[FFmpeg-devel] [PATCH 4/5] avformat/mov: Add support for exporting Video Extension Usage info

[Derek Buitenhuis]

On 6/10/2024 8:38 PM, James Almer wrote:
>> +    remaining = atom.size;
>> +    while (remaining > 0) {
> 
> Maybe this loop should call mov_read_default, with proj and eyes added 
> to mov_default_parse_table[]. Although i don't know if eyes may show up 
> as child for other parent boxes or not.
> At least with proj, i see it can be a child for sv3d, where only prhd is 
> expected as a child box in turn. But it shouldn't a problem to add a 
> mov_read_proj that handles both prhd and prji for this purpose.

Well, the proj box that that's in sv3d and this proj box are unrelated -
they both exist because Apple and Google don't play nice with eachother,
and both defined their own incompatible projection boxes, which exist in
entirely different parts of the file, so it seemed kind of wrong to handle
it that way...

The other reason I left it this way is because it left it easier for us to
implement the 'must' box if we wanted to, which needs to keep track of what
boxes have been seen inside the 'vexu' box, and its inner boxes.

To my knowledge eyes (and indeed all the other boxes inside the 'vexu' box besides
the 'proj' box) only appear in the 'vexu' box.

- Derek