How to determine and normalise AC3 volume?

[JimmyBarnes]

With DVDs, I have always assumed the AC3 volume was more or less correct.

But if audio subjectively seems too "soft", is there any program which can to determine AC3 volume in dB, and/or normalise the AC3 stream(s) if required?

TIA

JB

[Blue_MiSfit]

Sort of.

Dolby Digital is interesting in that it can contain a lot of dynamic range, and has metadata parameters to adjust its playback characteristics. In practice, this doesn't always work that well.

If you want to transcode the audio to another format like AAC, then eac3to can normalize very nicely.


eac3to input.ac3 output.m4a -normalize


If you want to do this to existing AC3s without transcoding there are a few options

1) Do it on playback with AC3Filter or FFDShow's audio processing filters. Both have normalization / DRC options (overriding the stream metadata)
2) Run the files through an overpriced but very effective Dolby DP600 program optimizer. It will analyze the stream in depth and re-write DRC metadata (among other things), so that you will get even loudness on playback. Pretty cool stuff, but it's like $20k or so... :p

~MiSfit

[JimmyBarnes]

Can one do something like:

eac3to input.ac3 output.ac3 -normalize