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View Full Version : Anyone Tried 2048x1080 (AKA 2k)



Dan_Kanes
06-17-2010, 05:51 PM
Anyone tried doing a 2048x1080 aka 2k Recording using the GH-1 Firmware hack?

I don't own a GH-1 right now - just curious - if we could get 2k, 4:2:2 footage from this camera it would be like a ghetto Si2k!

Ozpeter
06-17-2010, 06:01 PM
As far as I can see there is no such setting in Ptool.

WesScog
06-18-2010, 01:59 AM
I think that'd be WAY too much data for the camera.

As far as I have heard some people are doing 2000+ wide images, but they are accomplishing that with anamorphics.

Barry_Green
06-18-2010, 10:30 AM
The anamorphic wide image is being achieved through digital uprezzing, not through actually recording a wider image.

mpgxsvcd
06-18-2010, 10:43 AM
I shoot 1920x1080 @ 40 mb/sec MJPEG with my GF1. It is stable for all indoor shots but it will hit the bit rate write limit with any sunlight at all. It looks pretty outstanding.

I tried 2400 x 1350 and it froze instantly.

Does anyone have proof as to what the GF1 does when it records 1920x1080? It sure looks better than 720p to me. However, I don't know how to prove if it is better or not.

I will upload some 720p and 1080p samples later to show what I mean.

TrueIndigo
06-18-2010, 11:09 AM
If we can change region of interest then CinemaScope format might be more practical regarding datarate (should be less than comparable 1080p). DCI spec for 2k cinemaScope (2.39:1) is 2048 x 858. If windowing height needs to be divisible by 16, the frame could be 2048 x 864 (just needs 6 pixel crop to height in post). Not sure how close this is to reality -- didn't NURBS shoot a MJPEG wide frame several weeks ago, though may have only lasted a few seconds before card error.

mpgxsvcd
06-18-2010, 12:03 PM
If we can change region of interest then CinemaScope format might be more practical regarding datarate (should be less than comparable 1080p). DCI spec for 2k cinemaScope (2.39:1) is 2048 x 858. If windowing height needs to be divisible by 16, the frame could be 2048 x 864 (just needs 6 pixel crop to height in post). Not sure how close this is to reality -- didn't NURBS shoot a MJPEG wide frame several weeks ago, though may have only lasted a few seconds before card error.

I would prefer to record 16:9 and crop that in post processing if you need a different aspect ratio.

Mike@AF
06-18-2010, 12:08 PM
I agree. I do that all the time. It would be nice if we could get 2.35 or 2.40 guidelines on the LCD though. I'll throw that in the request thread.

MR Fanny
06-19-2010, 12:12 AM
I agree. I do that all the time. It would be nice if we could get 2.35 or 2.40 guidelines on the LCD though. I'll through that in the request thread.


that would be shmick. we already have the horizontal guide assist that could possibly be modified. I just make do with a cut out sleeve that i put over my lcd to make sure everything is in anamorphic frame in post

TrueIndigo
06-19-2010, 09:03 AM
Yes, cropping 1920 x 1080 in post to CinemaScope format is fine for 16:9 output (no enlargement is required because you are already shooting in FHD). But the OP is interested in the possibility of 2k recording with the GH1 hack. This has certain advantages for the CinemaScope format, particularly as the datarate would be less than for standard FHD. Shooting 1080p for 2K CinemaScope requires an enlargement: 1920 x 1080 to 2048 x 1152 is a 6.67% uprez, and then you need to crop it by 294 vertical pixels to get back to 2048 x 858. If the wide 2k image could be recorded directly, this enlargement would be avoided and there would probably just be the need for a very slender height crop required (efficient use of pixels).

The potentials of the GH1 continue to fascinate me week by week. I hope the 2K option (in whatever format) becomes possible eventually. Isn't that the next step up in basic resolution from FHD? And now "everything" is 16:9 shape, CinemaScope is a welcome alternative (not right for all projects all of the time, but I do love that shape for composition).

Barry_Green
06-19-2010, 11:50 AM
I don't think we have any parameters identified for controlling the size of an AVCHD frame, do we? Perhaps cinemascope is possible in MJPG?

