[FFmpeg-user] Screencasting problem.

[Noufal Ibrahim]

Hello everyone,
        I've been trying to make screencasts using ffmpeg on a VM. 

        The command line I'm using is as follows. 

ffmpeg -f x11grab -s 1280x800  -r 50 -i :0.0 -f alsa -i pulse -sameq screencast.mpg


        and I get the screencast but during recording, I keep seeing
messages like this

[mpeg @ 0x7ca590]packet too large, ignoring buffer limits to mux it
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=327057 size=341185
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=329098 size=341185
[mpeg @ 0x7ca590]packet too large, ignoring buffer limits to mux it
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=329098 size=341185
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=331139 size=341185
[mpeg @ 0x7ca590]packet too large, ignoring buffer limits to mux it
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=331139 size=341185
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=333180 size=341185
[mpeg @ 0x7ca590]packet too large, ignoring buffer limits to mux it
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=333180 size=341185
[mpeg @ 0x7ca590]buffer underflow i=0 bufi=335221 size=341185

        When I'm done with the screencast (which is about 8 minutes
long), I hit `q` and get the video. If I try to watch it, the audio is
perfectly fine without any choppiness but the video seems to have
missing frames. This is a guess based on my observation that the mouse
and text cursors suddenly disappear and appear later. 

        I'm guessing that it's because of the problem I've pasted above
so I tried blindly passing -bufsize to the command line try to increase
the buffer size. Passing something like -bufsize 43000 makes the error
go away but I can't quit ffmpeg. It doesn't respond to `q` and Ctrl-C it
gives me a truncated video. 

        I'd appreciate any pointers to fix the choppy video problem. 

Thanks.

-- 
~noufal
http://nibrahim.net.in

Why don't you pair `em up in threes? -Yogi Berra