Patent Status of MPEG-1,H.261 and MPEG-2
Over 100 million DVD players have shipped in the US, and 100s of millions of mp3 players have shipped, yet Linux distributions like Fedora, Ubuntu and Opensuse don't include software to create files that these devices can play. The reason is because implementations of the MPEG-2 and MPEG-1 Audio Layer 3 (MP3) are considered patented so the Linux Distributors are avoiding a risk of patent infringement lawsuits. I went searching for answers to basic questions like what are all the patents claimed for MP3 and when do the claimed MPEG-2 patents expire and I did not find these on the web, so I decided to create this summary of the patent status of MPEG-1, H.261 and MPEG-2. I'm not a lawyer and I'm not an expert on video or audio compression so there are probably some mistakes in this, but its better than anything I've found on the internet. This article is US specific, but the patent databases listed usually have other countries patents listed as well.
US Patent Basics
Patents provide the owner of the patent with the right to exclude others from using, making and selling the patented invention (that is, if someone else makes, uses or sells the invention without permission, the patent owner can sue them). The goal of the patent system is to provide inventors an incentive to invent and publish their inventions. Whether and how well this works for software is subject to debate. There is debate if software in the US is patentable or not, but those are discussed elsewhere. Patents must be filed by no later than one year after the publication of a description of the invention (and putting implementing source code on a public website or ftp site counts as publication), otherwise they are invalid. Other restrictions on patents exist as well. After a certain period of time, the patents expire. Patents filed after June 8, 1995 last 20 years from the earliest date of filing. Patents filed before June 8, 1995 last the longer of 20 years from the filing date or 17 years from the grant date. If the patent has mistakes, it can be reissued, and in that case the patent will expire based on the date of the original patent. Patents can expire early if the renewal fees are not payed, and the can last longer if the Patent office is slow in granting the patent. (Sources: http://www.uspto.gov/go/pac/doc/general/#novelty, http://www.law.cornell.edu/uscode/35/154(a)(2).html, http://www.law.cornell.edu/uscode/35/154(c).html
http://www.uspto.gov/web/offices/pac/mpep/documents/2700_2701.htm#sect2701
http://www.uspto.gov/web/offices/pac/mpep/documents/2100_2128.htm
http://www.uspto.gov/web/offices/pac/mpep/documents/1400_1401.htm)
The patent status of a particular standard can vary. For
example, the Fortran
66 standard can almost certainly be implemented without infringing any
patents, since the standard is so old that any essential patents have
long since expired (improperly issued patents could exist so there is a
low but non-zero probability of getting sued). On the other hand,
MPEG-2 has many essential
patents (according to MPEG-LA) so it cannot be implemented and used
without either licensing the patents or infringing on them. For some
standards, the
patent owners have released their patent rights and allow anyone to
implement the standard using the patents without infringement. An
example of this is the
Theora video compression standard where On2 has licensed their patents.
However, just because a specification can be implemented without infringing patents doesn't mean that a particular implementation doesn't infringe patents. To invent an example, say you make a Fortran 66 compiler that will take a MPEG-2 video, decode it and look for fortran code and compile that code. Despite the fact that you could make a Fortran 66 compiler without infringing any valid and unexpired patents, this bizarre implementation would infringe on any MPEG-2 patents.
Searching for US Patent and Trademark Office's patent
database will produce large numbers of patents for many queries. For
example, searching
for Class
375/240.16,
which is Subject matter wherein a signal is produced which represents
the spacial change of an image portion, produced 1066 patents. That is
many more patents
than I want to look at. Smarter
searches could reduce this number based on other criteria such as
filing date, but still most searches for patents will quickly return
more patents than anyone can handle. Instead, I used the ITU's
and ISO's patent databases and the companies own claims for patents on
the standard. The
ISO's patent database misses patents that have successfully been sued
over so it should not be relied upon. On the other hand, companies that
claim that their patents cover
a standard and then ask for licensing fees have a bias to try and claim
that they own as many essential patents as possible. In my spot checks,
it
looks like some of the patents that companies are claiming cover the
standard are essential, and some look like they only cover possible
implementations of the standard. Because of this method of search, two
types of errors exist, errors of including patents that are not
required for implementing the standard and missing patents that are
required for implementing the standard.
