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August 22nd, 2007, 12:23 AM | #1 |
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Very very basic (dumb?) question re Cineform
Sorry for asking something so basic, but I'm just now starting to think about adding an HD camera and worrying a bit about HDV capture workflow.
1) If I bring data in from the camera via a Blackmagic card, will Cineform capture and compress to an intermediate file? 2) If so, does it make any difference how the camera is connected to the Blackmagic card? For example, if the camera is connected to the card by analog component cable, or by SDI, will this matter? Or is everything outboard of the card "invisible" to Cineform? In other words, if Cineform is ingesting and compressing the output of the card, I would think it wouldn't care how the input got into the card in the first place. 3) If the camera is connected directly to the PC by firewire, will Cineform capture? And if so, will there be any quality differences (particularly chroma) compared with bringing the video in via the Blackmagic card? 4) Am I right in thinking that by using Cineform I can avoid the need for the extremely high data rates needed for uncompressed HD, ie would normal disk drives work OK? I think this should be true as I saw a post saying that even a healthy notebook PC should be OK for capture, but just want to be really sure before starting to spend money on HD. |
August 22nd, 2007, 07:09 AM | #2 |
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1. Yes :)
2. You would get better quality ingesting from a digital source (HD-SDI or HDMI) than analogue component. I have to admit that results I've seen from Blackmagic's component input have been really poor - even at 10-bit uncompressed 4:2:2. That's on Decklink Extreme, will be doing Intensity Pro tests later. 3. If you're playing back footage from tape, there'll be zero difference between using HDMI/HD-SDI or firewire. If you're capturing 'live' from lens to digital output, there will be a quality increase as you're cutting out the MPEG2 HDV compression altogether. 4. CineForm has incredible compression in terms of filesizes while offering quality on par with an uncompressed capture. That's the codec's USP and that's why you should buy it :)
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August 22nd, 2007, 02:10 PM | #3 |
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Depends on the Camera and what it outputs via the HDMI or Firewire Port....
On the Canon HV20 the choice is HDMI or Firewire... But there are two different captures using HDMI... If you capture live from the HDMI, the footage is not compressed... If you capture via Tape from the HDMI the camera un-compresses the footage from 1440 that is on the tape to 1920 and the color 4:2:2 Firewire is 1440.... |
August 22nd, 2007, 06:49 PM | #4 | |
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Quote:
Correct me if I'm wrong with a logical technical explanation.
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August 22nd, 2007, 08:46 PM | #5 |
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It does not "uncompress"...not in the way you might be thinking. What it does is 're-size" the 1440x1080 footage back to 1920x1080 (after HDV compression of course). But I too have also read..many months back that it somehow spits out 4:2:2 colors with this method (Over HDMI and off tape) also. Guess we'll wait tll someone else can confirm.
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August 22nd, 2007, 09:18 PM | #6 |
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I was surprised to hear that the Intensity did a poor job of digitizing the analog input.
The thought process I was using was that if one captured from the analog stream, then there wouldn't have been any in-camera compression. And I was thinking that any of the digital captures would involve upsampling from the Mpeg-2 as would HDMI output. I guess it isn't as simple as all that! Actually, another reason for the question was that one camera that I'm looking at (JVC 110) seems to not have HDMI or SDI - just Firewire and analog. Maybe I should also be looking at a different camera. I hope someone from Cineform chimes in with a response to the comment about poor quality from analog. |
August 22nd, 2007, 10:18 PM | #7 |
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Sorry, I haven't tried the analog input on Intensity Pro to comment on the quality, it can't image it would be a distorted as MPEG compression, and it is certainly 4:2:2 not 4:2:0 when captured live. Most of the new cameras have digital outs, so use that if you can. The last camera I captured analog out with was the JVC HD100U with a AJA Xena LH card, the results were quite nice.
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August 22nd, 2007, 10:33 PM | #8 |
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I was thinking of the JVC 110 and it doesn't have HDMI or SDI. I was thinking exactly the same thing ie whether I might be better off with 4,2,2 analog vs 4,2,0 from Firewire.
I'll try to ask someone at Blackmagic the same question about analog quality. I think I mistakenly said I was hoping for someone from Cineform to answer when I really mean Blackmagic - sorry for the confusion. Although it would be really nice if I could find someone using analog in to Intensity to Cineforem to comment from the horse's mouth so to speak!!! |
August 22nd, 2007, 11:02 PM | #9 |
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I tested the Intensity's Pro analogue input yesterday - it's better than examples I've seen from Decklink Extreme component capture (even 8-bit vs 10-bit) but colour balance looks wrong (a tad washed out) and there's a definite lack of precision compared to HDMI.
The HDMI input, by the way, is second to none. I can't comment on HDV vs component by the way, as I do not use HDV at all.
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Company Website: Digital Foundry Ltd Video Games HD Blog: Digital Foundry@Eurogamer Last edited by Richard Leadbetter; August 23rd, 2007 at 02:57 AM. |
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