MP4 tools

Install this library

npm install @ludovicm67/mp4-tools

The following is exposed:

• Buffer: Buffer that works on both Node.js and browsers
• utils.blobToArrayBuffer: a function to convert a Blob to an ArrayBuffer
• fix: the function to use to fix a chunk by using the previous one

MP4 structure

MP4 files are structured into several different box types, each serving a specific purpose:

• ftyp (File Type Box): The first box in the file, declaring file type, compatibility, and specifications.
• moov (Movie Box): Contains all metadata about the video, like tracks, duration, etc. It includes sub-boxes:
  • mvhd (Movie Header Box): Global information about the movie.
  • trak (Track Box): A container for a single track (audio, video, etc.), with sub-boxes like tkhd (Track Header) and mdia (Media).
• moof (Movie Fragment Box): Contains all metadata about a single fragment of the movie, with sub-boxes like mfhd (Movie Fragment Header) and traf (Track Fragment).
• mdat (Media Data Box): Contains the actual media data, such as video frames and audio samples.

Command line tool

The cli folder contains a command line tool that can be used to fix or merge chunks.

Have a look at the README of the CLI for more information.