[Ffmpeg-devel] frame accept question

Rich Felker dalias
Fri Oct 7 04:43:24 CEST 2005

On Thu, Oct 06, 2005 at 06:09:11PM +0200, Martin Boehme wrote:
> Bram Biesbrouck wrote:
> >I used the output_example.c file as a framework for my program. In a loop 
> >of (say) 50 iterations, I feed the encoder 50 screenshots 
> >(encoder-framerate=25 fps, images are 1024x710 px, depth 24 and 32 bpp). I 
> >timed the generation of one image and it takes the generator about 10 ms, 
> >so that leaves 30 ms for the encoder to encode the frame (right?) at a 
> >correct framerate.
> >When I run the program, the loop (image-generation + encoding) takes about 
> >2.5 sec and the video plays back too fast (because of frame dropping I 
> >suppose). I tried to look up the length of the video but I couldn't find 
> >out how (mplayer says it's 0:00). I guess it's around 2 sec, but in theory 
> >it should be less, I think, because of the frame dropping.
> >
> >I don't really have a specific question, but can someone explain to me 
> >what's happening in this encoding-process?
> It simply sounds as if encoding is taking too long... for the resolution 
> of video that you're encoding, that sounds plausible. That also explains 
> why the video is playing too fast... 2.5 seconds worth of video is being 
> played in 2 seconds.
> The easiest solution to this is of course to just reduce the 
> framerate... to maybe 15 fps.

Reducing the resolution is a much better option. Reducing framerate is evil..


More information about the ffmpeg-devel mailing list