[FFmpeg-devel] [PATCH] lavf: add ffprobe demuxer

[Stefano Sabatini]

On date Saturday 2016-09-17 18:42:35 +0200, Paul B Mahol encoded:
> On 9/17/16, Stefano Sabatini <stefasab at gmail.com> wrote:
> > On date Sunday 2016-09-04 23:25:56 +0200, Michael Niedermayer encoded:
> >> On Sun, Sep 04, 2016 at 06:24:37PM +0200, Stefano Sabatini wrote:
> >> > From: Nicolas George <george at nsup.org>
> >> >
> >> > With several modifications and documentation by Stefano Sabatini
> >> > <stefasab at gmail.com>.
> >> >
> >> > Signed-off-by: Nicolas George <george at nsup.org>
> >> > ---
> >> >  doc/ffprobe-format.texi  | 130 ++++++++++++++++
> >> >  libavformat/Makefile     |   1 +
> >> >  libavformat/allformats.c |   2 +
> >> >  libavformat/ffprobedec.c | 397
> >> > +++++++++++++++++++++++++++++++++++++++++++++++
> >> >  4 files changed, 530 insertions(+)
> >> >  create mode 100644 doc/ffprobe-format.texi
> >> >  create mode 100644 libavformat/ffprobedec.c
> >>
> >> this seems not to apply cleanly
> >>
> >> can i pick this from some git repo ? (should work better than patch
> >> with unavailable ancestors)
> >
> > Updated, this should apply cleanly on master.
> 
> Why we need this hack?

My use case: I need to inject a metadata stream using the ff*
tools. Metadata must be specified in a textual format. I already
designed and implemented the fftextdata format, but that was regarded
too limited.

Example:
ffmpeg -i input.mp4 -copyts -i data.ffprobe -map 0:v -map 0:a -map 1:0 -codec:d copy input+data.ts

With this format we allow to cover my use case, and it provides a more
generic format for such purposes (since you can specify multiple
streams). Also, it's inspired by the ffprobe output, so it can be used
together with ffprobe (via simple text editing) to generate files
which can be edited and feed to ffmpeg.

It would be possible to use any binary format for injecting the
metadata, but this approach is not very scriptable. Alternatively a
custom program to convert a custom textual format to any binary format
we support, but this would imply an additional step I want to avoid.

That said, if someone want/can propose an alternative path to this I'm
very open to suggestions.
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