AAC encoders: Difference between revisions

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{{aac-encoders}}
These are some known [[AAC]] encoder implementations.
These are some known [[AAC]] encoder implementations.


==Nero AAC==
==Features==
{| class="wikitable"
!rowspan=2| Encoder
!colspan=2| Bitrate Modes
!colspan=3| Audio Object Types
!rowspan=2| Channels
!rowspan=2| Open Source
!rowspan=2| Platforms
!rowspan=2| Notes
|-
! CBR
! VBR
! LC
! HEv1 (SBR)
! HEv2 (SBR+PS)
|-
| [[Apple AAC]] ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||{{maybe}} ||8 ||{{no}} ||Mac, Windows || Distributed as binary library only, included in QuickTime/iTunes. Can be extracted and used with a CLI wrapper.
|-
| [[Fraunhofer FDK AAC]] ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||8 (7.1) ||{{maybe|Yes, but non-free}} ||Linux, Mac, Windows || Fraunhofer dumps its code into the Android Open Source Project now and then, but it is not developed in the open, and its license is considered non-free.
|-
| [[Fraunhofer]] "FhG" AAC ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||6 (5.1) ||{{no}} ||Windows ||  Distributed as binary library only, included in Winamp. Can be extracted and used with a CLI wrapper.
|-
| [[Nero AAC]] ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||{{yes}} ||6 (5.1) ||{{no}} ||Linux, Windows || Distributed as CLI encoder utility
|-
| [[libavcodec AAC|FFmpeg 3.0+ AAC encoder]] ||{{yes}} ||{{maybe|Poor}} ||{{yes}} ||{{no}} ||{{no}} ||8 (7.1) ||{{yes}} ||Linux, Mac, Windows ||
|-
| [[FAAC]] ||{{maybe|Not true CBR}} ||{{yes}} ||{{yes}} ||{{no}} ||{{no}} ||6 (5.1) ||{{maybe|Yes, but non-free}} ||Linux, Mac, Windows || FAAC contains some code which is published as Free Software, but as a whole it is only distributed under a proprietary license.
|-
| [[libavcodec AAC|Libav]] (pre-3.0 FFmpeg) AAC encoder ||{{maybe|Poor}} ||{{maybe|Poor}} ||{{yes}} ||{{no}} ||{{no}} ||2 ||{{yes}} ||Linux, Mac, Windows  ||
|-
| [[VisualOn AAC]] ||{{maybe|Very poor}} ||{{no}} ||{{yes}} ||{{no}} ||{{no}} ||2 ||{{maybe|Yes}} ||Linux, Mac, Windows || CBR is actually a really poor VBR at about 64kbps with lots of padding added to hit whatever target is requested. VisualOn claims to have the right to release the code under a Free Software license.
|-
| Microsoft MFT AAC ||{{yes}} ||{{no}} ||{{yes}} ||{{no}} ||{{no}} ||6 (5.1) ||{{no}} ||Windows || Only 2 channels in Windows 7, 6(5.1) in Windows 10. Only 44.1kHz and 48kHz sample rates supported. [https://msdn.microsoft.com/en-us/library/windows/desktop/dd742785(v=vs.85).aspx]
|}


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 [[iTunes]] CBR beats Nero's VBR at 128kbps). The codec also features the HE AAC standard for extremely low bitrates. The codec also allows for [[multichannel]] 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.
==FFmpeg/Libav native AAC encoder==
:''See [[Libavcodec AAC]].''
The native AAC encoder created in FFmpeg, and forked with Libav, was considered experimental and poor. A significant amount of work was done for the 3.0 release of FFmpeg (February 2016) to make its version usable and competitive with the rest of the AAC encoders. Libav has not merged this work and continues to use the older version of the AAC encoder. These encoders are LGPL-licensed open-source and can be built for any platform that the FFmpeg or Libav frameworks can be built.


===Recomended Nero AAC Presets===
Both FFmpeg and Libav can use the [[Fraunhofer FDK AAC]] library via libfdk-aac, and while the FFmpeg native encoder has become stable and good enough for common use, FDK is still considered the highest quality encoder available for use with FFmpeg. [https://trac.ffmpeg.org/wiki/Encode/AAC#fdk_aac] Libav also recommends using FDK AAC if it is available. [https://wiki.libav.org/Encoding/aac]


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.
==Fraunhofer AAC Encoders==
:''See [[Fraunhofer]].''


====High Quality====
[[Fraunhofer|Fraunhofer IIS]] develops two related AAC encoders:


: - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps
* The licensed AAC encoder that is included in Winamp.
* The [[Fraunhofer FDK AAC|FDK AAC]] encoder included in Android.


