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

[Anthony Chapellier]

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... ?

Thanks,

Anthony