MPEG-4 SLS
Encyclopedia
MPEG-4 SLS, or MPEG-4 Scalable to Lossless as per ISO/IEC
14496-3:2005/Amd 3:2006 (Scalable Lossless Coding), is an extension to the MPEG-4 Part 3
(MPEG-4
Audio) standard to allow lossless
audio compression scalable to lossy MPEG-4 General Audio coding methods (e.g. variations of AAC
). It was developed jointly by the Institute for Infocomm Research (I2R) and Fraunhofer
, which commercializes its implementation of a limited subset of the standard under the name of HD-AAC. Standardization of the HD-AAC profile for MPEG-4 Audio is under development (as of September 2009).
MPEG-4 SLS allows for having both a lossy layer and a lossless correction layer similar to Wavpack
Hybrid or OptimFROG
DualStream, allowing for backwards compatibility to MPEG AAC
-compliant bitstream
s. MPEG-4 SLS can also work without a lossy layer (a.k.a. "SLS Non-Core"), in which case it will not be backwards compatible, Lossy compression of files is necessary for files that need to be streamed to the Internet or played in devices with limited storage.
With DRM
, ripping of the lossless data or playback on non DRM
-enabled devices could be disabled.
MPEG-4 SLS is not related in any way to MPEG-4
ALS
(Audio Lossless Coding).
New lossless audio coding technologies that need higher bandwidth and larger storage capacities may now be appropriate for many applications and have been gaining attention in recent years. In addressing this need, MPEG issued a Call for Proposals (CfP) in October 2002 to solicit a technology that could address all these needs.
The CfP requested proposals for a lossless and scalable technology that was backward compatible with the existing MPEG AAC
codec
, and could operate efficiently at several different sampling rates and word length combinations. Institute for Infocomm Research (I2R) technologies were adopted for the scalable to lossless coding
(14496-3/AMD5) architecture Reference Model 0.
I2R offers a fully scalable to lossless audio coding solution. On top of the core AAC codec, a scalable extension layer increases the signal-to-noise ratio, reaching lossless quality at data rates comparable to those of current pure lossless audio codecs, that is, at average compression ratios of about 58%.
The scalability of the extension makes this combination a coding solution for production environments, where the result is to be transmitted to several recipients through channels of differing bandwidth
. Furthermore, for private and professional use in music archives, this enables storing the original music data and transferring compressed copies (e.g. to portable devices) without transcoding.
is Via Licensing Corporation. Licensors offering their SLS patents through the Via Licensing Corporation's licensing program include A*STAR Exploit Technologies Pte Ltd
(Singapore), Fraunhofer IIS (Germany), and Nippon Telegraph and Telephone
Corporation (Japan).
The licensing fees varies - e.g. a licensee shall pay $0.098 to the Via Licensing Corporation for each copy of PC software decoder sold or supplied.
released Highlighter, the first commercial HD-AAC release taken directly from 24-48 session files, encoded and sold directly to fans via the website PL70.net
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...
14496-3:2005/Amd 3:2006 (Scalable Lossless Coding), is an extension to the MPEG-4 Part 3
MPEG-4 Part 3
MPEG-4 Part 3 or MPEG-4 Audio is the third part of the ISO/IEC MPEG-4 international standard developed by Moving Picture Experts Group. It specifies audio coding methods...
(MPEG-4
MPEG-4
MPEG-4 is a method of defining compression of audio and visual digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group under the formal standard ISO/IEC...
Audio) standard to allow lossless
Lossless data compression
Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange...
audio compression scalable to lossy MPEG-4 General Audio coding methods (e.g. variations of AAC
Advanced Audio Coding
Advanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
). It was developed jointly by the Institute for Infocomm Research (I2R) and Fraunhofer
Fraunhofer Society
The Fraunhofer Society is a German research organization with 60 institutes spread throughout Germany, each focusing on different fields of applied science . It employs around 18,000, mainly scientists and engineers, with an annual research budget of about €1.65 billion...
, which commercializes its implementation of a limited subset of the standard under the name of HD-AAC. Standardization of the HD-AAC profile for MPEG-4 Audio is under development (as of September 2009).
MPEG-4 SLS allows for having both a lossy layer and a lossless correction layer similar to Wavpack
WavPack
WavPack is a free, open source lossless audio compression format developed by David Bryant.-Features:WavPack compression can compress 8-, 16-, 24-, and 32-bit fixed-point, and 32-bit floating point audio files in the .WAV file format. It also supports surround sound streams and high frequency...
Hybrid or OptimFROG
OptimFROG
OptimFROG is a proprietary lossless audio data compression codec developed by Florin Ghido. OptimFROG is optimized for very high compression ratios, even for the price of slower encoding and decoding.-OptimFROG DualStream:...
