bigbluebutton/bigbluebutton — pull request #373 by kepstin (2014-08-22 19:06:26+00:00)
Title: Rewrite audio processing to use ffmpeg

There's some fairly major changes here, including:

* All audio is resampled to 48kHz stereo on input, allowing files with
non-standard or varying rates to be mixed
* The audio processing is now done in a single pass; ffmpeg reads all
inputs, concatenates them, and outputs one file.