Recording a video from Linux desktop content, like for creating a screencast presentation, is quite simple with
recordmydesktop or its GUI version
However if you want to capture the system sound as well (not what you might speak live into a microphone), it gets a bit more difficult. Here is one possible solution with the pulseaudio sound server (available by default in Ubuntu Linux):
sudo apt-get install pavucontrol.
- In gtk-recordmydesktop, go to "Advanced -> Sound -> Device" and change the value from "DEFAULT" to "default".
- Do a test recording with
gtk-recordmydesktopand, while it's recording, in
pavucontrolgo to tab "Recording", there in entry "ALSA plug-in[recordmydesktop]:ALSA capture from" change the value from "Built-in Audio Analog Stereo" to "Monitor of Built-in Audio Analog Stereo".
- In tab "Input devices" use the dropdown on the bottom to display also monitor devices, look for the ""Monitor of Built-in Audio Analog Stereo" device and make sure it's not silenced and the volume gauge is at 100%. When something is playing through your speakers, you have to get a signal showing up there, independently of if you're recording at the moment.
- Record with
gtk-recordmydesktopas you're used to do.
This solution was taken from ubuntuforums.org thread 1509398.
There is also another solution involving only ALSA and the snd-aloop kernel module for recording from a loopback soundcard. However I could not get it to work.