I can tell that Xenon IMAX uses standard DCI frame containers: 4K Scope (4096x1716), 4K Flat (3996x2160) and 4K Full (4096x2160). No anamorphic lenses, no other resolutions and containers. And for my 3 years in cinema I have seen only one IMAX movie in 2K resolution, again in standard DCI container.
Also, the IMAX5 sound uses standard DCI 6ch layout for 5.1 setup.
Outputting DCP at 4096 x 3072
-
bengedlow
- Posts: 15
- Joined: Mon Mar 06, 2017 9:52 pm
Re: Outputting DCP at 4096 x 3072
Carsten, this is terrific.
I got my hands on one of our IMAX DCP's here, that turned out to be non-IMAX 2K, grrr. But it was very very simple. Good to know. And! We have arriving tomorrow a sample DCP done in LA for the laser setup, with the 12 channels.
When the drive arrives I can do screenshots of how it is set up. And perhaps even pull out a sample TIFF file (rather than DPX) -- I think they are creating TIFF 16bit. Then I can post the screenshots and an example frame from a just-created DCP. And maybe one of the internal files that represents the positioning of the audio.
I've been talking to Victor Sandrasagra (at EyeSteel), who put me on to you and DCP-o-matic ... and who is quite interested in seeing if an IMAX friendly config. can be set up.
I'm going to go back to 'filmmaking' this afternoon. But the moment the DCP gets here I'll do the screenshots, the TIFF (if I can get the MXF wrapper open) example frame.
Victor and I are suspecting that the 'laser' setup is just some hardware config. that allows the 'standard' 4K DCP to be sent to the two projectors simultaneously. Rather than some exotic hybrid patented process. Of course if there is proprietary angle to it, we won't be messing with that.
I'm going to peruse your audio suggestions. THAT I can understand and fix.
Thank you again for that, and I'll be back tomorrow...
Ben
I got my hands on one of our IMAX DCP's here, that turned out to be non-IMAX 2K, grrr. But it was very very simple. Good to know. And! We have arriving tomorrow a sample DCP done in LA for the laser setup, with the 12 channels.
When the drive arrives I can do screenshots of how it is set up. And perhaps even pull out a sample TIFF file (rather than DPX) -- I think they are creating TIFF 16bit. Then I can post the screenshots and an example frame from a just-created DCP. And maybe one of the internal files that represents the positioning of the audio.
I've been talking to Victor Sandrasagra (at EyeSteel), who put me on to you and DCP-o-matic ... and who is quite interested in seeing if an IMAX friendly config. can be set up.
I'm going to go back to 'filmmaking' this afternoon. But the moment the DCP gets here I'll do the screenshots, the TIFF (if I can get the MXF wrapper open) example frame.
Victor and I are suspecting that the 'laser' setup is just some hardware config. that allows the 'standard' 4K DCP to be sent to the two projectors simultaneously. Rather than some exotic hybrid patented process. Of course if there is proprietary angle to it, we won't be messing with that.
I'm going to peruse your audio suggestions. THAT I can understand and fix.
Thank you again for that, and I'll be back tomorrow...
Ben
-
bengedlow
- Posts: 15
- Joined: Mon Mar 06, 2017 9:52 pm
Re: Outputting DCP at 4096 x 3072
Carsten ... apologies. Snow storms in Montreal. Everything a bit in slow motion.
We had a screening. Looks like there is nothing 'proprietary' about DCP's and IMAX. We'd just need to be able to do the 4096 x 3072 frame. I'm waiting to have a talk with the fellow who mixed the 12.0. Apparently, the projectionist tells me that it's actually 16 audio tracks assigned to 12 channels. I'm going to find out from the horse's mouth how the tracks are assigned to the channels. A picture, with all the right terms.
I'm on an intense shoot Monday - Thursday. But then I plan to follow up on this, if that's cool. I think it could be done. It might even be that DCP-o-matic is almost perfectly set up to do it (might not have to do anything about the audio, just assign the tracks appropriately ... and the only thing requiring a tweak being the 'frame size' limitations.
