AAC encoders: Difference between revisions

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* The licensed AAC encoder that is included in Winamp.
* The licensed AAC encoder that is included in Winamp.
* The [[Fraunhofer FDK AAC|FDK AAC]] encoder included in Android.  
* The [[Fraunhofer FDK AAC|FDK AAC]] encoder included in Android.  
The licensed encoder included with Winamp is optimized for encoding music on desktop-class processors, while the Android version was optimized for low-delay encoding for real-time communication on embedded systems/mobile phones.


The VBR bitrate of the two encoders is essentially the same [http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=95989&view=findpost&p=801919].
The VBR bitrate of the two encoders is essentially the same [http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=95989&view=findpost&p=801919].
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==Nero AAC==
==Nero AAC==
:''See [[Nero AAC]].''
:''See [[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. When it was new, it was generally perceived to have the highest quality VBR LC AAC implementation (although [[QuickTime AAC]] beats 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. Nero AAC is available for free as a command line tool called "Nero AAC Codec" [http://www.nero.com/enu/company/about-nero/nero-aac-codec.php] (formerly Nero Digital Audio). In 2014, Nero removed all mention of the codec from the company's site for a brief time, but now it's back.
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. When it was new, it was generally perceived to have the highest quality VBR LC AAC implementation (although [[QuickTime AAC]] outperformed 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. Nero AAC is available for free as a suite of command line tools called "Nero AAC Codec" [http://www.nero.com/enu/company/about-nero/nero-aac-codec.php] (formerly Nero Digital Audio).  
 
===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====
The Nero AAC encoder was based on the earlier PsyTEL AAC encoder by Ivan Dimkovic.
 
: - 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].


==Apple's AAC Encoder==
==Apple's AAC Encoder==
:''See [[Apple AAC]].''


Another proprietary AAC implementation, [[Apple AAC|Apple's AAC encoder]] (formerly QuickTime) is known to be one of the highest quality medium-bitrate [[CBR]] LC AAC encoders.
Apple's proprietary AAC implementation, formerly part of QuickTime, 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.
The codec is available for free through the [[iTunes]] Digital Jukebox.
More information can be found about Apple's AAC implementation on their {{brokenlink|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==


[[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]).
[[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==
==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.
[[PsyTEL]] was one of the first AAC encoders. It was created by Ivan Dimkovic, who would later work on Nero AAC. 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.  


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


; -tape
==Coding Technologies==
; -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"
Coding Technologies (CT) is a Swedish/German company that works close to [[Fraunhofer|Fraunhofer IIS]] in development and research of new audio compression techniques.


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


; -if
They have licensed their encoding and decoding tools to several companies - E.G, Real Networks and Magix.
: Input filename. The name of the track to be encoded (must be a [[WAV]] file)


; -of
Does exist an encoder, [[Aacplusenc]], which is based on the Coding Technologies reference code
: Output filename. May be omitted, because encoder will automatically create the output file name from the input file name.


; -br
===Real/Helix Producer===
: 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
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].
: 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
===NEC/Panasonic===
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"


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


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


; -ihsc
Compaact! was a short-lived closed-source AAC encoder that could compete with FAAC in it's day. It is no longer developed.
: 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
===Imagine===
: 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.
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.


 
===Emuzed===
==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.
 
Does exist an encoder, [[Aacplusenc]], which is based on the Coding Technologies reference code
 
==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.
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]]
[[Category:Encoder/Decoder]]

Revision as of 19:57, 27 September 2014

Current AAC encoders
(most to least recommended)
1 Apple AAC M/W
2 FhG AAC (Winamp) W
3 Fraunhofer FDK AAC S/L/M/W
4 Nero AAC L/W
5 FFmpeg 3.0+ AAC encoder S/L/M/W
6 FAAC S/L/M/W
7 Libav (pre-3.0 FFmpeg) AAC encoder S/L/M/W
S Source code available; L Linux; M macOS; W Windows
List of AAC encoders

These are some known AAC encoder implementations.

Fraunhofer AAC Encoders

See Fraunhofer.

Fraunhofer IIS develops two related AAC encoders:

  • The licensed AAC encoder that is included in Winamp.
  • The FDK AAC encoder included in Android.

The licensed encoder included with Winamp is optimized for encoding music on desktop-class processors, while the Android version was optimized for low-delay encoding for real-time communication on embedded systems/mobile phones.

The VBR bitrate of the two encoders is essentially the same [1].

According to the July 2011 96kbps listening tests by IgorC, Winamp's Fraunhofer encoder is better than Nero AAC and tied with the Apple encoder (then part of QuickTime) [2].

Nero AAC

See 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. When it was new, it was generally perceived to have the highest quality VBR LC AAC implementation (although QuickTime AAC outperformed 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. Nero AAC is available for free as a suite of command line tools called "Nero AAC Codec" [3] (formerly Nero Digital Audio).

The Nero AAC encoder was based on the earlier PsyTEL AAC encoder by Ivan Dimkovic.

Apple's AAC Encoder

See Apple AAC.

Apple's proprietary AAC implementation, formerly part of QuickTime, 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.

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 last listening test).

PsyTEL

PsyTEL was one of the first AAC encoders. It was created by Ivan Dimkovic, who would later work on Nero AAC. 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.


Coding Technologies

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

They 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.

Does exist an encoder, Aacplusenc, which is based on the Coding Technologies reference code

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 ATRAC3 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 RealNetworks' press release, as well as Coding Technologies' aacPlus page.

NEC/Panasonic

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 NEC's press release.

Panasonic has developed an HE AAC codec together with NEC and Coding Technologies as described in this MPEG Industry Forum paper.

Others

HHI/zPlane (Compaact!)

Compaact! was a short-lived closed-source AAC encoder that could compete with FAAC in it's day. It is no longer developed.

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.

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 encoders & decoders page.