TMPGEnc plus skipping dropped frames

[balli]

This is my first post on Doom9. I've been a long time lurker and active AVS member, but this is the first time I've needed help with encoding.

Capping with VirtualVCR, 720 X 480 YUY2 29.97 FPS
Encoding with TMPGEnc Plus 2.5


I've been trying to cap and encode my family's old VHS cam-corder movies to put on DVD. I've had some success with it, but only when the tape is clean from beginning to end and produces no dropped frames.

The problem I'm having is when TMPG encounters a dropped frame, it just seems to skip right over and go to the next key frame. This results in the video playing rapidly whenever a section full of dropped frames is reached. Thus, the video gets ahead of the audio and the ever-looming sync problem comes up.

I've a workaround that works part of the time; I break up the capture .avi into clean parts and parts with dropped frames. When I encode a 10 second long clip full of dropped frames, TMPG seems to handle it alright and I get freeze-frames where there are dropped frames (which is what I want). But, sometimes this method results in drop-frame sections of video quickly repeating 2 or 3 times, which knocks it out of sync the other way (video gets behind the audio). Nonetheless, it's a PITA to do it this way.

So, what could I be doing wrong? I'm running absolutely no filters. I've looked through the settings a hundred times and can't see anything logically set wrong. Maybe something wrong in environmental setting? Is there a better way to go about this?
Thanks!

[Erik_Osterholm]

I think the obvious partial solution is to avoid dropping frames. What format are you capturing to, incidentally? Raw? HuffYUV? From your post, it looks like you may be capturing raw, and then the probably reason for dropped frames is that your disk isn't fast enough. Using HuffYUV should significantly reduce frame droppage.

You might mess with the VFAPI settings to increase or decrease various priorities to mess with that...searching for "dropped frames" in this forum yielded that as a potential fix, but the specific situation in that case was a capture to MPEG1. I don't know if changing to DirectShow or some other format will help.

Lastly, you might be able to play with Avisynth and get it to duplicate the dropped frames. If you can do this, then TMPGEnc wouldn't even know there was a frame dropped..it would only see a duplicate image and should encode that as normal.

[balli]

I'm capturing with HuffyUV. The cause of the dropped frames is bad cuts between scenes. My current workaround is to cap right up to the point of a bad cut, then skip past the 1 or 2 seconds of bad video and then begin capping again. This gives satisfactory results, but I've got a couple dozen tapes and this will be a hassle to have to babysit each capture.

When I open up a capture with vdub I can see that the dropped frames are actually duplicate frames. What I don't understand is why tmpg wants to skip over them. Is there a way to change their designation from drop frame to key frame using vdub or avisynth?

I'll mess with the VFAPI settings to see if I can make an improvement, although I don't know what I'm doing ;) .

I'll check out avisynth. I haven't messed with it much.