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ttestpers
16th September 2001, 18:19
Hi,

I'm a newbie when it comes to video capture.. and I have a fundamental problem with capuring video itself. Please help me out!

When I use the capture mode in VirtualDub (1.4.5) I get perfect quality when it is set to "Overlay" when I capture from my digital sat-receiver via composite (thru scart). (I'm merely viewing the tv content om my computer screen). However, as soon as I begin to capture the video to disk and then play it back the quality is horrible with washed out colors, few colors, higher brightness, small horizontal lines all over the screen reminding me of some kind of interlacing and strange (slower?) framerate.

Actually, when I'm not capturing to disk and merely watching the video input on my scree, I get the *exactly* same effect (degradation) on screen if I change "Overlay" to "Preview" from the video menu.

PS. I'm using Asus 8200 Deluxe on Win2000 Sp2, VirtualDub set to 720x480 in UYVY (whatever that is? can't change it anyway..) and compression set to "No recompression: UYVY". The PC is a 1333 MHz with 2 IBM 60GXP in striped mode.

PS.2. Since the Asus 8200 only has s-video in I had to use a scart->s-video adapter. But I don't think this should be the problem since I'm using composite anyway and it looks correct in the Overlay mode.

any help appreciated!
Robin
ttestpers@hotmail.com

lukesvideo
17th September 2001, 04:35
Try reading some older threads here that talk about ASUS's horrible Windows 2000 drivers and ways to work around them.

Also make sure you have the latest version of DirectX and the video capture updates. Try using Huffyuv instead of uncompressed video. Check to see if the same problem occurs at lower resolutions. Try reinstalling your display driver. See if the same thing happens when you using ASUS's capture software (assuming there is one).

-Cart
www.geocities.com/lukesvideo/index.html (http://www.geocities.com/lukesvideo/index.html)

ttestpers
17th September 2001, 13:43
Wow, this was it (huffyuv)! Can't believe it really..

So if I get it right, the card didn't capture in overlay mode, only displaying the video on my screen. Ok, but it still seems to me the capture drivers must be broken or something since the capture should be lossless (just like huffyuv). I mean, since the codec isn't doing the capture itself, the "No recompression" (codec) must be the broken part, right?

Anyway, The picture quality is ok now, my only problem is a *lot* of dropped frames, it looks like perhaps 15-16 fps on a 25 fps capture and it's very jumpy. It also seems lagged from the input by up to 1-2 seconds. I've tried capture at 50 fps as well and the result is the same (~15-16 fps).

PS. I forgot to mention last time that I'm using Asus 12.90 display drivers and NVidia WDM 1.04 capture drivers and that I'm capturing a PAL signal.

thanks a lot for helping me out,
Robin
ttestpers@hotmail.com

lukesvideo
18th September 2001, 12:40
"No recompression" doesn't use a codec, so the problem probably lies in the drivers or other software.

Don't increase the capture rate beyond 25 fps.
Have you tried capturing at a lower resolution like 384x288 to see if you get the same frame drops and audio desynchronization? Turning off the oeverlay/preview is also a good idea.

-Cart
www.geocities.com/lukesvideo/index.html (http://www.geocities.com/lukesvideo/index.html)

ttestpers
23rd September 2001, 20:26
thanks for the answers, really appreciate them!

The framrate problem is exactly the same as this this guy is having:

groups.google.com/groups?...%26meta%3D (http://groups.google.com/groups?hl=sv&threadm=Xns91123944F2C38Auerswalstudmailerun%4062.153.159.134&rnum=1&prev=/groups%3Fq%3Dvirtualdub%2B16.666%2Bfps%26hl%3Dsv%26meta%3D)

(paste it all into the browser).

/Robin
ttestpers@hotmail.com

lukesvideo
24th September 2001, 03:01
All I can say is that ASUS's driver appear to be terribly broken. Have you tried capturing with iuVCR or using alternate capture drivers (made by nVidia, I think)? Someone else had the same problem on my message boards, so if you go through the board on my site (probably the capture section), you may find some tips that I've forgotten.

-Cart
www.geocities.com/lukesvideo/index.html (http://www.geocities.com/lukesvideo/index.html)

anarco
1st February 2002, 00:36
but in case you still have the same problem, have you ever tried increasing the audio buffer in vdub ?
I noticed capturing without audio worked fine so I increased the audio buffer and everything worked out well...


anarco