About 24.3 fps out of VCR. Possible?

[StephLG]

Hi,

I'm experiencing a weird problem when trying to capture a recently duplicated SECAM VHS tape.
FYI, I capture at 720x576@25 fps and stereo 48KHz (for DVD authoring).

I tried to capture first with my DV500 card with its proprietary DV codec. I already did a lot of captures with it and had always obtained perfectly synchronized audio, no matter how long the capture was, due to the card's own audio+video management.
This time, with this particular tape, I have a huge synchronization problem, even after a few minutes. Audio is way late compared to video.

I then tried iuVCR, with HuffYUV codec and almost every synch option available. The result is still the same: out of synch after a few minutes, video ahead, with no dropped frame.

When captureing with iuVCR, I noticed that the detected video framerate was between 24.50 and 24.30, with a lot of variations. How is that possible?
I checked with other VHS tapes; captured about 10 minutes, with no dropped frame, perfectly synched audio, and a detected framerate of 25 fps!
So, the tape must be screwed up, right? When played on TV or even in the preview window of iuVCR, everything looks fine. Does it mean that the VCR which recorded the original tape has a problem?
Is there a way to force the framerate?

Edit:
Problem came indeed from the VCR in charge of the recording.
Thx for looking.

[cweb]

I think IMHO your PC might not be keeping up.

Try a faster huffy codec (a more recent compile) or the ffvfw one (choice of huffyuv, ffv1, mjpeg, mpeg1, etc etc). Search the forums for the main ffvfw thread and the link to athos' site where you can download it.

[TheJez]

Hi Steph,

Aparently this is caused during the recording of the tape. What might be a solution for you is capturing with VirtualDubSync. (Check google). This application measures the video frame rate and dynamically resamples the audio to match the video frame rate. Hopefully this will solve your problem.