Patent Status of MPEG-1,H.261 and MPEG-2

By jrincayc in Politics
Sun Jul 20, 2008 at 10:29:29 AM EST

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:,,

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.


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 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 Searching for H.261 show that there are the following patents listed:

  1. H261-03 and H261-34 PictureTel Corp. and Polycom, Inc.
  2. H261-29 Hitachi, Ltd.
  3. H261-30 Robert Bosch GmbH

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 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 Microsoft Media Player and 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 inAugust 1993. The draft standard was publicly available as ISO CD 11172 by December 6, 1991. Berkeley Plateau Multimedia Research Group created a software MPEG-1 video decoder by November of 1992 (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 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 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, 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, 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.


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.


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

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



US 4,833,543 Filed: 24 dec 1986 Granted: 23 may 1989 Expiration: 24 dec 2006 Image processing system and phaselocked loop used therein

US 4,970,590 Filed: 21 dec 1989 Granted: 13 nov 1990 Expiration: 21 dec 2009 System and device for package multiplexing in transmission of many data flows generated by a sole algorithm

US 5,453,790 Filed: 26 mar 1993 Granted: 26 sep 1995 Expiration: 26 mar 2013 Video decoder having asynchronous operation with respect to a video display

British Telecommunications plc

US 5,291,284 Filed: 23 jul 1991 Granted: 01 mar 1994 Expiration: 23 jul 2011 Predictive coding and decoding with error drift reduction

Canon Inc.

US 4,982,270 Filed: 03 feb 1989 Granted: 01 jan 1991 Expiration: 03 feb 2009 Video data transmitting system


US 5,068,724 Filed: 15 jun 1990 Granted: 26 nov 1991 Expiration: 15 jun 2010 Adaptive motion compensation for digital television

US 5,091,782 Filed: 09 apr 1990 Granted: 25 feb 1992 Expiration: 09 apr 2010 Apparatus and method for adaptively compressing successive blocks of digital video

US 5,093,720 Filed: 20 aug 1990 Granted: 03 mar 1992 Expiration: 20 aug 2010 Motion compensation for interlaced digital television signals

Columbia University

US RE35,093 Filed: 09 dec 1994 Granted: 21 nov 1995 Expiration: 03 dec 2010 Systems and methods for coding even fields of interlaced video sequences Reissue of 05193004 filed 03 dec 1990 granted 09 mar 1993

France Telecom R&D

US 4,796,087 Filed: 01 jun 1987 Granted: 03 jan 1989 Expiration: 01 jun 2007 Process for coding by transformation for the transmission of picture signals


US 5,235,618 Filed: 06 nov 1990 Granted: 10 aug 1993 Expiration: 06 nov 2010 Video signal coding apparatus, coding method used in the video signal coding apparatus and video signal coding transmission system having the video signal coding apparatus

General Electric

US 4,706,260 Filed: 07 nov 1986 Granted: 10 nov 1987 Expiration: 07 nov 2006 DPCM system with rate-of-fill control of buffer occupancy

US 4,813,056 Filed: 08 dec 1987 Granted: 14 mar 1989 Expiration: 08 dec 2007 Modified statistical coding of digital signals

General Instrument

US 4,394,774 Filed: 26 jun 1981 Granted: 19 jul 1983 Expiration: 26 jun 2001 Digital video compression system and methods utilizing scene adaptive coding with rate buffer feedback

US 4,698,672 Filed: 27 oct 1986 Granted: 06 oct 1987 Expiration: 27 oct 2006 Coding system for reducing redundancy

General Electric

US 5,426,464 Filed: 18 oct 1994 Granted: 20 jun 1995 Expiration: 18 oct 2014 Field elimination apparatus for a video compression/decompression system

US 5,486,864 Filed: 13 may 1993 Granted: 23 jan 1996 Expiration: 13 may 2013 Differential time code method and apparatus as for a compressed video signal

US 5,491,516 Filed: 14 jan 1993 Granted: 13 feb 1996 Expiration: 14 jan 2013 Field elimination apparatus for a video compression/decompression system

US 5,600,376 Filed: 20 mar 1995 Granted: 04 feb 1997 Expiration: 20 mar 2015 Field elimination apparatus for a video compression/decompression system

US 5,796,743 Filed: 23 may 1996 Granted: 18 aug 1998 Expiration: 23 may 2016 Data word indicator in a system for assembling transport data packets

