RealMedia, or also spelled as Real Media is a proprietary multimedia container format created by RealNetworks. Its filename extension is .rm. It is typically used in conjunction with RealVideo and RealAudio and is used for streaming content over the Internet. Typically these streams are in CBR (constant bitrate), but a container for VBR (variable bitrate) streams, named RMVB (RealMedia variable bitrate), has been developed.

Filename extension
Internet media typeapplication/vnd.rn-realmedia
Developed byRealNetworks
Type of formatContainer format
Open format?No
Free format?No


A RealMedia file consists of a series of chunks that can be of several different types:

  • .RMF: RealMedia file header
  • PROP: File properties header
  • MDPR: Media properties header
  • CONT: Content description header
  • DATA: Data header
  • INDX: Index header

Supported audio formatsEdit

  • RealAudio 1.0 (VSELP), IpcJ
  • RealAudio 2.0 (LD-CELP), 28_8
  • AC3, dnet
  • Sipro, sipr
  • Cook, cook
  • ATRAC3, atrc
  • RealAudio Lossless Format, ralf
  • LC-AAC, raac
  • HE-AAC, racp

Supported video formatsEdit

  • ClearVideo (from helix spec)
  • H.263, RV10
  • H.263, RV13
  • H.263+, RV20
  • H.264 precursor, RV30
  • H.264 precursor, RV40
  • H.263+ (RV20), RVTR

See alsoEdit