[FFmpeg-devel] Output to text file from filter

Stefano Sabatini stefasab at gmail.com
Wed Jul 11 00:13:33 CEST 2012

On date Tuesday 2012-07-10 20:36:30 +0200, Reimar Döffinger encoded:
> On Tue, Jul 10, 2012 at 06:48:53PM +0200, Nicolas George wrote:
> > Le tridi 23 messidor, an CCXX, Clément Bœsch a écrit :
> > > Did you look at how the scene cut is made in the select filter?
> > > http://ffmpeg.org/libavfilter.html#select
> > 
> > Since you speak of it, I must say I am really not fond of that approach.
> > 
> > Of course, having the feature right now is better than waiting forever for
> > the perfect design, so you were quite right to just go ahead, and it was
> > probably the most useful way of doing it. But now that we have time, we
> > should be looking for generic solutions to that issue.
> > 
> > My main concern is that the scene change test can be useful for other things
> > than just selecting the frame: segmenting, updating on-screen text,
> > inserting another program, etc.
> > 
> > A solution that just came to my mind: let the filters attach arbitrary
> > key=value pairs to the frames. And, of course, let the select expressions
> > use any of these variables.
> Please do not make it filter-specific. Something like this is needed to
> add proper decode support for ATSC closed-caption subtitling, since
> there the data needs to be reorder together with the frames.
> However in this case IMHO you could just as well have the filter
> create a data stream with that information, I don't think there
> is any particular need for it to be in the AVFrame.

The plan was to add metadata in AVFrame, and propagate it to
libavfilter (metadata in AVFrame was already done for SOCIS 2011, I'll
rebase the patchset and send to this list soon).
FFmpeg = Fascinating and Foolish Mind-dumbing Pure Enlightened Guru

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