Query re: divx -> dvd

A

aeaston

1
I followed the divx to dvd tutorial. Seemed to go ok, except for a few problems with the ac3 file that was produced. The source avi was using xvid and ac3 sound. To produce the dvd I used the mp2 file that was produced by dvd2svcd instead of the ac3 file (which maestro and dvd author said was corrupt).

I've since managed to produce a valid ac3 file using an older version of besweet (though I haven't authored a DVD with it). What I'm wondering though is do I benefit any by using an ac3 file over the mp2?

The mp2 file seemed to work fine, only error I had after authoring with TMPGENC was something about the (average?) bit rate being too high and the resulting DVD being non-standard. Plays in my parents ****ty grundig just fine though. Are some other DVD players likely to have problems with it?

Any advice appreciated..

Andrew
 
D

dreadycarpenter

New member
I would use the source ac3 with out re-encoding, chances are it is the original ac3 track from the DVD, so should be DVD compliant, I've found that ac3 compresses smaller than mp2, unless it is 5.1.
anyway.. ac3 and mp2 are DVD compliant audio formats.... all DVD players support ac3, but not all support mp2
so use the source ac3, if it is not DVD compliant... uncompress as .wav then re-encode with ffmpeg-GUI
hope this helps ;)
 
ChickenMan

ChickenMan

1
Just to clarify the situation, MP2 as a lone audio track is NOT dvd compliant for NTSC players, but IS for PAL players. AC3 is a manditory requiment for first audio track for NTSC dvd's, but is not for PAL. This means if its PAL than it should play fine according to dvd compliance specs but practically, many PAL DVD Players still have problems with MP2 audio. Therefore I would, and always have, recommended you put an AC3 audio in and regardless of PAL or NTSC, it will always play.

MP2 and AC3 with the same bitrate are EXACTLY the same size. Of couse converting a 5.1ch AC3 @ 448 bitrate down to a MP2 @ 224 will be smaller, but you juct went from 5.1ch to 2ch. If thats okay with you, then go for it. But keeping the original AC3 audio is the most idea as its directly from the original DVD and will be the best quality with no conversions needed, just a quick fix.

Its very common to have probs with AC3 audio in AVI's but a quick run through BeSplice (w/ BeSplit) will fix the internal sync time code and make it compliant again. See the How to Fix Audio Sync probs Tutorial on how to use it.
 
A

aeaston

1
Much obliged.

Cheers folks. In my scenario the ac3 file is bigger than the mp2 file, so I guess the ac3 file has more channels.

I couldn't fix the ac3 file with the BeSweet i downloaded from www.doom9.net. But I downloaded the GUI from there and pointed it at the BeSweet that comes with DVD2SVCD (1.2.1 Build 3) and did a ac3 to ac3 conversion that seemed to produce a valid ac3 file.
 
A

aeaston

1
Typo?

Just went and read the tutorial regarding how to convert audio to ac3 audio. There's a line in there saying..

If the AVI contained AC3 audio, then simply use the Extracted_audio_1.mp3 and no conversion needed (many need to be "fixed" though with BeSplit).
Click to expand...
Should the Extracted_audio_1.mp3 read Extracted_audio_1.ac3?

If not I've managed to confuse myself further.
 
ChickenMan

ChickenMan

1
Yes, sorry my mistake, mp3 ac3 they all start looking the same after midnight. It should be Extracted_audio_1.ac3
 
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