Hydrogenaudio Knowledgebase - User contributions [en]

AAC encoders

2004-11-08T23:11:41Z

201.255.92.107: /* PsyTEL */

These are some known AAC encoder implementations.

=Nero AAC=

A commercial implementation of both LC AAC and HE AAC, Nero AAC is distributed with Nero 6 which incorporates
Nero Digital. Generally accepted to have the highest quality [[VBR]] LC AAC implementation (although QuickTime beat
it in CBR at 128kbps). The codec also features the HE AAC standard for extremely low bitrates. The codec also allows
for multi-channel surround sound encoding. Unfortunately, unlike iTunes, it's not freeware, and requires the acquisition
of the entire Nero 6 suite for usage of the AAC encoder alone.

==Recomended Nero AAC Presets==

===High Quality===

: - VBR/Stereo - Transparent, 110-150 Kb/s (LC AAC)
: - VBR/Stereo - Extreme, 140-190 Kb/s (LC AAC)

===Portable===

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC)
: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC)

===Small Filesize===

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC)
: - CBR/Stereo - 80 Kb/s (HE AAC)

The High Quality presets are for the archival of music, while the Small Filesize presets are 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].

=QuickTime AAC=

Another commercial AAC implementation, QuickTime AAC is known to have the highest quality medium-bitrate [[CBR]] LC
AAC encoder. While the current version only supports 2 channel audio, it is hoped multi-channel support, along with
[[VBR]] encoding will be added in a future version.

Although this is a comercial implementation and part of the QuickTime Pro package, the codec is available for free
through the [http://www.apple.com/itunes/ iTunes Digital Jukebox]

Update: It is rumored that the next major version of Apple's codec (included in iTunes 5.0, as a part of iLife 5.0 in Mac OSX Tiger to be released early next year) will support AAC HE & [[VBR]] encoding.

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

=FAAC=

FAAC is a free and open-source LC AAC encoder. Its quality has improved drastically over the last few months and
is now a viable alternative to the commercial encoders (although, at least at 128kbps, not as good as the free
iTunes encoder).

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.

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
multi-channel support has bugs that make it unusable, but it's 2 channel had the best quality available in its day.
Since the implementation of Nero AAC, this codec has become obselete. It's is now outclassed by both Nero AAC
and iTunes.

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 set best output file name.

; -br
: BitRate switch. 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) header. 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, and can improve. 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 provides an MPEG-4 LC AAC plugin for Adobe Audition. This plugin provides file input and output
for the MPEG-4 audio specification, defined in ISO/IEC 14496-3. More info can be found at the
[http://imaginetechnology.net/plugins.html imagine website].

=Coding Technologies=

RealNetworks has incorporated Coding Technologies’ 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 RealMedia 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].

=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 supports 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 a 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=
[[Real Producer|Real/Helix Producer]]: http://helixcommunity.org

AAC encoders

2004-11-08T23:08:49Z

201.255.92.107: /* FAAC */

These are some known AAC encoder implementations.

=Nero AAC=

A commercial implementation of both LC AAC and HE AAC, Nero AAC is distributed with Nero 6 which incorporates
Nero Digital. Generally accepted to have the highest quality [[VBR]] LC AAC implementation (although QuickTime beat
it in CBR at 128kbps). The codec also features the HE AAC standard for extremely low bitrates. The codec also allows
for multi-channel surround sound encoding. Unfortunately, unlike iTunes, it's not freeware, and requires the acquisition
of the entire Nero 6 suite for usage of the AAC encoder alone.

==Recomended Nero AAC Presets==

===High Quality===

: - VBR/Stereo - Transparent, 110-150 Kb/s (LC AAC)
: - VBR/Stereo - Extreme, 140-190 Kb/s (LC AAC)

===Portable===

: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC)
: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC)

===Small Filesize===

: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC)
: - CBR/Stereo - 80 Kb/s (HE AAC)

The High Quality presets are for the archival of music, while the Small Filesize presets are 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].

=QuickTime AAC=

Another commercial AAC implementation, QuickTime AAC is known to have the highest quality medium-bitrate [[CBR]] LC
AAC encoder. While the current version only supports 2 channel audio, it is hoped multi-channel support, along with
[[VBR]] encoding will be added in a future version.

Although this is a comercial implementation and part of the QuickTime Pro package, the codec is available for free
through the [http://www.apple.com/itunes/ iTunes Digital Jukebox]

Update: It is rumored that the next major version of Apple's codec (included in iTunes 5.0, as a part of iLife 5.0 in Mac OSX Tiger to be released early next year) will support AAC HE & [[VBR]] encoding.

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

=FAAC=

FAAC is a free and open-source LC AAC encoder. Its quality has improved drastically over the last few months and
is now a viable alternative to the commercial encoders (although, at least at 128kbps, not as good as the free
iTunes encoder).

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.

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
multi-channel support has bugs that make it unusable, but it's 2 channel had the best quality available in it's day.
Since the implementation of Nero AAC, this codec has become obselete. It's is now outclassed by both Nero AAC
and iTunes.

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 set best output file name.

; -br
: BitRate switch. 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) header. 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, and can improve. 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 provides an MPEG-4 LC AAC plugin for Adobe Audition. This plugin provides file input and output
for the MPEG-4 audio specification, defined in ISO/IEC 14496-3. More info can be found at the
[http://imaginetechnology.net/plugins.html imagine website].

=Coding Technologies=

RealNetworks has incorporated Coding Technologies’ 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 RealMedia 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].

=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 supports 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 a 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=
[[Real Producer|Real/Helix Producer]]: http://helixcommunity.org