Z1U -> Component -> HDMI -> Intensity -> Cineform???

[David Newman]

Originally Posted by James Huenergardt

David,

Here is what Gefen says:

"Our devices change absolutely nothing in the signal. What goes in is what comes out, unless documented otherwise."

I'm willing to buy one and send it to you if you want to test it out.

Jim

Jim,

OK Gefen is as clear as mud. Sampling a analog signal as 4:4:4 or 4:2:2 is hardly "chang(ing) absolutely nothing in the signal." So it is hard to know if this will work, although I'm hope that is what the DIPs are for. Obviously we have the Intensity card and a good range or HDV cameras. all any need is the cabling from component YPrPb into DB15 connector. We may have the needed cabled (untested for pinouts) so all we need is the Gefen box. If gefen won't break out a sample, then thank for the offer. Email me your Gefen contact, I might as well try them first.

[Marty Baggen]

Originally Posted by James Huenergardt

Marty,

It comes down to the cost of acquisition. To obtain uncompressed footage from my Z1U, I would have to invest in more expensive hardware. The Intensity card is retailing for $249 which is a lot less than buying a new graphics card and capture card. For the price of one piece of hardware, I can buy both the card and the converter and have uncompressed capture.

Maybe I'm missing something, but that's how I see it.

Jim

Okay, I see where you are coming from. From your post, I assumed you were looking for a "cleaner" signal, not realizing uncompressed was your capturing objective.

As noted in a separate post, that is a huge task....not only to work with the massive files and bandwidth, but how do you capture from the camera in the field? Unless you are exclusively in a studio environment, the logistics are mind-boggling....and for the most part, a marginal improvement.

This angle has been discussed in many forums at length. Some maniacs have actually done the hauling around of their megasystems to tap into their uncompressed camera outputs.

Not for the faint-hearted.

[David Newman]

Originally Posted by Dave Nelson

...
Cineform's software will reduce the hard disk requirements but you will still need a fast dual core processor and some fast hard drives to keep up with the huge stream of uncompressed data (1.6 Gbps) that comes out of the HDMI port without dropping frames.

See Cineform's site at http://cineform.com/products/TechNot.../Intensity.htm for some preliminary system requirements for capturing data from the Intensity card with the Beta version of their software.
...

I just updated the info at http://cineform.com/products/TechNot.../Intensity.htm. The computer requirements just dropped 20%-30%, so any good dual core system should work fine -- not just the high end ones. This is the current Aspect HD download and Prospect HD in 30 minutes. It is getting easier.

[James Huenergardt]

Marty,

Yes, hauling around a large system doesn't work for a lot of productions, but when I'm shooting on a green screen in a studio, it can make my life as a compositor a LOT easier to have that uncompressed footage on my system.

Maybe someday, laptop technology will be adequate for such aspirations and I can capture directly to my laptop, which is a LOT nicer than hauling around my dual processor system around.

Unless I'm not understanding something here, uncompressed video is a BIG improvement over compressed video. Maybe not to the eye shown on a screen, but for compositing, my understanding is that it IS a BIG improvement.

Please enlighten me if I am not understanding this correctly.

Jim

[David Newman]

Originally Posted by James Huenergardt

Unless I'm not understanding something here, uncompressed video is a BIG improvement over compressed video. Maybe not to the eye shown on a screen, but for compositing, my understanding is that it IS a BIG improvement.

Yes, just as 6:1 wavelet compression (PHD Filmscan mode) is a lot better than 30:1 MPEG (60i HDV). Uncompressed is best, but a total pain to manage (disk size/data rates.) We are trying for the next best thing without the disk issues.

[Marty Baggen]

Originally Posted by James Huenergardt

Marty,

Yes, hauling around a large system doesn't work for a lot of productions, but when I'm shooting on a green screen in a studio, it can make my life as a compositor a LOT easier to have that uncompressed footage on my system.

Maybe someday, laptop technology will be adequate for such aspirations and I can capture directly to my laptop, which is a LOT nicer than hauling around my dual processor system around.

