Processing Performance (Speed) in VirtualDub

[aggies11]

I'l try to make this as brief as possible

I am capturing 640x480 NTSC interlaced video at 29.97 fps, into huffyuv. My machine handles it fine (about 30-40% CPU usage, with no dropped frames).

When I try to deinterlace the capped avi in virtualdub (Area Based filter) I get a fps of about 5-10 (the processing is moving at less than realtime speeds). Further investigation in virtual dub shows that, any operation (even a no filter, plain "save") in "Full Processing Mode" gets me at best 10-15fps processing speed. Only direct stream copy mode gets me close to realtime (30fps) speed, but in that mode, I can't use any filters. The other two modes are in between (15-25fps).

So what I am wondering is: Are these results typical? (Ie. Should it be taking approximately 5-6 times realtime to perform the de-interlacing on video of this spec?

For reference: I'm running an AMD XP1700+, 256MB DDR-266, 40GB 7200rpm Seagate Drive, with a MSI Gf4-MX440-VTD (Phillips 7108E chip) to cap.

I can't try any filters while capturing, because virtualdub requires the use of RGB colourspace, and my card's WDM drivers only seem to support uyvy (no other options).

I was hoping to achieve close to real-time deinterlacing to minimize the amount of time spent processing. (I'm archiving a bunch of VHS tapes, with the hope of converting them to Divx files and SVCD's, so alot of processing is already necessary).

Thanks for your help

Aggies

[essexlad]

Err, it could be about right.

I have a 1.1 GHZ Athlon and when I run the Smart Deinterlacer I'm processing at about 6 or 7 frames a second !

[uxbridge]

the values you have are typical.
You could save time in using frameserver from Vdub though.
This will avoid you saving intermediate files.

Ciao

[SaSi]

Your results are typical. I am getting 12~15fps with a P4/2.67 machine with the source video on one drive and the new file on another - it helps a lot. I don't de-interlace, only lighter filters. Tried once the smart-de-interlace add-in filter for VDUB and it went along doing 5-8 fps.

I have noticed that VDUB goes faster under Win2K or XP if you modify the running priority to idle or anything lower than normal. It appears that in normal priority it's strugling for resources and the OS is not giving them away. Reducing priority usually gives me an extra 1~1.5fps extra speed, which for PAL is almost 6% increase !!!

An idea would be to use DSCALER. It's supposed to do capture and de-interlace. Haven't tried it myself, but hear friends tell me that they can capture and de-interlace in realtime. And de-scaler has a reputation for the best de-interlacing program, I'm told.

[aggies11]

Thanks for all the responses

It looks like I'l check out DSCALER, as my last hope, heh.

I made sure my computer was fast enough to handle capturing at 720x480 (slightly bigger than my target 640x480), and also fast enough to encode DivX at that resolution in realtime. Unfortunately I just assumed that deinterlacing would be less intense than the above *doh*.

For reference, what I need all this for is: I have a friend who has alot of old TV shows on VHS, that I have never seen. I always thought it'd be neat to have a copy of them for myself (he is very protective of his tapes, heh). With standard VHS dubbing, I could copy them as I watch. But then I found about vid capture, and storing the files on CD, which would be a ton more convenient (better quality then a 2nd gen tape, and alot less space!). So the goal was to be able to cap and encode them, largely as I watch em, Since I'm going to be watching them anyway. With realtime encoding, I'd be able to have a finished product, in 2x the length of the show. So there isn't too much deadtime.

Now with de-interlacing, it looks like it'l be taking 1x to cap, 5x to deinterlace, + 1x to encode. So each show will be taking 7x it's length, which is a whole lot of deadtime, and becomes alot less convenient than just vhs copying. My primary goal is just to have all this stuff watched, the archiving of it, is more of a bonus, if it's not too much hassle.

So hopefully DSCALER is the silver bullet I need!

Thanks for all your time

Aggies

[SaSi]

If what you want to do is capture VHS and convert to MPEG-1 for VCD, then there are simpler and faster ways to do that.

First, you don't need to de-interlace in a separate step. Any MPEG encoder will take interlaced AVI and convert to MPEG-1 which is progressive. So the de-interlace step is, in my opinion, redundant.

You can avoid the separate capture and encode steps by using some of the MPEG-1 capture USB blocks. The ones that capture in VCD format are fairly cheap now (<60$) and should be good enough for capturing old VHS tape.

The only thing you would need after capturing would be to trim the stream and remove extra material keeping the show/episode only. There are a few tools to do that (to MPEG-1 streams).

[Claire]

Concerning deinterlacing in VurtualDub, there is a good collection of filters at related site http://shelob.mordor.net/dgraft/other.html.

Also I recommend AlparySoft Denoise Filter for VirtualDub
http://www.alparysoft.com/prod/denoise-for-vd.phtml

AlparySoft Deinterlace Filter for VirtualDub
http://www.alparysoft.com/prod/deinterlace-for-vd.phtml