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-   Panasonic P2HD / DVCPRO HD Camcorders (https://www.dvinfo.net/forum/panasonic-p2hd-dvcpro-hd-camcorders/)
-   -   Press Release: FireStore for DVCPRO HD (https://www.dvinfo.net/forum/panasonic-p2hd-dvcpro-hd-camcorders/50832-press-release-firestore-dvcpro-hd.html)

Barry Green October 10th, 2005 11:22 PM

Superb! Hopefully they will implement the logic to allow active-frame-only recording. Four hours of continuous 720/24p footage puts the recording capacity in the same ballpark as other FireStores...

Daniel Kohl October 11th, 2005 02:51 AM

Hi Barry,

can you explain what active frames are in ten words or less? Or better yet give us an indication as to where we can find out more about the difference between the DVC Pro HD codec and the HDDV codec.

This may not be the right place for this question, but are you implying that there are GOP (groups of pictures) in the DVC Pro HD codec or what are active frames? And or how would active frame only recording work?

I guess I should do a search.... I found something:

http://www.dvinfo.net/conf/showpost....09&postcount=5

sorry that didn't work how I expected, here is the whole thread ...

http://www.dvinfo.net/conf/showthread.php?t=22531

Dan Euritt October 11th, 2005 09:02 PM

the fs-100 may currently be rated to have a 100 gb hdd, but by the time it gets released and commonly available, laptop hdd's will be bigger than that, with sata interfaces and 7200 rpm spindle speeds... it's already happened.

the laptop computer market has been red-hot for awhile now, so hdd manufacturers have lots of product in the engineering pipeline.

Jan Crittenden Livingston October 13th, 2005 06:19 AM

Quote:

Originally Posted by Barry Green
Has it been verified if the FireStore will allow for storing "active frames" only? If so, that would mean over FOUR hours of 720/24p. But last I heard it might just store the raw stream directly, without parsing out the duplicate frames (which would mean 720/24p would also deliver only 100 minutes). Do you have any more info on this?


Hi,

As far as I am aware the signal that comes out of the firewire port is strictly 60i or 60P. If I hear differently I will let you all know.

Best,

Jan

Kevin Dooley October 13th, 2005 09:48 PM

I expected the stream to be a normal 60p/i.... The only question left is what will the Firestore do?

Slightly off topic... does the Varicam have Firewire out? If so, this could be a neat addition to a Varicam set up too...

Ram Ganesh October 18th, 2005 12:34 AM

Quote:

Originally Posted by Daniel Kohl
Hi Barry,

can you explain what active frames are in ten words or less?

the firestore always records at 60 - so for 30fps, each frame is recorded twice... and for 1fps - each frame is recorded 60times.

but in P2 - only 'active' frames are recorded - so 24fps will be just 24 frames.

Daniel Kohl October 18th, 2005 03:02 AM

Quote:

Originally Posted by Ram Ganesh
the firestore always records at 60

I thought I was begining to understand what active frames are.

But this stament is confusing.

The Firestore records 60fps (you mean the NTSC version right)?
Do you mean in general or only with the AG-HVX200?
Do you mean each frame is recorded twice or each field (I guess it would depend on if the camera is in p or i mode)?

How many times does the Firestore record each frame at 25fps?

Can you clarify please?

Scott Anderson October 18th, 2005 10:03 AM

The Firestore recording at 60fps has nothing to do with being NTSC. It is an engineering cost-saving measure. In a camera that is capable of multiple frame rates, it would be very difficult and costly to design every component in the system to support all those multiple frame rates.

In the Varicam, for instance, no matter what frame rate you shoot in, the camera always records the maximum frame rate (60) to tape. A simple indetifying "flag" is added to the signal to indentify the frame rate shot. That way, parts of the DSP and the tape transport never have to adapt to many different frame rates. They just have to record duplicate frames, which is much easier to do, from an engineering and design standpoint.

Having the Firewire out support multiple frame rates, then designing the Firestore to recognize and adapt to all those frame rates would require extra circutry. Instead, the camera simply duplicates frames somewhere earlier in the capture, then sends a 60fps signal out through the Firewire. The Firewire and the Firestore hardware only have to function at one frame rate.

P2 recording being a software-based process is easier to adapt. You only need to write the software differently in order to drop those extra frames before they are recorded to the card.

The Firewire DVCProHD deck operates in a similar manner. Although it records at 60fps, when you digitize into FCP, for instance, the software recognizes those duplicate frames and only digitizes the active frames. I would expect a similar feature to be available with the Firestore. Even if the Firestore always throttles at 60fps, you should have an option to throw away those duplicate frames when editing, thereby saving storage space on a local HD or archival medium.

Daniel Kohl October 18th, 2005 12:50 PM

Quote:

Originally Posted by Daniel Kohl
Do you mean each frame is recorded twice or each field (I guess it would depend on if the camera is in p or i mode)?

How many times does the Firestore record each frame at 25fps?

Can you clarify please?

Hi Scott,

Thanks for that very clear and easy to understand explanation.

I don't understand how the FS-100 is "throttled" though. Doesn't the FS-100 just accept the data flow coming out of the camera as it is, just like tape does. It seems to me that you are suggesting that it would be nice if the FS-100 would "throttle" to match what is being flagged. What I am asking is, what does the FS-100 do differently than say FCP capturing directly from the Varicam?

Since the Varicam apparently uses frames per second (I'm assuming non interlaced) then is the interlacing process also a software function that takes place after the video material has been recorded? (I'm not sure why I want to know this) Or have I got this all wrong anyway?

Sorry if I am being thick here.

Jon Bickford October 25th, 2005 09:38 AM

also, will the firestore be able to capture footage with variable frame rates?

-Jon


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