MPEG-2

MPEG-2 (a.k.a. H.222/H.262 as defined by the ITU) is a standard for "the generic coding of moving pictures and associated audio information".[1] It describes a combination of lossy video compression and lossy audio data compression methods, which permit storage and transmission of movies using currently available storage media and transmission bandwidth. While MPEG-2 is not as efficient as newer standards such as H.264/AVC and H.265/HEVC, backwards compatibility with existing hardware and software means it is still widely used, for example in over-the-air digital television broadcasting and in the DVD-Video standard.

MPEG
MPEG-2 is used in Digital Video Broadcast and DVDs. The MPEG transport stream, TS, and MPEG program stream, PS, are container formats.

Main characteristics

MPEG-2 is widely used as the format of digital television signals that are broadcast by terrestrial (over-the-air), cable, and direct broadcast satellite TV systems. It also specifies the format of movies and other programs that are distributed on DVD and similar discs. TV stations, TV receivers, DVD players, and other equipment are often designed to this standard. MPEG-2 was the second of several standards developed by the Moving Pictures Expert Group (MPEG) and is an international standard (ISO/IEC 13818). Parts 1 and 2 of MPEG-2 were developed in a collaboration with ITU-T, and they have a respective catalog number in the ITU-T Recommendation Series.

While MPEG-2 is the core of most digital television and DVD formats, it does not completely specify them. Regional institutions can adapt it to their needs by restricting and augmenting aspects of the standard. See Video profiles and levels.

Systems

MPEG-2 includes a Systems section, part 1, that defines two distinct, but related, container formats. One is the transport stream, a data packet format designed to transmit one data packet in four ATM data packets for streaming digital video and audio over fixed or mobile transmission mediums, where the beginning and the end of the stream may not be identified, such as radio frequency, cable and linear recording mediums, examples of which include ATSC/DVB/ISDB/SBTVD broadcasting, and HDV recording on tape. The other is the program stream, an extended version of the MPEG-1 container format with less overhead than transport stream. Program stream is designed for random access storage mediums such as hard disk drives, optical discs and flash memory.

Transport stream file formats include M2TS, which is used on Blu-ray discs, AVCHD on re-writable DVDs and HDV on compact flash cards. Program stream files include VOB on DVDs and Enhanced VOB on the short lived HD DVD. The standard MPEG-2 transport stream contains packets of 188 bytes. M2TS prepends each packet with 4 bytes containing a 2-bit copy permission indicator and 30-bit timestamp.

MPEG-2 Systems is formally known as ISO/IEC 13818-1 and as ITU-T Rec. H.222.0.[2][3] ISO authorized the "SMPTE Registration Authority, LLC" as the registration authority for MPEG-2 format identifiers. The registration descriptor of MPEG-2 transport is provided by ISO/IEC 13818-1 in order to enable users of the standard to unambiguously carry data when its format is not necessarily a recognized international standard. This provision will permit the MPEG-2 transport standard to carry all types of data while providing for a method of unambiguous identification of the characteristics of the underlying private data.[4]

Video

The Video section, part 2 of MPEG-2, is similar to the previous MPEG-1 standard, but also provides support for interlaced video, the format used by analog broadcast TV systems. MPEG-2 video is not optimized for low bit-rates, especially less than 1 Mbit/s at standard definition resolutions. All standards-compliant MPEG-2 Video decoders are fully capable of playing back MPEG-1 Video streams conforming to the Constrained Parameters Bitstream syntax. MPEG-2/Video is formally known as ISO/IEC 13818-2 and as ITU-T Rec. H.262.[5]

With some enhancements, MPEG-2 Video and Systems are also used in some HDTV transmission systems, and is the standard format for over-the-air ATSC digital television.

Audio

MPEG-2 introduces new audio encoding methods compared to MPEG-1:[6]

MPEG-2 Part 3

The MPEG-2 Audio section, defined in Part 3 (ISO/IEC 13818-3) of the standard, enhances MPEG-1's audio by allowing the coding of audio programs with more than two channels, up to 5.1 multichannel. This method is backwards-compatible (also known as MPEG-2 BC[7][8][9][10]), allowing MPEG-1 audio decoders to decode the two main stereo components of the presentation.[11] MPEG-2 part 3 also defined additional bit rates and sample rates for MPEG-1 Audio Layer I, II and III.[12]

MPEG-2 BC (backward compatible with MPEG-1 audio formats)[7][8][11]

  • low bitrate encoding with halved sampling rate (MPEG-1 Layer 1/2/3 LSF - a.k.a. MPEG-2 LSF - "Low Sampling Frequencies")
  • multichannel encoding with up to 5.1 channels, a.k.a. MPEG Multichannel

MPEG-2 Part 7

Part 7 (ISO/IEC 13818-7) of the MPEG-2 standard specifies a rather different, non-backwards-compatible audio format[9] (also known as MPEG-2 NBC[7][8][13]). Part 7 is referred to as MPEG-2 AAC. AAC is more efficient than the previous MPEG audio standards, and is in some ways less complicated than its predecessor, MPEG-1 Audio, Layer 3, in that it does not have the hybrid filter bank. It supports from 1 to 48 channels at sampling rates of 8 to 96 kHz, with multichannel, multilingual, and multiprogram capabilities.[6] Advanced Audio is also defined in Part 3 of the MPEG-4 standard.

