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MPEG program stream

MPEG Program Stream
Filename extension.mpg, .mpeg, .m2p, .ps
Internet media typevideo/MP2P, video/MP1S[1]
Developed byMPEG
Initial release1993 (1993)[2]
Type of formatMedia container
Container forAudio, video, data
Extended toVOB, EVO, MOD
Standard(s)ISO/IEC 11172-1,[2] ISO/IEC 13818-1,[3] ITU-T H.222.0[4][5]

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[6]/ITU-T H.222.0[4][5]). The MPEG-2 Program Stream is analogous and similar to ISO/IEC 11172 Systems layer and it is forward compatible.[7][8]

Program streams are used on DVD-Video discs and HD DVD video discs, but with some restrictions and extensions.[9][10] The filename extensions are VOB and EVO respectively.

Contents

Coding structure

Program streams are created by combining one or more Packetized Elementary Streams (PES), which have a common time base, into a single stream. It is designed for reasonably reliable media such as disks, in contrast to MPEG transport stream which is for data transmission in which loss of data is likely. Program streams have variable size records and minimal use of start codes which would make over the air reception difficult, but has less overhead. Program stream coding layer allows only one program of one or more elementary streams to be packaged into a single stream, in contrast to transport stream, which allows multiple programs.[7]

MPEG-2 Program stream can contain MPEG-1 Part 2 video, MPEG-2 Part 2 video, MPEG-1 Part 3 audio (MP3, MP2, MP1) or MPEG-2 Part 3 audio.[7] It can also contain MPEG-4 Part 2 video, MPEG-2 Part 7 audio (AAC) or MPEG-4 Part 3 (AAC) audio,[7] but they are rarely used.[citation needed] The MPEG-2 Program stream has provisions for non-standard data (e.g. AC-3 audio or subtitles) in the form of so-called private streams.[11] International Organization for Standardization authorized SMPTE Registration Authority, LLC as the registration authority for MPEG-2 format identifiers. It publishes list of compression formats which can be encapsulated in MPEG-2 transport stream and program stream.[12]

Coding details

If you open up an unencrypted VOB file or other program stream with a hex editor you will see the following structure.

Partial Program Stream Pack header format[13]
NameNumber
of bits		Description
sync bytes320x000001BA
marker bits201b
System clock [32..30]3System Clock Reference (SCR) bits 32 to 30
marker bit11 Bit always set.
System clock [29..15]15System clock bits 29 to 15
marker bit11 Bit always set.
System clock [14..0]15System clock bits 14 to 0
marker bit11 Bit always set.
SCR extension9 
marker bit11 Bit always set.
bit rate22In units of 50 bytes per second.
marker bits211 Bits always set.
reserved5reserved for future use
stuffing length3 
stuffing bytes8*stuffing length 
system header (optional)0 or moreif system header start code follows: 0x000001BB
Partial system header format
NameNumber
of bytes		Description
sync bytes40x000001BB
header length2 
rate bound and marker bits3 
audio bound and flags1 
flags, marker bit, and video bound1 
Packet rate restriction and reserved byte1 

See also

References

  1. ^ "RFC 3555 - MIME Type Registration of RTP Payload Formats". 2003-07. http://tools.ietf.org/html/rfc3555#pa ge-39. Retrieved 2010-03-20.
  2. ^ a b ISO (1993). "ISO/IEC 11172-1:1993 - Information technology -- Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s -- Part 1: Systems". http://www.iso.org/iso/iso_catalogue/ catalogue_tc/catalogue_detail.htm?csn umber=19180. Retrieved 2010-07-18.
  3. ^ ISO (1996). "ISO/IEC 13818-1:1996 - Information technology -- Generic coding of moving pictures and associated audio information: Systems". http://www.iso.org/iso/iso_catalogue/ catalogue_ics/catalogue_detail_ics.ht m?csnumber=22989. Retrieved 2010-07-18.
  4. ^ a b ITU-T (2006-05). "H.222.0 Summary". http://www.itu.int/dms_pubrec/itu-t/r ec/h/T-REC-H.222.0-200605-I!!SUM-HTM- E.htm. Retrieved 2010-06-03.
  5. ^ a b ITU-T. "H.222.0 : Information technology - Generic coding of moving pictures and associated audio information: Systems". http://www.itu.int/rec/T-REC-H.222.0. Retrieved 2010-06-03.
  6. ^ (PDF) ISO/IEC 13818-1:2000 - Information technology -- Generic coding of moving pictures and associated audio information: Systems, neuron2.net, 2000-12-01, http://neuron2.net/library/mpeg2/iso1 3818-1.pdf, retrieved 2010-06-03
  7. ^ a b c d ISO (2000-12-01) ISO/IEC 13818-1 : 2000, Second edition Page X, Retrieved on 2009-07-25
  8. ^ Data Broadcasting, MPEG-2 Transport Basics, MPEG-2 Program Stream, Retrieved on 2009-07-25
  9. ^ DVD - MPeg differences, Retrieved on 2009-07-24
  10. ^ MPEG.org (July 21, 1996) DVD Technical Notes - Video Data Specifications, Retrieved on 2009-07-25
  11. ^ What is a VOB file, Retrieved on 2009-07-26
  12. ^ SMPTE Registration Authority, LLC - registration authority for MPEG-2 format identifiers Retrieved on 2009-07-06
  13. ^ Pack Header

External links

(Sebelumnya) MPD (programming language)MPEG Streamclip (Berikutnya)