mdat (Media Data): Holds the actual video and audio payloads.
The internal structure of an MP4 file consists of several critical components that define how the media is stored and played: 7311ec4d36f2e22759710f68b51f1725 mp4
While MP4 is a container, it typically uses the H.264 (AVC) or MPEG-4 codec for video and AAC for audio. How to Open and Play MP4 Files mdat (Media Data): Holds the actual video and audio payloads