Capture confusion?

[Bill Anderson]

Hi Def, in the past, has generally been associated with faster drives, raid arrays and the fastest processors for any workable real time effects, etc. Now I am confused with the claims, and I don't doubt the authors of these claims, that DVC pro HD can be firewire captured on a laptop from the camera whilst filming. Oh, and now you can also play HD back on an ipod. A laptop will sustain 100mbps? Heck I thought the 5400rpms were taxed at DV's 25mbps! What am I missing? Also, these claims seem to contradict the panic over P2's managabilty, and, given the amount of incredulity expressed at HD on laptops and ipods, I know I'm not the only one that seems to be missing the boat here, so any breakdown of data rates and drive requirements for capture of DVC PRO HD would put a lot of minds at rest.

Thanks.

[Barry Green]

In the past, Hi Def was edited uncompressed. Yes that meant RAID arrays, etc. You were dealing with about 170 megabytes per second.

With DVCPRO-HD, you now have desktop HD editing over firewire. Apple first introduced it in Final Cut Pro HD -- it's already out there, has been for -- how long, six months or a year? It's already available. You can run multiple streams of real-time high-def footage on an FCP-HD system.

100mbps equates to about 12.5 megabytes per second. Most 2.5" drives can easily sustain that data rate. 3.5" desktop drives are much faster, but laptop 2.5" drives can handle that with no sweat.

The ipod test that they keep mentioning was a 720/24p data stream. That means 40mbps, not 100. The little 1.8" drives in ipods would be *very* taxed to try to sustain a 100mbps data stream, but 40 is within their capabilities.

If you want to know what system specs it takes to edit DVCPRO-HD, just look at the system recommendations for FCP-HD or Avid Express HD. Those are two systems that are shipping today that can natively edit the format.

[Chris Hurd]

Howdy from Texas,

Originally Posted by Bill Anderson

Heck I thought the 5400rpms were taxed at DV's 25mbps!

Not in my experience... when I first started using the FireStore FS-1, it recorded DV25 video to a 4200rpm Lacie PocketDrive with no ill effects or dropped frames whatsoever. 5400rpm is recommended for editing, but you can get by with a slower drive for straight captures.

[Craig Schober]

"100mbps equates to about 12.5 megabytes per second. Most 2.5" drives can easily sustain that data rate. 3.5" desktop drives are much faster, but laptop 2.5" drives can handle that with no sweat."

if the panasonic tops out out at 100Mbps in HD data output, why are the p2 cards needed at 640Mbps or even the p2s cards at 320Mbps? how can anyone not suspect panasonic of trying to profit unreasonably from overpriced p2 cards when a simple 5400rpm drive would capture 10 times the data fast enough at a fraction of the price?

[Peter Jefferson]

"why are the p2 cards needed at 640Mbps or even the p2s cards at 320Mbps?"

why?? well if theyre any slower, how long do u think it would take to transfer that across to ur workstation??

[Jan Crittenden Livingston]

Originally Posted by Barry Green

The ipod test that they keep mentioning was a 720/24p data stream. That means 40mbps, not 100. The little 1.8" drives in ipods would be *very* taxed to try to sustain a 100mbps data stream, but 40 is within their capabilities.

The iPod test was a transfer, not a capture. Please note the difference.

Best,

Jan

[Craig Schober]

Originally Posted by Peter Jefferson

"why are the p2 cards needed at 640Mbps or even the p2s cards at 320Mbps?"

why?? well if theyre any slower, how long do u think it would take to transfer that across to ur workstation??

i think the speed difference is negligible. when you're shooting narratives with multiple takes, there is no difference between 30 seconds and 1 minute. as soon as you introduce a "dumping" process that interrupts the production and creates another camera assistant position (ironically is exactly what this and similar dv cameras attempt to eliminate) you're changing the workflow of video aquisition and making it similar to that of film (check the gate, change the mag, etc.).