View Full Version : Blackmagic/FCP: Capture to Prores HQ?


Matthew Wauhkonen
March 16th, 2009, 03:00 PM
Hi, can I use a blackmagic intensity in a mac pro to capture to prores HQ (220mb/sec=28ishMb/sec?) via an hv30 through HDMI? (No, I'm not shooting to HDV first; the camera will be tethered.)

The mac pro can compress to prores in real time, right? And I won't need any sort of RAID array or fast drive, correct? And how do I then remove pulldown if shooting in 24p?

Thanks,

-Matt

Doug Tessler
March 16th, 2009, 07:42 PM
You will need a raid to be able to capture at that data rate . So I think you will not be ble to do this without serious hardware

Doug

Matthew Wauhkonen
March 16th, 2009, 08:00 PM
Ah, I was afraid of that.

From what I've read, WD raptors (10krpm) claim transfer rates around 200M/b a second, while pro-res HQ 1080p/60i is only about 28M/b a second, but I have noticed drive performance is generally much slower than specifications suggest.

That said, is the mac pro even fast enough to compress to prores in real time from 1080p HDMI or would I have to capture full raster uncompressed (which would need a very large RAID array) in the first place?

I can't afford a RAID array right now; I only make about $250/week at my job and have other expenses.

Deke Kincaid
March 17th, 2009, 09:32 AM
Then work within your means and just capture to the internal hdv.

Matthew Wauhkonen
March 17th, 2009, 04:29 PM
Hey, that's not the right attitude! I find HDV fine for most stuff, but I'm doing mostly greenscreen (and occasional motion-matching) to match primary photography shot on a red; HDV leaves bad edges around keyed footage and heavy grading tears it apart. It's gotta be pro-res or cineform or something much better than hdv.

How about using terminal to make a RAM disk? There's got to be some way...

Anyhow, once I have all the hardware I'll test things out and see what's up; I'm surprised more people haven't tried this.

Henry Olonga
March 17th, 2009, 05:30 PM
You can record to a mac pro single HDD if you choose to compress to a manageable data rate - no need for a raid.I am on a PC.I have been recording to a laptop for over a year now with a magma chassis through a Blackmagic design Intensity card to Cineform.The highest data rate for Cineform is around 24 MB/s and my notebook has handled it well.Awesome quality and no problems.HDD keeps up and I can shoot all day till it is full.I suspect the HDD you mentioned is up to the task so you should have no problems.As long as you have the CPU up to the task it is doable.Test test and test again.Best wishes.

Matthew Wauhkonen
March 19th, 2009, 05:17 PM
It works fine, fast enough for prores hq; probably two raid0 drives could do uncompressed 8 bit YUV... Really shows the hv30's faults, unfortunately....

Matthew Wauhkonen
March 20th, 2009, 08:49 PM
http://home.comcast.net/~amuletman/h264.mov

If only there weren't a 6-foot tether....

Christopher Drews
March 20th, 2009, 09:02 PM
You will need a raid to be able to capture at that data rate . So I think you will not be ble to do this without serious hardware

Doug

You do *NOT* need a raid to capture Pro-Res HQ to a 7200 3gbs internal SATA drive. I do this all the time and a user here, shot an entire feature film, capturing Pro-Res HQ without a RAID - all to an internal drive in his Mac Pro.

The only requisite is a capture card that supports Pro-Res acceleration. There are two to choose from: the Blackmagic Decklink and the other is the AJA Kona / IoHD.

Sorry, but I wanted to clarify that.
-C

Doug Tessler
March 20th, 2009, 11:55 PM
With a capture card yes but why