TrueIndigo
06-19-2010, 04:27 PM
Yes, I think the 2K experiments were in MJPEG. An exciting and unique possibility if it can be made reliable for practical use.

FlyingDutchman
06-27-2010, 12:38 PM
I was reading this thread last night, I'm highly interested in 2K / cinemascope, so.... I made a new version of the firmware, loaded it - and was filming today with this resolution:

the frame could be 2048 x 864 (just needs 6 pixel crop to height in post). Not sure how close this is to reality -- didn't NURBS shoot a MJPEG wide frame several weeks ago, though may have only lasted a few seconds before card error.
Principially it works (in Mpeg, res. 2048 x 864, qual. 384/330/300/276) - I got quite some "card speed" messages with recording braking down (filming with a Transcend class 10 16GB card), esp. when filming with normal DoF - but this is not so dramatic to me, since I use it for free, creative work and I ilke shallow DoF. This is also not a big problem, since usually it breaks down immediately - of if not, I can film for minutes without a problem. So all I have to do, is delete the 1 sec. clips from time to time...

The problem though, as I suspected, it's just 16:9 material squeezed vertically (instead of horizontally, like the way it is, when you use these "1440x1920"Mpeg settings).
So is this because of me, being too ignorant, and not knowing where to change the aspect ratio in Ptool? Or is this option not (yet) "regularly" available in Ptool (3.37d)?
If it isn't: is it available in some older version, or is there some trick one can achieve this (without having to buy anamorphic lenses)?
Being able to change aspect ratio would really be great for me... I'm planning on using this for some art projects, would love to be able to do something like 6:1 as well, for projections on 360 screens - so tips are greatly appreciated :dankk2:

Cheers, FD


Oh and btw I'll upload some of the 2048 x 864 footage soon...

Lpowell
06-27-2010, 01:11 PM
The problem though, as I suspected, it's just 16:9 material squeezed vertically (instead of horizontally, like the way it is, when you use these "1440x1920"Mpeg settings).
Your suspicions are correct, I did some experiments with MJPEG frame size at an earlier point and it became apparent that the anamorphic squeeze did nothing but degrade the image quality.

The GH1 appears to be hard-wired with two native video frame sizes: 1280x720 and 1920x1080. The normal video modes are scanned in a manner that produces undistorted, square pixels. When you hack the frame size in PTool, all you're doing is altering the sensor scan to produce squeezed, non-square pixels in one of the two built-in frame sizes.

What makes it appear to be a wider frame is that the GH1 writes your patched screen dimensions into the movie's metadata. Your video editor then reads the patched screen size and automatically stretches the squeezed video to make the pixels appear to be square. However, in many cases, I observed that the GH1 did not produce a technically correct anamorphic image, and the required stretch was not the same as the patched dimensions that I chose.

FlyingDutchman
06-27-2010, 01:46 PM
I observed that the GH1 did not produce a technically correct anamorphic image, and the required stretch was not the same as the patched dimensions that I chose.
Ok, that's new to me - I'm gonna watch it closer when I'm editing the stuff next time... So you mean also regarding 1440x1080 / 1280x1080? Because I thought, everybody was quite enthusiastic regarding these modes?

Lpowell
06-27-2010, 08:32 PM
I don't know about the 1080p modes in MJPEG, what I tried was a 1600x720p 70mm widescreen anamorphic squeeze. While the GH1 wrote the metadata correctly, the image was squeezed about 10% less than intended.

FlyingDutchman
06-28-2010, 12:36 AM
Hmm, did you manage to change to aspect ratio then, or was it like in my case - only pixel size changes, AR staying the same? Because simply "unsqueezing" for 10% in FCP / Afx is not the biggest problem ;-)

Lpowell
06-28-2010, 01:30 AM
The aspect ratio that changed was only the pixel aspect ratio - the GH1 still recorded in 1280x720p resolution. But each of the 1280 pixels in a line was increased in width, which made the recorded image in-camera look too narrow. But in After Effects, the 1600x720p frame size that was written into the movie's metadata caused the frame width to be stretched to the intended aspect ratio. The GH1, however, did not make the pixels wide enough to fit the full width of the 1600-pixel frame, and the image looked like it was stretched too wide by about 10%.