Problems capturing at 640x480 with WinTVGo card

[therick]

Alright, I have tried to capture from my satellite reciever at 640x480 a few times and the same thing happens every time...at 2:00 EXACTLY I begin to drop frames like crazy...why would it work for 2 minutes and THEN start dropping frames? I have read that the WinTVGo card should be able to do 640x480...hell their software has the setting...so what is my problem?

I am using VirtualDub w/Huffy and my setup is...

Windows 2000
AMD Duron 950
512 MB RAM
OS drive: IBM 9 Gig ATA66
Capture Drive: IBM 60 Gig ATA100 (37 MB/sec write)

Any advice would be much appreciated...

[stanwebber]

do you know how to adjust the disk i/o cache in virtualdub? this setting is quite volatile and often the cause of massive frame drops no matter how fast your system is. i recommend an initial setting of 512k, 32 buffers, disable windows write buffer(if applicable under win2k). you will need to experiment from there to fine tune the settings for your hardware(too-large total cache-size is actually worse than too-small so dont go overboard). your system should easily be able to capture 640x480 /w compression

[therick]

hey stan the man...thanks for your help on both my posts. It is funny how they join...from your reply to my other question I need to get the capture in 640x480 so I can get my LDs to look the best that they can.

Where I am: I set the Disk I/O 512k and 32 chunks, and taaadaaa!...no more frame droppage! But now I can see weird lines in the AVI...480x480 did this too, but when I encode it to .mpg, they disappear...with 640x480 the lines DO NOT disappear. So what next? I tried moved the chunks up to 40, but I still get lines. Any ideas on what else could be wrong? I am sure that it is a VDub setting somewhere, but I just don't know....any help would be much appreciated...

[N0SoopForU]

Are you sure the lines you are referring to aren't interlacing artifacts? Anything captured at a vertical resolution >= 480 lines will usually be interlaced.

If the lines are present only scenes with motion, then your video is interlaced and you need to deinterlace it inorder to get rid of those lines...that is if your goal is to have a non-interlaced final video.

For more information, check out:

http://www.geocities.com/lukesvideo/interlacing.html


<font size=-1>[ This Message was edited by: N0SoopForU on 2001-11-07 18:02:24 ]</font>

[stanwebber]

where in the image do the lines appear and at what frequency? what is your final target resolution?

[therick]

Well, I would like to go down to 480x480(for SVCD)...and I don't think that the problem is interlacing...interlacing would be like every other line, right? This isn't every other line...but it DOES occur with motion...only I get any where from 2-4 lines to 10-12 lines(depending on the amount of motion). Also they do not stretch completely across the frame from left to right..just over about 1/3 of the frame, and they occur from the left side, right side, and in the middle...don't interlacing artifacts go all the way across? Man this is hard to explain...but it doesn't look like the interlacing artifacts pictures in that web page. Thanks for your help guys...

[therick]

Oh, and I am trying to capture from my LaserDisc player now...is that the problem? I should be able to cature it at 640x480...right?

The whole reason I am doing this is because I have read that capturing at a higher resolution (640x480) and resizing with VDub (to 480x480) produces better quality than simply capturing at the desired resolution (480x480) and

To NoSoup...I do want an interlaced final video because I want to go to SVCD...at least this is my understanding...I can capture at 480x480 and go to SVCD with no problem...but not at 640x480....

[stanwebber]

sorry, i got nothing. if capturing at your target resolution 480x480 solves the problem i'd go with that. laserdisc outputs an analog signal and the bt8x8 chipset samples the image full-frame before resizing so essentially it would be a contest between the brooktree chipset & virtualdub. the bt8x8 resizing algorithm is quite good on its own

[ember]

Therick -
tell me, do u live in UK/Europe and do you find that those stripy lines on capture are more prominent when the scene contains dark blue/mauve colours?

[Anonymous65]

If you have a strange motion artifact that is not interlacing artifact, then it might be that the fields are in wrong order. Swap the field order and try again.

[therick]

stan...thanks a bunch for all your help...480x480 is smaller on my 60 gig anyway

ember...no I am in the US(SC)...but now that you mention it...I am doing Return of the Jedi and the motion scenes on Endor DO NOT have as many lines as the final space battle scenes...have you had this problem? Do you know how to fix it?

skittlesen...do you mean the feild order in TMPGEnc? I oriinally had that set to B...but the .mpg was jumpy on my DVD player, so I switched to B (thanks to this site) and I had no more problems...I guess my question is do you mean the field order in TMPGEnc? Or is this a setting in VDub also?

Again guys thanks for the help...

[therick]

alright, I am a retard...I switched the field order from A to B...not from B to B...god I am dumb