MPEG-2 NBC (Non-Backward Compatible)[7][8]

  • MPEG-2 AAC
  • multichannel encoding with up to 48 channels

ISO/IEC 13818

MPEG-2 standards are published as parts of ISO/IEC 13818. Each part covers a certain aspect of the whole specification.

Part 1
Systems – describes synchronization and multiplexing of video and audio. (It is also known as ITU-T Rec. H.222.0.[2]) See MPEG transport stream and MPEG program stream.
Part 2
Video – video coding format for interlaced and non-interlaced video signals (Also known as ITU-T Rec. H.262).
Part 3
Audio – audio coding format for perceptual coding of audio signals. A multichannel-enabled extension and extension of bit rates and sample rates for MPEG-1 Audio Layer I, II and III of MPEG-1 audio.
Part 4
Describes procedures for testing compliance.
Part 5
Describes systems for Software simulation.
Part 6
Describes extensions for DSM-CC (Digital Storage Media Command and Control).
Part 7
Advanced Audio Coding (AAC).
Part 8
10-bit video extension. Primary application was studio video, allowing artifact-free processing without giving up compression. Part 8 has been withdrawn due to lack of interest by industry.
Part 9
Extension for real time interfaces.
Part 10
Conformance extensions for DSM-CC.
Part 11
Intellectual property management (IPMP)
MPEG-2 Parts[14][15]
Part Number First public release date (First edition) Latest public release date (edition) Latest amend- ment Identical ITU-T Rec. Title Description
Part 1 ISO/IEC 13818-1 1996 2015 2016[16] H.222.0 Systems
Part 2 ISO/IEC 13818-2 1996 2013 H.262 Video
Part 3 ISO/IEC 13818-3 1995 1998 Audio MPEG-2 BC - backwards compatible with MPEG-1 Audio
Part 4 ISO/IEC 13818-4 1998 2004 2009[17] Conformance testing
Part 5 ISO/IEC TR 13818-5 1997 2005 Software simulation
Part 6 ISO/IEC 13818-6 1998 1998 2001[18] Extensions for DSM-CC extensions for Digital Storage Media Command and Control[19][20]
Part 7 ISO/IEC 13818-7 1997 2006 2007[21] Advanced Audio Coding (AAC) MPEG-2 NBC Audio - Non-Backwards Compatible with MPEG-1 Audio
Part 8 dropped 10-Bit Video The work began in 1995, but was terminated in 2007 because of low industry interest.[22][23]
Part 9 ISO/IEC 13818-9 1996 1996 Extension for real time interface for systems decoders
Part 10 ISO/IEC 13818-10 1999 1999 Conformance extensions for Digital Storage Media Command and Control (DSM-CC)
Part 11 ISO/IEC 13818-11 2004 2004 IPMP on MPEG-2 systems Intellectual Property Management and Protection on the MPEG-2 system[24][25] (XML IPMP messages are also defined in ISO/IEC 23001-3[26])

History

MPEG-2 evolved out of the shortcomings of MPEG-1.

MPEG-1's known weaknesses:

  • An audio compression system limited to two channels (stereo).
  • No standardized support for interlaced video with poor compression when used for interlaced video
  • Only one standardized "profile" (Constrained Parameters Bitstream), which was unsuited for higher resolution video. MPEG-1 could support 4k video but there was no easy way to encode video for higher resolutions, and identify hardware capable of supporting it, as the limitations of such hardware were not defined.
  • Support for only one chroma subsampling, 4:2:0.

Sakae Okubo of NTT was also the ITU-T coordinator for developing the H.262/MPEG-2 Part 2 video coding standard and the requirements chairman in MPEG for the MPEG-2 set of standards.[27]

Filename extensions

.mpg, .mpeg, .m2v, .mp2, .mp3 are some of a number of filename extensions used for MPEG-1 or MPEG-2 audio and video file formats.

Applications

DVD-Video

The DVD-Video standard uses MPEG-2 video, but imposes some restrictions:

