically over the last few years and FAAC is nowadays a viable alternative to the commercial encoders (although, at 128kbps or lower bitrates, not at the same quality level as some of them, according to Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last listening test]).

The default quality setting is -q 100 -c 16000 (~120kbps average bitrate), for better quality encodings use -q 150 -c 22000 (~175kbps average bitrate).

More information can be found at [http://www.audiocoding.com/ AudioCoding]

==HHI/zPlane (Compaact!)==

Compaact is one of the newest AAC encoders. Like Nero AAC, compaact is not free, however it does offer an impressive feature set. Roberto Amorim's last AAC test showed that at 128kbps, Compaact! is tied with both the FAAC and Coding Technologies (Real) encoders. Compaact! features both the LC and Main Object Types, [[CBR]], [[VBR]], [[Multichannel]], high resolution (24bit/96kHz) encoding, and command line support. Development on Compaact has stopped.

For portable encoding, try -q5 to -q6. For music archive purposes, try -q7 to -q8.

More information can be found at the [http://www.compaact.com/aacPage.php?SPRACHE=UK&PAGE=compaact Compaact website].

==PsyTEL==

The creation of Ivan Dimkovic (who now works on Nero AAC), PsyTEL AAC was one of the first AAC encoders. Its multichannel support has bugs that make it unusable, but its stereo mode had the best quality available in its day. Since the implementation of Nero AAC, this codec has become obsolete. It's is now outclassed by both Nero AAC and [[iTunes]] - both offer higher quality and are much faster encoders.

The PsyTEL encoder can be found in the AAC section of [http://www.rjamorim.com/rrw/ ReallyRareWares]

===Usability (Psytel aacenc/fastenc)===

; -tape
; -radio
; -internet
; -streaming
; -normal
; -extreme
; -archive
; -ultra

For music encoding. The quality ranges from -tape (lowest [[VBR]] quality) to -ultra (highest VBR quality). Ultra is considered overkill for most audio tracks, i.e: shouldn't be used except for extremely difficult music signals. Example: aacenc -extreme -if "audio file.wav"

===Encoder switches (Psytel aacenc/fastenc)===

; -if
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)

; -of
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.

; -br
: Bitrate switch ([[CBR]] mode). Sets the number of bits utilized per second for the encoding process. Example: aacenc -br 192 -if "audio file.wav"

; -vbrhi
: High quality [[VBR]] mode. Can be used with -br switch to select base BitRate. If -br is not specified, it takes as default 64kbps/channel. Example: aacenc -br 192 -vbrhi -if "audio file.wav"

; -vr
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"

; -c
: LowPassFilter cut-off (in Hertz). Not recommended. Example: aacenc -br 128 -c 15995 -if "audio file.wav"

; -qual
: Encoder quality level (1 to 9). 9 is usually taken as default, but you can use smaller numbers if you need high speed and high quality isn't essential. Example: aacenc -br 192 -qual 9 -if "audio file.wav"

; -adif
: Use adif instead of adts (default) headers. For compatibility with some decoder software and hardware players. Example: aacenc -br 192 -adif -if "audio file.wav"

; -nh
: No headers (raw iso aac stream). For decoder compatibility. Example: aacenc -br 192 -nh -if "audio file.wav"

; -profile "x"
: Choose iso aac encoding profile:
:: 0 - low complexity (default, recommended)
:: 1 - main (not recommended, buggy)
:: 2 - main ltp (mpeg-4 only)

: Only lc profile is playable on hardware players so far. Example: aacenc -br 192 -profile 2 -if "audio file.wav"

; -ihsc
: Improved human speech coding. Best for human voice encoding. Not recommended for low Bitrates or [CBR] coding. Example: aacenc -vbrhi -br 192 -ihsc -if "audio file.wav"

; -low_ath
: Tells encoder to use highest sensitivity threshold of audibility. Not recommended on Bitrates lower than 192kbps. Example: aacenc -br 192 -low_ath -if "audio file.wav"

; -pns
: (perceptual noise substitution) - Improves the quality at very low Bitrates. Should be used only at 64kbps or less. Example: aacenc -br 56 -pns -if "audio file.wav"

==Imagine==

Imagine Technology provided an [[MPEG-4]] LC AAC plugin for [[Adobe Audition]]. This plugin provided file input and output for the MPEG-4 AAC specification, defined in ISO/IEC 14496-3. After Imagine was bought by Ingenient Technologies, they stopped marketing the Audition plugin.

