Find correct audio gain level

[walzing]

Hi,

I just started to convert my DVD Collections (TV Shows) to MKV as I want to have it on my HTPC.
Now I found a TV Show collection, that has very different audio levels for english and german audio tracks.
Is there a tool, to find out, what is the 'average' and 'max' audio level of one mkv file (audio tracks are ac3)? Or if there is not tool to analyze a mkv, I can demux the file to get the ac3 streams.
If I can find out the difference between 2 tracks, I can adjust audio gain level in handbrake to fix the low volume track.

thx in advance
Walzing

[AlanHK]

I use the Replaygain method.
Many audio tools have this built in.
It can take a few minutes for each track to analyse.
Then it gives you a dB figure to adjust the volume.
http://wiki.hydrogenaudio.org/index.php?title=ReplayGain


I've got scripts that do this automatically using Avisynth.
Or you can open a video in Audacity (it can extract most kinds of audio by itself, including VOBs, though I don't know what it does with multiple sound tracks) and use Replaygain on the Effects menu to analyse.
Then apply the gain it tells you when making the MKV.

[walzing]

Thank you - I used Foobar 2000 and did a replaygain scan on both audio tracks.
But before I had to convert them to aac (ac3 was not supported).
Foobar reported a gain of 8,81db for the german track and 9,42db for the english track.
But I can't believe that there is only a delta of 1db.

[AlanHK]

Well, I've found Replaygain gives me consistent volume.
Perhaps the backgound, music, is different?

Or it could be the "clipping" setting. I turn off clip prevention, because, unlike music, it doesn't matter if loud sound in dramas, like explosions, gunshots, are distorted. More important that the dialogue is consistent volume. Otherwise the volume boost is limited by the loudest sections.

[walzing]

It's seems it is no problem with the audio level.
Something in my setup maybe the problem.
I transcoded the 2 audio tracks from ac3 to acc. And if I play the acc version, german and english audio tracks are nearly the same volume.
So it seems to be my HTPC setup. My HTPC is connected via SPDIF to my Yamaha RX V471. And I currently have only 4.1 (which is configured in my Yamaha). However - it seems that when playing this 5.1 AC3 version the center channel is not distributed across the 2 front speakers. When using 5.1 ACC it seems to work.

cu
Walzing

[hello_hello]

AC3 can contain dialogue normalisation info. The idea being you can go from one video to the next and the dialogue will always be the same volume (it effects the volume over-all, which is altered to ensure the dialogue is at a set level). Much of the time, this gets the player to turn the over-all volume down, which results in AC3 audio sounding quieter than other audio.

The problem could simply be the player is obeying the dialogue normalization, which is generally ignored when converting AC3 to another format. The whole idea of having a centre channel would be to have a centre channel, not necessarily for the centre channel audio to be spread across the stereo channels.