[FFmpeg-devel] Encoding video stream into CIF and 25 fps video format

Michel Bardiaux mbardiaux
Fri Oct 5 15:46:00 CEST 2007

Anthony Chapellier a ?crit :
> Hi,
> I'm a beginner with video codecs and ffmpeg so I'd appreciate some help.^^
> I'm doing some devel on a program which encode a video stream provided 
> by a webcam using h263 codec from libavcodec library. Until today, the 
> program has been working perfectly fine and encoded the video into QCIF 
> and 10fps video format.
> However, I wish to change those settings and encode the video into CIF 
> and 25 fps video format. And this is my big problem !!! Firstly I'm 
> unable to get 25 fps, the video stream don't go over 15 fps... 
> Secondary, when I try to encode the video into CIF I got a lot of error 
> messages :
> - rc buffer underflow
> - concealing xxx DC, xxx AC, xxx MV errors
> And something weird is that the video quality is really good during a 
> few seconds and after that it's full of grey pixels.So do you know how I 
> could solve this problem ? is there some setting I didn't well like 
> buffer size, bit rate or something else... ?

We cant do anything without the exact command used and its output messages.

Michel Bardiaux
R&D Director
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