H.261
One of the earliest compressed video specifications to be created was ITU's H.261 protocol. This was initially designed for use over ISDN lines. The specification is available for from from http://www.itu.int/rec/T-REC-H.261 for free. The first version was finished on November 1988, but many portions were "under study". The second version was finished on December 1990. This version included motion vectors, and other compression techniques used in MPEG-1 and later video compression codecs. H.261 has not been used nearly as much as the MPEG standards, but since it was finished in December 1990, it provides a useful piece of prior art when examining other patents. The ITU has patent database at http://www.itu.int/ipr/IPRSearch.aspx?iprtype=PS Searching for H.261 show that there are the following patents listed:
- H261-03 and H261-34 PictureTel Corp. and Polycom, Inc.
- 4 794 455 US
- H261-29 Hitachi, Ltd.
- H01-229161 JP -application
- H261-30 Robert Bosch GmbH
- 3 46 636 B1 and 3 46 637 B1 EP
- 3 46 635 B1 EP
- 2 79 053 B1 EP
- 8 34 233 B1 EP Appl. No. 503503/96 (JP), 9 83 219 (US)
The US patent 4,794,455 expired in March 21 of this year. In the database the following companies are listed as not having any patents: Sony Corporation, Bellcore, AT&T Corp., Nortel Networks Limited, Vistacom Industries, Inc., Graphics Communication Technologies, Ltd., Nippon Telegraph and Telephone Corporation, KDDI Corporation, Alcatel, Compression Labs, Inc., Toshiba Corporation, AEG Aktiengesellschaft, British Telecommunications plc, Philips Kommunikations Industrie AG, Royal PTT Nederland N. V., Sharp Corporation, GPT Data Systems, A GEC Plessey Telecommunications Division, Société Anonyme de Télécommunications, Philips Electronics N.V., Oki Electric Industry Co., Ltd., Centro Studi e Laboratori Telecommunicazioni SPA, Matsushita Communication Industrial Co., Ltd., Mitsubishi Electric Corp., Fujitsu Ltd., NEC CORPORATION, France Telecom/France Telecom Research and Development Center, Electronics and Telecommunications Research Institute.
The application 9 83 219 seems to be talking about
US 6,198,849, which was filed in December 19, 1997, well after both
the H.261 and MPEG-1 were created. US 6,198,849 mentions H.263 in the
summary, so it probably does
not actually apply to H.261 (Just because someone claims a patent is
required, doesn't mean that is. If you're actually implementing H.261,
don't take my word on
this, look at the patent yourself). The ITU database states that it may
not be complete, so there
may be other H.261 patents. H.261
is only 18 years old, so a patent that was filed before December 1991
would still be in effect (assuming fees paid ...) and the H.261
standard would not count as prior art for that patent though the patent
might be invalid for other reasons. H.261 quite possibly is patent
free, at least in the US.
MPEG-1 ISO/IEC 11172
MPEG-1 (wp) is a widely used standard for compressing video and audio. The various parts of the standard can be purchased from the ISO or ANSI (Part 1, 2, 3). It is used for [http://en.wikipedia.org/wiki/Video_CD video cds] and most DVD players can play these cds. MPEG-1 is a subset of MPEG-2, so any complete MPEG-2 player can play MPEG-1 video and audio as well. Both [http://support.microsoft.com/kb/316992 Microsoft Media Player] and [http://www.apple.com/quicktime/player/specs.html Apple Quicktime] play MPEG-1. There are three different ways audio can be encoded in MPEG-1. The simplest is layer 1, layer 2 is more complicated and Layer 3 (also know as MP3) is the most complex. A near complete draft of MPEG-1 was created in September 1990 and the final version of the decoding spec (ISO 11172-1,2,3) was published in [http://www.chiariglione.org/mpeg/meetings/paris94/paris_press.htm August 1993]. The draft standard was publicly available as [http://bmrc.berkeley.edu/research/mpeg/software/Old/mpegfa31.txt ISO CD 11172] by [http://bmrc.berkeley.edu/research/mpeg/software/Old/Mpeg93.ps.gz December 6, 1991]. [http://bmrc.berkeley.edu/frame/research/mpeg/ Berkeley Plateau Multimedia Research Group] created a [http://bmrc.berkeley.edu/research/publications/1992/101/101.html software MPEG-1 video decoder] by November of 1992 ( [http://bmrc.berkeley.edu/research/mpeg/software/Old/ Old versions download]). Reference encoders and decoders were published in 1998 by the ISO and the source code can be downloaded.
