Sync problems when converting from .mp3 to anything (.ac3 or .mp2)

[Drenhead]

I have a XVID file of a TV show episode that has the .mp3 audio file as VBR. When I open it up in Virtualdub, it tells me:

"Variable bit rate audio detected. VBR audio in AVI is non-standard and you may encounter sync errors up to 6358ms when attempting to extract WAV files or processing the audio in Direct Stream Copy mode. Full Processing mode is recommended to decompress or recompress the audio. (bitrate: 130.6 +- 21.0kbps)"

I used Full processing mode to extract the WAV file, but when I try to convert it to .AC3 and then mux it back in with the video, the audio is still out of sync. Any suggestions on how I should be handling the audio so it syncs with the video?

Thanks for all advice.

[setarip_old]

Hi!

Of course, the question that immediately comes to mind is - Why did you create the original video with VBR audio if you intended to finalize it with .AC3 audio?

Be that as it may, try the following (It's not nearly as complicated as it looks, just a lot of words ;>} ):

Converting .AVIs with VBR-MP3 Audio

Simply use NanDub or VirtualDubMOD (Different than standard VirtualDub), to save the audio stream as an Uncompressed PCM (WAV) file as follows:
1) Load your original .AVI into NanDub

2)Set "Video" to "Direct Stream Copy"

3) Set "Audio" to "Full Processing Mode" (NanDub only -For VirtualDubMOD>"Streams>"Stream list">>rightclick on the listed audiostream and then select "Full Processing Mode")
From the "Audio" dropdown menu, select "Compression" and choose "No compression(PCM)" (NanDub only - For VirtualDubMOD>"Streams>"Stream list">>rightclick on the listed audiostream and then select "Compression" and choose "No compression(PCM)")

4) From the "File" dropdown menu, select "Save WAV" (In VirtualDubMOD, "Save WAV" is located under the "Streams" drodpown menu) (Enter a new filename with a ".WAV" extender).Click on "OK"

5) Then save the .AVI as a silent .AVI (NanDub - set "Audio" to "No audio" after you've saved the WAV file. - For VirtualDubMOD>"Streams>"Stream list">>click on the listed audiostream and then select "Disable").


Then close NanDub and restart it
Set "Audio" to "No audio" (Not necessary under VirtualDubMOD)
Load your silent .AVI
Set "Video" to "Direct Stream Copy"
Under "Audio" click on "WAV Audio" and load your .WAV (In VirtualDubMOD, Streams>>Add)
Set "Audio" to "Full Processing Mode" (In VirtualDubMOD, Streams>>Rightclick on the listed audiostream, click on "Direct Stream Copy")
From the "Audio" (In VirtualDubMOD, "Streams") dropdown menu, select "Compression" (In VirtualDubMOD, rightclick on the listed audiostream, click on "Compression") and choose the appropriate .MP3 settings. Click on "OK"
From the "File" dropdown menu, select "Save as AVI" (In VirtualDubMOD, "Save as") and save your file with a new filename.

[BigDid]

I have a XVID file of a TV show episode that has the .mp3 audio file as VBR. When I open it up in Virtualdub, it tells me:...
Hi,

Setarip_old gave a long and detailed answer for how-to do full processing; but I'm kind of curious, beside the alert message given by Vdub, did you really, effectively hear (and see) an out of synch problem?

My question is because I use ABR mp3 all the time and each time I open that kind of avi in VdubMod I have the same kind of alert, and I just answer no to recode to CBR :)

Now to be perfectly honest I open these avi in VDM cause I sometime have out of synch problems with my capture sources so I just put some delay (usually +15 to 20 ms) for the audio and keep the ABR mp3. If you want to change the delay there are quite a few threads, specially in the AutoGk section, and Setarip_old is the one (once again :) ) giving the how-to do it.

Did

[Drenhead]

Thanks for the info.

To answer your first question, I didn't create the file. It was downloaded. I am trying to convert it to a .mpg file that I can watch on my Tivo. I usually don't have this many problems, but this one is giving me fits. I have created the new .avi, but i still have to convert it to .mpg. Should the sync problem be gone now? I'll give it a try and let you know.

[ilovejedd]

Yep. As I thought... Rule 6 violation?

[vlada]

ilovejedd> In my country (Czech Republic) it is completely legal to download anything from internet (FTP/P2P). But it's illegal to backup your original DVD with CSS.

Drenhead> I would suggest you to use AVI-Mux GUI for demuxing AVI with MP3 VBR sound track. Or you can use Avidemux for your AVI to MPG conversion.

[Drenhead]

Thanks to everyone that gave suggestions. I got it to work using Avidemux. Thanks to vlada for that suggestion. BTW, this was not a protected file, so I don't think this violated Rule 6.

Thanks again.