LG Electronics

US RE37,057 Filed: 18 may 1998 Granted: 20 feb 2001 Expiration: 14 nov 2014 Apparatus and method for converting an HDTV signal to a non-HDTV signal Reissue of 05519446 filed 14 nov 1994 granted 21 may 1996

US RE37,568 Filed: 31 mar 1999 Granted: 05 mar 2002 Expiration: 30 nov 2013 Inverse Quantizer Reissue of 05617094 filed 30 nov 1993 granted 01 apr 1997


US RE35,910 Filed: 12 may 1994 Granted: 29 sep 1998 Expiration: 11 may 2010 Moving image signal encoding apparatus and decoding apparatus Reissue of 05113255 filed 11 may 1990 granted 12 may 1992

US RE36,015 Filed: 02 oct 1995 Granted: 29 dec 1998 Expiration: 27 mar 2012 Apparatus and method for processing groups of fields in a video data compression system Reissue of 05293229 filed 27 mar 1992 granted 08 mar 1994

US RE36,507 Filed: 21 oct 1997 Granted: 18 jan 2000 Expiration: 27 mar 2012 Apparatus and method for processing groups of fields in a video data compression system to encode a single frame as an I-field and a P-field Reissue of 05293229 filed 27 mar 1992 granted 08 mar 1994

US RE39,276 Filed: 27 apr 2000 Granted: 12 sep 2006 Expiration: 20 jul 2014 Method for determining motion compensation Reissue of 05745182 filed 20 jul 1994 granted 28 apr 1998

US RE39,278 Filed: 13 apr 2001 Granted: 12 sep 2006 Expiration: 20 jul 2014 Method for determining motion compensation Reissue of 05745182 filed 20 jul 1994 granted 28 apr 1998

US RE39,280 Filed: 30 may 2001 Granted: 12 sep 2006 Expiration: 20 jul 2014 Method for determining motion compensation Reissue of 05745182 filed 20 jul 1994 granted 28 apr 1998

US 5,223,949 Filed: 17 apr 1992 Granted: 29 jun 1993 Expiration: 17 apr 2012 Coding means for a signal processing system

US 5,412,430 Filed: 04 may 1994 Granted: 02 may 1995 Expiration: 04 may 2014 Image coding method and image coding apparatus

US 5,784,107 Filed: 23 jan 1996 Granted: 21 jul 1998 Expiration: 23 jan 2016 Method and apparatus for picture coding and method and apparatus for picture decoding


US 4,954,892 Filed: 04 oct 1989 Granted: 04 sep 1990 Expiration: 04 oct 2009 Buffer controlled picture signal encoding and decoding system

US 5,072,295 Filed: 20 aug 1990 Granted: 10 dec 1991 Expiration: 20 aug 2010 Adaptive quantization coder/decoder with limiter circuitry

US 5,268,846 Filed: 10 apr 1991 Granted: 07 dec 1993 Expiration: 10 apr 2011 Method and apparatus for nonsequential multimedia data interchange in a data processing system

US 5,949,489 Filed: 31 jul 1998 Granted: 07 sep 1999 Expiration: 31 jul 2018 Image signal coding system

US 5,963,258 Filed: 31 jul 1998 Granted: 05 oct 1999 Expiration: 31 jul 2018 Image signal coding system

US 5,970,175 Filed: 26 oct 1998 Granted: 19 oct 1999 Expiration: 26 oct 2018 Image signal coding system

US 5,990,960 Filed: 09 dec 1998 Granted: 23 nov 1999 Expiration: 09 dec 2018 Image signal coding system

US 6,002,439 Filed: 27 may 1999 Granted: 14 dec 1999 Expiration: 27 may 2019 Image signal coding system

US 6,097,759 Filed: 22 nov 1999 Granted: 01 aug 2000 Expiration: 22 nov 2019 Image signal coding system

US 6,188,794 Filed: 20 may 1999 Granted: 13 feb 2001 Expiration: 20 may 2019 Image signal coding system

US 6,307,973 Filed: 04 dec 2000 Granted: 23 oct 2001 Expiration: 04 dec 2020 Image signal coding system


US 4,849,812 Filed: 24 feb 1988 Granted: 18 jul 1989 Expiration: 24 feb 2008 Television system in which digitized picture signals subjected to a transform coding are transmitted from an encoding station to a decoding station