  1. ^ 1.85:1 and 2.35:1, among others, are often listed as valid DVD aspect ratios, but are wider film aspects with letterbox style padding to create a 16:9 image
  • Allowed frame rates
    • 29.97 interlaced frame/s (NTSC)
    • 23.978 progressive frame/s (for NTSC 2:3 pull-down to 29.97[dvdrates 1])
    • 25 interlaced frame/s (PAL)
  1. ^ By using a pattern of REPEAT_FIRST_FIELD flags on the headers of encoded pictures, pictures can be displayed for either two or three fields and almost any picture display rate (minimum ⅔ of the frame rate) can be achieved. This is most often used to display 23.976 (approximately film rate) video on NTSC. See telecine for more information on how this works.
  • Audio + video bitrate
    • Video peak 9.8 Mbit/s
    • Total peak 10.08 Mbit/s
    • Minimum 300 kbit/s
  • YUV 4:2:0
  • Additional subtitles possible
  • Closed captioning (NTSC only)
  • Audio
    • Linear Pulse Code Modulation (LPCM): 48 kHz or 96 kHz; 16- or 24-bit; up to six channels (not all combinations possible due to bitrate constraints)
    • MPEG Layer 2 (MP2): 48 kHz, up to 5.1 channels (required in PAL players only)
    • Dolby Digital (DD, also known as AC-3): 48 kHz, 32–448 kbit/s, up to 5.1 channels
    • Digital Theater Systems (DTS): 754 kbit/s or 1510 kbit/s (not required for DVD player compliance)
    • NTSC DVDs must contain at least one LPCM or Dolby Digital audio track.
    • PAL DVDs must contain at least one MPEG Layer 2, LPCM, or Dolby Digital audio track.
    • Players are not required to play back audio with more than two channels, but must be able to downmix multichannel audio to two channels.
  • GOP structure (Group Of Pictures)
    • Sequence header must be present at the beginning of every GOP
    • Maximum frames per GOP: 18 (NTSC) / 15 (PAL), i.e. 0.6 seconds both
    • Closed GOP required for multi-angle DVDs

HDV

HDV is a format for recording and playback of high-definition MPEG-2 video on a DV cassette tape.

MOD and TOD

MOD and TOD are recording formats for use in consumer digital file-based camcorders.

XDCAM

XDCAM is a professional file-based video recording format.

DVB

Application-specific restrictions on MPEG-2 video in the DVB standard:

Allowed resolutions for SDTV:

  • 720, 640, 544, 528, 480 or 352 × 480 pixel, 24/1.001, 24, 30/1.001 or 30 frame/s
  • 352 × 240 pixel, 24/1.001, 24, 30/1.001 or 30 frame/s
  • 720, 704, 544, 528, 480 or 352 × 576 pixel, 25 frame/s
  • 352 × 288 pixel, 25 frame/s

For HDTV:

  • 720 x 576 x 50 frame/s progressive (576p50)
  • 1280 x 720 x 25 or 50 frame/s progressive (720p50)
  • 1440 or 1920 x 1080 x 25 frame/s progressive (1080p25 = film mode)
  • 1440 or 1920 x 1080 x 25 frame/s interlace (1080i50)

ATSC

The ATSC A/53 standard used in the United States, uses MPEG-2 video at the Main Profile @ High Level (MP@HL), with additional restrictions such as the maximum bitrate of 19.39 Mbit/s for broadcast television and 38.8 Mbit/s for cable television, 4:2:0 chroma subsampling format, and mandatory colorimetry information.

ATSC allows the following video resolutions, aspect ratios, and frame/field rates:

  • 1920 × 1080 pixel (16:9, square pixels), at 30p, 29.97p, 24p, 23.976p, 60i, 59.94i.
  • 1280 × 720 pixel (16:9, square pixels), at 60p, 59.94p, 30p, 29.97p, 24p, or 23.976p
  • 704 × 480 pixel (4:3 or 16:9, non-square pixels), at 60p, 59.94p, 30p, 29.97p, 24p, 23.976p, 60i, or 59.94i
  • 640 × 480 pixel (4:3, square pixels), at 60p, 59.94p, 30p, 29.97p, 24p, 23.976p, 60i, or 59.94i

ATSC standard A/63 defines additional resolutions and aspect rates for 50 Hz (PAL) signal.

The ATSC specification and MPEG-2 allow the use of progressive frames, even within an interlaced video sequence. For example, a station that transmits 1080i60 video sequence can use a coding method where those 60 fields are coded with 24 progressive frames and metadata instructs the decoder to interlace them and perform 3:2 pulldown before display. This allows broadcasters to switch between 60 Hz interlaced (news, soap operas) and 24 Hz progressive (prime-time) content without ending the MPEG-2 sequence and introducing a several seconds of delay as the TV switches formats. This is the reason why 1080p30 and 1080p24 sequences allowed by the ATSC specification are not used in practice.

The 1080-line formats are encoded with 1920 × 1088 pixel luma matrices and 960 × 540 chroma matrices, but the last 8 lines are discarded by the MPEG-2 decoding and display process.

ATSC A/72 is the newest revision of ATSC standards for digital television, which allows the use of H.264/AVC video coding format and 1080p60 signal.

MPEG-2 audio was a contender for the ATSC standard during the DTV "Grand Alliance" shootout, but lost out to Dolby AC-3.

ISDB-T

Technical features of MPEG-2 in ATSC are also valid for ISDB-T, except that in the main TS has aggregated a second program for mobile devices compressed in MPEG-4 H.264 AVC for video and AAC-LC for audio, mainly known as 1seg.