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


: - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps
According to the July 2011 96kbps [[Hydrogenaudio Listening Tests|listening tests]] by IgorC, Winamp's Fraunhofer encoder is better than [[Nero AAC]] and tied with the [[Apple AAC|Apple encoder]] (then part of QuickTime) [http://listening-tests.hydrogenaud.io/igorc/aac-96-a/results.html].


====Small Filesize====
==Nero AAC==
 
:''See [[Nero AAC]].''
: - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps
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).  
 
 
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].


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


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


Another proprietaryl AAC implementation, [[iTunes]] AAC 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 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==


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


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


===Usability (Psytel aacenc/fastenc)===
==Coding Technologies derived==


; -tape
[[Coding Technologies]] (CT) was a Swedish/German company that worked closely with [[Fraunhofer|Fraunhofer IIS]] in development and research of new audio compression techniques.
; -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"
They have licensed their encoding and decoding tools to several companies including Real Networks and Magix.


===Encoder switches (Psytel aacenc/fastenc)===
===Real/Helix Producer===


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


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


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


; -vr
===Others===
: Lower quality [[VBR]] mode. Recommended for internet streaming. Example: aacenc -vr -if "audio file.wav"
* [[Aacplusenc]], which is based on the Coding Technologies reference code.


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


; -qual
===HHI/zPlane (Compaact!)===
: 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
Compaact! was a short-lived closed-source AAC encoder that could compete with FAAC in it's day. It is no longer developed.
: 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
===Imagine===
:  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.
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.
 
 
==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.
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]]

Latest revision as of 22:17, 29 January 2017

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.

Features

Encoder Bitrate Modes Audio Object Types Channels Open Source Platforms Notes
CBR VBR LC HEv1 (SBR) HEv2 (SBR+PS)
Apple AAC Yes Yes Yes Yes Maybe 8 No Mac, Windows Distributed as binary library only, included in QuickTime/iTunes. Can be extracted and used with a CLI wrapper.
Fraunhofer FDK AAC Yes Yes Yes Yes Yes 8 (7.1) Yes, but non-free Linux, Mac, Windows Fraunhofer dumps its code into the Android Open Source Project now and then, but it is not developed in the open, and its license is considered non-free.
Fraunhofer "FhG" AAC Yes Yes Yes Yes Yes 6 (5.1) No Windows Distributed as binary library only, included in Winamp. Can be extracted and used with a CLI wrapper.
Nero AAC Yes Yes Yes Yes Yes 6 (5.1) No Linux, Windows Distributed as CLI encoder utility
FFmpeg 3.0+ AAC encoder Yes Poor Yes No No 8 (7.1) Yes Linux, Mac, Windows
FAAC Not true CBR Yes Yes No No 6 (5.1) Yes, but non-free Linux, Mac, Windows FAAC contains some code which is published as Free Software, but as a whole it is only distributed under a proprietary license.
Libav (pre-3.0 FFmpeg) AAC encoder Poor Poor Yes No No 2 Yes Linux, Mac, Windows
VisualOn AAC Very poor No Yes No No 2 Yes Linux, Mac, Windows CBR is actually a really poor VBR at about 64kbps with lots of padding added to hit whatever target is requested. VisualOn claims to have the right to release the code under a Free Software license.
Microsoft MFT AAC Yes No Yes No No 6 (5.1) No Windows Only 2 channels in Windows 7, 6(5.1) in Windows 10. Only 44.1kHz and 48kHz sample rates supported. [1]

FFmpeg/Libav native AAC encoder

See Libavcodec AAC.

The native AAC encoder created in FFmpeg, and forked with Libav, was considered experimental and poor. A significant amount of work was done for the 3.0 release of FFmpeg (February 2016) to make its version usable and competitive with the rest of the AAC encoders. Libav has not merged this work and continues to use the older version of the AAC encoder. These encoders are LGPL-licensed open-source and can be built for any platform that the FFmpeg or Libav frameworks can be built.

Both FFmpeg and Libav can use the Fraunhofer FDK AAC library via libfdk-aac, and while the FFmpeg native encoder has become stable and good enough for common use, FDK is still considered the highest quality encoder available for use with FFmpeg. [2] Libav also recommends using FDK AAC if it is available. [3]

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 includes low-delay encoding for real-time communication on embedded systems/mobile phones.

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) [4].

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" [5] (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 derived

Coding Technologies (CT) was a Swedish/German company that worked closely with Fraunhofer IIS in development and research of new audio compression techniques.

They have licensed their encoding and decoding tools to several companies including Real Networks and Magix.

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

  • Aacplusenc, which is based on the Coding Technologies reference code.

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.

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