[FFmpeg-user] Issue when adding a title to an audio stream within a mp4 file

[Moritz Barsnick]

On Wed, Feb 24, 2021 at 17:37:18 +0100, PPRJ01 wrote:
> I observed that the command below seem to work properly when adding a title to an audio stream within an MP4 file :
>
>       ffmpeg -i INPUT.mp4 -c copy -metadata:s:a:0 "title=mono" OUTPUT.mp4
>
> Both VLC and Exiftool do display correctly the audio stream title of the OUTPUT.mp4 file when needed.
>
> The point is that neither ffmpeg nor ffprobe can do it.

Indeed, I can confirm this. ffmpeg is able to insert the per-track
"title", but not able to extract it.

(Technical detail: it's the "name" atom beneath the "udta" atom beneath
the "trck" atom.)

> Maybe this is a designed behavior of ffmpeg/ffprobe.
> Or a bug ?

A shortcoming.

I'm able to change the ffmpeg source code to parse the per-track title,
but cannot get it inserted properly in the demuxer metadata.

Moritz