2 Questions: Audio Re-syncing & DVD contents

[roubaix]

Hi everyone, I have two questions and neither one is simple but they are related..... :P

First off, I have a DVD-R of some content which someone recorded of TV - the problem is that the audio and the video is not synced correctly. My question is this:

Is there a simple way to match up the audio and video? Now read my next question!

This same DVD was authored with chapters and a menu by the person who recorded it - those are not important to me and I would rather just have a the audio issues fixed.

So, hopefully you can see the relationship between these issues - here is the VIDEO_TS folder content:

VIDEO_TS.BUP 8 KB
VIDEO_TS.IFO 8 KB
VTS_01_0.BUP 32 KB
VTS_01_0.IFO 32 KB
VTS_01_0.VOB 472 KB
VTS_01_1.VOB 1,023.8 MB
VTS_01_2.VOB 186.2 MB

THANK YOU EVERYONE! I realize this may not be a simple question(s) but I appreciate the help!

[tomlee59]

Well, there are several possible answers depending on the nature of the sync problem, and on what you plan to view the DVD with. I will assume that you wish to end up with a truly fixed DVD that can be played on a standalone player. Here's what I do; others may offer better suggestions:

First, rip the disc as a single VOB, then demux into elementary streams.

If the sync error is a fixed offset, then a simple remux operation will take care of the problem. VLC is very useful in determining the correct offset value (in the preferences menu you can specify a time offset in milliseconds). Verify the offset value at several points in the movie to confirm that it is truly a fixed value. Then, in ffmpegx, remux with an offset that is the algebraic inverse of the number you discovered with VLC. So, if you had to dial in a +500ms offset in VLC, you would type a value of -500 in ffmpegx's muxing tool. Mux, reauthor, and burn.

If the sync error is not fixed, but drifts at a constant rate, then you can use a tool such as Audacity to stretch or compress the audio track as necessary. Again using VLC, determine the offset value at the beginning, middle and end of the movie. Call these values toffset, tmid and tfinal. Verify that these values increase linearly. Using the "change tempo" tool in Audacity, lengthen the audio by an amount equal to (tfinal - toffset). Then mux the resulting lengthened stream with the video, and use an offset of value -toffset. Author and burn.

If the error does not vary at a constant rate, life is much more painful. If you can identify regions within which the error is roughly constant (or at least drifts at a fixed rate), you can chop up your movie into those segments, resync each segment separately, and splice the repaired segments back together.

Good luck!

[roubaix]

Thanks for the advice, I'll check back!