VFW - WDM & WinTV - What's the difference?

[TMcD]

I have a WinTV (stereo) card shipping with CD version 4.8 (should be the same software (latest) as found on their site.)

It installs VFW drivers, but from what I understand VFW is an old way to go about things. WFM is the "new" way.

What is the difference between VFW and WDM?

Any reason why one would be better than the other for certain applications. (My main goal is to record TV shows.)

Thanks,
Troy

[stanwebber]

the vfw(video for windows) architecture has known unresolved bugs & is being phased out by directshow, but the real issue is compatibility with 3rd party applications. wdm(windows driver model) still has yet to gain widespread acceptance, but this is likely to change soon with the release of xp(win2k/xp are directshow only)

[TMcD]

Thanks.

I thought it was just me, but it looks like, not too much supporting WDM.

As for XP, I'm sticking with Win98SE until XP has the bugs worked out of it, not to mention companies getting drivers for use with XP.

Thanks,
Troy

[Geek Funk]

Hauppauge has VFW drivers and WDM drivers for WinTV PCI cards although they warn about the risks of using WDM drivers.

I suspect that at one time the WinTV capture cards were all VFW devices. Some on the store shelves still use VFW.

I've been trying with the latest drivers, VFW and WDM. It seems that the drivers work best for the cards they were designed for.

I have a WinTV Go card, and WDM drivers work OK. The VFW drivers seem to work better.

With respect to potential conflicts between video devices, I've noticed that some USB web cameras use VFW and others use WDM, and the kinds that uses WDM have problems working on the same system that has a VFW based video capture card.

[Geek Funk]

OH, I forgot to say that you can't capture video with the WinTV Go card if you use the WDM drivers.

[TMcD]

Thanks.

I am getting better file sizes. Just what I was looking for.

There is one more problem to remove.. Maybe you'll have an idea.

I use VirtualDUB to capture from the TV tuner, but I when view the video, it looks like the video was recorded in preview mode. I mean the scan lines are sort of seen, especially around certain parts where there is movement, such as a hand gesture.

I have tried the VirtualDUB de-interlace filter (while recording), but that didn't help at all. ??

Thanks,
Troy

[stanwebber]

sounds perfectly normal to me. video is field-based(60hz/50hz = 60/50fields per sec = 30/25frames per sec); however, your pc video system is frame-based. essentially, what you are seeing is every other scanline perpetually shifted 1/60th(ntsc) of a sec ahead in time or a telecine pattern of 2bad frames for every 3. whether or not you should deinterlace depends on your source and target medium

<font size=-1>[ This Message was edited by: stanwebber on 2001-11-14 05:07:15 ]</font>

[markm]

WinTV cards capture with the field order backwards. Virtual Dub has a setting to swap the fields during capture, and Huffy and PicVideo codecs both support swapping fields on playback. The will make a noticable difference, but the effect will likely still be there, since as was pointed out, it's supposed to be.

[jvilhauer]

Once you've captured to the avi file, exit capture mode, re-open the avi file, and THEN apply the deinterlace filter. You'll see the filter effect in the right pane. There are a number of deinterlace filters out there, and some do a great job. I'm not sure about this, but I don't believe the filters have any effect during capture, and if they did, it would seem that they would chew up CPU time, causing dropped frames, etc.