I've been learning about screen recording in Linux so I can make a demo/tutorial for Hooke. There seem to be a number of options (Xvidcap, recordMyDesktop, etc.), but my favorite approach is to use ffmpeg directly from the command line (If you're only interested in recording terminal sessions, look at script). You may recall ffmpeg from my earlier post about video encoding. For those to lazy to read the man page, here are some highlights:
$ ffmpeg -f alsa -i hw:0 out.wav
$ ffmpeg -f x11grab -r 30 -s 1280x1024 -i :0.0 out.mpg
Record audio and video:
$ ffmpeg -f alsa -i hw:0 -f x11grab -r 30 -s svga -i :0.0 out.mpg
The trouble will be getting your audio/video captured, encoded, and stored to disk fast enough to keep up with your desired frame rate. Smaller sizes, slower frame rates, simpler encodings, and writing to ramdisks will all help with that. You can create a ramdisk with something like
$ mkdir /tmp/ramdisk $ sudo mount -t tmpfs none /tmp/ramdisk -o size=256m
It's also possible that passing the
-sameq option to ffmpeg will
help, but I'm not entirely convinced.
Anything recorded or encoded by ffmpeg should be playable in mplayer (as far as I know), or you can transcode it into a format of your choice (see my video encoding post for hints.
Note to Gentoo users: you'll need to compile ffmpeg with the
enabled to get the x11grab video input device.
If you can't get ffmpeg to work, an example
looks something like:
recordmydesktop --height 600 --width 880 --channels 1 --overwrite -o ramdisk/setup.ogv
Some benefits recordmydesktop:
- it uses
libxdamageto only monitor regions of your window that have changed (I'm not sure how ffmpeg's x11grab works).
- it doesn't encode the video until after encoding finishes (although you can encode on the fly if you like).