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.ISO (2000-12-01) ISO/IEC 13818-1 : 2000, Second edition Page X, Retrieved on 2009-07-25Data Broadcasting, MPEG-2 Transport Basics, MPEG-2 Program Stream, Retrieved on 2009-07-25
Program streams are used on DVD-Video discs and HD DVD video discs, but with some restrictions and extensions.DVD - MPeg differences, Retrieved on 2009-07-24MPEG.org (July 21, 1996) DVD Technical Notes - Video Data Specifications , Retrieved on 2009-07-25 The filename extensions are VOB and EVO respectively.
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.
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. It can also contain MPEG-4 Part 2 video, MPEG-2 Part 7 audio (AAC) or MPEG-4 Part 3 (AAC) audio, but they are rarely used. 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.What is a VOB file, Retrieved on 2009-07-26 International Organization for Standardization authorized SMPTE Registration Authority, LLC as the registration authority for MPEG-2 format identifiers. It publishes a list of compression formats which can be encapsulated in MPEG-2 transport stream and program stream.
Coding details + Partial MPEG-2 Program Stream pack header formatNameNumberof bitsDescriptionsync bytes320x000001BAmarker bits201b for MPEG-2 version. The marker bits for the MPEG-1 version are 4 bits with value 0010b.System clock [32..30]3System Clock Reference (SCR) bits 32 to 30marker bit11 Bit always set.System clock [29..15]15System clock bits 29 to 15marker bit11 Bit always set.System clock [14..0]15System clock bits 14 to 0marker bit11 Bit always set.SCR extension9marker bit11 Bit always set.bit rate22In units of 50 bytes per second.marker bits211 Bits always set.reserved5reserved for future usestuffing length3stuffing bytes8*stuffing lengthsystem header (optional)0 or more if system header start code follows: 0x000001BB
+ Partial system header formatNameNumberof bytesDescriptionsync bytes40x000001BBheader length2rate bound and marker bits3audio bound and flags1flags, marker bit, and video bound1Packet rate restriction and reserved byte1
See also Elementary stream MPEG transport stream
References
External links MPEG-2 Official MPEG web site BBC On MPEG RFC 3555 - MIME Type Registration of RTP Payload Formats (video/MP2P, video/MP1S)