Weak sound using ac3machine

[Hironimo]

Hi there.
I have 3 AVI files which contain a film. They have an ac3 audio track. Until i found ac3machine i did not find a way how to create a valid ac3 file for using to make a dvd.
ac3machine works, but the sound output level is far to silent compared to the original.

Is anyone else aware of this? I tried several options, but nothing helped. What should I do to make an wav ac3 to a real ac3? I tried
headac3he which would work if the ac3 did not have some glitches in it that occoured through fitting together the three avis with virtualdub. It create a valid ac3 with correct audio levels, but is broken at the point where the second avi started.

So, how to use ac3machine and maintain the audio levels?

Thanx!

[benf2]

did u play with the normalization... did u try turning it off?

[Hironimo]

Do you mean Dialog Normalisation Reduction?
That was the only option that says anthing about Normalisation.
I think I tried it out, but will do again to make sure.

But I think this will not help as I just found a FAQ on AC3:

9.__Is it possible to re-encode an AC3 file and why would I want to do this?
Yes it’s possible to transcode an AC3 file to a lower bitrate. Two software packages are capable of the transcode, SurCode Dolby Digital Encode and BeSweet/AC3enc. BeSweet is currently _much_ faster than the SurCode package providing very similar results in regard to quality. Be aware that a gain bug exists in the BeSweet/AC3enc package which causes the overall volume of the track to be lower than the original AC3. DSPguru and the AC3enc developers are aware of this bug and hope to address it in the future.

So this is actually a bug. I will see to get the SurCode package and see if results are better there.

Morkeleb

[benf2]

I believe Surcode is for DTS, i think u need sonic foundry soft encoder for ac3.... also did u try using headac3 found on doom downloads?

[auenf]

Originally posted by benf2
I believe Surcode is for DTS, i think u need sonic foundry soft encoder for ac3.... also did u try using headac3 found on doom downloads?

www.minnetonkaaudio.com

there is a Surecode version for 1 or 2ch DD for DVD, (up to) 5.1ch DD for DVD or CD, and a 5.1 DTS for DVD or CD.

Enf...

[Hironimo]

I did try headac3 (before even seeing to ac3machine) - it would be good if the ac3 wav would not have errors in it which only reencoding can fix.
I tried to find sonic foundry soft encoder but could not get it anywhere. I read its not on the marked anymore and rather rare these days. Could you give me a tip on where to find it?
I am confused about that surcode thing, there are so many programs and would not know what is for what - but it states in the faq besides ac3machine (using besweet ofcourse) its the other ac3 encoder around - they probably forgot sonic foundry?

I would be grateful for tips cause i am still no step closer to getting and acceptable ac3 audio.

Cheers,
Hironimo

[Hironimo]

Hi there.

I finally could fix the problem.
BeSplit did the job. It could convert the ac3 wav properly to plain ac3 and fix the errors in it. I am just using IfoEdit to mux the streams together.
Hold on with me until it's done so I can confirm that it plays properly ...
Well, it plays properly, and audio syncronisation is ok too it seemes, but playtime, which ought to be 2:59:29 is just 2:23:27.

Is there a way to fix this?

Hironimo

[Hironimo]

I found that the relation is exactly the 3:2 pulldown. originally the video was 23.976 fps which i pulldowned to 29.97. The time relation is the same in the wrong and true play time of the video. Somehow i must do the pulldown differently.
Any hints?

Hiro

[Hironimo]

You might wonder why I answer to myself practically :)
Well, some of you might profit of the experience i gain as i go with trying ...

Ifedit does seem to have serious problems with (re-)muxing, not only into an existing project/dvd but also creating a brand new one. I cannot trace down whats wrong or if it can be calssified as a bug or just incompatibility, but no matter.

I used SpruceUp to mux the files i had to a very simple dvd (without chapter points sorrowfully, that is very clumsy to work with in SpruceUp) and it worked perfectly.

So my impression: don't let ifoedit do muxing.

Morkeleb