Decode AC3 Track to WAV

[MBoufleur]

Hi, does anyone know how the AC3 decoding process takes place in DGIndex?
I decoded a lot of DVD´s using this option because it´s really fast, but there was one that just didn´t work. I had to demux the AC3 and use BeSweet to decode this to WAV, but the result seemed to be kind of different related to others (mainly the Gain Level, but there could be other differences as well).
I read in some old posts that the right way to do it would be to use BeSweet or HeadAC3he to do the AC3 to WAV, but I was hopping that decode process may have already been got better during this time :D

[neuron2]

there was one that just didn´t work Your problem statement is too vague to allow me to address it.

If you'd like to make available a fragment of the source VOB, I can have a look at it.

[MBoufleur]

Sure, I can make it available. The problem is that VTS_01_1.VOB is 1GB. Wich tool do you advice to trim a small part of it?

[neuron2]

Please tell me what "didn't work" means.

You can use any VOB splitter tool you like.

[MBoufleur]

Ok, go to this address (http://paginas.terra.com.br/informatica/Boufleur/), and grab the VOB file there (It´s about 10MB)

When you try to open it with DGindex, it shows AC3 1/0 0
Strange... It´s the first time it happened with me (0Kbps?). When demuxed using DGIndex, and Decoded with BeSweet, I could see that it´s actually 2/0 384kbps. This DVD is one of those made with stand alone DVD Recorders, but we used other titles recorded from the same source and they didn´t have this kind of issues.
You can check the VOB to see if there is anything worth debbuging, but at first I was mainly concerned with the comparison between DGIndex WAV decoding Vs. BeSweet WAV decoding. :D

By the way, great site (http://neuron2.net/)! DGIndex and some of your filters are helping a lot in some post-production processes.

[neuron2]

Thanks for the test file, Marcelo.

It was some audio data emulating a sync word. I made a hack for it. Can you please test this:

http://neuron2.net/dgmpgdec/dgindex149b1.zip

[MBoufleur]

Thanks Donald, it works like a charm! Now about the situation I mentioned before, is there a real difference between BeSweet and AC3 to Wav decoding process? This time I didn´t have any problems with gain or anything else.

[neuron2]

I don't know what you mean by "real difference". DGIndex is based on ac3dec, while BeSweet uses Azid (I think). You'd have to post in the Audio subforum for a better answer, methinks.