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I am using VirtualDub 1.10.4 to capture audio and video from video-only DirectShow device:

[dshow @ 0000018baeadb920] DirectShow video device options (from video devices)
[dshow @ 0000018baeadb920]  Pin "Video YUV Out" (alternative pin name "2")
[dshow @ 0000018baeadb920]   pixel_format=uyvy422  min s=160x120 fps=25 max s=720x576 fps=25
[dshow @ 0000018baeadb920]   pixel_format=uyvy422  min s=160x120 fps=29.97 max s=720x486 fps=29.97
[dshow @ 0000018baeadb920]   pixel_format=uyvy422  min s=160x120 fps=29.97 max s=720x480 fps=29.97
[dshow @ 0000018baeadb920]  Pin "Audio PCM Out" (alternative pin name "3")
[dshow @ 0000018baeadb920] Crossbar Switching Information for ezcap Video Grabber:
[dshow @ 0000018baeadb920]   Crossbar Output pin 0: "Video Decoder" related output pin: 1 current input pin: 1 compatible input pins: 1 2
[dshow @ 0000018baeadb920]   Crossbar Output pin 1: "Audio Decoder" related output pin: 0 current input pin: 5 compatible input pins: 5
[dshow @ 0000018baeadb920]   Crossbar Input pin 0 - "Video Tuner" related input pin: 4
[dshow @ 0000018baeadb920]   Crossbar Input pin 1 - "Video Composite" related input pin: 5
[dshow @ 0000018baeadb920]   Crossbar Input pin 2 - "S-Video" related input pin: 5
[dshow @ 0000018baeadb920]   Crossbar Input pin 3 - "Video YRYBY" related input pin: 5
[dshow @ 0000018baeadb920]   Crossbar Input pin 4 - "Audio Tuner" related input pin: 0
[dshow @ 0000018baeadb920]   Crossbar Input pin 5 - "Audio Line" related input pin: 1

For some reason, when I start capture I get a black screen for 2 seconds, then for another roughly 2 seconds it kind of blinks and only then the capture starts. All the while audio is playing and being captured. This results in video being delayed by 4 seconds roughly.

Now a few things to note:

  • If I only preview audio and video w/o capturing it both audio and video in VD are synchronized.
  • If I am capturing audio and video and displaying both video and have audio playback enabled, then again audio and video are in sync in VD but NOT in sync in the avi generated.
  • I tried it with all kinds of options: video - overlay and no display; audio - with playback and without; tried all kinds of timing settings and all combinations of them; tried running with admin mode; tried capturing both audio and video in raw uncompressed format; tried increasing buffer sizes. All made no difference!

Now, I think this delay is somewhat random and not necessarily exactly 4 seconds, 4 seconds is the average. Hence I do not want to fiddle with post-processing and remuxing to manually correct for that. I have about 100 VHS to capture and do not want to go manually through each one.

Why am I not using other video capture tools? Because either they do not work (ffmpeg does not let me capture audio with this setup - see this, or they have other issues (not related to a/v sync)).

And finally: I did verify through different independent means that the issue is not with the VCR or the USB capture device or the VHS itself. It really is a software-related issue. I could capture it just fine with video and audio in sync using ArcSoft ShowBiz for example, but am not using it because it has other issues.

So, what am I missing in VD setup so that it causes this video delay (or equivalently premature audio capture)?

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I had the same problem while setting up my vdub. As soon as i disabled video compression the recordings started with video and audio at the same time.

Previous to this I had been playing with the timing options and as it stands: first 2 tick boxes are off radio button set to Do not resync next 2 tick boxes off audio latency set to Fixed and 300 - no idea why it works but when i changed it it stopped working use audio timestamp on disable timestamp for preview off force audio check on ignore video timstamps off no idea if they will work for you but just FYI on my settings

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