Unless I'm not understanding something here, uncompressed video is a BIG improvement over compressed video. Maybe not to the eye shown on a screen, but for compositing, my understanding is that it IS a BIG improvement.

Please enlighten me if I am not understanding this correctly.

Jim

Jim,

I can certainly appreciate the demands of compositing. It sounds to me like you have a good grasp of what you would like to do.

I wonder if you need pure uncompressed however. Rather than shoot for the moon, why not apply various levels of compression to the HDMI input?

My only experience is with SD uncompressed, which I used for years. It was hard to admit it, but even for comping and green screen, there was no visual, or functional difference between uncompressed (approx 22 mb/sec) and mild compression, say.... 13 mb/sec.

I wonder if the same scale-of-compression would hold true in your situation?

What sort of control will you have over compression parameters?

Marty

[James Huenergardt]

I guess that depends on Cineform and HDLink. I know that using Cineform files from my Z1U is quite easy, and fast on my Dual Opteron 246 machine.

However, I understand that uncompressed is an entirely different ballgame.

You're right, I probably don't need uncompressed, but as David said, 30:1 compression for HDV is pretty compressed. Enough so, that I see quite a few artifacts in my footage.

Having true 4:2:2 colorspace will also help.

But you're right Marty, you have to know what you need and what it's going to cost you $$$ and otherwise before you make the jump. I just know how nice a green screen shot with my Nikon D70 works compared to stuff out of my Z1U.

Jim

[Marty Baggen]

Jim,

you are in a position, much better than most of us, of pushing the capabilities/limitations of the camera.

One of the big fears when HDV hit the market was its ability to green screen.

My guess is that bypassing the internal MPEG compression of the camera is the most significant step you could take......Then of course, the problem iis...how to ingest whatever form that signal emerges, be it component, HDMI, etc.

Full-res (non-firewire) HD capture systems are not cheap (the new Blackmagic card notwithstanding).

If I were in your shoes, I would set up some sort of test environment where you can do an A/B test of a scene, both via firewire (and the MPEG compressor of the Z1U) and a component feed from the Z1U. Maybe capture a scene and playback to a monitor via DVI, then switch to the component inputs of the same scene, assuming a multiple input monitor.

The above test would be much more meaningful if you could somehow apply a key.... but then things get complicated. If you had access to a studio switcher with a keyer... that would be the ultimate means of testing.

My point is that you need to determine if you are gaining enough quality by avoiding the MPEG compressor. My guess is that you would be.... but, if it still isn't good enough for what you need.... then you have determined it is pointless to spend more money on the HDMI card. And that is equally important information to have.

Marty

[James Huenergardt]

David,

Did you receive the contact info for the folks at Gefen? I emailed it to you. If not, here it is now.

Robert Van
Gefen E-Mail Support Coordinator
Technical Support Engineer
818-884-6294

[Alex Raskin]

I had to build an entire uncompressed HD capture system (fed from the component out of Z1) to be able to pull good green screens from HDV cam.

Once you avoid the tape/firewire and associated MPEG compression blocks, you're in better shape.

That's what my system affords.

However, there's still an issue with the color sampling of only 4:2:0 in the output component signal as well. (I do capture the stream as 4:2:2 on recording, but this is simply on the storage codec side - it won't restore the missing color information.) This issue still stands between you and good green screen.

Bottom line: even with the uncompressed component signal capture, pulling a matte from HDV cam signal is not easy.

Using MPEG compressed HDV signal for that is still possible but very dicey.

[Olivier Vanaschen]

I'm also pretty interested in that kind of setup, FX1 PAL to AnalogHD-to-HDMI Converter - Intensity Capture Card.

Would this converter work you think?

http://www.converters.tv/products/hdtv_to_hdtv/321.html


Cheers,

[Daniel Browning]

I'm interested in using the Gefen adapter with the Intensity card. If anyone can find out if it works (if it can truly output 4:2:2 YPrPb), please let the world know.