[FFmpeg-user] combining concat filter with closed caption extraction

[Leo Butler]

Nicolas George <george at nsup.org> writes:

>> Rather than creating the file C.mkv in the first pass, can the lavfi
>> filter use the video output stream of the concat filter directly?
>
> My answer is the same: 'movie=C.mkv[out0+subcc]' is just another input,
> like B.ts. You can see that because they both have -i in from of them:
> they are the same.

So the `obvious' answer is no: ffmpeg cannot/does not use an output
stream from a filter as an input in this fashion? If the answer is so
obvious, why not just write one word instead of many?

----

I am still not clear about the documentation for the movie source
(https://ffmpeg.org/ffmpeg-all.html#toc-movie-1). The description of

filename

    The name of the resource to read (not necessarily a file; it can
    also be a device or a stream accessed through some protocol).
    
leaves it open in my mind if `a stream' might be an output stream
produced by a filter.

Leo