Cap ok, but VDub plays clip out of synch; other players ok

[jlietz]

I am capturing some home movies using ATI MMC 9.02 and a TBC-1000. When viewing the raw footage with Windows Media Player or ATI's File Player (after capturing) the audio and video are in synch, as would be expected when using a TBC. However, if I view the video in VirtualDub they are about 1 sec out of synch. Too bad I didn't notice until I had already used VirtualDub to edit 4 tapes! Has anyone experienced this? And do you know what could be causing this? I want to repeat that all other players I have tried do not exhibit this behavior.
I have also used Vdub in the past without incident. The only difference now is that I'm using a TBC, but that really shouldn't matter should it?
Thanks.

[Tommyknocker]

All the time. VDub is not a great player, just a great dubbing/editing program.

[jlietz]

All the time. VDub is not a great player, just a great dubbing/editing program.

But it's editing out of synch too. The edited video exhibits the same problem.

[Tommyknocker]

Check the audio=>Interleaving function and make sure no values are in the Delay audio track box.

[jlietz]

It says 0 ms. But under "Audio block placement" it says "Preload 500 ms of audio before video starts"

[Tommyknocker]

When you convert, do you use Full processing or Direct Stream copy

[jlietz]

I always use Direct Stream Copy on both video and audio.

[Steen4]

Try opening the file in question in virtualdub, then go to File > File Information. Check the audio length and the video length: are they the same? If not, this is the root of your problem; many video applications capture slightly differing durations of audio and video. Appending more slightly mismatched files or video segments only compounds the problem. Here is a workaround that I use: Open the file in virtualdub, then step through the timeline until you arrive at the first frame you intend to keep (you did start your capture a few seconds before the start of your target program, right?). Hit <HOME>. Next, step backwards from the end of your file until you arrive at the final frame you intend to keep. Hit <END>. Go to the Audio menu pulldown and select "Direct Stream," then go to the Video pulldown and do the same. All that's left is to go to file and click on "Save AVI." The resulting file should be no more trouble. You can discard the older version of the file. Let us know how it goes.

[jlietz]

Try opening the file in question in virtualdub, then go to File > File Information. Check the audio length and the video length: are they the same? If not, this is the root of your problem; many video applications capture slightly differing durations of audio and video. Appending more slightly mismatched files or video segments only compounds the problem.

Well, I think you're on to something there. After checking all 15 or so clips, the audio length is shorter than the video length by about .50 sec. However, this doesn't seem to be affecting other players. Is it possible that Vdub is misreporting the information?

Here is a workaround that I use: Open the file in virtualdub, then step through the timeline until you arrive at the first frame you intend to keep (you did start your capture a few seconds before the start of your target program, right?). Hit <HOME>. Next, step backwards from the end of your file until you arrive at the final frame you intend to keep. Hit <END>. Go to the Audio menu pulldown and select "Direct Stream," then go to the Video pulldown and do the same. All that's left is to go to file and click on "Save AVI." The resulting file should be no more trouble. You can discard the older version of the file. Let us know how it goes.

This the exact process I use to edit clips is Vdub (is there any other way???) The clips are still out of synch after the edit.

[jlietz]

Ok, I did some tests with various hardware and software configurations.

When I capture with ATI MMC 9.02 the audio and video lengths differ anywhere from .46 to .48 seconds. The audio time is shorter so I hear the sound before the mouth moves. This happens whether I play the tape (VHS-C) on the orignal camcorder, or on my JVC HR-S9911U, or on my HR-S9911U in conjunction with the TBC-1000.
When I capture with VDUB using the HR-S9911U the difference is down to .04 seconds (not noticeable in the video) except now the video length is shorter. When I turn on the TBC-1000 the difference is .01 seconds.
So, it looks like for some reason ATI MMC 9.02 (I tested with 9.03 too) is not synching the audio and video, even though the signal should be in perect synch when it arrives at the capture card due to the TBC-1000. My capture card is the Radeon All-in-Wonder 9600. One would think those two would play nice with each other. Any thoughts (other than chuck MMC and use Vdub to capture )?

[Steen4]

What exactly do you mean by,"when I turn on the TBC-1000"? Are you saying that your video is routed through the TBC-1000, but you're still able to capture with it off (which is impossible)? Or am I merely misinterpreting your last post? Also, do you route your audio directly to the sound card/capture device, or does it also pass through the tbc? Routing both audio AND video through the device is critical in keeping the relative timing of the streams. I'm not all that familiar with the ATI capture software. Does it have a dynamic resampling feature to keep the streams synched up? Do you have the capture sync enabled in VirtualDub? In capture mode, go to Capture > Timing, and make sure the "Adjust Video Clock Dynamically..." box is checked. Personally, I'd rather have the audio resampled dynamically, the way VirtualDubSync and Virtual VCR do it, since there is less chance of getting dropped frames, but whatever works...

[jlietz]

What exactly do you mean by,"when I turn on the TBC-1000"? Are you saying that your video is routed through the TBC-1000, but you're still able to capture with it off (which is impossible)? Or am I merely misinterpreting your last post?

"When I turn on the TBC-1000" was short for "When I route the signal through the TBC instead of bypassing it by making a direct connection between my player and my capture device..."
Funny side note - the first time I hooked up my TBC I spent 10 minutes connecting and reconnecting the wiring because I couldn't get a signal. Turns out you must power it on first

Also, do you route your audio directly to the sound card/capture device, or does it also pass through the tbc?

It passes through the TBC.

Do you have the capture sync enabled in VirtualDub? In capture mode, go to Capture > Timing, and make sure the "Adjust Video Clock Dynamically..." box is checked.

It is checked.

I talked with LordSmurf (over at digitalfaq.com) and he is suggesting that I do a few more tests (try a different codec, etc...). I'll let you guys know if I come up with anything. Thanks for the help so far.