Blu-ray

MPEG-2 is one of the three supported coding formats supported by Blu-ray Disc. Early Blu-ray releases typically used MPEG-2 video, but recent releases are almost always in H.264 or occasionally VC-1.

Patent pool

All MPEG-2 patents are officially expired and can be used freely.[28]

MPEG LA, a private patent licensing organization, has acquired rights from over 20 corporations and one university to license a patent pool of approximately 640 worldwide patents, which it claims are the "essential" to use of MPEG-2 technology, although many of the patents have since expired.[29][30] Where software patentability is upheld, the use of MPEG-2 requires the payment of licensing fees to the patent holders. Other patents are licensed by Audio MPEG, Inc.[31] The development of the standard itself took less time than the patent negotiations.[32][33] Patent pooling between essential and peripheral patent holders in the MPEG-2 pool is the subject of a study by the University of Wisconsin.[34] Over half of the patents expired in 2012.[35]

According to the MPEG-2 licensing agreement any use of MPEG-2 technology is subject to royalties.[36] MPEG-2 encoders are subject to a royalty of $2.00 per unit, decoders are subject to a royalty of $2.00 per unit, and royalty-based sales of encoders and decoders are subject to different rules and $2.50 per unit.[36] Also, any packaged medium (DVDs/Data Streams) is subject to licence fees according to length of recording/broadcast.[36] A criticism of the MPEG-2 patent pool is that even though the number of patents will decrease from 1,048 to 416 by June 2013 the license fee has not decreased with the expiration rate of MPEG-2 patents.[37][38][39][40] Since January 1, 2010, the MPEG-2 patent pool has remained at $2 for a decoding license and $2 for an encoding license.[36][38][39] By 2015 more than 90% of the MPEG-2 patents will have expired but as long as there are one or more active patents in the MPEG-2 patent pool in either the country of manufacture or the country of sale the MPEG-2 license agreement requires that licensees pay a license fee that does not change based on the number of patents that have expired.[36][37][38][39][40]

Patents (U.S. only)

The last United States patent expired on 13 February 2018.[41]