The ISO has a [http://www.iso.org/patents patent
database] (Use the JCT1 one, and search for 11172) which lists one
MPEG-1
patent owned by the Compusonics Corporation, US 4,472,747, which
expired in 2003. So,
is MPEG-1 be implemented without worrying about infringing patents?
Nope. MPEG-1 Layer 3 audio has
at least three separate companies that claim to have patents,
Alcatel-Lucent,
Thompson and
AudioMPEG. All
their claimed US MP3
patents are listed in the MP3 patent appendix below. The last of these
patents
expires in March of 2020. If
you only look at the MP3 patents filed before December 1992 (one year
after the decoding spec was published), then the last decoding patent
expires in December of 2012. AudioMPEG
claims that their patents cover MPEG-1 layers 1,2 and 3. The other
companies just
talk about Layer 3. So,
at the minimum, fully decoding and encoding MPEG-1 audio is patented.
The
[http://patft1.uspto.gov/netacgi/nph-Parser?patentnumber=4,972,484 US
4,972,484] patent "Method of transmitting or storing masked sub-band
coded audio signals" seems to expire July 21 this year. That patent
describes the
basic algorithm used for Layer 2 audio. While there may be other
Layer 2 patents, the expiration of 4,972,484 could make Layer 2 audio
patent free in the US. It
is quite possible that some of the claimed MP3 patents are could either
be invalided by prior art, or could be avoided by using a different
method of implementation.
So, assuming MPEG-1 with Layer 2 audio is patent free,
but MP3 is not, what would that allow without patent issues? It would
not allow fully
conforming MPEG-1 decoders because they require MPEG-1 Layer 3 audio
which is probably patented till at least December of 2012. In other
words, the MPEG-1 decoder would not have
sound if it found MP3 data. MPEG-1 encoders would be possible, since
they could just encode the audio with the Layer 2 method.
Video CDs use Layer 2 audio,
so both encoding and decoding could be done for them. If it was done
carefully,
encoding for DVD could be done since MPEG-2 is fully backward
compatible with MPEG-1.
MPEG-2
MPEG-2, like MPEG-1 is a video and audio compression standard. It added features like interlaced video and better error handing to MPEG-1. MPEG LA has a patent list available of patents that MPEG-LA considers essential to implementing MPEG-2. The last US patent on that list, [http://patft1.uspto.gov/netacgi/nph-Parser?patentnumber=7,292,657 US 7,292,657], expires in 2023. So baring either a lot of patents being declared invalid, or software patents either being declared invalid or having their term retroactively reduced or the companies that own the patents allowing them to be freely used, MPEG-2 will be difficult to implement without patent infringement for a while. Since MPEG-2 also includes MPEG-1, all the audio patents in it also apply (Interestingly, MPEG-LA's list does not include these). Quicktime and Windows Media Player's free version do not play MPEG-2, possibly because of the extra patents that apply to MPEG-2 compared to MPEG-1. At least some MPEG-2 patents clearly do not apply to MPEG-1, such as US 5,093,720, which deals with interlaced video. If you are trying to figure out what patents might exist for MPEG-1, the older MPEG-2 patents should be looked at.
What Can Be Done?
First of all, if you need video in an open source program, use one of the alternatives that are widely distributed already in open source programs such as Theora/ Vorbis and Motion JPEG. On2 has patents that Theora contains, but they have granted a license to use them. If you need a video format that almost certainly patent free, and supported by Quicktime and Windows Media Player and most open source players, try Motion JPEG. Motion JPEG has fairly substantial file sizes since it basically is a series of JPEG pictures. While there certainly could be the potential for a patent infringement case when using one of these, they are widely distributed, so unless you have a lot of money you will probably not get sued over them.
