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Tomas Koolhaas

AG-HVX200

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Hi,

 

Well, not really; that's pretty much it.

 

The best way I can think of explaining it is this: jet planes and cars both run on oil, but they don't take the same fuel.

 

Technically speaking, Firewire is a networking protocol rather like the combination of Internet Protocol and Ethernet. Much as we might say "IP over Ethernet" or "IP over ATM" (for a DSL phone-line internet connection) it's more complete to say "DV over 1394" rather than just saying "1394" and assuming everyone knows what we mean - especially now we can also have HDV over 1394! In fact, it's perfectly possible to set up an IP network over Firewire. IEEE-1394 doesn't specify what goes over the network, just how it's transported; the specification for what we call "firewire" determines how what the connectors look like, how data is routed, and how it's broken up into chunks so that can happen ("Packetisation"). It doesn't say anything at all about what that data represents, whether it's IP network packets (in the case of a computer network), part of a video stream (in the case of a 1394 video device), or SCSI commands and data (in the case of a 1394 hard disk.)

 

Therefore, if you plug a firewire hard disk into a camera, the resulting two-node 1394 network should - assuming the implementation in the camera is sufficiently general - handshake, identify nodes, establish a routing structure, and, without getting into the real grit of it generally initialise - at which point the camera will say "Here, have some video," and the hard disk will say "What's that got to do with me?"

 

Compare this to something like SDI. The first line of the first page of the spec says something like "This is a specification for a digital video transport protocol." If you have a BNC labelled "SDI", then it's going to be a video device, and it knows what is expected of it. Firewire is a general networking protocol that's quite similar to the combination of Ethernet and the IP protocol used for the internet, and you could use it to connect more or less any sort of data devices you wanted.

 

There is a further consideration here that's worth mentioning because it's one principal way that 1394 differs from Ethernet - there are provisions for scheduled service. Basically, this means that a device that require and will continue to require a known amount of bandwidth can request it, and have it allocated, so a video device can ask for its 25-megabit allocation and know that it will be available indefinitely.

The point here is that a hard disk does not use this "streaming" approach to data transfer over 1394, it uses unscheduled transfers, meaning it gets the data in chunks as and when there's time on the bus to send it. Firewire is very clever in this way, and there can be several "fluent" allocated streams going on with the unscheduled traffic fitting in around it, but the way a video camera sends data down 1394 is fundamentally different to the way a hard disk expects to receive it.

 

Even once you've satisfied the lower-level networking requirements, you have to address the filesystem issue. You can view a hard disk as like a large, empty library; the filesystem is the Dewey decimal system used to index it. Various different computers and operating systems use different variations on this; the one used by Windows XP is called NTFS, but they do basically the same job. The hard disk itself has no knowledge of this system; it just writes blocks of data where it's told to, and the maintenance and understanding of this system is the sole responsibility of the operating system.

 

A video camera has no understanding of what a file is, let alone how to write it to a hard disk in a format that a computer will understand. Most of the 1394 video hard disk recorders, such as Firestore, write video files to the disk using the FAT32 filesystem, which most computers can read as standard. Implementing that system, especially in an embedded hardware device rather than in operating system software, is a major software engineering project. Even more than that, most of these devices will wrap the video up in a Quicktime or AVI movie file, which is yet another layer of framing and presentation that has to be done. You could stream raw 1394 data to a hard disk, but it wouldn't be readable by things like Final Cut. There are actually programs which will play raw DV captures, but they're pretty much lab interest only.

 

So, there's a pile of stuff between a camera and a hard disk, some of which is moderately advanced software engineering - which is why things like Firestore are reasonably expensive. Really the only commonality between the 1394 connectors on the camera and a firewire hard disk is the network protocol and the shape of the plugs and sockets. The data formatting could hardly be more different.

 

Phil

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It seems that the HVX2000 1080 output will work in some capacity with Final cut pro. HD,

but what about Avid? does anyone know if it will support the 1080 footage from the HVX?

Also, I don't know much about editing programs so this may be a stupid question, but is there a program that would allow you to shoot onto DVCPRO HD tape 720p at 24p, then use the HVX as a deck to export/import this footage straight into an editing program like Avid or Final cut?

Cheers.

Tomas.

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Hi,

 

Companies are generally very bad at answering awkward questions like these, even though they greatly impact the value of the camera. God knows why, because we'll find out in the end, anyway - but I wouldn't expect any solid answers on questions like the VT ability until there's a production model in the hands of someone who doesn't work for Panasonic.

 

Phil

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Hi Phil, great post up above! Technobabble is truly an acquired taste. :-p

 

You would think an NTFS version of the FireStore would be available as well. I'd much rather have each take as its own file than have the longer ones segmented, but I guess a lot of software nowadays can automatically detect segmented AVI files and join them with ease.

 

Ehh. This is OT; I'm finished :ph34r:

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Hi,

 

To be fair, I'm not entirely sure there isn't a Firestore-like device that'll record to an NTFS volume; Microsoft have licenced it to a few people, mainly people who want to make disk management and repair tools. However, given the trouble that the Linux crowd have had writing an NTFS filesystem driver, it's clearly not simple.

 

FAT32 isn't too bad at all, especially if you never need to delete a file or do directories.

 

Phil

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Hello,

Does anyone actually know when one of these cameras will be available to buy? I have tried googling but have only gotten 'Fall 2005' as an answer, I wondered if anyone had any inside info. as to when they will be available for purchase.

Also, did anyone ever actually say whether or not you could use the camera as a deck to export footage shot at 24p 720p on DVCPROHD tapes straight into an AVID style sytem? maybe someone already did but I got lost in the technobabble!

Cheers.

Tomas.

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Hello,

Does anyone actually know when one of these cameras will be available to buy? I have tried googling but have only gotten 'Fall 2005' as an answer, I wondered if anyone had any inside info. as to when they will be available for purchase.

Also, did anyone ever actually say whether or not you could use the camera as a deck to export footage shot at 24p 720p on DVCPROHD tapes straight into an AVID style sytem? maybe someone already did but I got lost in the technobabble!

Cheers.

Tomas.

The Panasonic reps have consistently said November/December. There is no DVCPRO HD deck on the camera itself, therefore there is no way to export that footage through this camera.

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The Panasonic reps have consistently said November/December. ...

 

FYI: The Panasonic product manager for the HVX-200 posted some interesting info over on creativecow.net yesterday:

http://forums.creativecow.net/cgi-bin/new_...3&postid=855009

 

Al the best,

 

- Peter DeCrescenzo

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FYI: The Panasonic product manager for the HVX-200 posted some interesting info over on creativecow.net yesterday:

http://forums.creativecow.net/cgi-bin/new_...3&postid=855009

 

Al the best,

 

- Peter DeCrescenzo

The first "engineering sample" will actually be on display at IBC (http://www.ibc.org/) on a week from Friday. Hopefully some samples will come from that. Unfortunately for anyone in America wanting to attend, it takes place in the Netherlands...

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It's not HDV. It's DVCPRO HD.

COULD SOMEONE EXPLAIN ME WHAT THE DIFERENCES ARE BETWEN THE FORMATS THAT THE PANASONIC P2 ALLOWED YOU TO SHOOT. THE 720P AND THE DVC-PRO THING ECT.?I JUST WANT TO HEARD A GOOD EXPLANATION THANK YOU.

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