FireStore @ 1080/24p vs 25p

Emanuel

Emanuel

Cross-Examiner
If «you'll be recording an effective 80mb/sec within a 100mb/sec stream (1080/24p), so you'd only get a 20% space loss by using Firewire over P2»? So, 100Mb or 90Mb @ Firestore aren't 100 or 90 minutes @ 1080/24p, isn't it? But only 80 or 72 minutes (?)...

And @ 1080/25p (no pulldown), because you'll get the full 100mb/sec stream, more 20%?
 
Ok - yeah now I'm sort of on your train of thought, still a little unsure if I follow completly.

So you are querying if the PAL signal at 1080/25p - 1440x1080 takes advantage of the full bandwidth? I suppose its two things, one the PAL HVX, and two it will depend on how the Firestore chooses to accept the data.

Am I following correctly?
 
Nathan_Rodger said:
Ok - yeah now I'm sort of on your train of thought, still a little unsure if I follow completly.(...)Am I following correctly?
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Yup!...

So you are querying if the PAL signal at 1080/25p - 1440x1080 takes advantage of the full bandwidth?
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[1] 1440x1080 vs 1280x1080 is apparently an advantage, only I don't know if noticeable @ 35mm film-out, for instance?

[2] But I'm not sure (I'm not the technical guy) if so or if the point is purely a bit rate issue (100 mega bits/second that @ 24p will be just 80% with a 20% Firestore space loss if this device only works with 100 instead of 80 as far as it happens @P2).

I suppose its two things, one the PAL HVX, and two it will depend on how the Firestore chooses to accept the data.

Am I following correctly?
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Yes I think so! And I ask [3] if it will not be or it is 100 mega bits/second...the panorama will not be like this:

100 or 90Gb Firestore

80 or 72 minutes @ 1080/24p
100 or 90 minutes @ 1080/25p
 
Yeah I'm not so sure after having thought about it.

If you look at it from a data point of view - (now I'm speculating - as I'm not sure of the specifics of the codec) Does each frame of the 1440*1080 25P contain more data than the each frame of the 1280*1080 24p equivalent? As I said, I haven't studied if NTSC covers for that with more colour depth, or better sound or SOMEthing, but if all else was equal, it would stand to reason that each "PAL" frame is actually a bigger file.

Therefore 25 of those a second should definitely be a larger file at say 10 seconds, than 10 secs of the 24p equivalent. As such you would get LESS time per Gb on PAL than NTSC.

Cheers, Nathan.
 
As a strictly data rate issue, all 1080 is going to be stored on the FireStore at 100 megabits per second. When shooting 1080, you'll get exactly the same recording time whether shooting 1080/24p, 1080/25p, 1080/30p, 1080/50i or 1080/60i.
 
Well, according to the spec sheet from japan, there are two different recording modes in 720: either "native" (meaning active frames only) or "over 60" (meaning all 60 frames are present, and duplicates are added to round out a 30p or 24p or whatever sequence so it fills 60 frames). It's my understanding that the firewire output is always "over 60", which is the same way the VariCam records.

So I think that the firestore would be receiving an "over 60" data stream. The question becomes: does it just blindly store the whole stream? Or does it have the intelligence to parse the stream and discard the duplicate frames?
 
Focus Enhancement already announced the HVX drive - why dont they just go ahead and clear up that issue once for all.... intelligent drive or dumb drive... whats it going to be...?
 
redindian said:
Focus Enhancement already announced the HVX drive - why dont they just go ahead and clear up that issue once for all.... intelligent drive or dumb drive... whats it going to be...?
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Dear redindian, because it's important to pronounce our concerns before than late...
 
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