See also

References

  1. ^ "ISO/IEC 13818-1:2000 - Information technology -- Generic coding of moving pictures and associated audio information: Systems". www.iso.org. Archived from the original on 20 May 2007. Retrieved 4 May 2018.
  2. ^ a b ITU-T. "H.222.0 : Information technology - Generic coding of moving pictures and associated audio information: Systems". Archived from the original on 2012-09-03. Retrieved 2010-06-03.
  3. ^ ITU-T (May 2006). "H.222.0 Summary". Archived from the original on 2011-05-19. Retrieved 2010-06-03.
  4. ^ SMPTE Registration Authority, LLC - registration authority for MPEG-2 format identifiers Archived 2010-01-28 at the Wayback Machine Retrieved on 2009-07-06
  5. ^ "H.262 : Information technology - Generic coding of moving pictures and associated audio information: Video". ITU-T Website. International Telecommunication Union - Telecommunication Standardization Sector (ITU-T). February 2000. Archived from the original on 2012-08-22. Retrieved 2009-08-13.
  6. ^ a b D. Thom, H. Purnhagen, and the MPEG Audio Subgroup (October 1998). "MPEG Audio FAQ Version 9 - MPEG Audio". Archived from the original on 2011-08-07. Retrieved 2009-10-31.CS1 maint: Multiple names: authors list (link)
  7. ^ a b c d ISO (October 1998). "MPEG Audio FAQ Version 9 - MPEG-1 and MPEG-2 BC". ISO. Archived from the original on 2010-02-18. Retrieved 2009-10-28.
  8. ^ a b c d MPEG.ORG. "AAC". Archived from the original on 2007-08-31. Retrieved 2009-10-28.
  9. ^ a b ISO (2006-01-15), ISO/IEC 13818-7, Fourth edition, Part 7 - Advanced Audio Coding (AAC) (PDF), archived (PDF) from the original on 2009-03-06, retrieved 2009-10-28
  10. ^ ISO (2004-10-15), ISO/IEC 13818-7, Third edition, Part 7 - Advanced Audio Coding (AAC) (PDF), archived from the original (PDF) on 2011-07-13, retrieved 2009-10-19
  11. ^ a b Werner Oomen; Leon van de Kerkhof. "MPEG-2 Audio Layer I/II". chiariglione.org. Archived from the original on 2010-04-30. Retrieved 2009-12-29.
  12. ^ Predrag Supurovic, MPEG Audio Frame Header Archived 2015-02-08 at the Wayback Machine, Retrieved on 2009-07-11
  13. ^ ISO (March 1996). "Florence Press Release". ISO. Archived from the original on 2010-04-08. Retrieved 2009-10-28.
  14. ^ MPEG. "MPEG standards". chiariglione.org. Archived from the original on 2014-07-21. Retrieved 2014-07-24.
  15. ^ ISO. "ISO/IEC JTC 1/SC 29 - Coding of audio, picture, multimedia and hypermedia information". Archived from the original on 2017-08-30. Retrieved 2017-08-30.
  16. ^ ISO. "ISO/IEC 13818-1:2015/Amd 6:2016, Carriage of Quality Metadata in MPEG-2 Systems". Archived from the original on 2017-08-30. Retrieved 2017-08-30.
  17. ^ ISO. "ISO/IEC 13818-4:2004/Amd 3:2009, Level for 1080@50p/60p conformance testing". Archived from the original on 2017-08-30. Retrieved 2017-08-30.
  18. ^ ISO. "ISO/IEC 13818-6:1998/Amd 3:2001, Transport buffer model in support of synchronized user-to-network download protocol". Archived from the original on 2017-08-30. Retrieved 2017-08-30.
  19. ^ MPEG (1997-02-21). "DSM-CC FAQ Version 1.0". MPEG. Archived from the original on 2010-05-11. Retrieved 2010-08-01.
  20. ^ IEEE (1996). "An Introduction to Digital Storage Media - Command and Control (DSM-CC)". MPEG. Archived from the original on 2010-05-20. Retrieved 2010-08-01.
  21. ^ ISO. "ISO/IEC 13818-7:2006/Amd 1:2007, Transport of MPEG Surround in AAC". Archived from the original on 2017-08-30. Retrieved 2017-08-30.
  22. ^ chiariglione.org (2010-02-04). "Riding the Media Bits, The development of MPEG-2 - Part A". Archived from the original on 2011-11-01. Retrieved 2010-02-09.
  23. ^ Van der Meer, Jan (2014). Fundamentals and Evolution of MPEG-2 Systems: Paving the MPEG Road.
  24. ^ "MPEG Intellectual Property Management and Protection". MPEG. April 2009. Archived from the original on 2010-04-30. Retrieved 2010-08-01.
  25. ^ IPMP in MPEG – W3C DRM workshop 22/23 January 2001 (PPT), archived from the original on 16 July 2012, retrieved 2010-08-01
  26. ^ ISO. "ISO/IEC 23001-3:2008, Information technology -- MPEG systems technologies -- Part 3: XML IPMP messages". Archived from the original on 2017-08-30. Retrieved 2009-10-29.
  27. ^ "Sakae Okubo". ITU. Archived from the original on 2005-03-02. Retrieved 2017-01-27.
  28. ^ "OSNews.com". mobile.osnews.com. Archived from the original on 26 December 2017. Retrieved 4 May 2018.
  29. ^ Mpeg La Archived 2008-06-05 at the Wayback Machine
  30. ^ "audioMPEG.com - - - US Patents". archive.org. 18 March 2004. Archived from the original on 18 March 2004. Retrieved 4 May 2018.
  31. ^ "Sisvel - We protect ideas - Home". Archived from the original on 2013-01-02.
  32. ^ "Audio/Video - GNU Project - Free-Software Foundation". Archived from the original on 2012-12-24.
  33. ^ [1] Archived 2008-05-28 at the Wayback Machine
  34. ^ Quint, Dan; Amit Gandhi. "Economics of Patent Pools When Some (but not all) Patents are Essential". Working Paper. Archived from the original on 2010-07-10. Retrieved 2009-10-11.
  35. ^ "Half of MPEG-2 Patents Expire in 2012". Archived from the original on 2012-09-24.
  36. ^ a b c d e "MPEG-2 License Agreement". MPEG LA. 2013-05-13. Archived from the original on 2013-05-30. Retrieved 2013-05-19.
  37. ^ a b "Patent Pools May Create Anticompetitive Effects, New Report Finds". Business Wire. 2013-05-09. Archived from the original on 2014-08-20. Retrieved 2013-06-06.
  38. ^ a b c Steve Pociask (2013-05-13). "Consumer tech rip-off from patent pools". The Daily Caller. Archived from the original on 2013-07-21. Retrieved 2013-05-19.
  39. ^ a b c Bret Swanson (2013-04-30). "MPEG-LA Shows Need to Rebuild IP Foundations". Forbes. Archived from the original on 2013-04-30. Retrieved 2013-05-19.
  40. ^ a b Steve Forbes (2013-03-18). "America's patent system is all wrong for today's high-tech world". Fox News Channel. Archived from the original on 2013-06-16. Retrieved 2013-06-05.
  41. ^ Richard Chirgwin (15 February 2018). "Waddawewant? Free video codecs! When dowe .. oh, look, the last MPEG-2 patent expired!". The Register. Archived from the original on 15 February 2018.

External links

.m2ts

M2TS is a filename extension used for the Blu-ray Disc Audio-Video (BDAV) MPEG-2 Transport Stream (M2TS) container file format. It is used for multiplexing audio, video and other streams. It is based on the MPEG-2 transport stream container. This container format is commonly used for high definition video on Blu-ray Disc and AVCHD.

ATSC standards

Advanced Television Systems Committee (ATSC) standards are a set of standards for digital television transmission over terrestrial, cable, and satellite networks. It is largely a replacement for the analog NTSC standard, and like that standard, used mostly in the United States, Mexico and Canada. Other former users of NTSC, like Japan, have not used ATSC during their digital television transition because they adopted their own system called ISDB.

