[FFmpeg-devel] [PATCH v2 00/11] fix broken CC detection and ffprobe fields (cover letter)

[Marth64]

As it stands today, ffprobe has two stream-level fields (closed_captions and film_grain)
that do not work. Their value is always 0 because ffprobe cannot access the internal
codec properties in the stream context when it is setting up its internal streams.

Additionally, avformat/dump used to successfully print about the presence of
Closed Captions (EIA-608/CEA-708) and the presence of film grain. This does
not work either anymore, because avformat_find_stream_info() does not copy
them in the skeleton context it uses after calling codec_close(). 

To clarify: the aforementioned features/code are broken.

So, to the user, Closed Caption detection as a feature is broken, and ffprobe
and the dump is essentially having two fields that do not work.

This patchset aims to fix the issue by:
(1) Adding a video stream disposition, AV_DISPOSITION_CAPTIONS_EIA608 that
    can be set in avformat_find_stream_info(), and using it to express
    the presence of Closed Captions (EIA-608/CEA-708)
(2) Removing the broken fields from ffprobe entirely, since it cannot access
    the underlying data and in v1 of this set the concept of providing this
    access to private fields was rejected (rightfully so)
(3) Copying the stream properties in avformat_find_stream_info() so that
    the dump function (which is internal to lavf) can print the presence of
    the film grain properties now

View the diff on GitHub:
https://github.com/FFmpeg/FFmpeg/compare/master...Marth64x:FFmpeg:fix_cc