David McGiffert
April 28th, 2007, 11:50 AM
Is there a way to capture uncompressed from
an XHA-1? I'm obviously alittle lacking on education.
Thanks,
David
an XHA-1? I'm obviously alittle lacking on education.
Thanks,
David
View Full Version : uncompressed from XHA-1? David McGiffert April 28th, 2007, 11:50 AM Is there a way to capture uncompressed from an XHA-1? I'm obviously alittle lacking on education. Thanks, David Doug Tessler April 28th, 2007, 01:58 PM You can capture through firewire which is HDV format. The G1 has a breakout box panel that you could do uncompressed . But its still very acceptable while editing in FCP or Premiere etc. Hope this helps u out ! Doug T Ben Hayflick April 28th, 2007, 02:36 PM And the A1's analog component is uncompressed 4:2:2. David McGiffert April 28th, 2007, 05:01 PM Thanks guys, ok. Analog component input it is... (edit) IF it is 4:2:2 Sometimes I fall off learning curve... David Mike Gorski April 28th, 2007, 06:32 PM I was thinking about this since the AJA IO-HD unit would come in handy allowing for on the spot live recording of uncompressed 4:2:2 colorspace via analog imputs utilizing the new apple lossless compression. This would be key since the amount of data transfer is manageable as opposed to the tremendous 1.4 GB/s. My questions is can anyone tell me if the analog out puts of the XH-A1 offer true uncompressed 10 bit 4:2:2 HD video? And if so how well does the converted analog signal look as opposed to the HDV signal. I have huge intrest in this as a future option when technology gets better and the ability to record high motion video without suffering from heavy artifacts as a result of the GOP based compression. Anyone else on the same page or looking in the direction I am? Bill Doyle April 29th, 2007, 05:19 AM I'm with you on that one Mike. I'm also trying to see just what the workflow possibilities are for HDV users with the the ioHD- will it allow us to capture using ProRes 422 for all editing before transcoding to MPEG2 or is ProRes best left for effects and titles? Bill Harm Millaard April 29th, 2007, 05:31 AM And the A1's analog component is uncompressed 4:2:2. In the manual it only states Component Out terminal is 1080i (D3) compatible. Where can I find confirmation for your claim? David McGiffert April 29th, 2007, 08:33 AM And the A1's analog component is uncompressed 4:2:2. I've been poking around too Ben and can't find any specific's to verify that either... Where? David Pavel Sedlak April 29th, 2007, 01:37 PM D3 1080i is YPrPb HDTV (EIA 770.3) - EIA/CEA-770.3-A(B) standart, which defines a wideband analog component interface. This is made from HDV/ HD mpeg2 (MP@ML, 4:2:0 HDV), so I think it canť be better (than this compressed HDV). Uncompressed/lossles compressed signal try get from G1 (if you capture by HD SDI out), but in this class of camcorders it's not mean big difference. Ben Hayflick April 29th, 2007, 10:11 PM AFAIK the A1's analog component out bypasses the HDV codec altogether, i.e. is pre HDV encoding and yields a 4:2:2 image. Here's a thread which discusses a bit: http://www.dvxuser.com/V6/showthread.php?t=93666&highlight=analog+component I've seen this confirmed on other threads many times. Do a search for analog component here or at dvxuser and see what turns up. Barlow Elton April 29th, 2007, 10:24 PM The LIVE camera signal (not VTR-mode HDV playback) via the analog component connector is true uncompressed 4:2:2. I've done my own captures into a Kona card and compared it to the same image from HDV (you can record HDV and uncompressed at the same time) and it does indeed contain more color info--but here's the deal...the difference is very subtle. It's not nearly as radical *perceptually* as a lot of people think it is. As to whether it's true 10 bit 4:2:2--I think the image is quantized to 8 bit via DSP and then spit out uncompressed, so capturing to a 10 bit codec won't likely help anything. Ben Hayflick April 29th, 2007, 10:31 PM Exactly. I have read that it's 8-bit 4:2:2 via live capture only. Recording to a Firestore or Mini-DV tape forces HDV encoding, dropping it to 4:2:0. I saw a comparison of stills from 4:2:2 vs. 4:2:0 (yours, Barlow?), and it's not nearly enough to consider shooting tethered. They were extremely close. If you're in a studio situation where you're shooting tethered, then it might be an option. But for run and gun or more portable work, the HDV 4:2:0 properly handled is 99.9% as stunning. Barlow Elton April 30th, 2007, 12:46 AM I saw a comparison of stills from 4:2:2 vs. 4:2:0 (yours, Barlow?), and it's not nearly enough to consider shooting tethered. They were extremely close. If you're in a studio situation where you're shooting tethered, then it might be an option. But for run and gun or more portable work, the HDV 4:2:0 properly handled is 99.9% as stunning. Yeah that was me, and I think you're correct for the most part. The difference is a bit more pronounced if you need to push the image (heavy CC, fx etc) a great deal in post. That's where very good 4:2:2 acquisition can help a great deal. HDV pushed hard and recompressed (conforming or "rebuilding" GOPs) will show the blockies whereas lossless (Sheer, uncompressed) or lightly compressed (ProRes, CineForm) will be clean. David McGiffert April 30th, 2007, 07:59 AM Barlow, Ben an all... Thanks for all the information...I feel better about the A1's HDV capability as opposed to worring about no ability for uncompressed coming out from the camera. This is a great learning curve. My next hurdle is figuring out if there is any way to retain that image quality (or close) from fcp to DVD output. Now THAT's frustrating. Thank you again, David Mark Fry April 30th, 2007, 08:58 