Audio is deafeningly loud when authoring DVD

[VenusAndMars]

I get the problem that the audio somehow gets amplified when I burn a DVD to where the sound is badly distorted and loud enough to wake the dead. I have used AVStoDVD and DVDfab - both give the same result.

The .avi plays fine in all respects and this is an entirely new phenomenon as I have authored many a DVD with no problems of this kind.
Any ideas? Me, I'm completely flustered and more than just a tad discombobulated...

[LMotlow]

AVI? What encoding for the AVI? AVi is a container, not a format. DixV? h264? QuickTime? Something else? What's the original audio sampling rate? If AVstoDVD can't fix the volume, demux the audio in something like Audacity and remux when you re-encode.

I thought AVS2DVD could fix volume? Been a long time for that one, though, I don't remember.

[VenusAndMars]

"What encoding for the AVI?" Hmm.. in AVStoDVD it looks like this...



...but should I have to care wether it's Xvid or divX? That seems beside the point. You say: "If AVstoDVD can't fix the volume..." AVstoDVD doesn't offer to fix anything. There is nothing to fix. The volume of the original file is fine.

I have made many DVD's from .avi files (yes, AVi is a container, not a format but that has never been an issue) and it has just worked. Watching the DVD or the original .avi has been the same thing as regards volume. Why should I have to involve Audacity to demux/remux all of a sudden?

[LMotlow]

The volume of the original is fine, but you say the volume on the re-encodes is too loud. So use something to lower the volume. Your AVI's sampling rate might have something with it, or the cause could be elsewhere. All we know about your AVI is that it's 23.976 progessive Xvid. You'll need 3:2 pulldown to make that DVD/MPEG1 compliant and the audio sampling rate should be 48KHz. BTW, I don't think you can make a to-spec MPEG-1 DVD with a frame size of 640x352. Someone correct me if I'm wrong on that. I never tried it.

[VenusAndMars]

But...what is causing this unwanted amplification? Are you saying that there has been a mistake made when the original DVD of the movie 'Straight Time' was ripped into the .avi file I'm using, and that this mistake now results in extreme amplification of the soundtrack?

When the .avi plays back perfectly, sound and all, and it is only when attempting to make a DVD out of it again that the sound-thingy happens?

I don't get it. This all sounds weird to me. Man, where is Baldrick when you need him?

[jagabo]

But...what is causing this unwanted amplification?

Your AC3 decoder is probably set up with a 10 to 20dB gain.

Are you saying that there has been a mistake made when the original DVD of the movie 'Straight Time' was ripped into the .avi file I'm using, and that this mistake now results in extreme amplification of the soundtrack?

Most likely whoever encoded the AVI file normalized the original AC3 audio to 0 dB when converting to MP3.

[VenusAndMars]

OK, thanks jagabo. You say: "Your AC3 decoder is probably set up with a 10 to 20dB gain." and: "Most likely whoever encoded the AVI file normalized the original AC3 audio to 0 dB..."

This sounds very reasonable to me, amateur bungler that I am, but what can I do about it? Seems to me that nowhere in the process has AVStoDVD offered a chance to do anything about the sound, neither as regards gain or any other aspect of it.

Also, if what you say is true, then how come the original .avi plays perfectly in, say, the KMPlayer w/o my having to adjust the volume of this movie as compared to any other I play? I don't use 'normalization' in KMPlayer.

[jagabo]

OK, thanks jagabo. You say: "Your AC3 decoder is probably set up with a 10 to 20dB gain." and: "Most likely whoever encoded the AVI file normalized the original AC3 audio to 0 dB..."

This sounds very reasonable to me, amateur bungler that I am, but what can I do about it?

Do what others have suggested, reduce the volume of the audio using some other tool before encoding as AC3. Or change your AC3 decoder settings and turn off the gain.

Also, if what you say is true, then how come the original .avi plays perfectly in, say, the KMPlayer w/o my having to adjust the volume of this movie as compared to any other I play? I don't use 'normalization' in KMPlayer.

The AVI file has MP3 audio. Your MP3 decoder isn't boosting the volume so it plays normally.

[VenusAndMars]

Right, thanks jagabo. I would instinctively go with turning off whatever gain the AC3 decoder is set to.
I'm sure this is obvious and basic to you but it isn't to me - where/how do I do that?

[jagabo]

I would instinctively go with turning off whatever gain the AC3 decoder is set to.
I'm sure this is obvious and basic to you but it isn't to me - where/how do I do that?

Depends on what AC3 decoder or player you're using. Look for an AC3 decoder in your Start menu. Or controls in the player you're using.

[VenusAndMars]

I wasn't aware until today that I had been using an AC3 decoder. What I do know is that I use KMPlayer or VLC for playback. I just want some DVD-making software like AVStoDVD, DVDFab or DVDFlick where I load the .avi, make some minor adjustments as regards output (aspect ratio, PAL or NTSC etc) then hit the start-button and get a DVD.
That's all the involvement I want, and it has worked fine for scores of movies. Obviously there is something different about the source file this time since both AVStoDVD and DVDFab result in a DVD that's much too loud, but I'll just have to let it go. Enough is enough. Thanks anyway.

[HarpMaster]

There is a way to adjust your audio volume in the preferences section, audio tab in AVStoDVD. It shouldn't be too hard to experiment
with finding a suitable volume, without using any other software. I have used this to do the opposite and increase the volume for
a DVD I was authoring.

[VenusAndMars]

Thank you HarpMaster. There is a 'Normalize Audio' option on the Audio tab:



but it gives no clue as to wether the value (default being 1.0) is the volume as expressed in dB's or if it's a factor. Supposing it is a factor, 1.0 being 100% i.e. 'leave as is', and 0.5 corresponding to a reduction of 50% of input volume, I could try that.

Does this seem reasonable? I can't run this experiment just now as I'm soon off to work, but I'll do it this evening and 'report back'.

Meanwhile, thanks for bearing with me;)

[VenusAndMars]

I was just about to start up AVStoDVD to experiment with tweaking the Normalize Audio value when I remembered that the DVD files from the last try were still there.
So I looked them up in order to delete them when, for no reason whatever, I dragged the VIDEO_TS folder onto VLC and - lo and behold - the sound was perfect...I don't know what was wrong when I wrote the OP but whatever it was, now everything's fine as wine.