If you want to create or use open source MPEG-1 software
in the US, here are some things that can be done to work towards
clearing MPEG-1 for use. Prior
art is useful for reducing the possible valid patents, so it is useful
to find the oldest publications on MPEG-1 and the oldest source code
for MPEG-1. It
would be useful to have a comparison between the draft MPEG-1 standard
and the final MPEG-1 standard since this would allow the MPEG-1 Draft
date to be used as prior art (and the draft is no longer available for
purchase as far as I know). A detail comparison between H.261 and
MPEG-1 would allow
determining which patents might only apply to MPEG-1, and which can be
invalidated from H.261's 1990 specification.
The MPEG-2 patents that are too old to be invalidated by
the MPEG-1 standard or other prior art need to be checked to see if
MPEG-1 might use them. Categorizing
the MPEG-2 patents
into encoding and decoding and video or audio makes it easier to figure
out which ones apply for a given implementation. And of course, since I
only looked at US patents, the same types of things need to be done for
the German, Japanese
and other countries patents.
Summary
H.261 is probably patent free in the US, but there certainly could be patents that are not listed in the ITU database. There is a good chance that MPEG-1 with Layer 2 audio will soon be patent free, but it might not be. MPEG-1 layer 3 audio has many patents claimed for it. MPEG-2 is not patent free and it will be almost two decades before the MPEG-LA patents expire. There are no reliable lists of patents for the MPEG standards available on the web for free. Considering that MPEG-1 has been out for more than a decade, this is ridiculous. If you need to put video in an open source program, consider Theora or Motion JPEG. If you want to get a definite legal opinion on the patent status for H.261 or MPEG-1, you will probably spend a lot of money on Lawyers or spend a lot of time reading patents and patent law. Or just wait several years. Most (but not all) patents expire 20 years after they are filed, and the patents have to be filed within 1 year of publication, so 21 years after the standard is published, the patents mostly will have expired. H.261 is 21 years old in 2011, and MPEG-1 decoding (Draft) is 21 years old in 2012 and MPEG-1 reference encoding and decoding is 21 years old in 2019.
Disclaimers:
I am not a lawyer. I am not a MPEG or H.261 expert. This is not legal advice. This was written on my own time and I am speaking for myself and not my employer. Many of sites used in this have disclaimers that they can not provide legal advice or are not guaranteed to be complete. Non-US patents are generally ignored. If you want to use MPEG-1, H.261 or MPEG-2 right now, you are always perfectly free to negotiate with the patent owners (if you can find them all) for permission to do so. There are almost certainly mistakes in this, so be careful. If you need accurate information carefully check it yourself or pay a lawyer to do so. The patent data were automatically gathered and calculated with programs available at http://en.wikipedia.org/wiki/User:Jrincayc/Patent_utils
This work is licensed with the GNU Free Documentation
License, Version 1.2 or any later version published by the Free
Software Foundation; with no Invariant Sections, with no Front-Cover
Texts, and with no Back-Cover Texts.
MPEG-2 Patents
Source: http://www.mpegla.com/m2/m2-att1.pdf
Alcatel-Lucent
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British Telecommunications plc
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Canon Inc.
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CIF LICENSING, LLC
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Columbia University
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France Telecom R&D
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Fujitsu
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General Electric
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General Instrument
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General Electric
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LG Electronics
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Matsushita
