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HMDI capture with Blackmagic Intensity Pro

M

Marlin

macrumors member
Original poster
May 29, 2008
30
0
With all the complaints on HDV I'm wondering if this could be a solution to at least the capture of HDV. Blackmagic states on their site the card does the following.

1. use your camera's HMDI port instead of firewire and by pass the camera's HDV codec. I assume it will be uncompressed so 13GB will turn into 65GB or more. I'm not sure how big HMDI is. I'm guessing its HD

2. Use your TV as a monitor with the HMDI out port.

So this seems to answer all the capture issues but what about editing(pro res 422) or what and are there any benefits in rendering times etc. Seems to easy at $349

Thanks very much.
 
Marlin said:
1. use your camera's HMDI port instead of firewire and by pass the camera's HDV codec. I assume it will be uncompressed so 13GB will turn into 65GB or more. I'm not sure how big HMDI is. I'm guessing its HD
Click to expand...

That only applies if you are recording live. I.e recording when the camera is plugged straight into the computer. If you record when it is not plugged in then it gets encoded. It is HD and raw uncompressed 10-bit HD video takes up the following amount of space:

525 NTSC uncompressed;
8 bit @ 720 x 486 @ 29.97fps = 20 MB per/sec, or 70 GB per/hr.
10 bit @ 720 x 486 @ 29.97fps = 27 MB per/sec, or 94 GB per/hr.

625 PAL uncompressed;
8 bit @ 720 x 576 @ 25fps = 20 MB per/sec, or 70 GB per/hr.
10 bit @ 720 x 576 @ 25fps = 26 MB per/sec, or 93 GB per/hr.

720p HDTV uncompressed;
8 bit @ 1280 x 720 @ 59.94field = 105 MB per/sec, or 370 GB per/hr.
10 bit @ 1280 x 720 @ 59.94field = 140 MB per/sec, or 494 GB per/hr.

1080i and 1080p HDTV uncompressed;
8 bit @ 1920 x 1080 @ 24fps = 95 MB per/sec, or 334 GB per/hr.
10 bit @ 1920 x 1080 @ 24fps = 127 MB per/sec, or 445 GB per/hr.

8 bit @ 1920 x 1080 @ 25fps = 99 MB per/sec, or 348 GB per/hr.
10 bit @ 1920 x 1080 @ 25fps = 132 MB per/sec, or 463 GB per/hr.

8 bit @ 1920 x 1080 @ 29.97fps = 119 MB per/sec, or 417 GB per/hr.
10 bit @ 1920 x 1080 @ 29.97fps = 158 MB per/sec, or 556 GB per/hr.

1080i and 1080p HDTV RGB (4:4:4) uncompressed;
10 bit @ 1280 x 720p @ 60fps = 211 MB per/sec, or 742 GB per/hr.
10 bit @ 1920 x 1080 @ 24PsF = 190 MB per/sec, or 667 GB per/hr.
10 bit @ 1920 x 1080 @ 50i = 198 MB per/sec, or 695 GB per/hr.
10 bit @ 1920 x 1080 @ 60i = 237 MB per/sec, or 834 GB per/hr.
Click to expand...

for most of these you are looking at needing a RAID 0 array with 2 - 3 disks to deal with the data rate.
 
Marlin said:
1. use your camera's HMDI port instead of firewire and by pass the camera's HDV codec. I assume it will be uncompressed so 13GB will turn into 65GB or more. I'm not sure how big HMDI is. I'm guessing its HD
Click to expand...
I don't know what the complete list is, but you can capture to different codces such as DVCPro HD.


Lethal
 
Cromulent said:
for most of these you are looking at needing a RAID 0 array with 2 - 3 disks to deal with the data rate.
Click to expand...

3 is the bare minimum for one stream of playback... you'll need a lot more for a reliable setup (for uncompressed).... better to just use ProRes.

the intensity is good when you can record straight to the computer... I've heard about issues of using the FW for device control while capturing a tape over HDMI, so check into that before you buy.

really, if you're going to edit HDV with FCP, then all I'd do is set it to render in ProRes without transcoding all of the footage. then you get the speed benefit without the massive storage problem.
 
Yea how dumb can I get, of course if the camera has to put it on tape it has to use the codec, Thanks for the rest of the info. yes I'll only use pro res when needed thanks
 
byme said:
Why the codec is the YUV 8-bit and jpeg, but not the 10-bit RGB?
Click to expand...

Because what's coming into the card is 8-bit YCbCr and it doesn't have the hardware capability to convert to 10-bit RGB — and why would you want it to?
 
entry should be in RGB, because the decoder is set RGB output

I would like to know if capturing in RGB with the Blackmagic Intensity improve the image quality
 
I have two other problems

1) I want to capture while maintaining the resolution to 768x576 instead of bringing it to 720x576

2) I would like to maintain 50 fps and does not capture at 25 fps



how can I do?
 
You want YCbCr/YPbPr (which they're labelling YUV), 720x576, 25fps. That is correct for a PAL signal.

Digital TV is YCbCr and analog is YPbPr. Blackmagic Design, for some reason, refer to it as YUV. I don't know if the Intensity can capture RGB, but doing so is pointless. It will not improve the image.

PAL resolution is 720x576. TVs, computers, etc. all know to stretch it out appropriately.

25fps is actually 50i — which, again, is what PAL is.
 
Thanks for your answer

Now I have a big problem

I realized that the material deinterlacer, setting PAL in preferences, with the Blackmagic becomes interlaced

This evening I arrived a videoprocessor (I paid € 1800) that I use also for deinterlacer

may not have the option 576p in Blackmagic?
 
Nothing really uses 576p. It's 576psf — which is progressive images stored as interlaced frames.

If this is just a hobby, that processor is an expensive addition. Is it a realtime one for a projector?
 
I never had much luck coming off of Firewire with my HVR-Z7U, even using ProRes. The capture I have gotten using the Intensity cards has always been superior.

My current setup for capture is 6x 750GB Seagate 7200.11 drives, RAID 0+1. BlackMagic speed test average 230MB/s write and 210MB/s read off of the array. I use a second disk for the OS and applications so that I don't have any acess problems when writing to the array.

I used to capture uncompressed YUV 59.94 1080i on just two of these drives in RAID 0 and it worked, write speed was ~140MB/s, so you can go that route with the faster drives like the newer Seagate 7200.11 drives that have a high data density on the platters, and high data thoroughput. Older, slower, and smaller drives will not work without going to a larger array.

It should also be noted that Seagate just announced an even faster disk, the 7200.12 drives, which can (supposidly) offer sustained write speeds of up to 140MB/s on a single drive. Fast disks are the key to a good array.
 
FX120, what's your setup for the drives? is it an ESATA array with port multipliers or what? I had a 2 drive raid 0 internally and want to go even faster (but i have an external clone for stability)
 
ChemiosMurphy said:
FX120, what's your setup for the drives? is it an ESATA array with port multipliers or what? I had a 2 drive raid 0 internally and want to go even faster (but i have an external clone for stability)
Click to expand...

It's a long story...

It's a Windows machine, to sum it up.

I couldn't afford a Mac Pro + Fiber channel + external array so I built up a computer with a nVidia motherboard that supported internal RAID across 6 SATA ports. It's no mac, but for importing and transcoding it works well enough...
 
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