video formats

[cobra505]

2 quick questions on file formats

What is the format of vob files on a dvd? m2v, mpeg2, mpeg4?
Same question for vcds? Thanks Wayne.

[tgpo]

DVDs are MPEG2
VCDs are MPEG1

[galactica]

per the glossary:

MPEG-1
An ISO/IEC (International Organization for Standardization/ International Electrotechnical Commission) standard for medium quality and medium bitrate video and audio compression. It allows video to be compressed by the ratios in the range of 50:1 to 100:1, depending on image sequence type and desired quality. The encoded data rate is targeted at 1.5Mb/s - this was a reasonable transfer rate of a double-speed CD-ROM player (including audio and video). VHS-quality playback is expected from this level of compression. The Motion Picture Expert Group (MPEG) also established the MPEG-2 standard for high-quality video playback at a higher data rates. MPEG-1 is used in encoding video for VCD. MPEG FAQ


MPEG-2
An encoding standard designed as an extension of the MPEG-1 international standard for digital compression of audio and video signals. MPEG-1 was designed to code progressively scanned video at bit rates up to about 1.5 Mbit/s for applications such as CD-i. MPEG-2 is directed at broadcast formats at higher data rates; it provides increased support for efficiently coding interlaced video, supports a wide range of bit rates and provides for multichannel surround sound coding such as PCM, Dolby Digital, DTS and MPEG audio.


MPEG-3
A proposed variant of the MPEG video and audio compression algorithm and file format. MPEG-3 was intended as an extension of MPEG-2 to cater for HDTV but was eventually merged intoMPEG-2.

MPEG-3 should not be confused with MP3 which is MPEG-1 layer 3 popularly used for audio encoding.


MPEG-4
An ISO/IEC standard 14496 developed by the Moving Picture Experts Group (MPEG), the committee that also developed MPEG-1 and MPEG-2. These standards made interactive video on CD-ROM, DVD and Digital Television possible. MPEG-4 is the result of another international effort involving hundreds of researchers and engineers from all over the world. MPEG-4 was finalized in October 1998 and became an International Standard in 1999. The fully backward compatible extensions under the title of MPEG-4 Version 2 were frozen at the end of 1999, to acquire the formal International Standard Status early in 2000. Several extensions were added since and work on some specific work-items is still in progress.