Sean Oneil
Forum Replies Created
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[Herb Sevush] “I am aware of the none native nature of HD-SDI capture. I have had any number of problems using firewire and the 1200A =and my many conversations with the techs at Panasonic have not made me any too confident in trusting my HD workflow to firewire if it can be avoided. I’ll take any theoretic loss when using HD-SDI in exchange for it’s stability. In the case of 720P30 I’m seemingly stuck with firewire and am just trying to survive.”
Cool. Those are very valid reasons for not using a native workflow. I just get annoyed when people think that HD-SDI -> DVCProHD is native. And a lot of people do think that.
That’s strange that the Decklink can’t do 30p. One other thing you could use is the Panasonic Frame Rate Converter Utility. Or you could just edit your 60p footage on a 30p sequence.
Sean
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[walter biscardi] “With the AJA Kona boards, they are actually coming in native via HD-SDI. I’ve had many discussions with the tech gurus at AJA and when you come in via HD-SDI on a Kona board, you’re coming in native and actually it’s a bit cleaner thanks to some nice work AJA did tweaking the input. “
Walter, we’ve had this discussion before. If they told you that, they are lying. I mean, it’s almost like saying “A few reps from McDonald’s development team told me that Big Macs are are actually heathy for you.”
I have no problem with your workflow whatsoever. I do have a serious problem with false information being proclaimed by a Cow leader. HD-SDI capture is not native, and the definition of “native” is not in dispute.
This is how it works. An AJ-HD1400 w/ the HD-SDI option, for example, has an onboard decoder chip. On playback, it decodes the DVCProHD video to uncompressed video. The raster size is scaled from 970×720 to the standard 1280×720. This uncompressed video is serialized and fed to an HD-SDI transmitter chip. Anything plugged into that SDI port sees nothing more than a SMPTE compliant uncompressed serial digital video signal. It does not see anything having to do with the DVCProHD codec, or how to re-encode it losslessly. Nothing whatsoever.
Thus it is not native. It is a physical impossibility. Furthermore, if they “tweaked” the input to supposedly make it look better, that in and of itself proves it is not native. Additionally, it wouldn’t be the input that they tweaked, it would be the onboard encoder. If the input was tweaked it wouldn’t be SMTPE compliant. SDI is a pretty straightforward and the levels are not altered by the Kona or any other capture card.
Native means an exact 1:1 digital duplication of the data that is on the DVCPro tape. That’s what “native” means. Just as if you copied it from a P2 card or a hard drive. It doesn’t mean anything else. So if it looks better, then it isn’t native. Period. Just because it’s impossible to detect any differences visually or on a WFM, doesn’t make it native. The only way it can be called native is if the 1’s and 0’s on the tape are 100% identical to the Quicktime file you have captured.
If AJA claims it’s native, they risk being sued, because it isn’t. That’s why they don’t claim it – publicly at least. But don’t take my word for it. This is from the AJA website:
“The Panasonic DVCPROHD format takes advantage of KONA hardware as well. KONA’s precision hardware allows capture and playback of HD-SDI video to and from the DVCPROHD codec at a quality level virtually indistinguishable from native FireWire, while freeing up valuable RT processing power.”
Saying “virtually indistinguishable from native” explicitly means it is NOT native. Furthermore it does not say it looks better. How can it look better if it’s virtually indistinguishable?
It should also be noted that the topic creator is using Blackmagic hardware, not AJA.
Again, I’m well aware AJA thinks you should use their products for every workflow. No shit they think that. They have families to feed. I didn’t want to engage in this discussion but this kind of false information just annoys the crap out of me.
Sean
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Why do you prefer HD-SDI over firewire? You are aware that by using HD-SDI, you cannot capture natively?
I don’t wish to spark any argument over how trivial the generation quality hit is or isn’t. Just making sure you understand that just because you choose to re-encode the DVCProHD codec, that does not make it a native workflow.
Sean
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I have one in my list, and I sure didn’t make it.
Sean
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Here’s an interesting guide:
https://www.o0o.it/pro/Looks like he took two cheap Clovertown chips, modded them to run at 1333mhz FSB, and it worked. I wouldn’t mess with this myself. I just find it academically interesting.
Sean
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There are guides on the Google. Several people, including CNET, upgraded a quad to an octo before the official 8-core Mac Pro was announced. I’m not saying it’s a good idea or a good bargain. But I’m pretty certain Apple doesn’t have something in the EFI preventing compatible CPUs from working.
Sean
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How are you capturing it? Firewire? Final Cut already has an Easy Setup for 720p30 firewire capture.
Sean
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[Harry Bromley-Davenport] “One question: should I conform before or after I have converted the file to PAL using Nattress Convertor?”
You don’t use Nattress at all. Just conform the clips to 25, put them in a PAL sequence, and Final Cut 6 will automatically scale it for you.
Sean
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“Conforming One Clip at a Time” is the section with the instructions. The manual does not say PAL because PAL means is a standard that means multiple things. So instead the manual just says “25 fps.”
“Conforming” is the same thing as “speed change” – that’s what it means. While you can conform it to the proper 25fps, it will not convert it to a real PAL format for you. The resolution and color space will not be altered.
Sean
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[Scott Davis] “Sean, do you know if this set up would work with Pro-Rez? “
ProRes (HQ) HD is 220mbps. Less than 1/4th of the theoretical maximum bandwidth you can get from gigabit ethernet. So in short, yes, it should be fine. A lot of it will have to do with the drives you get more than anything.
Don’t take my word for it though please. My setup is different as I use a NAS box. Try before you buy. You have 3 machines already. Assuming you have a gigabit switch (you can buy a buy a really cheap one if not) share one of those machine’s drive’s and see what it’s like editing off it over the network. See if it’s quick and responsive enough to your liking.
You can call Small Tree as well. They know everything there is to know about this stuff and no doubt know of many customers who are doing this exact thing. Tell them you have three edit bays and you want to share storage. Since it’s only 3 stations and you aren’t using uncompressed video, you feel file sharing may be the best solution.
Sean