Problems with VHS to Huffyuv Codec Capturing

[SteveSH]

Hi,

I've been recently trying to convert my old vhs tapes to vcd with vdub and huffyuv but i'm getting a odd frame problem. It's hard to explain but while i'm watching the movie on vdub it's recording fine but when i play it back every now and then i'll see a frame flash really quickly of something that was played a few seconds ago. This only happens in certain parts of the video and the problem is worse in some areas than others. I'm only dropping like 2 or 3 frames every few 1000 and this has never happened before when i have captured from cable. Please keep in mind that this tape is home recorded and around 6 years old. Also, this problem occurs in PICVideo MJPEG but it doesn't happen nearly as often. Does anyone have a solution to this problem?

-SteveSH

[stanwebber]

huffyuv is not an efficient playback codec. unless your system is exceedingly fast, you will run into playback glitches. go over the affected area frame by frame in virtualdub to check if the problem does in fact exist. btw, your soundcard is a dog: 3 dropped frames per 1000 is way too many. actually 1 per 1000 is too many for that matter, but i still tell people it is acceptible

[SteveSH]

I just looked at it frame by frame and i can see it in the avi itself. I don't know if it's something i have set up wrong or if the problem is with the tape. It also is still there when converted to MPEG so i'm pretty sure its actually in the avi file.

[Torontonian]

What capturing card are you using now? ATI AIW?
Looks like your card wrongly detects some kind of macrovision protection on your tape (I've heard about alike problem for ATI cards using ATI chipset while capturing from old VHS tapes).
But if your card is bt8x8 based ... I'm giving in.

[SteveSH]

Well, it's WinTV PCI , so i guess your lost then.

[Shabubu]

I have this problem with tapes off a VHS Camcorder, the tapes were recorded in long play. But I lose at least 60% of the frames, it looks like the fields are all screwed up, with fields from a second ago blended with fields from the current time. It's really freaky. Yes, ALL other VHS sources cap fine, just this long play camcorder tapes.

[SteveSH]

The VHS data was originally on an old Video 8 or Supper 8 camcorder. Was there anything you could do about it, or is there a different setting i can use to combat this?

[SteveSH]

oh jeez typo, but has anyone found a way to fix this problem, i'm guessing someone could make a filter which would throw out the bad frame or something similar to that.

[mpack]

If I was asked to guess, I'd say that your capture card (actually the driver) has a pool of buffers which it uses round-robin style during the capture. If a frame glitches (ie. doesn't see frame start signal) due to a poor quality signal then it doesn't returns the buffer contents unmodified. However, higher levels in the driver don't notice this and merge the captured field into the current frame. Wild guess, like I said.

I can't think of any real cure, but IMHO the flaw would be less obvious if you just repeated the preceding good frame or field, or just delete the frame (including the audio).

Does VDub allow cut/paste of frame contents? It's something I've never tried.

[Shabubu]

The problem is that the capture card can't even handle the bad frames, and so drops a stupidly high number. Again as I said this only happens with an old video-8 cam tape. All others are fine. Deleting frames is an unrealistic solution (50%+ drops....)