RealMedia Variable Bitrate (RMVB) is a
variable bitrateextension of the RealMedia multimedia container formatdeveloped by RealNetworks.
As opposed to the more common
RealMediacontainer, which holds streaming mediaencoded at a constant bit rate, RMVB is typically used for multimedia content stored locally. Files using this format have the file extension ".rmvb".
Allegedly, RealMedia formats typically achieve much more efficient compression than
MPEG-4 Part 2codecs, such as DivXand XvidFact|date=July 2007, using compression similar to MPEG-4 Part 10 codecs [ [http://wiki.multimedia.cx/index.php?title=RealVideo_4 RealVideo 4 - MultimediaWiki ] ] , such as x264. For this reason, they have become noticeably present (though not entirely popular) on file sharingplatforms such as BitTorrent, eDonkeyand Gnutella.Limited support is available on some media players, generally on the Windows platform, including the proprietary RealPlayer10 and the open-sourced Media Player Classic, using an appropriate DirectShowfilter or Real Alternative. MPlayerand some other programs such as totem are able to play RMVB files in Linux/ UNIX-based x86machines through the use of WIN32DLLs or native closed-source libraries.
The file header for the format consists of the four
bytes".RMF" (hex 2E 52 4D 46), the same as the standard RealMediaformat.
Comparison of container formats
Comparison of media players
* [http://wiki.multimedia.cx/index.php?title=RealMedia RealMedia] File Format
Wikimedia Foundation. 2010.