Cybermail AV problem [@ 640x480]

[Vejita-sama]

I just got one, using Vitrual dub to capture. It works great at 352x240, but when I try to capture at ?x480 I get a message saying "can't caputure full screen interlace source, capture in preview mode or turn off overlay".

Set to 640x480, if I capture in preview mode I gets these 'horizontal lines' across the picture; same if I turn off overlay and capture.

Any ideas? The reviews/posts I read say people can capture at 720x480, so I'm not sure what I might be doing wrong. Running winME.

[TerryToonz]

Try the field swap option in the VirtualDub capture menu.

[WMike]

I've never been able to get the card to capture __ x 480, even with my 1.2 ghz Thunderbird and fast HD. My understanding is that the card wasn't rated to do that. Mind you, I haven't fooled with it too much to try and make it work, so maybe other folks have figured it out. I'll read other's experiences with interest.

Mike

[Anonymous65]

This card (or any BT8x8 chip) does not support overlay mode when capturing two fields (more than 240 vertical pixels). So, in Vdub, select Preview mode or turn off Overlay mode, and you can capture up to 640x480 if you PC can handle the stream.

[Cart Wheel]

Skittelsen is correct.

The horizonital lines are probably interlacing. Do they appear in areas with motion? Interlacing is an inherent part of most high resolution video.

It's also possible that the lines are the result of your your PCI bus not being fast enough for the capture card's buffer. If this is the case, you can try things like switching PCIU slots, removing other cards, dropping your display resolution/color depth, tweaking your BIOS, etc.

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

[Vejita-sama]

It's true that to capture I have to be in preview mode or turn off overlay. The thing is I set the resolution to 640x480 I see the lines (often with motion, they come off the moving object and go to the right edge of the screen) in the preview, and when I capture I capture them.

I've got a Tbird 1.2Ghz and WD 60GB 7200rpm/ATA100 HD so my system should be ok?!? Basically I capture what I see in the preview (as expected). Swapping field order has no noticable effect. Neither does capture with preview on or off (ie. capture with overlay and preview off).

[wingstar]

Try using Huffyuv2.1.1 or Picvideo codec. These codecs deinterlace while you capture at full resolution. It also reduce the AVI capture process load on your system so that you can achieve full resolution at full frame rate using slower system such as 433Mhz CPUs and 5400RPM drives. Only issue you will be dealing with is the file size limitation

[Cart Wheel]

Wingstar, neither Huffyuv nor PICVideo MJPEG deinterlace the video. The PICVideo codec does have an option for enhanced field separation, but that isn't related to actual deinterlacing. I agree with your other points though.

Vejita-sama, you're probabaly seeing interlacing artifacts. They are visible whenever you view interlaced video on a monitor. If you plan on outputting the video to TV, you can leave them in. If you want to watch the video on your computer, you should first try to inverse telecine the video and then deinterlace if that doesn't work.

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

[Vejita-sama]

Cart Wheel - so I shouldn't see the artifacts when if I encode the captured AVI -> MPEG1/2 and play it on my stand alone? Didn't think of that, I'll give it a try. I only want to make x(S)VCDs to play on my stand alone so I hope that's solves it, thanks.

[Cart Wheel]

It's always best to inverse telecine if possible. This reduces the number of frames by 20%, thus increasing the quality. However, you should only do this if your source video is telecined and your player supports 23.976 fps NTSC Film (x)(S)VCDs.

Unless your capture card really messed up the fields, theren't shouldn't be a problem when playing a truly interlaced (not telecined) (x)SVCD on your TV. Just remember to encode it as interlaced, and you may need to swap the field order setting if the resulting (x)SVCD looks very jerky.

If you're making a VCD from a truly interlaced source, you'll probably want to deinterlace to avoid ghosting/blurring. (VCDs only support one fields, so the lines you see would be blended together.)

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

[Vejita-sama]

Cartwheel thanks again, I'm going to try a few tests to see what I get. I'm capturing from a VHS source, which I'm told, is always interlaced (is that correct). My main computer is busy encoding MPEG2 files thou so I can't test anything until tomorrow

I'm at the point now that it makes sense to buy another computer JUST to enocde files on...

[Cart Wheel]

VHS is always interlaced, as is all standard video when played on a TV, but that doesn't necessarily mean that the video has interlacing. (You can display progressive video through an interlaced medium.) Of course, the vast majority of VHS tapes are going to be have interlacing, so you're probably correct in assuming that.

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