The ATSC standards were developed in the early 1990s by the Grand Alliance, a consortium of electronics and telecommunications companies that assembled to develop a specification for what is now known as HDTV. The standard is now administered by the Advanced Television Systems Committee. The standard includes a number of patented elements, and licensing is required for devices that use these parts of the standard. Key among these is the 8VSB modulation system used for over-the-air broadcasts.

ATSC includes two primary high definition video formats, 1080i and 720p. It also includes standard-definition formats, although initially only HDTV services were launched in the digital format. ATSC can carry multiple channels of information on a single stream, and it is common for there to be a single high-definition signal and several standard-definition signals carried on a single 6 MHz (former NTSC) channel allocation.

Advanced Audio Coding

Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at the same bit rate. The confusingly named AAC+ (HE-AAC) does so only at low bit rates and less so at high ones.

AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications. Part of AAC, HE-AAC ("AAC+"), is part of MPEG-4 Audio and also adopted into digital radio standards DAB+ and Digital Radio Mondiale, as well as mobile television standards DVB-H and ATSC-M/H.

AAC supports inclusion of 48 full-bandwidth (up to 96 kHz) audio channels in one stream plus 16 low frequency effects (LFE, limited to 120 Hz) channels, up to 16 "coupling" or dialog channels, and up to 16 data streams. The quality for stereo is satisfactory to modest requirements at 96 kbit/s in joint stereo mode; however, hi-fi transparency demands data rates of at least 128 kbit/s (VBR). Tests of MPEG-4 audio have shown that AAC meets the requirements referred to as "transparent" for the ITU at 128 kbit/s for stereo, and 320 kbit/s for 5.1 audio.AAC is the default or standard audio format for YouTube, iPhone, iPod, iPad, Nintendo DSi, Nintendo 3DS, iTunes, DivX Plus Web Player, PlayStation 3 and various Nokia Series 40 phones. It is supported on PlayStation Vita, Wii (with the Photo Channel 1.1 update installed), Sony Walkman MP3 series and later, Android and BlackBerry. AAC is also supported by manufacturers of in-dash car audio systems.

DVB-C

DVB-C stands for "Digital Video Broadcasting - Cable" and it is the DVB European consortium standard for the broadcast transmission of digital television over cable. This system transmits an MPEG-2 or MPEG-4 family digital audio/digital video stream, using a QAM modulation with channel coding. The standard was first published by the ETSI in 1994, and subsequently became the most widely used transmission system for digital cable television in Europe, Asia and South America. It is deployed worldwide in systems ranging from the larger cable television networks (CATV) down to smaller satellite master antenna TV (SMATV) systems.

DVB-S

Digital Video Broadcasting – Satellite (DVB-S) is the original DVB standard for Satellite Television and dates from 1995, in its first release, while development lasted from 1993 to 1997. The first commercial application was by Galaxy in Australia, enabling digitally broadcast, satellite-delivered Television to the public.

It is used via satellites serving every continent of the world. DVB-S is used in both Multiple Channel Per Carrier (MCPC) and Single channel per carrier modes for Broadcast Network feeds as well as for direct-broadcast satellite services like Sky (UK & Ireland) via Astra in Europe, Dish Network and Globecast in the U.S. and Bell TV in Canada.

While the actual DVB-S standard only specifies physical link characteristics and framing, the overlaid transport stream delivered by DVB-S is mandated as MPEG-2, known as MPEG transport stream (MPEG-TS).

Some amateur television repeaters also use this mode in the 1.2 GHz amateur band.

DVB-T

DVB-T is an abbreviation for "Digital Video Broadcasting — Terrestrial"; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998. This system transmits compressed digital audio, digital video and other data in an MPEG transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation. It is also the format widely used worldwide (including North America) for Electronic News Gathering for transmission of video and audio from a mobile newsgathering vehicle to a central receive point.

Elementary stream

An elementary stream (ES) as defined by the MPEG communication protocol is usually the output of an audio or video encoder. ES contains only one kind of data (e.g. audio, video, or closed caption). An elementary stream is often referred to as "elementary", "data", "audio", or "video" bitstreams or streams. The format of the elementary stream depends upon the codec or data carried in the stream, but will often carry a common header when packetized into a packetized elementary stream.

Enhanced VOB

Enhanced Video Object, also known as Enhanced VOB or EVO, is a container format for HD DVD video media. It contains the actual digital video, digital audio, subtitle and DVD menu contents in stream form. It is an extension to VOB. It can contain video encoded in H.264/MPEG-4 AVC, VC-1, or H.262/MPEG-2 Part 2 and audio encoded in AC-3, E-AC-3, Dolby TrueHD, DTS, DTS-HD, PCM, and MPEG-2 Part 3.

There are a few consumer software solutions that can play EVO files, such as PowerDVD, WinDVD for Windows and FFmpeg for Linux (unprotected EVO only), and the cross platform VLC Player.

