[FFmpeg-soc] libavfilter: fps ignored in ffmpeg command line

[Vitor Sessak]

Hi

Víctor Paesa wrote:
> Hi,
> 
> The filter fps seems ignored in the ffmpeg command line.
> This is the scenario:

[...]

> Input #0, avi, from 'input.avi':
>   Duration: 00:00:20.2, start: 0.000000, bitrate: 30349 kb/s
>     Stream #0.0: Video: dvvideo, yuv420p, 720x576 [PAR 0:1 DAR 0:1], 25.00 tb(r)
>     Stream #0.1: Audio: pcm_s16le, 48000 Hz, stereo, 1536 kb/s
> Output #0, avi, to 'output.avi':
>     Stream #0.0: Video: mpeg4, yuv420p, 720x576 [PAR 0:1 DAR 0:1],
> q=2-31, 200 kb/s, 25.00 tb(c)
>     Stream #0.1: Audio: mp2, 48000 Hz, stereo, 64 kb/s

[...]

> The input and output AVI have the same 25 fps.

I'm not really sure if the filter is supposed to change this. The filter
infrastructure is designed to get pictures+timestamps as input and give
pictures+timestamps as output. I'd say setting the output framerate is
beyond filtering. For example,

ffmpeg -i input.avi -vfilters fps=1 -r 25 -y output.avi

should give a 25 fps output but with a different frame every 1 second.
But indeed I get a crash with your command line and vf_fps.c do not
seems to handle a rate greater than the input rate. I'll have a look
into it...

-Vitor