DLP Projection Standards

[Jon Chema]

So I got word today that my local theatre will be showing a music video I directed for the artists CD-release party. I shot the thing on RED-MX and am wondering if there is a place I can find the standards for DLP theaters. I'm particularly curious as to what format, codec, and bit-rate I should finish with.

Does anyone have any idea?

 

[David Rasberry]

Check with the theater manager to see what they have installed. Most projectors have multiple input options, HDMI/DVI digital, RGBHV/VGA analog PC, YPbPr/YCbCr component, S-video, and composite video. Best option would be Blu-Ray or Laptop HD format via HDMI/DVI if possible. Interfacing to the audio system may be more of an issue. You need to find out what the input options are there too. Pre event site visit to figure out what you need is mandatory.

 

[Jon Chema]

Check with the theater manager to see what they have installed. Most projectors have multiple input options, HDMI/DVI digital, RGBHV/VGA analog PC, YPbPr/YCbCr component, S-video, and composite video. Best option would be Blu-Ray or Laptop HD format via HDMI/DVI if possible. Interfacing to the audio system may be more of an issue. You need to find out what the input options are there too. Pre event site visit to figure out what you need is mandatory.

Cool. Ideally, I'd like to export this to a flash-drive or harddrive as I don't have a blu-ray burner.

 

[David Rasberry]

Cool. Ideally, I'd like to export this to a flash-drive or harddrive as I don't have a blu-ray burner.

A lot of digital theaters have DVD players installed or interface points for computers to support rental functions. Some have servers for ads that you may be able to load your video onto.

 

[Greg M]

But note, they usually also have a separate projector for these sources (which is generally a consumer grade projector used for local advertising). The only way to to play to the DLP's is from a DCP

 

[David Rasberry]

But note, they usually also have a separate projector for these sources (which is generally a consumer grade projector used for local advertising). The only way to to play from the DLP's is from a DCP

It really depends on the particular projector installed and what input options are included. The big DLP's all have modular input options. A DCP server outputs standard dual-link HDSDI format digital video to the projector. But the projectors can accept multiple input formats. Connecting a laptop to one via RGBHV analog or DVI is usually not a problem. Access to an audio interface to the house system may be more of an issue than the projector.

 

[Greg M]

It really depends on the particular projector installed and what input options are included. The big DLP's all have modular input options. A DCP server outputs standard dual-link HDSDI format digital video to the projector. But the projectors can accept multiple input formats. Connecting a laptop to one via RGBHV analog or DVI is usually not a problem. Access to an audio interface to the house system may be more of an issue than the projector.

every cinema is different, as David suggested in his first post you really need to talk to the manager of your theater. From my experience, most local theaters only have DCP servers on the 2K or 4K projectors and you must use their smaller projectors for "other" content.

 

[Ryan Sims]

Getting a file into their server will be extremely difficult. Don't even go down DCP path. It's not worth it. Bring your own player of some type. Lots more ways to make it work that way. All of the high end cinema projectors I have worked with have a variety of useful inputs like HD-SDI, DVI and RGBHV. But the controls may be locked out and require a password. The local projectionist may not know the password or what even to do since they never change any of these settings. I like the WDTV as a cheap 1080p 24fps player of like 25Mb Mpeg files or 20Mb h.264 files. Look for the WDTV version that has component video as well as HDMI. This player is a great $130 backup plan. Bring an HDMI to DVI adapter as well. I've also seen several film festivals use mac-mini's as video servers. Your laptop might work.
Blu-ray could be an option as well.

As others said, sound could be tricky. Having a small audio mixer with balanced XLR outputs, unbalanced 1/4 inch jacks, and RCA outs could help.

Test everything days before the event at the theater if possible.

My bet is that the cinema projector will take just about any signal type you have, it's just that the theater management won't let you touch the thing since they don't have a clue how to set it up and are afraid you'll change a setting and they will not know how to get their movies back.

That being said, I had a friend use his RED via HD-SDI to a cinema projector to playback RAW R3D files to show a producer what RED footage could like in a theater setting.

 

[alexx_hg]

In most cases the theater is not the exclusive owner of the projector, distributors are involved with special financing and contracts.
That´s the reason why nearly all "consumer" inputs from a cinema DLP are restricted and deliver in best 720p. The only HD SDI input delivers FullHD.
But as others said get in contact with the manager, all is different...

