RealMedia

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Revision as of 23:49, 4 February 2006 by Multimedia Mike (talk | contribs) (outline basic RM chunk format and types)
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  • Extensions: rm, ra
  • Company: Real

Multimedia container format developed by Real and used almost exclusively for codecs developed by Real.

There are two different versions, the old RA files are just for audio.

RA Format

Real Format

All multi-byte numbers are stored in big endian format.

A RealMedia file consists of a series of chunks. Each chunk has the following format:

bytes 0-3    chunk type (FOURCC)
bytes 4-7    chunk size, including 8-byte preamble
bytes n..    chunk payload

Real chunk types:

  • .RMF: RealMedia file header
  • PROP: File properties
  • MDPR: Stream properties
  • CONT: Content description/metadata
  • DATA: File data
  • INDX: File index
  • '.','r','a',0xFD: Legacy RealAudio encapsulation
  • VIDO