RealMedia is a proprietary

multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradition ...

container format A container format (informally, sometimes called a wrapper) or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams. Notab ...

created by

RealNetworks RealNetworks, Inc. is a provider of artificial intelligence and computer vision based products. RealNetworks was a pioneer in Internet streaming software and services. They are based in Seattle, Washington, United States. The company also p ...

with the

filename extension A filename extension, file name extension or file extension is a suffix to the name of a computer file (e.g., .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically d ...

. RealMedia is generally used in conjunction with

RealVideo RealVideo, or also spelled as Real Video, is a suite of proprietary video compression formats developed by RealNetworks – the specific format changes with the version. It was first released in 1997 and was at version 10. RealVideo is supported ...

and

RealAudio RealAudio, or also spelled as Real Audio is a proprietary audio format developed by RealNetworks and first released in April 1995. It uses a variety of audio codecs, ranging from low-bitrate formats that can be used over dialup modems, to high-fid ...

, while also being used for

streaming Streaming media is multimedia that is delivered and consumed in a continuous manner from a source, with little or no intermediate storage in network elements. ''Streaming'' refers to the delivery method of content, rather than the content it ...

content over the Internet. Typically these streams are in CBR (

constant bitrate Constant bitrate (CBR) is a term used in telecommunications, relating to the quality of service. Compare with variable bitrate. When referring to codecs, constant bit rate encoding means that the rate at which a codec's output data should be cons ...

), but a container for VBR (

variable bitrate Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows a ...

) streams named

RMVB RealMedia Variable Bitrate (RMVB) is a variable bitrate extension of the RealMedia multimedia digital container format developed by RealNetworks. As opposed to the more common RealMedia container, which holds streaming media encoded at a constant b ...

(RealMedia variable bitrate) has been developed.

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

Supported audio formats

* RealAudio 1.0 (VSELP), * RealAudio 2.0 (LD-CELP), 28_8 * AC3, * * Cook, cook * ATRAC3, * RealAudio Lossless Format, * LC-AAC, * HE-AAC,

Supported video formats

* 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

Overview

Supported audio formats

Supported video formats

See also