...
I like the WDTV as a cheap 1080p 24fps player of like 25Mb Mpeg files or 20Mb h.264 files. Look for the WDTV version that has component video as well as HDMI. This player is a great $130 backup plan. Bring an HDMI to DVI adapter as well.
...

The small tiny WDTV also was my first thought, H264/30Mb/s should look impressive, but was disappointed because of only 720p. Finally had to play out with HDCam

bg
alex

 

[Vico Martin]

Some time ago I use a MBP and esata drive via DVI to DVI and woks fine, the hell is to calibrate this output but if you have time you can put it really close to your FCP sequence.

With an AJA or matrox solution you can calibrate more accurelly. If you never encapsulate a DCP, much better do this way. A well laptop gives you more advantages, think about the end of the reproduction with a media player...


good luck!
Vico.

 

[David Rasberry]

Projectors are not resolution limited by any non HDCP protected source. They will display any analog RGB or DVI digital input at the projector's full native resolution. Most accept pretty much anything up to 1900 x 1200 for an input.

 

[Ryan Sims]

The small tiny WDTV also was my first thought, H264/30Mb/s should look impressive, but was disappointed because of only 720p. Finally had to play out with HDCam

bg
alex

All the WDTV players besides the mini do 1080p 24fps H.264 and mpeg2
Here's the spec from the site - H.264 MP@L4.1 and HP@4.1 up to 1920x1080p24, 1920x1080i30, or 1280x720p60 resolution.
http://www.wdc.com/en/products/Products.asp?DriveID=734

If you need 30p, then it's limited to 720p. 1920x1080i30 is not bad either from a progressive source.

I've seen some of these older boxes that don't have Ethernet on sale for $60.
Much cheaper than HDCAM tape stock and rental of a deck.

I don't know the limits of what the highest bitrate these WDTV boxes will play. They don't publish the limits BTMK. I've tested 25Mbit MPEGs and 15Mbit H.264 for over 24hrs continuous playback with no problems.
20Mbit H.264 plays fine for me as well. Anyone know the bitrate limits?

 

[alexx_hg]

Hi Ryan,

This 720p playout was because of the restriction of the 2K Projector.
On my own Projectors and plasmas it works very well with 1080p/25.
Highest Bitrates before picture starts stuttering is around H264/34Mb/s and depends on the length of the movie. A 20min Movie with H264/30Mb/s worked without any problems (1week/8hrs/day).

Btw, even though the Quality of the picture is really great, you can`t switch off the silly on screen display, so a "professional" use is not recommended.

bg
alex

 

[alexx_hg]

...
Most accept pretty much anything up to 1900 x 1200 for an input.

Let's put it this way..."most"...but unfortunately not all because of internal restrictions

bg
alex

 

[Ryan Sims]

Btw, even though the Quality of the picture is really great, you can`t switch off the silly on screen display, so a "professional" use is not recommended.

bg
alex

Yes, the display at the beginning of playback is a pain. Wish there was a away to get rid of it. It will play an entire folder or drive worth of files (can set to loop forever) without showing the display or menu between file changes, once it shows the first one. So I have a black file that I stack before a main movie, hit play, let the menu pass and then switch the projector mute image off. It's a work around, but still a pain. The other problem is that there are no physical buttons on the units. You must have the IR remote control to do anything. Don't forget and leave remote at home, or you'll have nothing to play.

I wish someone would come out with cheap player that has this decoder chip but adds some pro remote controls hooks over Ethernet or RS-232.
The RED4K player will be super-sweet, but not anywhere close too the $100 price range.

 

[Erich Ocean]

If you're looking for super high-quality playback in a portable, field-ready device with tons of different output options, you're looking for the AJA Ki Pro.

You can put extremely high-quality ProRes footage on the recorder and it's got normal playback controls on the unit, plus RS-323 and Ethernet control. And it'll output (and convert on the fly) to virtually anything. More here: http://provideocoalition.com/index.php/shullfish/story/a_look_at_the_many_possible_uses_of_the_aja_kipro/

In my opinion, carrying a Ki Pro around is the best way to output a feature film on the cheap in a theatrical setting.

 

[Dan Hudgins]

Is 1.85:1 projection "real" for DLP/DCI?

Is 1.85:1 projection "real" for DLP/DCI?

I had a question on CML about the issue of Arri Alexa not supporting 1998x1080 as an output format for use with a DCI package.

