[LAU] Tutorial on sidechain compression in Qtractor and a question about screencasting

Jeremy Jongepier jeremy at autostatic.com
Tue Aug 24 08:22:57 UTC 2010

Hello all,

I've uploaded a new tutorial to YouTube: 

So using sidechain compression in Qtractor with the SC3 LADSPA plugin.

Concerning screencasting, anybody any experience with this? For this 
tutorial I used recordMyDesktop, but it captures video to Theora, so 
after editing and uploading the quality degrades considerably. The big 
advantage of recordMyDesktop though is that it has JACK support and that 
the overhead is pretty small so I can still run my setup at a decent 
I've also started playing around with FFmpeg. The video quality is 
waaaaay better if you capture to a lossless format but I'm having my 
thoughts on the audio part. I compiled FFmpeg myself with libjack-dev so 
it has JACK support. But FFmpeg apparently has troubles to keep up with 
latencies below 20ms, lots of xruns on the FFmpeg side (JACK doesn't 
complain though). And I have the feeling FFmpeg lags on the audio side.
So I'm thinking about capturing the video part with ffmpeg and the audio 
part with jack_capture and mux the stuff later. But if anyone has any 
other suggestions, let me know.



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