Problem converting Divx with AC3 to DVD

[ggm]

I have tried encoding using MainConcept, Honestech, TMPGEnc, and several DVD authoring programs that have built in encoders and the audio sync is always slightly out. Can someone give me some advice please.

[bugster]

How are you handling the audio. For AC3 Audio, I would always suggest extracting the audio first. Use virtualdub, audio->direct stream copy, then file -> save wav.
rename wav file to file.ac3, use ac3-fix.exe on it to remove th wav header that vdub adds. Keep this file seperate and encode your video only with your favourite encoder. Then use the audio file with the encoded video file when you author. It works for me.

[rsb]

I would always suggest extracting the audio first. Use virtualdub, audio->direct stream copy, then file -> save wav.
rename wav file to file.ac3, use ac3-fix.exe on it to remove th wav header that vdub adds.

Hi,
I've done steps above.
first I cannot rename to *.ac3.
e.g. A.wav it turned out to be A.ac3.wav.
second,

use ac3-fix.exe on it to remove th wav header that vdub adds

what does this mean?
What would happen if the step skipped?

thanks.

[mats.hogberg]

first I cannot rename to *.ac3.
e.g. A.wav it turned out to be A.ac3.wav.

First of all, tell your system to stop hiding known file type extensions (or rename it using the command prompt). In w2k, you set this by opening any filder, then select Tools -> Folder options (not sure on the exact wording, as I'm on a Swedish version of w2k), second tab from left (Show?). This stupid "feature" (hiding extensions) should never be activated, since it may lead to all kinds of problems. (What if you see a file named "britney_spreadeagled.jpg" and can't keep from taking a peek? It may in fact be the installation of the infamous virus britney_spreadeagled.jpg.exe that starts when you click on it (as you wont see the ".exe" part).

use ac3-fix.exe on it to remove th wav header that vdub adds

what does this mean?
What would happen if the step skipped?

It wont work as audio source for the rest of the process.

/Mats

[spectroelectro]

When you say "The audio sync is always slightly out," do you mean there is always a constant delay twixt audio & video? If so, you can fix this easily in TMPGenc by going into the SETTINGS menu then AUDIO you can introduce a dixed delay into the audio stream during encoding.
However, if you mean that the audio slides gradually out of sync with the video, then you are probably encountering a problem where your setting ont he audio doesn't match the setting on your MPEG encoder. This happened to me last night. TMPGenc has the annoying habit of allowing you to encode (without error messages) an MPEG-2 video with a 44.1 khz audio track. Without realizing it I had recorded an AVI with an incorrect 44.1 khz sampling rate to hard disk. When I converted the AVi file to MPEG-2, TMPGenc assumed the audio was 48 khz as is standard for DVDs, and the audio started sliding out of sync with the video. Once I saw my stupid mistake, I extracted the audio to a WAV file (as the moderater has already widely suggested) and then did a sample rate conversion to 48 khz. Then I re-ended with TMPGenc using the AVI file as the video source but the separate WAV file as the audio source. (MainConcept and all the other MPEG encoders typically let you select different sources for video and audio portions of the final MPEG-1 or MPEG-2 file.)
If you're dealing with source material that uses a different frame rate (PAL, 25 fps as compared to NTSC 29.97 fps) or a different sampling rate (going from SVCD with 44.1 khz to DVD with 48 khz) then the best procedure I've found is to use TMPGenc to read the file and SAVE AS -> AVI, then read file again and SAVE AS -> WAV. This gives you two separate files from an original MPEG-2 or MPEG-2 file which you can then process to get the correct frame rate and/or sampling rate and re-encode. This method always avoids sync problems, in my experience, in converting from PAL to NTSC or vice versa. It is tedious, but it always works. No fun to convert an MPEG-2 to AVI and then back again...but with PAL -> NTSC conversions I've not found a better method that reliably maintains audio sync.