Barry's book...

S

spikeman256

Active member
Barry's book is good...really good...grammar is good, flow is good, transisition is good, content is good, it all really is good....

I do have a simple question.

I'm at about page 90 or so.....

The HVX-200 films 720p and it films 1080i.
- 720 is progressive...entire frames at once.
- 1080 is interlaced...1/2 frames at once.

Can the HVX-200 "horsepower" only handle 1080 as 1080i (ie, interlaced, ie 1/2 frames at once), whereas it can handle 720 (lower res) as 720p (ie, *entire* frames at once ?

Is this the issue? Hi res is going to be a somewhat hampered (1080 *interlaced*, whereas slightly lower res (720 *progressive*) can be full frame refreshes since there are less pixels to refresh)?


I know I don't have a huge point here, just a clarification for my own noggin'.

- either you get great res (1080) @ 1/2 refreshes (interlaced)
- or you get pretty good res (720) @ full refreshes (progressive)

thanks.

-shannon
 
Internally the HVX handles all footage as 1080p. It's scanned off the chips into a 1920x1080 matrix, and all processing is done in 1080.

The issue comes about because there is no recording format or broadcast transmission standard for 1080p; the various countries and standards organizations settled on 1080i but not on 1080p. Because the HVX uses the existing DVCPRO-HD codec, which complies with broadcast standards etc., it is an interlaced data stream in 1080 mode.

So the HVX takes its internal progressive footage and separates it into "fields" to be transported and encoded in a 60i data stream. Your NLE will reassemble the fields back to their original progressive nature.

The HVX does true 1080/24P and 1080/30P. It has to disassemble the footage into interlaced pieces for compression and recording, but reassembles them back into their original progressive state in the editing app.
 
OK, so the issue isn't a "horsepower" limitation by the HVX-200 (since it does indeed do 1080 progressive internally), but more of a "standards" limitation...because there is no standard for 1080p, the HVX-200 acquieses by throttling down to 1080 interlaced.

...basically, the camera easily handles 1080p internally, but squirts it out as interlaced in order to maintain compatibility with current standards.

Is that right?
 
spikman: It doesn't matter that it spits it out as interlaced. Your NLE will discard the extra frames and fields, and build it back to 24p.

it IS 24p just like the DVX100. They fit ALL of the 24 full progressive frames into the interlaced stream, and then it is extracted in the NLE. It doesn't mean the quality is 1080i that's been deinterlaced. That's a whole 'nother ballgame. Just consider it true 1080p because that's what it is.

It is called 1080Pa to indeftify it as true 24p encoded to an interlaced stream.
 
yeah but.. will u have to tell your NLE that the 1080i footage is 1080p? or does the NLE automatically see is as 1080p? In other words... ion the settings of the NLE would you select your project type to be (i) or (p) ?
 
Since interlaced is *displayed* as odd lines/even lines, it sounds as if "interlaced" is more about how images/frames are *displayed*, not stored.

It would make sense that instead of displaying the odd lines and then the even lines, that an NLE could simply *combine* the odds & evens to make a single progressive frame *before* they are displayed (or processed or whatever).

Is this correct?
 
eagleye said:
Does this possibly mean a firmware upgrade could make it spit out 1080p once a standard is set?
Click to expand...
No, because the recording system (DVCPRO-HD) doesn't support it. It'd take an entirely new recording format to support 1080/60p.

But if you get the Hydra modification, then you can extract full 1080/60p. In fact it'll do 2K resolution at up to 60 fps. Hydra bypasses the HVX's recording system, so it can get full access to the variable-frame-rate 1080p footage and 2K footage that the chips are capable of generating.
 
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