Demuxing

Demuxing is an abbreviation of demultiplexing. Demuxing is the process of reading a multi-part stream and saving each part – audio, video, and subtitles (if any) – as a separate stream. It is the logical reverse of the muxing process.

For example, AVI is a container that means audio-video interleave. The processing of demuxing an AVI requires separating the audio and visual components so (after being decoded by other modules) they can finally reach the speaker and monitor, respectively.

Most media file formats are multiplexed together in this way and VLC uses demuxer modules to separate them. Examples of demuxers that VLC uses are asf (for ASF), ogg (for Ogg) and mkv (for Matroska).