[FFmpeg-user] sound balance on several files

[John Saturday]

Read chapter 2 and end table of document:
http://www.dolby.com/uploadedFiles/Assets/US/Doc/Professional/18_Metadata.Guide.pdf

Normalize to multiply of 3 dB level (-15, -18, -21 dB ...) without
clips. I use Audacity ( http://audacity.sourceforge.net/download/ ):
Analyze / Contrast... to see clips at waveform check View / Show
Clippings.

This is an actual level of right channel... to balance channels Split
Stereo Track (dropdown menu left at waveform), remove one channel and
measure contrast (dialogue level); Undo, remove other channel and
measure... Undo and amplify each channel separately and Make Stereo
Track (dropdown menu left at waveform).

DVD producers usually normalized at -27 dB but this is not a fixed
standard. First you need to measure and choice dialogue level for your
files: load files one by one, amplify to not clipping level and round
down measured contrast to multiply of 3 dB... After this choice your
dialogue level and calculate volume parameter for FFmpeg.