I seem to have gotten two conflicting answers,

Answer 1) resize width 1920x1080 to 1998x1080 and crop the height, so you use 1920x1038 of the camera output.

Answer 2) Pillar box the 1920x1080 into 1998x1080.

The Answer 2 person was adimate that Answer 1 is something that would not be done, and that ALL HD content would be pillar boxed to show as 16:9 only, and never as 1.85:1 as per the DCI standard, as far as I could make out.

That makes for the question,

Q1) What focal length lens is used for so called 1.85:1 projection to fit the screen with, since many screens now do not have adjustable curtains, if you show Pillar boxed HD on the screen you see black on the sides, that does not seem like something ANY theatre would do, if you use a shorter focal length lens then you over-project ALL 1.85:1 DCI packages and ONLY 16:9 is ever seen by the audience?

So which is true,

Q1A) Is 1.85:1 a sham for DCI since all projection with the "flat" lens is 16:9 anyway?

Q1B) Or is the person that said that V-crop from 16:9 to 1.85:1 for DCI projection is right rather than wrong?

It would be sad if the 1.85:1 format for DCI is a sham as the real screen area is 16:9, that means that theatre projection is just 1920x1080 HD for "flat" use.

==

In a related issue, I am working on 3D Stereo image formatting for my de-Bayer program I am working on.

Does anyone know the exact image sizes and pixel offsets for the upper left corner of those 2 images?

From what I understand there are 2x 1998x1080 1.85:1 images in a 4096x2160 black frame?

But I do not know if you center the images in the upper and lower half of the 4k frame, or you butt the images with the top and bottom making a larger black "frame line" between the two images, does anyone know the image areas and offsets used for DCI Stereo 3D 4k master frames?

It was pointed out on CML that Avatar was shot 1920x1080, does anyone know if they used 1920x1080 image pairs in their 4k masters, or were the HD frames adjusted to be 1998x1080?

I'm asking here since someone here may KNOW the answer, in fact, as to what the real use is for theatre projection of HD camera originated footage being used in a DCI package, since people here are experienced with 4K and Stereo to DCI package post...

Thanks in advance for any insight to the issue of only having two projection lenses on the DLP projector rather than three as would be needed for 16:9, 1.85:1, and 2.39:1 projection to match the screen width without curtains, or is it a requirement that all DCI theatres have curtains that are adjustable?

 

[Erich Ocean]

I had a question on CML about the issue of Arri Alexa not supporting 1998x1080 as an output format for use with a DCI package.

I seem to have gotten two conflicting answers,

Answer 1) resize width 1920x1080 to 1998x1080 and crop the height, so you use 1920x1038 of the camera output.

Answer 2) Pillar box the 1920x1080 into 1998x1080.

The Answer 2 person was adimate that Answer 1 is something that would not be done, and that ALL HD content would be pillar boxed to show as 16:9 only, and never as 1.85:1 as per the DCI standard, as far as I could make out.

Never having done this myself, but having read a lot on the DCI spec and how it is used, my understanding is that #2 is fine, since all theaters "overscan" anyway. The resulting image would simply have less overscan on the sides when fed a 1920 X 1080 picture, but would still be in the correct 1.85:1 aspect ratio (since the 1080 part is being overscanned -- by more -- as well).

 

[Jon Chema]

So as an update...I spoke to the head projectionist today. He informed me that the projectors are 2K DLP and I can throw the video on a flashdrive for playback. He told me that it must be formatted in ex2. He also said that people for the most part have the best luck with Jpeg2000 and XYZ color space. Does anyone know about this? What format should I use? Quicktime .mov with Jpeg2000 codec? What about bitrate? I want the best quality here but also want the video to be able to fit on a 8-16gb flashdrive.

 

[Erich Ocean]

people for the most part have the best luck with Jpeg2000 and XYZ color space. Does anyone know about this?

It sounds to me like he's talking about this: http://en.wikipedia.org/wiki/Digital_Cinema_Initiatives

You would need to create a DCP, if that is what he's talking about. Learn more here: http://en.wikipedia.org/wiki/Digital_Cinema_Package

Honestly, it's not particularly easy to do, though it can be done yourself. I think someone did a huge writeup here on REDUSER.

The bigger issue you'll have is that the color will be wrong, unless you're already using the P3 color space to do your color correction (and have an appropriately calibrated DI system to do it on). So, this is probably not the route you want to go down if you're not already doing a DI...