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-   -   4:4:4 10bit single CMOS HD project (https://www.dvinfo.net/forum/alternative-imaging-methods/25808-4-4-4-10bit-single-cmos-hd-project.html)

Rob Scott June 11th, 2004 08:25 AM

<<<-- Originally posted by Laurence Maher :
What I'm trying to figure out is, just how do i get my footage into Mac and FCP for editing, as I'm sick of PC non-stable systems. -->>>

OK, I'm not sure when this would be possible (it would require a 4- or 8-drive array inside a small enough box, etc.) ... But consider this possibility:

1 - Self-contained camera unit that captures to raw files
2 - Download the (large) raw files to your Mac
3 - Overnight run processing software to do Bayer filtering, color correction, gamma, etc. and compress to Aspect HD
4 - Delete the raw files and use the Aspect HD files as your "masters"

Obin Olson June 11th, 2004 08:35 AM

Mike lets stay in the hear and now ..I have a camera system...it shoots NOW ...it's what this thread is about... I understand what you want for a system but I am not selling a system. I am building one and if you wanted one well you could just follow in my footsteps and build one from what I am doing...lets just keep this on-track and about what we need NOW for our camera system(s) so we can go SHOOT and stop the idle chit-chat

Steve Nordhauser June 11th, 2004 08:40 AM

I agree with both of you. Rob needs to plan the future a bit since he is considering a large outlay of time (Rob, you've got mail) and needs a roadmap to cover where he is going. The work needs to be methodical, building up. Obin, you are right that basic functionality will be all that is required for a first usable release.

Mike Metken June 11th, 2004 08:45 AM

Obin,

agree. I just wanted to stress the fact that inexpensive field recording is available now straight into your NLE. The camera based recorder is further down the road.


Rob,

I think that Aspect HH only works with Windows and it is 8 bit. Prospect HD is 10 bit but for the next 4 months will only be sold packaged with Boxx RT.

Mike

Rob Scott June 11th, 2004 08:54 AM

<<<-- Originally posted by Mike Metken :
I think that Aspect HH only works with Windows and it is 8 bit. -->>>

Crap. Wasn't thinking about that. What about DVCPRO HD for FCP? Can you get that codec separately?

<<<-- Originally posted by Steve
...needs a roadmap to cover where he is going. The work needs to be methodical, building up. -->>>

Exactly. I'm going to start in Windows, with just basic CameraLink capture, preview, Bayer and output to 16-bit TIFF. Period.

But I'm trying to choose cross-platform tools so that the software could be easily ported to Mac OS X and Linux. I'm also going to try to develop it a modular fashion that parts of it could be used in embedded "firmware" inside a camera box itself.

(Unfortunately, IIRC, the CameraLink SDK supports Mac OS at all. Just Windows and Linux.)

Obin Olson June 11th, 2004 09:00 AM

that codec is 8 bit

Mike! c'mon man are you going to drag your AVID onto the set with all this software loading the system and try and hack a recording system out of it?? this is getting silly..we are NOT going to use our NLE computer TOWER to capture with...I am building a VERY small "capture" box that is FAR cheaper then my NLE system is and MUCH better for this task!!

Rob I was up till 4am last night reading shit and it sure looks like you could (in the future) build a box with a FPGA that could be programmed to capture and spit out image files...don't let this stray you from the path if BASIC software..but think how awesome that would be in the future..no PC at all jsut camera FPGA system and disk drives!

Mike Metken June 11th, 2004 09:10 AM

Rob,

DVCPRO HD is 8 bit also. I don't think that Panasonic would sell it separately, maybe only as some super expensive hardware solution.

10 bit gets expensive. When Prospect HD becomes available it may be $5K for the software alone. David Newman would know better.

I'd be satisfied with 8 bit Aspect HD. It is 4:2:2, up to 1440x1080p. You get the same or better quality than CineAlta recording. Major studo film productions have used that.

Obin,

I don't want to drag a computer to the set either. But you need a large monitor anyway. How are you going to hook it up to your camera?

Mike

Obin Olson June 11th, 2004 09:16 AM

8bit sucks, what you see is what you get with 8bit 10bit is alot more like film you can push it in post ...we need to stay with 10bit UNLESS we want to shoot at a high framerate then we can use 8bit for more fps recording if needed

Mike Metken June 11th, 2004 09:19 AM

Obin,

If you want 10 bit, then Mac with FCP HD is the best. Boxx RT with Prospect HD is over $25K.

Mike

Obin Olson June 11th, 2004 09:24 AM

Mike FYI can open and color correct with combustion after effects etc and then downrez and compress for editing in premiere pro

Rob Lohman June 11th, 2004 12:55 PM

Obin: I thought we always needed to shoot at higher framerates
due to the rolling shutter? Or can we fix this in some other way?

What did you find in regards to FPGA solution you are talking
about? Rob and myself have been talking a bit about FPGA
through e-mail.

Rob Scott June 11th, 2004 01:10 PM

<<<-- Originally posted by Rob Lohman : Obin: I thought we always needed to shoot at higher framerates
due to the rolling shutter? Or can we fix this in some other way?
-->>>

This is AIUI ("As I Understand It") ...

You can shoot at a standard frame rate (24 fps). Reading out at the maximum possible speed takes far less than 1/24 of a second, so you put "blanking" time between frames. This simulates a standard 1/48 second shutter speed (or faster) when you are shooting 24 fps.

I calculate that reading a frame from the chip actually takes about 1/70 second. Breaking this down into decimals ...

1/70 sec = 0.0143 sec
1/24 sec = 0.0417 sec

So, to capture at 24 fps you do the following steps ...
  • capture a frame in 0.0143 seconds
  • blank for 0.0274 seconds
  • capture the next frame ... etc.
Does this sound right, Steve?

Steve Nordhauser June 11th, 2004 01:16 PM

Although it is possible to adjust the vertical blanking time somewhat, what you proposed hasn't been attempted yet. It might take some firmware changes in the camera. What Obin was proposing is based on the rolling shutter artifact. Each line is sequentially read from top to bottom. That means that there is a temporal difference on any image of one frame time from the top line to the bottom. The faster you go, the less the difference. Obin wants to readout at twice the frame rate he needs and toss every other frame. This will get him the desired rate with no timing adustments but reduce the single frame time in half.

I will have to think about what Rob suggested though - extending vertical blanking for a full frame time.....hmmmm.

Rob Scott June 11th, 2004 01:23 PM

<<<-- Originally posted by Steve Nordhauser :
Obin wants to readout at twice the frame rate he needs and toss every other frame. -->>>

OK, then, it would be ... ?
  • capture a frame in 0.0143 seconds
  • blank for 0.0065 sec
  • capture a frame in 0.0143 seconds - throw it away
  • blank for 0.0065 sec
  • et cetera...
I think that would be equivalent. I will have to read the documentation and figure out what resolution it's possible to program the readout and blanking times.

Rob Lohman June 11th, 2004 01:35 PM

Somehow I have a very hard time understanding this rolling
shutter thing. I understand how you normally want to wait and
capture a frame to get a certain frame rate.

I was however perhaps incorrectly assuming that since this is
all digital I would simply get a frame in the frame grabbers
buffer. I thought that was the main reason it was there. In
other words, asks for 24 fps and you get a buffer that gets
filled with information 24 times a second.

How to sync all of this is a question indeed.


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