On Wed, 27 Nov 2024, Marth64 wrote:
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)
Manually mapping between different codec properties and stream dispositions seems ugly, and I am not sure if we should even use the disposition field for something like this.
I suggest you try adding the "properties" attribute to AVCodecParameters, because as far as I see it is very similar to profile or level. Can you see if that works? If it does, we might even promote the FF_CODEC_PROPERTY flags to AV_CODEC_PROPERTY so they will become properly public.
Thanks, Marton
(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 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
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