[FFmpeg-user] Picture jerky when screencasting?

[Etienne Buira]

On Fri, Jun 03, 2011 at 09:14:21PM -0700, lugoteehalt wrote:
> Great thanks.  Seems to be an exact copy.  It now works with:

Make sure of it (you can use diff -s file1 file2).

> ffmpeg -f alsa -ac 2 -i pulse -f x11grab -s cif -r 25 -s `xdpyinfo | grep
> 'dimensions:'| awk '{print $2}'` -fpre
> /usr/local/share/ffmpeg/libx264-lossless_ultrafast.ffpreset -i :0.0
> ~/out.mkv
> 
> The picture no longer jerks on iplayer fullscreen, nor is it much webcammy. 
> But the quality, while acceptable for most things, is not high.  Colour
> gradients are stepped for instance.  Hope this not off topic but could you
> suggest how to tweek the quality - it is a complex piece of software for
> someone new?

The command you give is not the initial one, and here, you don't use
libx264 at all. Use your initial command, with only -vpre changed to
-fpre pointing to a file you know for sure is an exact copy of the
original preset.
Bear in mind that options ordering matters.