Capturing VGA or DVI signals with a PCI card

[Acanthus]

Hi guys, im looking for an add in card (or external device, whatever) that can capture a VGA or DVI signal at 1024x768 (optimally 1600x1200). It must be able to save the signal in a format i can manipulate (no proprietary stuff) and it must be able to maintain at least 30fps.

Is there a product that does this?

 

[imported_kouch]

don't know about an external card, but you can easily do this in software. Check out FRAPS.

 

[Matthias99]

FRAPS will capture on the system you run it on -- but no, there are no (consumer-level) cards that can capture from these formats. Hardware capable of decoding and capturing VGA and DVI signals costs a *lot* of money.

 

[Acanthus]

Fraps will also drop 80% of my performance.

Going professional is not an issue, ive found some hardware designed to do this, but most of it is limited to 10fps and low resolutions, as well as being ancient so im sure driver support is terrible.

 

[Peter]

Sure DVI full-resolution grabbers exist. Every single TFT monitor out there does exactly this.

It's more of a Then-What question. What exactly are you going to do with a (roundabout) 150 MByte per second data stream?

 

[Acanthus]

Originally posted by: Peter
Sure DVI full-resolution grabbers exist. Every single TFT monitor out there does exactly this.

It's more of a Then-What question. What exactly are you going to do with a (roundabout) 150 MByte per second data stream?

Save it to a raid array, then edit, compress, etc.

 

[Matthias99]

I can't find anything for a PC that would let you grab DVI and turn it into a digital format the PC could use. Certainly it wouldn't fit on the PCI bus (133MBps) -- at 1600x1200 30FPS you're talking ~1600x1200*24*30 / 3 ~= 500MBps of data. Even at 1024x768 you'd be pushing over 200MBps. PCI-X could do it, maybe, but there don't seem to be any products available. DVI is only an "output" format; professional equipment (other than monitors) doesn't really handle it, because you'd never use it for connecting editing equipment.

Best it seems you could do right now would be to get an ATI card with a VGA->component adapter (or get an external transcoder), then go component->HD-SDI (via another transcoder), then get a professional-level HD-SDI capture card. Not cheap, though, and you're still only talking 1080i/p or 720p.

There seem to be VGA capture devices out there, but I'm having a tougher time finding solid information on them.

 

[Acanthus]

Originally posted by: Matthias99
I can't find anything for a PC that would let you grab DVI and turn it into a digital format the PC could use. Certainly it wouldn't fit on the PCI bus (133MBps) -- at 1600x1200 30FPS you're talking ~1600x1200*24*30 / 3 ~= 500MBps of data. Even at 1024x768 you'd be pushing over 200MBps. PCI-X could do it, maybe, but there don't seem to be any products available. DVI is only an "output" format; professional equipment (other than monitors) doesn't really handle it, because you'd never use it for connecting editing equipment.

Best it seems you could do right now would be to get an ATI card with a VGA->component adapter (or get an external transcoder), then go component->HD-SDI (via another transcoder), then get a professional-level HD-SDI capture card. Not cheap, though, and you're still only talking 1080i/p or 720p.

There seem to be VGA capture devices out there, but I'm having a tougher time finding solid information on them.

I was thinking a hardware card would do some kind of compression to reduce the insane sequential write speeds it would take.

The final resolution im looking for is 640x480 for the video im attempting to capture.

(and again, fraps sucks for this)

 

[Matthias99]

Originally posted by: Acanthus
I was thinking a hardware card would do some kind of compression to reduce the insane sequential write speeds it would take.

SDI capture is uncompressed (it has to be; it's for video production). Keeping up with 100+MBps video streams is up to the system; it's doable with a RAID array or a SAN/NAS solution.

The final resolution im looking for is 640x480 for the video im attempting to capture.

In that case, you might as well just use a good analog capture card from a TV-out mirroring the display. Downsampling to 640x480 is going to destroy any benefits of doing a high-res digital capture anyway.

 

[Acanthus]

Originally posted by: Matthias99

Originally posted by: Acanthus
I was thinking a hardware card would do some kind of compression to reduce the insane sequential write speeds it would take.

SDI capture is uncompressed (it has to be; it's for video production). Keeping up with 100+MBps video streams is up to the system; it's doable with a RAID array or a SAN/NAS solution.

The final resolution im looking for is 640x480 for the video im attempting to capture.

In that case, you might as well just use a good analog capture card from a TV-out mirroring the display. Downsampling to 640x480 is going to destroy any benefits of doing a high-res digital capture anyway.

I agree, but TVout from every production card ive tried from AIW to NV solutions has looked washed out and terrible.

 

[kki000]

you cannot capture dvi, its like feeding an elephant to a baby, way too much bandwidth.

Its why the broadcasters have based their HDTV copy protection schemes around it, HDCP.

For now its full proof copy protection.

There are ways to capture Hidef or even high resolution images to yer hardrive, but it has to happen way before it hits the dvi port.

K

 

[Acanthus]

Originally posted by: kki000
you cannot capture dvi, its like feeding an elephant to a baby, way too much bandwidth.

Its why the broadcasters have based their HDTV copy protection schemes around it, HDCP.

For now its full proof copy protection.

There are ways to capture Hidef or even high resolution images to yer hardrive, but it has to happen way before it hits the dvi port.

K

and those ways are?

 

[kki000]

Ive used a hidef capture card for a few yrs now, the hipix dtv200. It captures over the air hi definition to my hard drive at a clip of 8.4 gigs an hr. It records the actual mpeg 2 stream so its much less bandwidth.

Check out this forum,
avs hdtv recording forum

It deals mainly with recording hidef, but there are various threads on analog recordings, including wvhs which records hidef component outputs. If you can somehow pipe 1024 out to a component output, youshould be able to record it inthe analog domain with one of those.

Good luck.
K