DV Capture Smoothness

[zinga]

Am trying to capture DV via Firewire, but found something interesting/weird.
Have tried WinDV capturing as both type 1 and type 2 AVI, the video plays back a little jerky and blurry. Actually, the preview is like that too. Have tried using ffdshow decoder as well as whatever the other default DirectShow decoder happened to exist on my system (not sure what it is) as well as smplayer - get the same issue. (I don't think this is related to interlacing/deinterlacing)

In VirtualDub (1.9.7) Capture AVI, using the DirectShow capture device, the video preview looks quite smooth and nice (both with and without ffdshow). However, when I actually capture using VirtualDub, the played back AVI looks just as jerky as video captured with WinDV. I noticed that it's dumping as 25fps (note, this is a PAL camera) - just like WinDV, so I did try to up it to 50fps, however VirtualDub just seems to discard any framerate changes I make.

My guess is that VirtualDub is doing some sort of filtering, but I'm not sure. I did notice something interesting - when I pause the playback on the camera, the video preview in VirtualDub is a still image which shakes, whereas in WinDV, it's a still image.

Basically, I'd like to capture the video like the VirtualDub video preview. Does anyone know how, or why all of this is the case?

Many thanks in advance!

[Ghitulescu]

Important is that the AVIs are OK ;)

[GrofLuigi]

(I don't think this is related to interlacing/deinterlacing)
I do. :devil:

I suspect this is due to various mode(s) of presentation of the interlaced material to your screen (I can't think of a better word now). Like bob, weave or drop field...

The most important things to consider are: type of your monitor (CRT, LCD), settings of your video card driver related to video playback AND of course, of your video player/renderer.

As there are many variables to consider, maybe you can try playing with those settings, but for now, as a small experiment, could you try these things:

Virtual Dub:
in capture mode - [menu] Video - Preview Acceleration
in normal mode - [menu] Options - Preview Field Mode

and, If you have VideoLan (VLC Player), play the .avi and in [menu] Video - Deinterlace

Try all the methods listed in these places and tell us which of these options match what you like/don't like (does any one achieve the "smoothness" you desire?).

GL

[zinga]

Actually, thanks a lot for mentioning that GrofLuigi - I thought interlacing would mostly give a "sawtooth" effect, but it seems a bit different.
I fiddled with the deinterlace filter in ffdshow and found that Yadif with "Double Framerate" ticked gives the same effect as the VirtualDub preview, though other deinterlacers don't seem to be able to replicate this effect (why I didn't think interlacing was the issue). BTW, this is watching the captured type 1 AVI (so at least, I know that I'm not losing information by capturing this way)

(originally did try those VDub settings, only showing first or second fields but the preview still looked smooth)

Thanks again for your help! :)

[GrofLuigi]

My pleasure. :)

I noticed that "effect" sometimes, and I wish I could offer you some more technical (or definitive) explanation, but I can't...

And BTW, I like Yadif X 2 the best too. :cool:

(edit: maybe it's the obvious - the double framerate, and we're sensitive to it...)

GL