Swapping vob audio track

[tommy382]

I have some karaoke vob files and need to swap the two audio tracks: 0x80 and 0x81. I imagined this is a simple bit flip on the Vob's header file but can't find my answer after hours of googling. I saw a simlar thread http://forum.doom9.org/showthread.php?t=128493&highlight=audio+stream+swap but there isn't an answer there neither.

Does anyone know a quick way to do this? I don't mind writing my own program to do the bit flip but need to know the file layout of the vob file. I can't find this info anywhere.

Remember that these karaoke files are ripped vob files so I can't change in IFO file - there isn't any IFO file to change!

Also, if possible, I want a program that supports the command line so that I can batch processing thousands of files at once.

Thank you in advance.

[setarip_old]

Hi!Remember that these karaoke files are ripped vob files so I can't change in IFO file - there isn't any IFO file to change!Please clarify - Don't your original, commercial DVDs have .IFO files?

[tommy382]

Hi!Please clarify - Don't your original, commercial DVDs have .IFO files?
Yes but the files have been ripped and locating the original DVD is almost impossible. Can't it be done just on the vob file itself?

[foxyshadis]

Every packet has a track ID in its header, the stream doesn't have a master list that you can rearrange. You can find and rewrite track IDs in MPEG2 Program Streams easily - search for hex 000001xx where xx is the ID.

[tommy382]

Every packet has a track ID in its header, the stream doesn't have a master list that you can rearrange. You can find and rewrite track IDs in MPEG2 Program Streams easily - search for hex 000001xx where xx is the ID.
Can you give more details? Do I just change "00 00 01 80" with "00 00 01 81" and vice vesa? Using the hex editor, it only finds 16 occurance of "00 00 01 80". Shouldn't there be more? How many packets are there in a second of video? Is it just 1 packet per frame?