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This topic comprises 5 pages: 1 2 3 4 5
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Author
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Topic: Help playing 4K content.
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Kirk Futrell
Film Handler
Posts: 95
From: Nashville, TN / U.S.A.
Registered: Nov 2008
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posted 05-27-2015 10:22 AM
First off let me say that I have contacted both Barco and Doremi about the following and both have said as far as they can tell, everything is set up right, including the 4K playlist and the 4K license.
Recently I decided to revisit the issue of determining once and for all if I was actually playing true 4K content from our Showvault w/IMB to our Barco 4K-23B via ESATA connection. So I devised a test pattern that I thought would test the theory beyond a shadow of doubt. A fellow projectionist and I created a 4K image in photo shop that consisted of alternating black and white 1 pixel wide vertical lines. Then we made a 4K dcp of it using both DCP-O-Matic and OpenDCP (the latter was used so we could actually see the outputted jpeg2000 files). We then took one of the jpg2000 files and converted it to a 4K .png to make sure everything still looked good. I then uploaded that image to the Barco as a test pattern. The Barco displayed it correctly on the screen and you could see the individual 1 pixel lines. The DCP's we made also look correct if viewed using "NeoDcp" player.
However when we played the DCP through the Doremi, the image on screen was a gray image, as though it were downscaling the 4K to 2K and combining the black and white pixels. This happens on both of our Barco/Doremi setups. It looks the same in a 2K playlist as a 4K playlist. When viewing the video path for a 4K on the Barco the IMB says 4K and the ICP says 4K (well actually it only shows a 4K icon when in Scope. In flat, there is no icon at all, though both settings look the same on screen and i seem to be using the correct 4K pcf files) . I even tried turning off the scaling on the TI chip. With the scaling off both the 2K and 4K content in a 2K playlist are small on the screen, in a 4K playlist 2K and 4K content fill the screen. This last fact seems a little strange to me. It seems like the doremi is scaling down 4K to 2K for 2K playlists and then scaling up 2K to 4K for 4K playlists. Is it possible the Doremi is scaling 4K down to 2K then upscaling everything back up to 4K to fill the screen ?!?!
What I would love to have happen is that someone with a 4K setup could verify whether the DCP works correctly on their projector setup. I especially want to hear from someone with the same setup and someone with a different setup like a Doremi and anything but Barco or a Barco and anything but Doremi.
I am including a link to the files I have created and pictures of what the image looks like on a white piece of (unperforated) foamboard. The test DCP is very short (1 second) so you may have to pause it.
https://drive.google.com/file/d/0B5BJx3weEYk8QTdCbXdFaFhuODQ/view?usp=sharing
Hopefully the above does not break forum Rule #4 but, if it does, maybe someone can help me figure out a better way for people to access the files.
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Carsten Kurz
Film God
Posts: 4340
From: Cologne, NRW, Germany
Registered: Aug 2009
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posted 05-28-2015 05:14 AM
If the 4k png test-patterns resolve to the pixel level on screen, that can be ruled out.
@Kirk: 1s is too short for a DCP. Doremis used to have issues with DCPs so short. Even if they seem to play properly, you should at least prepare 5-10s. I doubt this is causing your issues, but you can never be sure...
The DCP/MXF will be larger with 5-10s, but with static J2k images, ZIP will do a good job to compress them further lossless.
These are two test DCPs created from a 4k 4096*2160 TIF checkerboard. One uses the full DCI 4k container, one a cropped flat container. No scaling/filtering applied during the DCP creation.
The resulting 10s DCPs with a silent 2ch audio track have a size of roughly 47MBytes, but ZIPcompress nicely to around 500kByte because the J2c frames are all the same and the audio is all zero. I used a target bandwidth of 200MBit/s, as some Doremis freak out at higher data rates.
https://dl.dropboxusercontent.com/u/5582554/4kCheckerFullC.zip
https://dl.dropboxusercontent.com/u/5582554/4kCheckerFlat.zip
As this is only for special testing, I didn't adhere to ISDCF naming convention.
This is the source file:
https://dl.dropboxusercontent.com/u/5582554/4k_full_checker.bmp.zip
(yes, it's 4096*2160 8bit RGB, ZIPed to a mere 54kByte)
- Carsten
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Kirk Futrell
Film Handler
Posts: 95
From: Nashville, TN / U.S.A.
Registered: Nov 2008
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posted 05-28-2015 03:17 PM
I will get a chance to try this stuff out tomorrow morning.
quote: Marco Giustini
Any chance your 4K license on the Doremi has expired?
Marco, If I remember the license is valid for something like 20 years or more. Also Doremi looked at the log files and said it "appears" I am outputting 4K, which corresponds to the fact that if I turn off scaling on the ICP the image still fills the screen when using a 4K playlist on the Doremi.
quote: Carsten Kurz
You should confront Doremi and Barco with photographs of the 4k testpattern vs. the 4k DCP.
Carsten,I've sent everything in the link to both Doremi and Barco. Doremi has been very communicative and genuinely interested/helpful. Barco refuses to look at anything that isn't "distributor created" and hasn't been willing to look at the files.
quote: Marco Giustini
Can you focus your picture so you see the pixels on screen? And how's your convergence?
In the picture titled 4Kdcp, you can see the pixels if you look closely, in the other picture you can clearly see the black 1 pixel lines, so its not a focus issue or convergence for that matter. Convergence is within spec.
quote:
@Kirk: 1s is too short for a DCP. Doremis used to have issues with DCPs so short. Even if they seem to play properly, you should at least prepare 5-10s. I doubt this is causing your issues, but you can never be sure...
I will recreate my DCP test tomorrow to be longer. I will check out your tests files tomorrow, too. Thanks for providing!
quote: Carsten Kurz
As far as I understood, he loaded his own 4k pattern into the Barco?
That's right. One of the files in my above link to the .zip file is the 4K .png I uploaded to our 23-Bs as a test pattern. If I remember correctly it was created in photoshop then repeated in Adobe Premiere so we could create a .tiff sequence then converted to jpg2000 with OpenDcp. We took one of those files and reconverted it to a .png to use as our test pattern, the extra steps being to verify that our DCP was created properly.
quote: Marco Giustini
Was the projector upgraded to 4K or did it come 4K from the factory? Is the projector set as 4K in the device manager on the Doremi?
Installed as 4K by me with my limited training from the Barco installation tech program. I will check the device manager for that option, I don't recall the settings. I imagine I would have set that option if I saw it.
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