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Mitsubishi
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Philips
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Samsung
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Scientific Atlanta
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Sony
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Thomson SA
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US 7,020,204 Filed: 08 feb 2002 Granted: 28 mar 2006 Expiration: 08 feb 2022 Adaptive method of encoding and decoding a series of pictures by transformation, and devices for implementing this method
Toshiba
US 5,317,397 Filed: 29 may 1992 Granted: 31 may 1994 Expiration: 29 may 2012 Predictive coding using spatial-temporal filtering and plural motion vectors
US 5,424,779 Filed: 24 nov 1993 Granted: 13 jun 1995 Expiration: 24 nov 2013 Video coding apparatus
US 5,467,136 Filed: 17 feb 1994 Granted: 14 nov 1995 Expiration: 17 feb 2014 Video decoder for determining a motion vector from a scaled vector and a difference vector
US 5,742,344 Filed: 03 apr 1996 Granted: 21 apr 1998 Expiration: 03 apr 2016 Motion compensated video decoding method and system for decoding a coded video signal using spatial and temporal filtering
US 5,986,713 Filed: 11 jun 1998 Granted: 16 nov 1999 Expiration: 11 jun 2018 Video coding apparatus using inter-field prediction
JVC
US RE34,965 Filed: 14 jan 1993 Granted: 13 jun 1995 Expiration: 18 jan 2010 Inter-frame predictive encoding system with encoded and transmitted prediction error Reissue of 04985768 filed 18 jan 1990 granted 15 jan 1991
US RE35,158 Filed: 28 dec 1992 Granted: 20 feb 1996 Expiration: 26 apr 2010 Apparatus for adaptive inter-frame predictive encoding of video signal Reissue of 04982285 filed 26 apr 1990 granted 01 jan 1991
US RE36,822 Filed: 02 oct 1998 Granted: 15 aug 2000 Expiration: 17 jun 2016 Moving image signal coding apparatus and coded signal decoding apparatus Reissue of 05748784 filed 17 jun 1996 granted 05 may 1998
US 5,103,307 Filed: 18 jan 1991 Granted: 07 apr 1992 Expiration: 18 jan 2011 Interframe predictive coding/decoding system for varying interval between independent frames
US 5,175,618 Filed: 30 oct 1991 Granted: 29 dec 1992 Expiration: 30 oct 2011 Compression method for interlace moving image signals
MPEG-1 Audio Layer 3 Patents
Source: http://www.tunequest.org/a-big-list-of-mp3-patents/20070226/ and http://www.audiompeg.com/us_patents.asp
Alcatel-Lucent
US 5,341,457 Filed: 20 aug 1993 Granted: 23 aug 1994 Expiration: 20 aug 2013 Perceptual coding of audio signals
US RE39,080 Filed: 13 aug 2002 Granted: 25 apr 2006 Expiration: 22 sep 2014 Rate loop processor for perceptual encoder/decoder Reissue of 05627938 filed 22 sep 1994 granted 06 may 1997
Audio MPEG, Inc
US 4,972,484 Filed: 21 jul 1988 Granted: 20 nov 1990 Expiration: 21 jul 2008 Method of transmitting or storing masked sub-band coded audio signals
US 5,214,678 Filed: 31 may 1990 Granted: 25 may 1993 Expiration: 31 may 2010 Digital transmission system using subband coding of a digital signal
US 5,323,396 Filed: 21 dec 1992 Granted: 21 jun 1994 Expiration: 21 dec 2012 Digital transmission system, transmitter and receiver for use in the transmission system
US 5,539,829 Filed: 07 jun 1995 Granted: 23 jul 1996 Expiration: 07 jun 2015 Subband coded digital transmission system using some composite signals
US 5,606,618 Filed: 27 dec 1993 Granted: 25 feb 1997 Expiration: 27 dec 2013 Subband coded digital transmission system using some composite signals
US 5,530,655 Filed: 06 jun 1995 Granted: 25 jun 1996 Expiration: 06 jun 2015 Digital sub-band transmission system with transmission of an additional signal
US 5,777,992 Filed: 07 jun 1995 Granted: 07 jul 1998 Expiration: 07 jun 2015 Decoder for decoding and encoded digital signal and a receiver comprising the decoder
US 6,289,308 Filed: 08 mar 2000 Granted: 11 sep 2001 Expiration: 08 mar 2020 Encoded wideband digital transmission signal and record carrier recorded with such a signal
US 5,481,643 Filed: 24 apr 1995 Granted: 02 jan 1996 Expiration: 24 apr 2015 Transmitter, receiver and record carrier for transmitting/receiving at least a first and a second signal component
