I am creating an MP4 muxer app using isobmff Library.
I have a fragmented MP4. Example structure: moof/mdat --> moof/mdat etc...
Now I want to transmux the fragmented MP4 into being a progressive MP4.
This will be done without external tools like FFmpeg.
Problem:
I need help to confirm if the following steps are correct for transmuxing.
(1) Make a Movie Box moov,
(2) Make a Track Box trak and a Media Box mdia.
(3) Calculating All moof Box data (such as duration) and allocate that into either the Track or the Media Box (as needed).
(4) ALL found mdat Boxes are merged one mdat Box.
Is this process correct for muxing from Frag-MP4 into a Progressive MP4?
Is there anything else that I need to be aware of?