H.262/MPEG-2 Part 2

H.262 or MPEG-2 Part 2 (formally known as ITU-T Recommendation H.262 and ISO/IEC 13818-2, also known as MPEG-2 Video) is a video coding format developed and maintained jointly by ITU-T Video Coding Experts Group (VCEG) and ISO/IEC Moving Picture Experts Group (MPEG). It is the second part of the ISO/IEC MPEG-2 standard. The ITU-T Recommendation H.262 and ISO/IEC 13818-2 documents are identical. The standard is available for a fee from the ITU-T and ISO.

MPEG-2 Video is similar to MPEG-1, but also provides support for interlaced video (an encoding technique used in analog NTSC, PAL and SECAM television systems). MPEG-2 video is not optimized for low bit-rates (less than 1 Mbit/s), but outperforms MPEG-1 at 3 Mbit/s and above. All standards-conforming MPEG-2 Video decoders are fully capable of playing back MPEG-1 Video streams.

MP3

MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio. Originally defined as the third audio format of the MPEG-1 standard, it was retained and further extended—defining additional bit-rates and support for more audio channels—as the third audio format of the subsequent MPEG-2 standard. A third version, known as MPEG 2.5—extended to better support lower bit rates—is commonly implemented, but is not a recognized standard.

MP3 (or mp3) as a file format commonly designates files containing an elementary stream of MPEG-1 audio and video encoded data, without other complexities of the MP3 standard.

In the aspects of MP3 pertaining to audio compression—the aspect of the standard most apparent to end-users (and for which is it best known)—MP3 uses lossy data-compression to encode data using inexact approximations and the partial discarding of data. This allows a large reduction in file sizes when compared to uncompressed audio. The combination of small size and acceptable fidelity led to a boom in the distribution of music over the Internet in the mid- to late-1990s, with MP3 serving as an enabling technology at a time when bandwidth and storage were still at a premium. The MP3 format soon became associated with controversies surrounding copyright infringement, music piracy, and the file ripping/sharing services MP3.com and Napster, among others. With the advent of portable media players, a product category also including smartphones, MP3 support remains near-universal.

MP3 compression works by reducing (or approximating) the accuracy of certain components of sound that are considered (by psychoacoustic analysis) to be beyond the hearing capabilities of most humans. This method is commonly referred to as perceptual coding or as psychoacoustic modeling. The remaining audio information is then recorded in a space-efficient manner. Compared to CD-quality digital audio, MP3 compression can commonly achieve a 75 to 95% reduction in size. For example, an MP3 encoded at a constant bitrate of 128 kbit/s would result in a file approximately 9% of the size of the original CD audio.The Moving Picture Experts Group (MPEG) designed MP3 as part of its MPEG-1, and later MPEG-2, standards. The first subgroup for audio was formed by several teams of engineers at CCETT, Matsushita, Philips, Sony, AT&T-Bell Labs, Thomson-Brandt, and others. MPEG-1 Audio (MPEG-1 Part 3), which included MPEG-1 Audio Layer I, II and III, was approved as a committee draft for an ISO/IEC standard in 1991, finalised in 1992, and published in 1993 as ISO/IEC 11172-3:1993. A backwards-compatible MPEG-2 Audio (MPEG-2 Part 3) extension with lower sample- and bit-rates was published in 1995 as ISO/IEC 13818-3:1995.

MPEG-1 Audio Layer II

MPEG-1 Audio Layer II or MPEG-2 Audio Layer II (MP2, sometimes incorrectly called Musicam or MUSICAM) is a lossy audio compression format defined by ISO/IEC 11172-3 alongside MPEG-1 Audio Layer I and MPEG-1 Audio Layer III (MP3). While MP3 is much more popular for PC and Internet applications, MP2 remains a dominant standard for audio broadcasting.

MPEG-2 Part 3

Part 3 of the MPEG-2 standard (formally known as ISO/IEC 13818-3, also known as MPEG-2 Audio or MPEG-2 BC) defines audio coding:

MPEG Multichannel - It enhances MPEG-1's audio by allowing the coding of audio programs with more than two channels, up to 5.1 multichannel. This method is backwards-compatible (also known as MPEG-2 BC), allowing MPEG-1 audio decoders to decode the two main stereo components of the presentation.

MPEG-2 Part 3 also defined additional bit rates and sample rates for MPEG-1 Audio Layer I, MPEG-1 Audio Layer II and MPEG-1 Audio Layer III (a.k.a. MP3).The MPEG-2 Part 3 should not be confused with MPEG-2 Part 7: AAC a.k.a. MPEG-2 NBC (Non-Backward Compatible) - the MPEG-2 Advanced Audio Coding with support for multichannel encoding (up to 48 channels).

MPEG-3

MPEG-3 is the designation for a group of audio and video coding standards agreed upon by the Moving Picture Experts Group (MPEG) designed to handle HDTV signals at 1080p in the range of 20 to 40 megabits per second. MPEG-3 was launched as an effort to address the need of an HDTV standard while work on MPEG-2 was underway, but it was soon discovered that MPEG-2, at high data rates, would accommodate HDTV. Thus, in 1992 HDTV was included as a separate profile in the MPEG-2 standard and MPEG-3 was rolled into MPEG-2.