US 5,544,247 Filed: 25 oct 1994 Granted: 06 aug 1996 Expiration: 25 oct 2014 Transmission and reception of a first and a second main signal component
US 5,610,985 Filed: 21 jan 1994 Granted: 11 mar 1997 Expiration: 21 jan 2014 Digital 3-channel transmission of left and right stereo signals and a center signal
US 5,740,317 Filed: 30 aug 1995 Granted: 14 apr 1998 Expiration: 30 aug 2015 Process for finding the overall monitoring threshold during a bit-rate-reducing source coding
US 5,878,080 Filed: 07 feb 1997 Granted: 02 mar 1999 Expiration: 07 feb 2017 N-channel transmission, compatible with 2-channel transmission and 1-channel transmission
US 5,960,037 Filed: 09 apr 1997 Granted: 28 sep 1999 Expiration: 09 apr 2017 Encoding of a plurality of information signals
US 5,991,715 Filed: 31 aug 1995 Granted: 23 nov 1999 Expiration: 31 aug 2015 Perceptual audio signal subband coding using value classes for successive scale factor differences
US 6,023,490 Filed: 09 apr 1997 Granted: 08 feb 2000 Expiration: 09 apr 2017 Encoding apparatus for encoding a plurality of information signals
Thomson
US 4,821,260 Filed: 16 dec 1987 Granted: 11 apr 1989 Expiration: 16 dec 2007 Transmission system
US 4,942,607 Filed: 03 feb 1988 Granted: 17 jul 1990 Expiration: 03 feb 2008 Method of transmitting an audio signal
US 5,214,742 Filed: 01 oct 1990 Granted: 25 may 1993 Expiration: 01 oct 2010 Method for transmitting a signal
US 5,227,990 Filed: 17 jan 1992 Granted: 13 jul 1993 Expiration: 17 jan 2012 Process for transmitting and receiving a signal
US 5,384,811 Filed: 24 aug 1992 Granted: 24 jan 1995 Expiration: 24 aug 2012 Method for the transmission of a signal
US 5,736,943 Filed: 31 may 1996 Granted: 07 apr 1998 Expiration: 31 may 2016 Method for determining the type of coding to be selected for coding at least two signals
US 5,455,833 Filed: 26 apr 1993 Granted: 03 oct 1995 Expiration: 26 apr 2013 Process for the detecting of errors in the transmission of frequency-coded digital signals
US 5,559,834 Filed: 15 apr 1994 Granted: 24 sep 1996 Expiration: 15 apr 2014 Method of reducing crosstalk in processing of acoustic or optical signals
US 5,321,729 Filed: 26 apr 1993 Granted: 14 jun 1994 Expiration: 26 apr 2013 Method for transmitting a signal
US 5,706,309 Filed: 02 may 1995 Granted: 06 jan 1998 Expiration: 02 may 2015 Process for transmitting and/or storing digital signals of multiple channels
US 5,701,346 Filed: 12 sep 1996 Granted: 23 dec 1997 Expiration: 12 sep 2016 Method of coding a plurality of audio signals
US 5,742,735 Filed: 25 aug 1994 Granted: 21 apr 1998 Expiration: 25 aug 2014 Digital adaptive transformation coding method
US 5,812,672 Filed: 15 dec 1994 Granted: 22 sep 1998 Expiration: 15 dec 2014 Method for reducing data in the transmission and/or storage of digital signals of several dependent channels
US 5,579,430 Filed: 26 jan 1995 Granted: 26 nov 1996 Expiration: 26 jan 2015 Digital encoding process
US 6,185,539 Filed: 26 may 1998 Granted: 06 feb 2001 Expiration: 26 may 2018 Process of low sampling rate digital encoding of audio signals
US 6,009,399 Filed: 16 apr 1997 Granted: 28 dec 1999 Expiration: 16 apr 2017 Method and apparatus for encoding digital signals employing bit allocation using combinations of different threshold models to achieve desired bit rates
US 5,924,060 Filed: 20 mar 1997 Granted: 13 jul 1999 Expiration: 20 mar 2017 Digital coding process for transmission or storage of acoustical signals by transforming of scanning values into spectral coefficients
US 5,703,999 Filed: 18 nov 1996 Granted: 30 dec 1997 Expiration: 18 nov 2016 Process for reducing data in the transmission and/or storage of digital signals from several interdependent channels
MPEG-1 Patent
Source: The ISO [http://www.iso.org/patents patent database] (Use the JCT1 one, and search for 11172)
Compusonics Corporation
US 4,472,747 Filed: 19 apr 1983 Granted: 18 sep 1984 Expiration: 19 apr 2003 Audio digital recording and playback system
H.261 Patent
Source: http://www.itu.int/ipr/IPRSearch.aspx?iprtype=PS Search H.261, and see the 3rd and 34th entry
PictureTel Corp. and Polycom, Inc.
US 4,794,455 Filed: 21 mar 1988 Granted: 27 dec 1988 Expiration: 21 mar 2008 Method and apparatus employing adaptive filtering for efficiently communicating image sequences