[FFmpeg-devel] [PATCH v2 2/2] ffprobe: Fix incorrect display of closed_captions property

[Anton Khirnov]

Quoting James Almer (2021-09-19 15:04:11)
> 
> Yes, something like that could be forced (ReadInterval in ffprobe).
> 
> > 
> > What you're essentially suggesting is more or less a duplication
> > of avformat_find_stream_info() and to run it right after
> > avformat_find_stream_info() has just been run.
> > 
> > I'm sure we can find a better solution :-)
> 
> We could always not print codec level information, like the presence of 
> closed captions in a bitstream, when container level information is 
> requested, as is the case of show_streams.
> It is in fact a per-frame property. One could even not show up until 
> halfways into the video and then not even avformat_find_stream_info() 
> would reflect it. And this flag is essentially a "The decoder found a CC 
> at some point" event flag rather than a stream parameter.
> 
> The fact ffprobe looks at the decoder context to print stream values to 
> begin with is questionable, and as mentioned, its output is not even 
> guaranteed and depends on external factors, like other user-provided 
> runtime options.

I agree. ffprobe should stop printing that field as a part of the global
stream information, it simply cannot work reliably.

Print it as a part of the frame data instead.

-- 
Anton Khirnov