Ticket #27 (closed enhancement: fixed)

Opened 2 years ago

Last modified 2 years ago

A52Codec Volume

Reported by: gbooker Assigned to: gbooker
Priority: normal Milestone: 1.7.5
Component: a52codec Version: 1.7.2
Severity: normal Keywords:
Cc:

Description (Last modified by gbooker)

I received this via email and decided to include it here so the public can see it and discuss:

Hi,

Sometimes I download movies or videos with AC3 audio tracks that play back very softly in QuickTime with the A52Codec.component. Even with the volume control at maximum, the playback remains too quiet (for my tastes, anyway).

Turning up the System volume or using VLC for playback are options, but is it possible to increase the loudness of playback by a few decibles?

I got this idea from the latest v 1.30b release of the Windows "AC3Filter.":

http://ac3filter.net/

"AC3 loudness increased by +6dB. Now it matches loudness of other decoders. I was noted about this problem a long time ago, but I wanted to be sure what I'm doing, because new version produces overflow with LOTS of movies. I checked everything and found that it is not a bug of the decoder, but mastering issues. Other decoders also produce the same overflow at the same places. Therefore, new version works as it must work."

So is this something that can be done in A52Codec.component as well?

Change History

03/30/07 16:00:43 changed by gbooker

  • description changed.

03/30/07 16:12:11 changed by gbooker

Now, my thoughts on the issue:

There is a significant problem with increasing the loudness of the decoder. I actually discovered that the decoder was already outputting audio which was 3dB higher than it was supposed to be. This was causing clipping in valid sources.

The real solution is dynamic range compression, which seems to be a bit broken, but I am working on it for the next release. Simply increasing the audio output by 6dB is a foolish prospect. Just because other decoders do it doesn't make them right. In fact, I would argue that they are just a set of lemming walking off a cliff.

We are mac users! Let's not use the simple and stupid solution that satisfies windows users but instead use an elegant and proper solution.

Comments?

03/31/07 17:35:13 changed by gbooker

  • description changed.

Removed submitter's name since he didn't want it public

04/06/07 13:43:04 changed by gbooker

  • status changed from new to assigned.
  • version set to 1.7.2.
  • milestone set to 1.7.5.

04/06/07 15:28:44 changed by gbooker

  • status changed from assigned to closed.
  • resolution set to fixed.

(In [40]) More on the dynamic range compression. Allows the user to reduce the dynamic range compression for soft sounds (make them louder). Fixes #27