Glossary A–ZLetter V
Video format (MP4)
The video format is the type of file in which a video is stored with picture, sound and additional information; the most widespread format is MP4.
It is also called a container because it combines different tracks in one file.
An MP4 file usually contains a video track in the H.264 codec and an audio track in AAC format. Other containers are MOV, WebM, AVI or MKV. MP4 is the usual choice for screen networks because almost all players can play it. Besides the container, other properties of the file matter: resolution, aspect ratio, frame rate, bit rate and whether a sound track is needed at all. A video for a portrait screen should be produced in portrait orientation.
The file extension alone says little: a file ending in MP4 may contain a codec the player does not recognise. Operators should therefore give agencies a short specification, such as MP4 with H.264, resolution no higher than the screen's, and no sound track or a quiet one. Videos with black bars, the wrong orientation or a different frame rate than intended should be converted before distribution.