Using a beamer as second screen for public presentation

[streamfuchs]

Hi everyone,

As I read in several posts here in the forum there are obviously some experiences with using the second screen for public presentation e.g. with a beamer.

It would be very helpfull for me when there is an experienced user that could tell be about the momentary situation with V 2.18.18:

Is it possible to do a reliable projection on the second screen without flicker, stutter or other artefacts?
When yes, is there a recommendation for hardware equipment?
When no, what are the restrictions at the moment?

As far as I could see, the playlist editor is still not working (no file list to choose from).
Am I correct?

We are operating a small non commercial cinema here in my hometown and we are evaluating whether dcp-o-matic could be a solution to play DCP packages from time to time (more and more often the film distributors want to send only DCP-packages).

Any help and information is very appreciated.

[carl]

For the playlist stuff you need to set up a Content directory in the "Locations" tab of player preferences... that is where the playlist editor looks for DCPs / other files to play.

Hopefully others can offer "real world" experience of using it.

One thing to be aware of is that if distributors want to send you encrypted DCPs they are unlikely to want to make KDMs for a DCP-o-matic-based system.

[streamfuchs]

Thanks for the hint with the content directory.
Now it is doing.

Because I am not very experienced with DCP at the moment:

As far as I understood DCP packages which are unencrypted, so for which I do not need a KDM should work with DCP-o-matic and the KDM of encrypted DCPs are not compatible with DCP-o-matic?
Probabely because the KDM is assigned to a specific cinema?

Is this correct so far?

[carl]

As far as I understood DCP packages which are unencrypted, so for which I do not need a KDM should work with DCP-o-matic

Correct.

KDM of encrypted DCPs are not compatible with DCP-o-matic?
Probabely because the KDM is assigned to a specific cinema?

Each KDM is indeed assigned to a specific cinema. A distributor could make a KDM for your copy of DCP-o-matic, but then you would be able to make an unencrypted copy of the DCP, so the distributor would probably refuse to do it.

[Carsten]

@streamfuchs: Where are you located?

[streamfuchs]

Hi Carsten,

I am located in the north of Germany.

[streamfuchs]

With the infos from carl I like to repeat my original question, perhaps someone can give me some information about that:

When operating with non encrypted DCP filesets:

Is it possible to do a reliable projection on the second screen without flicker, stutter or other artefacts?
When yes, is there a recommendation for hardware equipment?
When no, what are the quality restrictions at the moment?

Thanks for any information

[Carsten]

Okay, I guessed it from your use of the word 'beamer'.

I guess you should use a windows based desktop machine. Fast notebooks may work. It is hard to guess the performance needs for the player . You need full screen playback at 2K resolutions. You can reduce playback resolution, but that will be noticeable on a larger screen. 4K DCPs will only be possible when playback resolution is reduced to 1/2, but that would be still 2k, so, okay.

Do you have any machines you can test this on?

I am an exhibitor located in the middle of germany. Only very few distributors will publish DCPs without encryption - from my experience, 'Die Filmagentinnen', and 'Neue Visionen'. They still have a nice choice of Arthouse titles.

There are other software based DCP players, A-Cinema, and NeoDCP, but they cost something in the 1000€-3000€ range, plus the necessary playback hardware.

[streamfuchs]

I forgot to mention that we want to use 2k only (or to be correct HD 1080p) not 4K (UHD).

I tried dcp-o-matic with my own Windows based desktop machine which is a Ryzen 9 3900X Processor with 64 GB RAM and a NVIDIA Geforce RTX 2060 Super graphic card using my OLED 65´screen as second display in 1080p-mode.

So my hardware configuration is not really state of the art and some years old.

I realized with e.g. 24fps material that there are some stutter effects from time to time.
So the question is whether actual hardware with a reliable actual graphic card could avoid these artefacts.

I tried A-Cinema which uses the DCP engine developed by Fraunhofer some months ago but without the dcp license and only with MP4-files.
One problem with A-Cinema is that the content with a certain framerate is always scaled to 50, 60 or 59 fps because the developer represents the opinion that these shutter artefacts occure least when playing back in princible with these high frame rates.

I made other experiences: The best way of playing back e.g. 24fps material is to playback 24fps. Same with all other framerates.
So the stutter problem is also not solved in A-cinema, I have got no experiences with NeoDCP.

The real question is whether a windows based computer is able to playback videos without any stutter effects at all.
As far as I know there is no synchronized reference forcing the CPU (playing back the content) and the graphics card (displaying the content) working with exact the same framerate. So from time to time the system has to skip frames which leads us to the stutter.

Obviously linux based systems might be a better solution, I am not shure about that.

And this is for me the most important question: Is there a windows based hardware configuration which avoids stutter arfefacts in a reliable way.

[Carsten]

I guess one would need VSync capabilities to make sure that playback and display frame rate are always in sync. I can only guess, but would think that this is not possible with DCP-o-matic player. However, Carl may want to investigate. The 60fps-only playback of A-Cinema is indeed a known weakness that Stephan Wein refuses to acknowledge.

DCI/hardware players work completely different, they don't use classic graphics cards and always play frame accurate any supported frame rate (even 23.97 in MPEG-2, if necessary).

I noticed even expensive pro-playback software solutions in use at film festivals play back at 60fps.

Wondering wether a second hand Dolby DSS200 could solve your problem. There used to be a way to disable link encryption on them in order to play unencrypted content. They can be bought quite cheap now.

You may also try NeoDCP: https://www.neodcp.com