US 4,901,075 Filed: 11 sep 1987 Granted: 13 feb 1990 Expiration: 11 sep 2007 Method and apparatus for bit rate reduction

US 5,021,879 Filed: 24 sep 1990 Granted: 04 jun 1991 Expiration: 24 sep 2010 System for transmitting video pictures

US 5,027,206 Filed: 13 sep 1989 Granted: 25 jun 1991 Expiration: 13 sep 2009 High-definition television systems

US 5,128,758 Filed: 02 jun 1989 Granted: 07 jul 1992 Expiration: 02 jun 2009 Method and apparatus for digitally processing a high definition television augmentation signal

US 5,179,442 Filed: 26 nov 1990 Granted: 12 jan 1993 Expiration: 26 nov 2010 Method and apparatus for digitally processing a high definition television augmentation signal

US 5,333,135 Filed: 01 feb 1993 Granted: 26 jul 1994 Expiration: 01 feb 2013 Identification of a data stream transmitted as a sequence of packets

US 5,606,539 Filed: 31 aug 1994 Granted: 25 feb 1997 Expiration: 31 aug 2014 Method and apparatus for encoding and decoding an audio and/or video signal, and a record carrier for use with such apparatus

US 5,608,697 Filed: 18 mar 1996 Granted: 04 mar 1997 Expiration: 18 mar 2016 Record carrier containing an audio and/or video signal which has been encoded and includes a decoder delay time parameter indicating a time delay for one or more portions of the signal

US 5,740,310 Filed: 28 jun 1994 Granted: 14 apr 1998 Expiration: 28 jun 2014 Method of maintaining display continuity from a CD with slow-motion or freeze capability

US 5,844,867 Filed: 09 sep 1996 Granted: 01 dec 1998 Expiration: 09 sep 2016 Methods and apparatus for encoding and decoding an audio and/or video signal, and a record carrier used therewith or produced therefrom


US 5,461,421 Filed: 29 nov 1993 Granted: 24 oct 1995 Expiration: 29 nov 2013 Encoding and decoding method and apparatus thereof

US 5,467,086 Filed: 18 jun 1993 Granted: 14 nov 1995 Expiration: 18 jun 2013 Apparatus and method of coding/decoding video data

US 5,654,706 Filed: 18 dec 1996 Granted: 05 aug 1997 Expiration: 18 dec 2016 System for variable length decoding digital transmission data which has been compressed by selecting a scanning pattern

US 6,680,975 Filed: 02 nov 2000 Granted: 20 jan 2004 Expiration: 02 nov 2020 Signal encoding and decoding system and method

US 7,292,657 Filed: 03 jul 2003 Granted: 06 nov 2007 Expiration: 03 jul 2023 Signal compressing signal

Scientific Atlanta

US 5,418,782 Filed: 06 jan 1994 Granted: 23 may 1995 Expiration: 06 jan 2014 Methods and apparatus for providing virtual service selection in a multi-service communications system

US 5,420,866 Filed: 29 mar 1994 Granted: 30 may 1995 Expiration: 29 mar 2014 Methods for providing conditional access information to decoders in a packet-based multiplexed communications system

US 5,457,701 Filed: 06 jan 1994 Granted: 10 oct 1995 Expiration: 06 jan 2014 Method for indicating packet errors in a packet-based multi-hop communications system


US 4,864,393 Filed: 31 may 1988 Granted: 05 sep 1989 Expiration: 31 may 2008 Motion vector estimation in television images

US RE37,222 Filed: 19 jul 1994 Granted: 12 jun 2001 Expiration: 12 oct 2010 Video signal transmitting system Reissue of 05132792 filed 12 oct 1990 granted 21 jul 1992

US 5,191,436 Filed: 30 apr 1991 Granted: 02 mar 1993 Expiration: 30 apr 2011 Method for recording coded motion picture data

US 5,291,486 Filed: 07 aug 1992 Granted: 01 mar 1994 Expiration: 07 aug 2012 Data multiplexing apparatus and multiplexed data demultiplexing apparatus

US 5,298,991 Filed: 24 jul 1992 Granted: 29 mar 1994 Expiration: 24 jul 2012 Variable length coding apparatus and method for motion vector

US 5,343,248 Filed: 16 jul 1992 Granted: 30 aug 1994 Expiration: 16 jul 2012 Moving image compressing and recording medium and moving image data encoder and decoder

