Troubleshoot vdub captured audio glitch

[cybertheque]

Greetings,

I have an audio glitch that needs a resolution before I begin doing production captures;
about thirty-four minutes into a huffyuv avi analog capture (1hr 34min 42sec) done by
virtualdub 1.8.6 (s-vhs source deck -> tbc -> btwincap -> vdub 1.8.6) the audio
suddenly drops pitch, sits in the basement for a few seconds, rapidly increases pitch
overshooting the original rate by a large amount and gradually drops pitch to
regain sync over about 3000 frames. An mp3 of this segment of audio is here:

http://www.cybertheque.org/video/video-debug/farpoint-badaudio.mp3

I can make the original avi clip of this region available for analysis, as well as
a wav file of the audio and an mpg of the clip. There were no errors in log files
or realtime reporting during the capture; processing of this region also reveals
no errors. No frames were dropped during capture and no sync errors were
reported. I am reluctant to trust the system until I understand the possible
failure modes here.

All speculation, recommendations for tests, analysis proposals, etc. much appreciated.

Michael

[M Bruner]

And what happens when you try to capture the audio only?

[cybertheque]

Issue is currently under analysis and discussion on the Virtualdub.org forum

Michael