issue with joining VOBs

[ktnwin]

I have been successfully joining VOBs to make custom karaoke disc (that contains only the songs I like to sing with).
Recently, I ran into audio problem with some discs.
Apparently, if I mix VOBs from two different DVDs, it is possible that the resulting DVD disc will have problems with VOBs coming from one of those source DVDs. The problem appears to be caused by the different audio sampling rates of the two sources DVDs. Let's say songs #1, #3, #5, etc.. come from disc 1 and the even songs came from disc 2. The only the odd numbered songs have audio, the even one are all muted. On the computer, they play OK with audio everywhere.
f I group all songs from disc 1 first (song#1 to 10) followed by songs from disc #2 (song #11 to 20) then song #1 to 10 are fine with audio, song #11 and on have no audio.
Have anyone run into this problem ? and how to solve it.

[jimmalenko]

What process / software are you using to join the VOBs ?

If the audio has different sampling rates, I think this might be contributing to your problem. TMPGEnc DVD Author (30 day fully functional free trial) will upsample to 48KHz automatically for you, or you can demux the VOBs, resample the audio then remux and reauthor.

[borax]

As all the files are created from vobs, it is ensured that the sampling rate is 48 kHz. But there may be differences in the bitrates and/or number and type of channels.

IMHO there are two possibilities to get around this problem:
- Put each song into an own titleset on the DVD (if and how this can be done, depends on your authoring program, limit is 99 titlesets)
- Demultiplex all the 'song vobs' and transcode the audio streams into one specific format (like: 2 channel, joint stereo, 48 kHz, 192 kBit as ac3 or mp2). This can be done with BeSweet or other advanced audio tools (cooledit, goldwave...) Then you may use the resulting elementary streams, join them with mpeg2schnitt/cuttermaran and author also as a single titleset with chaptermarks to access each song individually.

[ktnwin]

Thanks for the replies, I am quite familiar with the process of:
demux video, audio
upsample audio
re-author using the video and new audio stream
But this takes a lot of time (and not very user friendly).
TMPGenc DVD Author seems to do this job automatically and that's what I am looking for. Will give a try.