Add silence
Sometimes audio files are too short and do not match the length of the video files.
Instead of making another reel with a silent soundtrack, you can add some silence to the audio files using Sox.
To make a 48 khz 24 bit 10 second silent wav file with sox:
sox -n -r 48000 -b24 silent10sec.wav trim 0.0 10.0
To add this to the end of another 48 khz 24 bit sound file with sox:
sox film.LFE.wav silent10sec.wav film2.LFE.wav
Extract Channels
Extract channels from interleaved 5.1 sound files
If the file is L, R, C, LFE, LS, RS
sox film51.wav left.wav remix 1 sox film51.wav right.wav remix 2 sox film51.wav center.wav remix 3 sox film51.wav lfe.wav remix 4 sox film51.wav ls.wav remix 5 sox film51.wav rs.wav remix 6
Note: You can check the interleaved audio file in Adobe Audition to see if it is L,R,C,LFE,LS,RS
Installation
In Ubuntu Linux you install sox using sudo apt install sox
On Windows, you can install sox using Bash on Ubuntu on Windows and install sox with apt install sox or get the binaries from the Sox homepage.
On a Mac, you can install sox using homebrew and install sox with brew install sox or get the binaries from the Sox homepage.