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-   -   datarate requirement for editing uncompressed HDV in FCP4 on dual 800 G4 (https://www.dvinfo.net/forum/final-cut-suite/13852-datarate-requirement-editing-uncompressed-hdv-fcp4-dual-800-g4.html)

Gordon Teifel August 28th, 2003 12:45 PM

datarate requirement for editing uncompressed HDV in FCP4 on dual 800 G4
What's the datarate requirement for editing uncompressed HDV content from my JVC GR-HD1? The drive connnectivity choices may be FC, ultra320SCSI, FW800 or? Otherwise, compressed HDV is just fine with normal FW400.

My research seems to be an Xserve with 720GB RAID on the Fibre Channel, or 10K ultra 320 SCSI drives in RAID, or would a SAN FireWire cube work in uncompressed HDTV editing?

If 5 separate FW external drives are RAIDed, does the datarate increase by 5?

Maybe too many questions, but if DV loads a drive with 13GB/hour content, what's the 720P drive space/hour?

Glenn Chan August 28th, 2003 03:11 PM

Medea sells a RAID box that has 4 ATA drives (RAIDed together) and it connects to your computer via SCSI (you need a SCSI adapter too). This is cheaper than the XSERV RAID I believe. The Apple website has information on which XSERV you need for the HD format you will be using (720i or 1080i).

RAIDing with SCSI drives is probably not worth it.

5 FW drives RAIDed together will give less than 5 times the speed. xlr8yourmac.com has some benchmarks on FW800 RAID. The optimal setup is one drive a channel, which means that if you want 5 drives then you need 4 FW800 PCI cars which will suck up the PCI slots on your computer. I'm not sure how many drives you need in a FW800 RAID to support uncompressed HD.

Adrian Douglas August 28th, 2003 07:58 PM

What do you mean by "uncompressed", the HD1 outputs it's HD stream as MPEG2 dosen't it? This shouldn't require expensive RAID arrays and SCSI drives.

Jeff Donald August 28th, 2003 08:05 PM

I'm not sure there is software, yet, to edit the HD1 on Mac, is there?

Gordon Teifel August 28th, 2003 08:16 PM

You're right about the software. Although Steve Mullen is working on his 4HDV package to allow the Mac to edit this MPEG4-TS in Final Cut Pro.

The GR-HD1 will output 720P, 1080I and 480P formats in uncompressed format. This is an amazingly robust camcorder to spew out these formats on demand.

I need to ask enough discerning questions to get the knowledgeable answers for cost effective equipment planning.

The datarate for uncompressed HDTV at 720P is still unanswered.

Thanks for the collective responses.

Jeff Donald August 29th, 2003 03:37 AM

JVC must have specs on this, it's their camera. Have you asked on our HD-1 forum, that Steve moderates? Some JVC people show up from time to time there and may be of help. How does it output the data? Via FireWire? The specs for FireWire are widely known and would not require expensive RAID's in most cases.

Adrian Douglas August 29th, 2003 07:23 AM

Looking at the Japanese version there is a D1 output on it. Is this on the US model as well?

Scott Anderson August 29th, 2003 02:32 PM

What the Japanese are calling a "d1" connector is simply a breakout to analog component. All digitizing to/from the computer is still done via firewire (400), but instead of transmitting DV25 data, the firewire is transmitting the camera's original MPEG2 Transport Stream.

Also, the MPEG2TS, even though it's 720P High Definition at 30fps, because it's MPEG2 inter-frame compressed, the data rate is even less than DV (about 19Mb/s as opposed to DV's 25!)

Also, if I understand the scant information that Steve is giving out about his 4HDV package, the HD-10's MPEG2TS will be upconverted to something that FCP can still edit in realtime, then the final output will be recompressed as an mpeg2TS to go back to the camera, or to a DVHS deck.

This is basically the same thing that cineform is doing with the plugin for Premiere. They are upconverting to a proprietary codec at around 48-80Mbits/s, meaning you can get 2 streams (A&B roll) on a single 7200rpm IDE drive! Or, 4 streams+transitions on 2 IDE striped as RAID0.

I think that SCSI is on it's way out. Even the super-high end RAID's are all going to IDE or serial ATA drives, sometimes with as many as 16 in a 3U rack unit!

As for the original question of editing UNCOMPRESSED HD from the HD-1 or HD-10, the short answer is you won't edit uncompressed, but some version of mild compression (cineforem calls it "visually lossless")

It seems that with the original footage being an MPEG2TS, you can get away with compressed footage just fine in editing, still do keys, composites, etc just fine, then go back to the cam with virtually no loss, and do it with off the shelf drives!

Oh things are getting very interesting...

Jeff Donald August 29th, 2003 05:30 PM

I would say that this isn't real uncompressed footage, not over FireWire 400. I would be looking at FireWire 800 and 800 RAID 0. The other option would be IDE RAID 0. Either option will be plenty fast enough.

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