What is a codec?
Definition
A codec is the method used to compress video or audio into a file and decompress it for playback.
H.264, HEVC and AV1 are video codecs; AAC and Opus are audio codecs. The codec decides how small a file can be for a given quality and which devices can play it. A codec is not the same as a file format: an MP4 file is a container that holds streams compressed with a codec.
Related terms
- H.264
- H.264 is the most widely supported video codec: nearly every browser, phone, computer and video site can play it.
- HEVC
- HEVC, or H.265, is a video codec that produces files roughly half the size of H.264 at similar quality.
- MP4
- MP4 is a file format that holds video, audio and timing information in one file; it is the standard format for sharing video.
- Bitrate
- Bitrate is the amount of data a video uses per second, usually measured in megabits per second (Mbps).