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Topic: AC3 Volume Issues (* Throws Hands Up *) (Read 3871 times) previous topic - next topic
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AC3 Volume Issues (* Throws Hands Up *)

Okay, my ego's all beaten to death on this one and it's quite simply time to ask for help from higher powers.  Here's the backstory.

1. I used MPlayer to dump (decode) DVD AC3 audio to PCM WAV...for like fifteen movies.
2. "Hmmm...this sounds too quiet, I'll boost all of them by 17.5 dB."  (I'm not always the brightest bulb.)
3. "No, that's not technically correct, I'll deamplify them by that 17.5 dB to get back to where I started."
4. "This normalization thingie doesn't produce anywhere near consistent volumes across different movies."
5. "Hmmm...I'm going back to the 17.5 dB increase."
6. "Nope, that was an unwise decision, I'm removing that 17.5 dB and shall now look further into DRC."

This was all over the course of a month.  So now these poor, molested WAV files of mine have been amplified and deamplified several times.  So far as I can tell, they sound the same as they used to (did a test of an abused one against a fresh rip).

So the first issue is, are my WAV files too banged up from all the volume changes (possibly caused by any hard limiting in the amplification process)?

The next question is, and for crying out loud, how do I properly rip DVD AC3 audio to a decent-volumed WAV.  I've heard about using dynamic range compression, but I'm totally lost.

AC3 Volume Issues (* Throws Hands Up *)

Reply #1 –
Why not encode the WAV files using a lossless codec and apply ReplayGain?
lossyWAV -q X -a 4 -s h -A --feedback 2 --limit 15848 --scale 0.5 | FLAC -5 -e -p -b 512 -P=4096 -S- (having set foobar to output 24-bit PCM; scaling by 0.5 gives the ANS headroom to work)