AM My next hurdle is figuring out if there is any way to retain that image quality (or close) from fcp to DVD output. Now THAT's frustrating. DVD Video is standard definition MPEG2 at up to 8Mbps (or thereabouts). You can store other formats of video file on DVD discs, such as the high-def versions of Windows Media or QuickTime, but that's not "normal" DVD Video. There may be one or two players around that will read them, but otherwise you're limited to playing back from a computer, AFAIK. (Please tell me if there's a practical alternative yet.) For the moment, I'm down-converting in the camera, then editing and authoring in standard def, widescreen DV. There's a fair increase in picture quality over my XM1, and I've not had to upgrade my computer. Maybe in 18 months or so, the HD-DVD vs BluRay arguments will be resolved and affordable players will be in the shops, but I'm not holding my breath. Geoff Dills April 30th, 2007, 09:39 AM Downconverting in the camera is going to give you the poorest quality from HDV. Best method, tho takes a lot of rendering time, is to cut in HDV, then export to MPEG. The difference in the image quality is significant. Mark Fry April 30th, 2007, 09:46 AM Downconverting in the camera is going to give you the poorest quality from HDV. Best method, tho takes a lot of rendering time, is to cut in HDV, then export to MPEG. The difference in the image quality is significant. Yes - when I've upgraded my computer, this is what I expect I'll do. The final render to SD DVD format will probably be no slower than my current machine which takes about 4 hours for a 90 minute avi file using Canopus ProCoder Express. I leave it running over night! Will Griffith April 30th, 2007, 11:07 AM Analog component works great with a Blackmagic HD card. it is easier to key than HDV and yields more resolution. But is obviously NOT portable. :( Maksim Yankovskiy April 30th, 2007, 12:38 PM What does "not portable" means in this context? But is obviously NOT portable. :( Will Griffith April 30th, 2007, 12:40 PM Your would need to be connected to a MacPro or similar w/fast HD array. -will Mike Gorski April 30th, 2007, 02:03 PM Well portability has been solved with the AJA IO-HD Apple ProRes 422 converter. Using a Mac platform such as the a fully furnished Macbook Pro you can take uncompressed HD with the 4:2:2 colorspace at full 1920X1080 resolution and have this awesome machine convert it via ProRes 422 realtime. You'll transfer data that can be handled by Firewire to connect to your laptop and be completely free from the tower. The data rate is almost that of SD video and can be a feasible solution in the future. I know this is something thats making a huge impact on my first HD purchase. What I want to know is if the analog output of the A1 is full uncompressed HD and is beneficial like the Sony HVR-V1's HDMI output. If so, how good is the conversion of the analog signal to a digital signal? Can't wait to hear some results. Will Griffith April 30th, 2007, 02:11 PM It will be better than recording to tape, but it will not be as pristine as the V1U HDMI nor the G1 HDSDI, or H1...etc. etc. It is analog, so there will be an amount of noise that is not present in a digital signal. However.... it is still much more info than HDV, which is good. The new IO will help greatly, but it still is not a portable solution, like say a 4:2:2 Firestore type device which is completely cable, AC, etc. free. (Which I hope is introduced by someone sometime soon). So in conclusion... HDV looks mighty fine from the A1 and the component output looks even better IMO. Jonathan Gentry April 30th, 2007, 09:03 PM Would anyone with a G1 please post a grab from the SDI Out vs HDV to tape so we can compare color etc. Has anyone seen this done on any other site? A picture tells a thousand words. Would also be neat to see this comparison with some movement in the shot to see if there is difference in artifacts. I've been very impressed with Canon's HDV quality and seen very little artifacts/blocks in the shots. In real world use the Canon footage in HDV is pretty incredible. -Jonathan Mike Gorski April 30th, 2007, 09:48 PM It will be better than recording to tape, but it will not be as pristine as the V1U HDMI nor the G1 HDSDI, or H1...etc. etc. It is analog, so there will be an amount of noise that is not present in a digital signal. However.... it is still much more info than HDV, which is good. The new IO will help greatly, but it still is not a portable solution, like say a 4:2:2 Firestore type device which is completely cable, AC, etc. free. (Which I hope is introduced by someone sometime soon). So in conclusion... HDV looks mighty fine from the A1 and the component output looks even better IMO. Good catch, I thought I read somewhere that it was fully portable but it isn't. It needs AC electricity to run so maybe in the future we can see maybe a simplified version for portability? I know I'm thinking really far a head of the game but the IO-HD is a start. Barlow Elton May 1st, 2007, 01:08 PM It will be better than recording to tape, but it will not be as pristine as the V1U HDMI nor the G1 HDSDI, or H1...etc. etc. SDI and analog are virtually the same as far as I can tell. The Kona card has very good converters, and the Canon's DAC ain't half bad, so the net result is basically an indistinguishable difference. Will Griffith May 1st, 2007, 01:14 PM Comparing H1 HDSDI to A1 analog here on a Decklink HD shows more noise on the A1, the AJA card may look a lot better. Regardless....both look great. If anyone wants to see some frames from greenscreen H1 HDSDI capture we just did today to DVCPROHD email me griffithwb msha com the A1 would look very similar |