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  1. Just wanted to get a feel for the best VirtualDub sync settings. Looking over the rev. notes, it seems many of the options/features were designed with hardware limitations of the time in mind, but I am wondering if it is just better not to let VirtualDub resync anything at all.

    What are your thoughts?
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  2. It is certainly better, if your hardware will do it without needing frames dropped/inserted to keep the video synched to audio.
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  3. Allow me to rephrase the question for clarity:

    If I have good hardware, will it actually hurt the capture to leave sync settings on rather than turn them all off? I just tested with all sync settings off and the tape was still in sync at the end. Would this mean there is no need for correction?
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  4. Member
    Join Date: Mar 2008
    Location: United States
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    Some of the sync settings apply more to scenarios where the audio is captured through a different
    input (eg. the soundcard) Vs. the video+audio going through the same capture device.
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  5. I am using a Diamond VC500 with an AVT 8710, which I have so far had decent results. I did some research, and while I can't tell whether the VC500 has integrated sync, I have tested both with sync audio to video and turning off all settings. I haven't had any noticeable sync issues with either.

    I realize that a part of the sync correction is frame timing due to the variable rate of VHS, but I am concerned that it will either retime a correct stream or not retime an incorrect stream.

    What settings should I be going for?
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  6. It's possible leaving the sync settings on can hurt the capture; otherwise the author wouldn't have bothered to include the option of disabling resync when integrated AV is detected. (The VC500 is integrated: video and audio are both captured by it.)

    Originally Posted by premiumcapture View Post
    I realize that a part of the sync correction is frame timing due to the variable rate of VHS
    Err..?
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  7. Just trying to figure out which is best, though I haven't really had any issues with any of the settings. One thing I picked up on was something called 'relative latency.' The rating for my last capture was 47ms, and I wasn't sure if the audio is delayed by that much or its just processing time. The integrated setting I get, but is it safe to assume that the capture is in sync because I am capturing through the same device?

    Originally Posted by vaporeon800 View Post
    Err..?
    VHS has a variable frame rate, it is not a perfect 29.97 stream.
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  8. Member
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    This is how I set mine up, using in Avermedia PCIe capture card.
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  9. My settings are quite different (also using an AVerMedia PCIe card among others).

    Click image for larger version

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    I would check the "Automatically disable" box, but I already have it manually disabled anyway and I'm apparently superstitious about messing with it when it seems to be working. I don't have any justification for setting latency to Fixed. Actually the more I look at it the more that looks wrong, but I played around with it 2 years ago and it isn't creating noticeable problems.

    I found that when I unchecked the first two boxes, VDub would never drop/insert even when it was absolutely necessary to maintain sync (like if I decide to try capturing 720p60 with a slow x264vfw preset and my CPU is completely unable to compress the frames on time). The video track would just end up short.

    Originally Posted by premiumcapture View Post
    The integrated setting I get, but is it safe to assume that the capture is in sync because I am capturing through the same device?
    Sadly, no.

    Originally Posted by premiumcapture View Post
    VHS has a variable frame rate, it is not a perfect 29.97 stream.
    Can you point me to a source for this? Google Books isn't finding anything.
    Last edited by vaporeon800; 8th Aug 2014 at 01:36.
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  10. Interesting, especially considering its the same piece of equipment! I tried capturing a terrible EP tape today with no sync and the result was hilarious. Sync is not bad!

    As far as the VFR - I mixed up my terminology.
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  11. Member
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    Location: United States
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    Perhaps there is something inherently less stable about capturing through USB Vs. PCIe (just speculation).
    Have you tried capturing with alternate software? Perhaps iuVCR would work.

    A while back I captured a childrens tape that had a section which had been damaged by my daughter when she was very young.
    Using a cheap Sony VCR and no TBC, the machine kept playing and the computer kept capturing. When I played
    back the file, the thing was perfectly in sync even though at one point the picture almost disappears because
    of the damage. I was either using STOIK or iuVCR at the time.

    I'll post a clip if I can find it. Here's the clip of some children singing, despite the massive tape damage,
    the clip synced right back up:
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    Last edited by davexnet; 8th Aug 2014 at 12:44.
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