In general, DemoRecorder can record from all sources which you can select in the Mixer-application ( such as "alsamixer" ). What can be selected, depends on your sound card.
Most sound cards allow to select between microphone and line-in.
On notebooks, you can usually also choose between the built-in microphone of the notebook and an external microphone which is plugged into the microphone jack of your notebook.
So if you want to record from these kind of sources, please start your mixer application and select the right sources...
On the other hand, if you also want to record sound that is being produced by the programs which you are recording, then read on:
Unfortunately, most sound cards cannot capture their output to their input-subsystem. But as mentioned above, they usually can capture from a variety of sources and also mix them together. Most sound cards support at least one "Mic"-Input and one "Line-In"-Input. The "Line-In"-Input is important for the following solution:
What may work is to connect the "Line-Out"-Jack with the "Line-In"-Jack of your sound card with a 1:1 connected Stereo cable, possibly with a galvanic separation device in between. Please do *not* connect "Line-Out" with the "Microphone"-Jack because the microphone outputs a power-supply for the microphone and if you connect that power-supply with the Line-Out, you may damage your sound-card. (The "Mic"-jack uses a Stereo-connector but only supports Mono-microphones. The other channel is used for the power-supply. )
Hope this helps,
P.S.: Future versions of DemoRecorder may also support direct capturing of sound-output at a software level before it reaches the sound card. As of now I do not know whether this is possible but I must admit that I didn't do extensive research into that direction. What I can tell is that there is no obvious solution for software-based capturing of sound output.
A possible alternative solution would be direct interfacing between your application and DemoRecorder. We provide a custom development service, so you can order some customizations of DemoRecorder which are needed for that purpose.
Interview on the Linux Link Tech Show. Please select Episode 154.
DemoRecorder featured in Linux-User Magazine (in German)