Missing audio when converting AVI to MPEG and playing in DVD player

[sydneydawg]

I am experiencing a strange problem that I hope some of the experienced DVD creators have solved.

I have old S-VHS tapes that I have captured with my DV camcorder (a JVC camcorder). I then downloaded the files to the computer, MPEG compressed them, and then authored a DVD.

When I play the DVD in the computer - audio is fine, video is fine, everything is great
When I play the DVD on my DVD player - no audio. Video is fine - but audio is missing.

HOWEVER
- this problem is specific to only some captured tapes - on one tape that I captured, everything works fine. On another tape that I captured, the audio is missing when played in the DVD player
- I have re-captured (from Analog -> DV - > computer) and experienced the same problem.
- For scenes that were taken directly with the DV camera - no problems.

I have tried the following:
(a). MPEG compressed using various software (Nero, Ulead, FFMPEG) - same problem on same clips
(b). Authored the DVDs using various software (Nero, Ulead, freeware packages) - same problem on same clips
(c). Tried using various audio compression, AC-3, LPCM, MPEG-2 audio. Same problem for all audio compression types,.

Also, everything works just fine when using a clips sourced directly from the DV camera (eg, it only manifests on occasions when there is an analog - digital conversion to the DV campera, and then only on some tapes).

All the tests lead me to believe that there is something in the DV-AVI file that is causing problems for the MPEG compressed stream. The thing that drives me crazy is that audio works fine when it plays in my computer DVD player and it only is manifested when played on my ordinary DVD player.

Any suggestions would be most worthwhile because I am stumped.

Regards,
Michael

[sydneydawg]

Problem solved!

When I have struggled with a problem such as this and gotten nowhere, I finally decide to consult my engineering friends at work. We meet for lunch and have a problems solving exercise.

It took only 20 minutes of discussion before we were able to deduce the problem - mostly because of the tests that I had already done.

Problem was simple:
My S-VHS camcorder is mono. The DV camcorder is stereo. The connections allow only one channel, and the DV camcorder did not copy the one channel to both channels. When playing through the software DVD player on my computer, it obviously has a threshold to determine when the signal is mono, and then copies the result to both speakers. The connection between my DVD player and TV is mono. However, it was connected with the silent channel! When I came home, I switched the left and right to the TV - and everything worked fine.

Solution:
(a). Find software that copies the audio to both channels
(b). Recaptured from S-VHS to the DV camcorder with the DV camcorder set as mono rather than stereo.

-Michael