Will report back here the moment I find out what's needed.
All the best,
Ben
We had a screening. Looks like there is nothing 'proprietary' about DCP's and IMAX. We'd just need to be able to do the 4096 x 3072 frame. I'm waiting to have a talk with the fellow who mixed the 12.0. Apparently, the projectionist tells me that it's actually 16 audio tracks assigned to 12 channels. I'm going to find out from the horse's mouth how the tracks are assigned to the channels. A picture, with all the right terms.
I'm on an intense shoot Monday - Thursday. But then I plan to follow up on this, if that's cool. I think it could be done. It might even be that DCP-o-matic is almost perfectly set up to do it (might not have to do anything about the audio, just assign the tracks appropriately ... and the only thing requiring a tweak being the 'frame size' limitations.
Will report back here the moment I find out what's needed.
All the best,
Ben
-
carl
- Site Admin
- Posts: 2548
- Joined: Thu Nov 14, 2013 2:53 pm
Re: Outputting DCP at 4096 x 3072
We can easily support a bigger frame size if that's all that is required...
-
scorpio81
- Posts: 116
- Joined: Mon May 09, 2016 7:19 am
Re: Outputting DCP at 4096 x 3072
But the bigger frame size (bigger than standard 2K or 4K frame sizes) will no longer be DCI compliant.
The current DCI specs only allow the following frame sizes: 4096x2160 for 4K and 2048x1080 for 2K. There is a statement in the specs that an image can only contain active pixels thus making it possible for an image to be smaller than maximum frame size. But not bigger. The current decoders shall decode and output only 4096x2160 image and may reject a bigger image.
I know that IMAX may use enhanced DCP but it is unknown if it allows images bigger than 4K. And more, IMAX uses standard 4K laser projectors that are DCI compliant and have native 4096x2160 resolution. And it is forbidden by the specs to do downscaling. So if a decoder can output images bigger than 4K then I guess a projector will reject it. I don't believe a projector will crop an image to standard 4K.
So, I believe there's a hardware limitation to image size.
Of course I may be wrong on this.
The current DCI specs only allow the following frame sizes: 4096x2160 for 4K and 2048x1080 for 2K. There is a statement in the specs that an image can only contain active pixels thus making it possible for an image to be smaller than maximum frame size. But not bigger. The current decoders shall decode and output only 4096x2160 image and may reject a bigger image.
I know that IMAX may use enhanced DCP but it is unknown if it allows images bigger than 4K. And more, IMAX uses standard 4K laser projectors that are DCI compliant and have native 4096x2160 resolution. And it is forbidden by the specs to do downscaling. So if a decoder can output images bigger than 4K then I guess a projector will reject it. I don't believe a projector will crop an image to standard 4K.
So, I believe there's a hardware limitation to image size.
Of course I may be wrong on this.
-
Carsten
- Posts: 2804
- Joined: Tue Apr 15, 2014 9:11 pm
- Location: Germany
Re: Outputting DCP at 4096 x 3072
Hmm. There has always been obscure information about IMAX projection systems. It started with their 2*2k systems using a 'black box' to overlay two 2k images. I heard similar things about the laser systems overlaying a sharp and a blurred image or something.
I would go on and create a 'standard' 3996*2160 test DCP, maybe with markers, and play that. As I said, these systems need to be able to play standard DCPs in 2D, I can't imagine they are remastering each and every trailer in every language version in order to play them at all the various IMAX locations.
IMAX is very fond of their own mastering for DMR, laser, etc., but this is just needed to show off very special aspects of their system, like full 1.44:1 aspect ratio or so.
- Carsten
I would go on and create a 'standard' 3996*2160 test DCP, maybe with markers, and play that. As I said, these systems need to be able to play standard DCPs in 2D, I can't imagine they are remastering each and every trailer in every language version in order to play them at all the various IMAX locations.
IMAX is very fond of their own mastering for DMR, laser, etc., but this is just needed to show off very special aspects of their system, like full 1.44:1 aspect ratio or so.
- Carsten