Problems capturing analog to DV AVI

[waldi]

I get a statter effect when I capture using my ATI Radeon 9800 AIW card from the TV tuner or from VHS into DV AVI. This only happens to fast moving objects which creates a sort of a "stair" effect. Slow motion picture is captured OK.

What is weird is that I can capture the same thing in AVI native format (much bigger file 1GB per minute) using the Mainconcept or Adobe with the Mainconcept plug-in, and I have no problem. Capturing straight to MPEG-2 is fine as well.

Why there is a problem with capturing into DV AVI, but there is no problem with capturing into native or other compression formats?

I've tried MS DV codes, Mainconcept DV codec, Panasonic DV codec, and it's the same thing. I'm starting to believe that it must be my ATI card, but this does not explain why native and mpeg capture is OK.

My PC is brand new. Asus P4C800, P4 3.2E, 2 10K Raptor SATA drives running in RAID0 with Win XP on it, capturing into 2 separate 10K SCSI drives running software RAID 0 as well. I get sustained transfer/read/write rates well above 100MB/sec.

You can see from my system setup why this bothers me so much.

Please Help! Thanks!

[Ron B]

Hello-I capture from analog to AVI with my ATI AIW 9800Pro as well. Perhaps the effect you are seeing is the result of an interlaced signal on a computer monitor. You should not notice it on a TV screen. The AVI format does suck up the HD space.

[waldi]

Thanks for the reply.

Do you capture to DV AVI though? or to Native raw AVI? If you haven't tried capturing into DV AVI, could you please try it and let me know if you have a problem or not.

This whole thing still confuses me since other formats playback with no problems. I want to capture to DV AVI because this is the best format for editting.

I've tried to compress DV AVI to MPEG-2 afterwards, but the "stair" effect doesn't seem to go away. Compressing straight to MPEG-2 has no issues.

This is so annoying!!!!!!!!!!!!

I could capture as RAW (native) and then compress to MPEG-2 (that works as well), but I would need about 70 GB to capture 1 hour tape.

So you don't think this is a video card problem?

I've also tried to use my DV camcorder and capture to DV AVI using passthrough and that works OK as well. That's why I'm suspecting that my ATI Radeon 9800 AIW maybe at fault.

Even though I found a way around to do it, I would like to know what the problem is.

Thanks for your help!

[BSR]

Regarding the playback, if you don't see lines(stair step) with interlaced footage on your computer monitor, then that means that what ever program you are using to view the video is doing the deinterlacing on the fly for viewing purposes.

I think the only way your going to feel better, is to burn a DVD of your video captures and play them on your TV. I think they will look fine, but you should test.

I've also tried to use my DV camcorder and capture to DV AVI using passthrough and that works OK as well. That's why I'm suspecting that my ATI Radeon 9800 AIW maybe at fault.

I use a DV cam with passthrough to capture video, and depending on which program I use to view, depends on if I see interlaced lines or not. Virtualdubmod shows me the interlaced lines.

[erratic]

I've also tried to use my DV camcorder and capture to DV AVI using passthrough and that works OK as well. That's why I'm suspecting that my ATI Radeon 9800 AIW maybe at fault.

Video captured with an ATI Radeon card is upper field first. DV should be lower field first, so you're asking for field order problems.

Better codecs for upper field first video: PICVideo MJPEG and Huffyuv.

When you use your camcorder's passthrough the resulting avi files are lower field first, so that's fine, but you shouldn't use a DV codec with an ATI Radeon card.

If you still want to use a DV codec with your Radeon card you should realize that your DV files will be upper field first and you will have to convert them to mpeg-2 as upper field first, but most video editing software will assume your DV files are lower field first, so you're still asking for field order probems when editing the video.

[FulciLives]

Are computers fast enough to capture analog video as DV AVI when using a non-hardware method?

I thought that was hard to do (if not impossible) unless it was hardware enabled (i.e., Canopus ADVC-100 or DataVideo DAC-100 etc.)

- John "FulciLives" Coleman

[BSR]

I have toyed with capturing DV through my leadtek card at half D1 resolution, it worked.
Full D1, if I remember correctly, gave me dropped frames.
It's been awhile since I toyed with that. I only use my passthrough on the DVcam for DV, no dropped frames.

FulciLives:Now theres a familiar face I haven't seen in a while, the convolution3D man. Welcome back, I enjoyed reading your posts.

[bugster]

Are computers fast enough to capture analog video as DV AVI when using a non-hardware method?

I have not tried it but would have thought the CPU processing requirement for DV capture was less than for on-the-fly mpeg compression which many people do. Though the output files are bigger so maybe disk IO is the bottleneck here (~25Mbs I think)