MPEG LA

MPEG LA is an American company based in Denver, Colorado that licenses patent pools covering essential patents required for use of the MPEG-2, MPEG-4, IEEE 1394, VC-1, ATSC, MVC, MPEG-2 Systems, AVC/H.264 and HEVC standards.MPEG LA is not affiliated with MPEG, the Moving Picture Experts Group.

MPEG Multichannel

MPEG Multichannel is an extension to the MPEG-1 Layer II audio compression specification, as defined in the MPEG-2 Audio standard (ISO/IEC 13818-3) which allows it provide up to 5.1-channels (surround sound) of audio. To maintain backwards compatibility with the older 2-channel (stereo) audio specification, it uses a channel matrixing scheme, where the additional channels are mixed into the two backwards compatible channels. Extra information in the data stream (ignored by older hardware) contains signals to process extra channels from the matrix.It was originally a mandatory part of the DVD specification for European DVDs, but was dropped in late 1997, and is rarely used as a result.

The Super Video CD (SVCD) standard supports MPEG Multichannel. Player support for this audio format is nearly non-existent however, and it is rarely used.

MPEG Multichannel audio was proposed for use in the ATSC digital TV broadcasting standard, but Dolby Digital (aka. AC-3, A/52) was chosen instead. This is a matter of significant controversy, as it has been revealed that the organizations (The Massachusetts Institute of Technology and Zenith Electronics) behind 2 of the 4 voting board members received tens of millions of dollars of compensation from secret deals with Dolby Laboratories in exchange for their votes.MPEG Multichannel–compatible equipment would bear either the MPEG Multichannel or MPEG Empowered logos.

MPEG program stream

Program stream (PS or MPEG-PS) is a container format for multiplexing digital audio, video and more. The PS format is specified in MPEG-1 Part 1 (ISO/IEC 11172-1) and MPEG-2 Part 1, Systems (ISO/IEC standard 13818-1/ITU-T H.222.0). The MPEG-2 Program Stream is analogous and similar to ISO/IEC 11172 Systems layer and it is forward compatible.Program streams are used on DVD-Video discs and HD DVD video discs, but with some restrictions and extensions. The filename extensions are VOB and EVO respectively.

MPEG transport stream

MPEG transport stream (transport stream, MPEG-TS, MTS or TS) is a standard digital container format for transmission and storage of audio, video, and Program and System Information Protocol (PSIP) data. It is used in broadcast systems such as DVB, ATSC and IPTV.

Transport stream specifies a container format encapsulating packetized elementary streams, with error correction and synchronization pattern features for maintaining transmission integrity when the communication channel carrying the stream is degraded.

Transport streams differ from the similarly-named MPEG program stream in several important ways: program streams are designed for reasonably reliable media, such as discs (like DVDs), while transport streams are designed for less reliable transmission, namely terrestrial or satellite broadcast. Further, a transport stream may carry multiple programs.

Transport stream is specified in MPEG-2 Part 1, Systems, formally known as ISO/IEC standard 13818-1 or ITU-T Rec. H.222.0.

Macroblock

Macroblock is a processing unit in image and video compression formats based on linear block transforms, such as the discrete cosine transform (DCT). A macroblock typically consists of 16×16 samples, and is further subdivided into transform blocks, and may be further subdivided into prediction blocks. Formats which are based on macroblocks include JPEG, where they are called MCU blocks, H.261, MPEG-1 Part 2, H.262/MPEG-2 Part 2, H.263, MPEG-4 Part 2, and H.264/MPEG-4 AVC. In H.265/HEVC, the macroblock as a basic processing unit has been replaced by the coding tree unit.

Moving Picture Experts Group

The Moving Picture Experts Group (MPEG) is a working group of authorities that was formed by ISO and IEC to set standards for audio and video compression and transmission. It was established in 1988 by the initiative of Hiroshi Yasuda (Nippon Telegraph and Telephone) and Leonardo Chiariglione, group Chair since its inception. The first MPEG meeting was in May 1988 in Ottawa, Canada. As of late 2005, MPEG has grown to include approximately 350 members per meeting from various industries, universities, and research institutions. MPEG's official designation is ISO/IEC JTC 1/SC 29/WG 11 – Coding of moving pictures and audio (ISO/IEC Joint Technical Committee 1, Subcommittee 29, Working Group 11).

MPEG-1 Parts
MPEG-2 Parts
MPEG-4 Parts
MPEG-7 Parts
MPEG-21 Parts
MPEG-D Parts
MPEG-G Parts
MPEG-H Parts
Other
Video
compression
Audio
compression
Image
compression
Containers
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High-definition (HD)
Concepts
Analog broadcast
(All defunct)
Digital broadcast
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HD media and
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ISO/IEC standards
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