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capture with express card
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Hello, Ben.
Don’t worry. We are not starting anything 🙂
When I said “wrong” I was only (and really only) commenting Walter’s comment that the signal would go straight to the hard drive. It doesn’t, and I think I explained clearly why it doesn’t.
What’s the bottleneck? You’re right in that it usually works. BUT, beside “bandwidth” there’s another thing called “latency”. How long it takes to go from A to B (and back to B, in this case). Also, there is a signifiicant performance hit, since the Firewire port is not carrying information in one direction but in both, so you have “traffic” between what goes in and what goes out. The Express Card should work better (in the same way, PCI Express works better). By better I don;t mean just getting it to work (the daisy chain thing should work) but things like RT performance, for instance. I know people are using ExpressCards succesfully, so it must be a conflict with the partricular card model, a driver issue or a FCP configuration issue.
All the best!Adolfo Rozenfeld
Buenos Aires – Argentina
https://www.adolforozenfeld.com
adolfo(AT)adolforozenfeld.com -
Alfonso
What Walter said was: “No it doesn’t go to the Mac Drive first. If you set the External drive as the Capture drive, then it goes directly to the External drive. Footage will only go to the Mac drive first if you set the Mac as your Capture Scratch.”
This is correct. It doesn’t go anywhere near the system drive in this instance. That’s all he said.
My point is even simpler: There is no bottleneck in DV capture using FW this way – even FW400 has a far wider bus bandwidth than DV requires – more than a factor of ten. The FW passthrough on the drive can easily cope with DV streams at 3.6Mb/s passing each way. That is NOT, nor ever has been, the reason why people can’t capture using this method – it’s simply an incompatability with the camera, which MAY be the case here. Firewire was designed with consistantly high video bitrates in mind, as opposed to the data ‘bursts’ that USB2 uses, which is what makes a FW400 bus more than adequate for the AJA IO to pass on 10-bit uncompressed SDI. Almost everything else in this setup, including the firewire drive (wherever it is connected) is a speed bottleneck compared to the FW bus.
Everything you suggest about the theoretical advantages of a second firewire bus are correct – it’s quicker on paper. But there’s so much headroom in a DV system, you’ll never see the difference. It may even be the only solution in this case, but since I think we scared the questioner off a long time ago, I guess we’ll never know 😉
Ben
Editec Broadcast Editing Ltd
EVS & FCP specialists for live OB operations.“The Supercar Run” now available for international distribution from http://www.electricsky.com
See you at IBC – we’re there with our FCP/replay truck…
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The plot thickens…I have FW 400 and I had the camera going into the left side with the express card … through the system out the right side of the MCP 15 inch. It was going into the Lacie Porsche 250 G…in which anyway I set it up, will not hold the capture, “an error occurred during capture” … it will cycle through an entire hour tape and nothing…. until I hit escape or run the tape out, but I of course notice no file of material coming up on the media window during timecode break so I do not wait that long. Here is the interesting part ! The 1st porsche drive works fine and holds information and files from other test… but when I set the other drive that is daisy chained from it (drive 2) as the capture scratch it works fine…so the 1st drive will let material go through it into the other drive but not hold a capture…I mean I can let it go and now I have the 1st drive plugged into the other FW 400 port in the express card next to the camera FW and it now set for wave and thumb files and other drive drive on the right side of the MCP set for capture scratch, but I still cannot sleep well not knowing the problem. My wife thought at supper I was having an affair as I was pondering my drive situation in a daze of wonder…~
Now someone mentioned a setting for the capture as DV/NTSC…this material and settings I am using is HDV 1080 60i 30
easy setup
sequnece matchesYou guys are great and I thank you for all the help so far
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one drive seems to work and the other seems to not work despite arrangment or settings, however the one that deos not work allows flow through it and also holds other information fine.
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No,No, No 🙂
Final Cut Pro is much more specific in terms of what it expects from a Firewire port than a Hard Drive is.
In fact, FCP is expecting the standard Firewire chipsets on a Mac, nothing more, nothing less.
Connect your drive to the built-in Firewire port and the hard drive to the ExpressCard.
This may explain why it didn’t work well.
‘Adolfo Rozenfeld
Buenos Aires – Argentina
https://www.adolforozenfeld.com
adolfo(AT)adolforozenfeld.com -
I meant connect your DV/HDV devices to the built-in port and the hard drive to the ExpressCard port.
Adolfo Rozenfeld
Buenos Aires – Argentina
https://www.adolforozenfeld.com
adolfo(AT)adolforozenfeld.com -
It works better now with deck going directly into the MBP. The other drive is not working with the capture but I have one that works fine and as far as I am concerned the problem is solved and the workflow has given me peace of mind. I love the Cow!
Thank you all for you help!
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I’m glad it was helpful for you. It’s worth noting, in case this is useful for you in the future, that nowadays 7200 RPM drives go faster than the FW400 transfer ceiling. It’s not uncommon for last generation drives to achieve sustained transfer rates of 60-65 MB/s (FW400’s ceiling is 50 MB/s).
So, in the future, you may consider getting a Firewire 800 or SATA ExpressCard. They can more than accomodate the newer drives’ speed and, with the right adapter cable, Firewire 800 is backwards compatible with Firewire 400: you can connect FW 400 drives using a 6 to 9 pin cable.ExpressCard rocks. PCI Express on a laptop! In a not so distant future, people doing video on laptops will wonder how we lived without it until now 🙂
Adolfo Rozenfeld
Buenos Aires – Argentina
https://www.adolforozenfeld.com
adolfo(AT)adolforozenfeld.com -
Just one small probably glaringly obvious thing. Are your Firewire drives formatted as MacOSX Journaled? Have you double checked?
I had a similar problem and although I always format my drives MacOSX, one drive was funky. A double-check showed it to be MS-DOS. I could swear I had formatted it. It turned out a client I had sent it to, copied stuff off it, re-formatted it MS-DOS, then copied stuff back. So I didn’t notice.Now I always double-check.
Neil
FCP Editor, Mumbai, India.
Completely PAL.
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