US 5,428,396 Filed: 27 dec 1993 Granted: 27 jun 1995 Expiration: 27 dec 2013 Variable length coding/decoding method for motion vectors

US 5,461,420 Filed: 17 sep 1993 Granted: 24 oct 1995 Expiration: 17 sep 2013 Apparatus for coding and decoding a digital video signal derived from a motion picture film source

US 5,481,553 Filed: 28 feb 1994 Granted: 02 jan 1996 Expiration: 28 feb 2014 Methods and apparatus for preventing rounding errors when transform coefficients representing a motion picture signal are inversely transformed

US 5,510,840 Filed: 15 may 1995 Granted: 23 apr 1996 Expiration: 15 may 2015 Methods and devices for encoding and decoding frame signals and recording medium therefor

US 5,539,466 Filed: 26 sep 1994 Granted: 23 jul 1996 Expiration: 26 sep 2014 Efficient coding apparatus for picture signal and decoding apparatus therefor

US 5,543,847 Filed: 13 dec 1993 Granted: 06 aug 1996 Expiration: 13 dec 2013 Picture coding and decoding method for random accessing

US 5,559,557 Filed: 28 sep 1993 Granted: 24 sep 1996 Expiration: 28 sep 2013 Motion video coding with adaptive precision for DC component coefficient quantization and variable length coding

US 5,663,763 Filed: 18 oct 1993 Granted: 02 sep 1997 Expiration: 18 oct 2013 Picture signal encoding method and apparatus and picture signal decoding method and apparatus

US 5,666,461 Filed: 30 may 1995 Granted: 09 sep 1997 Expiration: 30 may 2015 High efficiency encoding and decoding of picture signals and recording medium containing same

US 5,701,164 Filed: 19 dec 1996 Granted: 23 dec 1997 Expiration: 19 dec 2016 Macroblock coding including difference between motion vectors

US 5,946,042 Filed: 02 jul 1997 Granted: 31 aug 1999 Expiration: 02 jul 2017 Macroblock coding including difference between motion vectors

US 5,982,437 Filed: 15 oct 1993 Granted: 09 nov 1999 Expiration: 15 oct 2013 Coding method and system, and decoding method and system

US 6,040,863 Filed: 18 dec 1998 Granted: 21 mar 2000 Expiration: 18 dec 2018 Method of coding and decoding motion vector and apparatus therefor, and method of coding and decoding picture signal and apparatus therefor

US 6,160,849 Filed: 30 may 1995 Granted: 12 dec 2000 Expiration: 30 may 2015 Selectable field and frame based predictive video coding

Thomson SA

US 4,800,432 Filed: 24 oct 1986 Granted: 24 jan 1989 Expiration: 24 oct 2006 Video Difference key generator

US 4,969,055 Filed: 25 aug 1988 Granted: 06 nov 1990 Expiration: 25 aug 2008 Method for recording and/or reproducing digitally coded signals with interframe and interframe coding

US 5,289,276 Filed: 19 jun 1992 Granted: 22 feb 1994 Expiration: 19 jun 2012 Method and apparatus for conveying compressed video data over a noisy communication channel

US 5,365,272 Filed: 02 jul 1993 Granted: 15 nov 1994 Expiration: 02 jul 2013 Method for formatting compressed video data into transport cells

US 5,381,181 Filed: 13 may 1993 Granted: 10 jan 1995 Expiration: 13 may 2013 Clock recovery apparatus as for a compressed video signal

US 5,422,676 Filed: 22 oct 1993 Granted: 06 jun 1995 Expiration: 22 oct 2013 System for coding an image representative signal

US 5,442,400 Filed: 29 apr 1993 Granted: 15 aug 1995 Expiration: 29 apr 2013 Error concealment apparatus for MPEG-like video data

US 5,459,789 Filed: 22 apr 1994 Granted: 17 oct 1995 Expiration: 22 apr 2014 Packet TV program component detector

US 5,483,287 Filed: 03 aug 1994 Granted: 09 jan 1996 Expiration: 03 aug 2014 Method for forming transport cells for conveying compressed video data

US 5,565,923 Filed: 22 aug 1995 Granted: 15 oct 1996 Expiration: 22 aug 2015 Apparatus for formatting a digital signal to include multiple time stamps for system synchronization

US 5,784,110 Filed: 23 may 1996 Granted: 21 jul 1998 Expiration: 23 may 2016 Data processor for assembling transport data packets

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


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


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: and


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


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 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: 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