Release Date : 05/2025
Platforms : Linux
License : MIT License, Free To Use, Attribution suggested
Download : V4l2Camera git repo
Description : JSON driven MP4 file decoder.
walkMP4 is part of the v4l2Camera open source package but I figured I would call it out specifically here.
It uses a JSON data dictionary to decode the ATOMs in the MP4 file format. It produces colour coded output that can be used to determine the actual content of an MP4 file.
I used it as a debug utility for the camControl app when producing MP4 file output, directly from AVC1 encoded frames, without using an MP4 API. I was able to determine where I had screwed up in my coding (which happens a lot :).
The entire thing is driven from a data dictionary that can be extended without having to re-code the utility.
walkMP4 is open source and is currently at version 0.1.10