Comment 3 for bug 910654

I've noticed significantly lower framerate using the gstreamer backend.

I'm recording at 1920x1080 on a 2.66GHz Core2Duo with 8GB RAM and an SSD.

I have made some comparative videos so you can see the difference. Sample 1 and 2 were made by checking lp:kazam out and installing then running it. All recorded on the same hardware under the same workload.

http://popey.com/~alan/kazam/sample1.webm - kazam gstreamer backend
http://popey.com/~alan/kazam/sample2.webm - kazam ffmpeg backend
http://popey.com/~alan/kazam/sample3.mkv - ffscreencast.sh from http://launchpad.net/ffscreencast

Sample 1 shows the worst framerate.
Sample 2 shows a better framerate but the bitrate is way too low for 1920x1080 at more than 10fps
Sample 3 shows a decent framerate and bitrate.

I realise the bitrate for Sample 3 is very high, but I can dial that down and stil get a decent framerate and picture quality.

The command used in Sample 3 was:-

ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1920x1200 -i :0.0 -aq 100 -acodec libfaac -vcodec libx264 -vpre lossless_ultrafast -threads 0 -sameq sample3.mkv