==Coding Technologies==

Coding Technologies (CT) is a Swedish/German company that works close to FhG IIS in development and research of new audio compression techniques.

Thet have distinguished themselves in development of parametric coding methods, such as [[SBR]] and Parametric Stereo. SBR is the technology behind the quality boost in MP3pro and HE AAC/AACplus.

They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.

==FhG==

[http://www.iis.fraunhofer.de/amm/techinf/aac/ Audio & Multimedia MPEG-2 AAC]

==Emuzed==

Emuzed develops and sells various products and technologies for the PC multimedia and embedded multimedia markets. They have ported and optimized codecs for MPEG-4 ASP and AAC LC for a chip vendor preparing to offer bundled multimedia hardware and software. More info can be found at their [http://www.emuzed.com/encoders.html encoders & decoders] page.

==NEC==

NEC Corporation has developed an LC AAC decoding algorithm for mobile devices. They have also developed a codec named MPEG-4 AAC Ext.1, which they claim decreases bitrate while maintaining the same audio quality. The new MPEG-4 AAC Ext.1 coding technology also features high compatibility with current MPEG-4 AAC. For more information, see [http://www.neceurope.com/release.asp?parentid=671&Area=1 NEC's press release].

==Panasonic==

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in
[http://www.telos-systems.com/techtalk/hosted/m4-in-30100%20(M4IF_HE_AAC_paper).pdf this MPEG Industry Forum paper].

==Real/Helix Producer==

RealNetworks has incorporated Coding Technologies/FhG's MPEG-4 AAC / aacPlus™ technology and software within RealNetworks’ software products. As a result, in the newest version of RealProducer 10, AAC has replaced [[ATRAC]]3 as the high bitrate audio codec, and that software can encode AAC files wrapped in the [[MP4]] container. In addition, the Producer SDK on Windows also includes HE-AAC encoding. More info can be found at [http://www.realnetworks.com/company/press/releases/2004/codingtech.html RealNetworks' press release], as well as Coding Technologies' [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus page].

[[Category:Encoder/Decoder]]

Nero AAC

2006-11-30T16:05:30Z

Jarsonic:

A commercial implementation of both LC AAC and HE AAC, Nero AAC is produced by Nero AG as part of their Nero Digital line of products. It is generally percieved to have the highest quality [[VBR]] LC AAC implementation (although QuickTime bests it in [[CBR]] mode at 128kbps). The codec can also create HEv1/v2 AAC streams for extremely low bitrates and supports multi-channel surround sound encoding. As of May 2006, Nero AAC is available for free as a command line tool called "Nero Digital Audio".

==Command Line Options==

===Usage===
neroAacEnc.exe [options] -if <input-file> -of <output-file>

<input-file>: Path to source file to encode. The file must be in Microsoft WAV format and contain PCM data. Specify - to encode from stdin.

<output-file>: Path to output file to encode to, in MP4 format.

===Quality/Bitrate Control===

'''-q <number>''':
Enables "target quality" mode. <number> is floating-point number between 0 and 1.

'''-br <number>''':
Specifies "target bitrate" mode. <number> is target bitrate in bits per second.

'''-cbr <number>''':
Specifies "target bitrate (streaming)" mode. <number> is target bitrate in bits per second.

When none of above quality/bitrate options is used, the encoder defaults to equivalent of -q 0.5

===Multipass Encoding===
'''-2pass''':
Enables two-pass encoding mode. Note that two-pass more requires a physical file as input, rather than stdin.

'''-2passperiod <number>''': Overrides two-pass encoding bitrate averaging period, in milliseconds. Specify zero to use least restrictive value possible (default).

===Advanced Features / Troubleshooting===
'''-lc''': Forces use of LC AAC profile (HE features disabled)

'''-he''': Forces use of HE AAC profile (HEv2 features disabled)

'''-hev2''': Forces use of HEv2 AAC profile

Note that the above switches (-lc, -he, -hev2) should not be used; optimal AAC profile is automatically determined from quality/bitrate settings when no override is specified.

'''-hinttrack''': Generates an RTP hint track in output MP4 file.

'''-ignorelength''': Ignores length signaled by WAV headers of input file. Useful for certain frontends using stdin.

== External References ==

[ftp://ftp6.nero.com/infosheets/Nero_Digital/db_nerodigital5.pdf Nero Digital PDF]

[http://www.nerodigital.com/ Nero Digital Website].