Quicktime Mov with Left Stereo into Mono/Dual Stereo I recorded a screencast using an external microphone and quicktime.  However, the audio is only on the left channel.  Is there a way via an apple tool, command line, or otherwise to convert a left channel only quicktime movie into mono or copy to both channels?
I use ffmpegX a lot for transcoding video files from one format to another, there is an option to set audio channels to Mono see the docs.