v4l - capture and watch at the same time

Question

Capturing v4l and line-in audio using mencoder works very well, but I would like to record real-time game play video from consoles plugged into the video card.

I've used xawtv for this (Works quite well, can preview and record in real time), but when I enable any deinterlacing or aspect ration options the video fails to record. I have to record raw and re-encode the video with the appropriate filters later to get something workable.

Other things I have tried:

• tvtime with xvidcap and jack audio capture - xvidcap drops frames and muxing the audio is impossible as it will go out of sync (I have not found muxer options that work to force a correct frame rate)

• mencoder capture to file, attempt to pipe tail of file to mplayer. mencoder works great, piping the file is far too heavy to attempt gameplay.

So, v4l capture and preview simultaneously, recommendations?

Answer 1

I use xvidcap. To solve the sync out I have installed the PulseAudio mixer (pavucontrol).

Also I choose a low fps, because I use a laptop which is not very powerful.

First I run pavucontrol:

$ pavucontrol

Then I run xvidcap in this way:

$ padsp xvidcap --fps 10 --cap_geometry 1440x900+0+0 --file "file1.mpeg"

padsp is the pulseaudio wrapper. Options are only an example, you choose your own.

Then go to pavucontrol, in the recording tab. This tab works only when a video program is running. Here you can choose the audio source you want to record. Finally start recording.