*maybe* a newbie question about audio sync

[phatcorns]

Ok, fairly complicated to explain, but I bet there is a fairly easy way to solve this problem.

Let's say I rip chapters 2-7, cutting off chapters 1, 8, and 9. I use stream selection and I only rip the video track and the 2ch English audio track.

So then I have a VOB that contains the video track (I assume this is mpeg2?) and an AC3 audio track.

I load this up into Virtual Dub Mod and I demux the audio out. So now I have the AC3 audio track seperate. I then use BeSweet and BeLight and load that AC3 file up. I set it to automatic delay based on the information from the AC3 file. Then I output to a 128 Constant Bitrate, 44,100Hz sampling rate, Mp3 file.

Then I use Virtual Dub Mod again and I output the VOB file to a 362 by 272 resolution Xvid AVI.

Ok, so now I have an Xvid AVI file and an Mp3 file.

So, what I am actually doing here is muxing these two files together in a format called PMP. For those of you who don't know what this is, it's a custom PSP (Playstation Portable) format that allows you run full resolution videos on your PSP (PSP's normal video's resolution is crippled to a much smaller size). The stipulations of PMP is that the video needs to be Xvid and either resolution 480 by 272 for 16:9 or 362 by 272 for 4:3. The audio needs to be Mp3 at 44,100Hz sampling rate.

So with all of that in mind, here is my problem. When I mux my Xvid AVI and Mp3 file into the PMP format, the audio is out of sync. The audio is also out of sync if I mux the two into another format, like AVI. The audio gradually gets more out of sync as the video goes on.

My guess is that the Xvid AVI file and the Mp3 file are different lengths and causes sync problems. However, I have no clue how to fix this. I'm sure there is a very simple answer, but I have not been able to find it anywhere.

I have been using AutoGK in the meantime for all of my 16:9 videos, but since AutoGK cannot encode into 362 by 272 resolution, my 4:3 videos are out of luck.

Thanks for reading and thanks for ANY help!

[setarip_old]

Hi!

Load the file into VirtualDub, VirtualDubMod, or NanDub.
Set BOTH "Video"(VirtualDub, VirtualDubMod and NanDub) and "Audio"
(VirtualDub and NanDub - VirtualDubMOD>"Streams>"Stream list") to "Direct Stream Copy".

A) If the difference between audio and video is constant throughout the

video:

From the "Audio" dropdown menu, select "Interleaving" (For

VirtualDubMOD, rightclick on the listed audiostream and then select

"Interleaving")
Under "Audio skew correction", set an appropriate number of

milliseconds (positive or negative) in the box labelled "Delay audio track

by"
Save with a new filename


B) If the difference increases as the movie plays:

From under the "Video" dropdown menu, select "Framerate" - and

select "Change so video and audio durations match"
Save with a new filename

Let us know of your success ;>}

[phatcorns]

Hey, thanks for the reply, I actually saw this same reply while searching for answers, but I'm still not quite clear.

Do I take my VOB file, load it up in Vdub, direct stream copy both audio and video, and then output it as a new VOB file?

THEN, do I take that new VOB file, and continue on with my compression and demuxing?

EDIT:
I tried it, but I don't have an option to save the new file as a VOB using Virtual Dub. Any tips?

[setarip_old]

and then output it as a new VOB file?No - VirtualDubMOD's output is only .AVI, which is what your initial post to this thread indicated you are converting your .VOB to (XviD-compressed .AVI)...

[phatcorns]

I still don't know how to convert it to AVI then if I'm supposed to leave both audio and video on Direct Stream Copy. I tried outputting to AVI, but it didn't work.

[setarip_old]

In your initial post to this thread, you stated that you had already used VirtualDubMOD to create an out-of-synch XviD-compressed .AVI.

In order to (hopefully) synchronize it, load that out-of-synch XviD-compressed .AVI into VirtualDubMOD and follow the applicable instructions already provided to you in post #2 in this thread...