[FFmpeg-devel] ffprobe closed_captions json output not set while text output is set

[Pieter Viljoen]

Please reconsider an abandoned patch to allow consistent behavior in closed
caption detection between ffprobe with and without "-print_format json".
https://patchwork.ffmpeg.org/project/ffmpeg/patch/MN2PR04MB59815313285AA685E37D09AEBAB09@MN2PR04MB5981.namprd04.prod.outlook.com/

I also asked for solutions on reddit, videohelp, IRC, ffmpeg-user,
resorting to asking on ffmpeg-devel.

I would like to add the ability to detect and remove closed captions from
video streams using ffmpeg, in an open source tool I maintain that cleans
up media files for direct play on Plex, Emby, Jellyfin, etc. (
https://github.com/ptr727/PlexCleaner)

When I run ffprobe in JSON output mode, it is not setting the
"closed_captions" attribute.
When I run ffprobe in default output mode, it does correctly identify
closed captions in video streams and prints "Closed Captions" in the stream
descriptor.

The divergent behavior appears to be a ffprobe bug.

Details of the problem is described where I asked for help on reddit and
videohelp:
https://www.reddit.com/r/ffmpeg/comments/tcnhto/how_to_detect_closed_captions_in_video_stream/
https://forum.videohelp.com/threads/405123-Detect-embedded-closed-captions-in-video-stream-using-ffprobe-json-output

I did not get any help, but after lots of googling I did find an abandoned
patch that describes exactly the problem I am experiencing:
https://patchwork.ffmpeg.org/project/ffmpeg/patch/MN2PR04MB59815313285AA685E37D09AEBAB09@MN2PR04MB5981.namprd04.prod.outlook.com/
https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=&submitter=&state=*&q=closed_captions&archive=both&delegate=
https://www.mail-archive.com/ffmpeg-devel@ffmpeg.org/msg126211.html

The proposed patch seemed trivial, but I do not understand the nuances of
the objections.

I'd like the patch to be please re-considered, or an alternative proposed
that allows ffprobe's JSON output to return correct closed_captions values.

---
Pieter