Video Containers
Wikipedia defines a video file format as “A container or wrapper format is a meta-file format whose specification describes how data and meta-data is stored (not coded).” What does this mean?
Well, when you look at a multimedia file, you will notice that the file names end with, for example – .mov, .ogg, .wmv, .flv, .mp4, .mpeg, etc. These extensions indicate the video file format. Essentially, videos are packaged up into encapsulation containers, or wrapper formats, that contain all the information needed to present video. Videos have a lot of different information that can be “wrapped” up into these containers – including the video stream, audio stream, metadata, subtitles, chapter-information, synchronization information, etc. For multimedia data streams to be useful in stored or transmitted form, they must be encapsulated together in a container format.