DualStream, allowing for backwards compatibility to MPEG AAC
Advanced Audio Coding
Advanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
-compliant bitstream
Bitstream
A bitstream or bit stream is a time series of bits.A bytestream is a series of bytes, typically of 8 bits each, and can be regarded as a special case of a bitstream....
s. MPEG-4 SLS can also work without a lossy layer (a.k.a. "SLS Non-Core"), in which case it will not be backwards compatible, Lossy compression of files is necessary for files that need to be streamed to the Internet or played in devices with limited storage.
With DRM
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
, ripping of the lossless data or playback on non DRM
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
-enabled devices could be disabled.
MPEG-4 SLS is not related in any way to MPEG-4
MPEG-4
MPEG-4 is a method of defining compression of audio and visual digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group under the formal standard ISO/IEC...
ALS
Audio Lossless Coding
MPEG-4 Audio Lossless Coding, also known as MPEG-4 ALS, is an extension to the MPEG-4 Part 3 audio standard to allow lossless audio compression. The extension was finalized in December 2005 and published as ISO/IEC 14496-3:2005/Amd 2:2006 in 2006...
(Audio Lossless Coding).
Background
Market demand for highly compressed, lossy audio compression technologies is slowly diminishing, as network and storage technologies continually improve their ability to deliver high-sampling-rate, high-resolution audio.New lossless audio coding technologies that need higher bandwidth and larger storage capacities may now be appropriate for many applications and have been gaining attention in recent years. In addressing this need, MPEG issued a Call for Proposals (CfP) in October 2002 to solicit a technology that could address all these needs.
The CfP requested proposals for a lossless and scalable technology that was backward compatible with the existing MPEG AAC
Advanced Audio Coding
Advanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
, and could operate efficiently at several different sampling rates and word length combinations. Institute for Infocomm Research (I2R) technologies were adopted for the scalable to lossless coding
Coding
Coding may refer to:* Channel coding in coding theory* Line coding* Computer programming, the process of designing, writing, testing, debugging / troubleshooting, and maintaining the source code of computer programs...
(14496-3/AMD5) architecture Reference Model 0.
I2R offers a fully scalable to lossless audio coding solution. On top of the core AAC codec, a scalable extension layer increases the signal-to-noise ratio, reaching lossless quality at data rates comparable to those of current pure lossless audio codecs, that is, at average compression ratios of about 58%.
The scalability of the extension makes this combination a coding solution for production environments, where the result is to be transmitted to several recipients through channels of differing bandwidth
Bandwidth (computing)
In computer networking and computer science, bandwidth, network bandwidth, data bandwidth, or digital bandwidth is a measure of available or consumed data communication resources expressed in bits/second or multiples of it .Note that in textbooks on wireless communications, modem data transmission,...
. Furthermore, for private and professional use in music archives, this enables storing the original music data and transferring compressed copies (e.g. to portable devices) without transcoding.
Licensing
The Licensing Administrator for the MPEG-4 Audio patent poolPatent pool
In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology. The creation of a patent pool can save patentees and licensees time and money, and, in case of blocking patents, it may also be the only reasonable method...
is Via Licensing Corporation. Licensors offering their SLS patents through the Via Licensing Corporation's licensing program include A*STAR Exploit Technologies Pte Ltd
Agency for Science, Technology and Research
The Agency for Science, Technology and Research is a statutory board under the Ministry of Trade and Industry of Singapore...
(Singapore), Fraunhofer IIS (Germany), and Nippon Telegraph and Telephone
Nippon Telegraph and Telephone
, commonly known as NTT, is a Japanese telecommunications company headquartered in Tokyo, Japan. Ranked the 31st in Fortune Global 500, NTT is the largest telecommunications company in Asia, and the second-largest in the world in terms of revenue....
Corporation (Japan).
The licensing fees varies - e.g. a licensee shall pay $0.098 to the Via Licensing Corporation for each copy of PC software decoder sold or supplied.
Releases
In 2011, Los Angeles based hip hop group People Under The StairsPeople Under the Stairs
People Under the Stairs is a hip hop group from Los Angeles, California formed in 1997 by Thes One and Double K. The group has released eight critically acclaimed full-length albums and performed on every continent except Antarctica. It is estimated that the group has performed well over 1,000 sold...
released Highlighter, the first commercial HD-AAC release taken directly from 24-48 session files, encoded and sold directly to fans via the website PL70.net
See also
- Bitrate peelingBitrate peelingBitrate Peeling is a technique used in Ogg Vorbis audio encoded streams, wherein a stream can be encoded at one bitrate but can be served at that or any lower bitrate....
, in Ogg Vorbis - WavPackWavPackWavPack is a free, open source lossless audio compression format developed by David Bryant.-Features:WavPack compression can compress 8-, 16-, 24-, and 32-bit fixed-point, and 32-bit floating point audio files in the .WAV file format. It also supports surround sound streams and high frequency...
, and OptimFROG DualStream, other formats with lossy + correction