RealMedia
RealMedia is a proprietary multimedia container format created by RealNetworks. Its 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, but a container for VBR streams, named RMVB, has been developed.
Support of RealMedia is available in a few multimedia players for different architectures/platforms, including RealPlayer and the Real Alternative codec pack. The open source DAP firmware Rockbox has added support for reading RM containers as of 6 July 2009, although only certain formats used in RM files are playable.Overview
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
- RealAudio 1.0, IpcJ
- RealAudio 2.0, 28_8
- AC3, dnet
- Sipro, sipr
- Cook, cook
- ATRAC3, atrc
- RealAudio Lossless Format, ralf
- LC-AAC, raac
- HE-AAC, racp
- ClearVideo
- H.263, RV10
- H.263, RV13
- H.263+, RV20
- H.264 precursor, RV30
- H.264 precursor, RV40
- H.263+, RVTR
