Basic HDSDI computer question from a freelance shooter...
 

Hi,
I am a freelance shooter with experience in shooting HD (not post)...with a variety of different cameras (XLH1, HVX, Z1U). However, I am exploring the options of shooting with an XLH1 and going direct to my G5 2.0 (AGP)...for certain shoots (and of course bypassing HDV).
My question is, can you capture HDSDI directly to a lossless compresstion format, or do you have to capture uncompressed then re-compress the footage? From what I have read and searched, the Decklink HD 4:2:2 gives the best bang for the buck, and would allow me to monitor FCP editing footage through the analog out to my Panasonic Plasma.
If anyone can help answer these basic questions...it would be much appreciated! Alternate suggestions are welcome as well...
Thanks everyone,

Brian Broz

Decklink HD doesn't have analog audio output. SDI only. The plus version has AES/SPDIF out, I believe, so if you have a receiver that can accept that you'd be ok. The other issue is that the Decklink only has SDI video out, so you won't be able to monitor without a conveter to your plasma. The KonaLH card has analog audio I/O and component HD I/O, so that could work for you, but it costs about $1K more than the basic Decklink HD.

The other thing is...you will need to recompress your HDV footage unless you have an insane multi-terabyte RAID to work with. A 2 TB RAID will give you 3-4 hrs of uncompressed HD. Thus, the need to work in an intermediate codec.

I recommend PhotoJPEG 1920x1080 @ 75% quality. It's 4.2.2. and nearly lossless, plus it's a square pixel format which is nice when working with Photoshop and After Effects, Motion etc.

DVCProHD is good too.

Hi Barlow,

Thanks for the prompt reply. The Decklink HD Pro has analog component out to connect to my plasma...that should work fine, no? As for audio...digital out would be fine in my application.

So, again...sorry for the dumb question...but can I record to an intermediate codec (PhotoJPEG 1920x1080) direct from the camera to decklink/G5...once I have set up a raid?
I have no need for uncompressed, but would obviously like less compression than HDV :-) DVCPro HD would be a great option as well.

Thanks (anyone) for further input.

Cheers,

Brian Broz

You don't even need a RAID for PhotoJPEG. It's about 12MBs for 75% and 36MBs for 100% (hardly a visual difference). DVCProHD is around 14MBs.
All fine with todays SATA and Firewire drives, but you do get more realtime performance with a fast G5 combined with a RAID. Scrubbing on the timeline is more responsive too.

I wasn't aware that the Decklink HD Pro had analog HD out. That's great if true. I think I would go with that one, but the Kona is very very nice too.

Sorry, I forgot about your other question. Yes, you can capture SDI live camera head output to FCP in PhotoJPEG, DVCProHD, Uncompressed etc.

The other thing you need to be aware of is you will need to convert the analog audio out of the camera to AES/SPDIF audio if you get the Decklink. Either that or use the miniplug sound port on the G5 from the RCA outs of the H1.

Barlow can you really capture live photojpeg at 75% and 100% on your system with the Kona? I was told the Decklink could only do 25% for HD.

I can do 75% on a good day and 70% all day on Decklink card and a Firewire 800 dvBOX drive.

I can't quite do full 1080 res with the Kona. A G5 Quad might. I think the Decklink actually has acceleration built-in to the card that gets the job done for Robert. I'm considering getting the basic Decklink HD card just for this purpose.

Well you guys just sold me on a mac and decklink setup for this summer. I couldn't decide what system I wanted to get. I love photojpeg at 75% and think it looks amazing. I cannot imagine needing any higher quality than that for HD any time in the near future.

Robert what speed system do you have? Do you feel as though you could get a clear 75% or higher if you could go with a faster system?

Sorry one last question guys. How is the editing performance with FCP and photojpeg at 75%?

Robert,
How much of this limitation the card or the computer or the drive ?
(What computer do you run?)
Thanks,
J

Good question John. I'm going to try to contact AJA and Blackmagic Design and see what the deal is with PhotoJPEG and the G5. I have a feeling a Quad and the Decklink with a 2 drive SATA RAID would be more than adequate...but it seems like my Dual 2.7 should be able to hack it.

I'm on a Dual 2.7 with 4GB RAM and a dvBOX 800GB Firewire 800 drive from Promax.

I don't think the limitations are the card or the drive. I'm thinking it's processor speed. But I'm no expert in whether or not JPEG compression is a processor intensive computation or not. DVCProHD (DV100) seems to have better performance on capture. But P-JPEG@75 seems to perform equally as well on playback. It's only on capture that I take a performance hit with P-JPEG@75,

The Quad's and the Decklink are the safe bet. I do think it's somewhat CPU dependent to always get 75% quality at full raster.

I have this outside hope that faster Intel Macs and Cineform may arrive and be the new killer intermediate path in FCP6. Don't have any evidence, but I have a sneaking suspicion this may happen in the near future. But right here and now, PhotoJPEG is very nice.

thank you guys for the info. Trying to get info from eith AJA or Blackmagic on codecs and speed has been very hard. You would think they would want to answer my questions to make a sale.

So do you guys think a dual 2.5 G5 with 4.5GB of ram and the Decklink HD PRO and some raid drives be a half decent setup? You guys said the DVCPro HD is a less processor hungry task? What will the difference in image quality be?

Sorry for all the questions but I had just picked up my Canon XL H1 and I'm looking for a cost effective way of using what I already have to record in uncompressed, mainly only when I record on green.

Thanks,

Jon

Jonathan,

You should be fine. Give PhotoJPEG a try...at the very least DVCProHD will capture fine, and it's very usable too. The difference in visual quality is fairly negligible. I've been using DVCProHD for quite awhile since I got the H1, but only recently tried out PhotoJPEG and found that I prefer it...but only slightly. The biggest advantage of PhotoJPEG is you can adjust the quality of the codec to fit the bit rate you want to work at, and it's a full-raster square pixel format which makes it a bit easier to use as far as integrating material from graphics programs. There's no pixel aspect ratio to adjust for when working in Photoshop, for instance.