[Ffmpeg-devel] ffmpeg to ffserver makes underflows, to file it works

Stefan de Konink skinkie
Sun Mar 5 04:21:32 CET 2006


I'm trying to implement a low-budget, two week, video record device. I 
tryed serveral other solutions, but they seemed too slow for my machines 
(gstreamer) or just unworkable (mplayer/sox -> icecast).

The ffserver (with MaxFileSize) and the provided ffmpeg frontend looked 
very ok, it even passed the to be encoded parameters. But with the same 
parameters on commandline I get different behavior.

For example:

ffmpeg -deinterlace -ad /dev/sound/dsp1 -vd /dev/video0 -r 25 -b 200 -s 
352x288 -f avi -vcodec msmpeg4 -acodec mp3 -ac 2 -ar 22050 test4.avi

Works with one warning:
[msmpeg4 @ 0xb7edb1a8]removing common factors from framerate

Now streaming to ffserver (on another system behind a switch):
ffmpeg -deinterlace -ad /dev/sound/dsp1 -vd /dev/video0 -r 25 -b 200 -s 
352x288 -f ffm -vcodec msmpeg4 -acodec mp3 -ac 2 -ar 22050

(I use the same params in the ffserver.conf under Stream.)

I get lots of:
[msmpeg4 @ 0xb7e3a1a8]rc buffer underflow

With a load of 0.36 on a PIII, using the CVS version of ffmpeg, I wonder 
if it would be possible to decrease the server strictness, and just 
allow the client to send when it is done. Due to the interruptload of 
the videocapture I don't want it running on the fileserver itself.

Is there any config option available that creates a bigger time window 
to fill the buffer?

Yours Sincerely,

Stefan de Konink

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