Can't Convert 3D DCP to 2D ProRes

Anything and everything to do with DCP-o-matic.
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martianmaine
Posts: 2
Joined: Mon May 09, 2022 3:15 pm

Can't Convert 3D DCP to 2D ProRes

Post by martianmaine »

Hi,

I'm trying to export a 3D DCP Video File I have to a proper 2D ProRes file for playback. The first time I tried doing this, the program read the file as being at 48fps because of both the left and right frames playing back to back. Because of this, DCP-O-Matic said that it would be skipping every other frame, which I'll admit is ideal, but unfortunately this only shortens the run time of the video by half, so only the first half of the video properly exports. When I tried changing the settings to read at 24fps, instead of it exporting the whole video it just exported the first half again, but now it's showing both the left and right frames back to back. So it's the proper length it should be, but it's not skipping every other frame as it was doing when it was at 48fps, so now it's just the first half of the video in slow motion. I've tried changing the export settings so the program would read it as a 3D file and export it as two ProRes files (one for the left frame and the other for the right frame) but now I just get the following error every time I try to do this: "Error: Programming error at ../src/lib/ffmpef_encover.cc:244". I've also tried exporting it as a regular 2D ProRes file with just the 3D box checked off but, while it does start to export the video properly, the program eventually crashes before the exporting is complete. I feel incredibly stumped now. I could just use HandBrake to convert the file to a more playable codec, but they don't have a ProRes option and the only options it offers are heavily compressed options. Any other ProRes conversion program either costs money or only covers the first half of the video. Is there any chance someone can help me with this issue?
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Can't Convert 3D DCP to 2D ProRes

Post by Carsten »

I think you have to tell DCP-o-matic first that this IS a 3D DCP (DCP settings). I am just downloading a commercial 3D DCP trailer and will give it a try myself. Which platform/DCP-o-matic version are you using?


Did you load the source file as DCP, or as MXF ('Add File', or 'Add DCP')?


Okay: 2.16.9. on a Mac: Pretty straight, I create a new project '3D_2D'. I add just the 3D DCP trailer using 'Add DCP'. DCP-o-matic immediately indicates it as 3D-DCP in source tab. It is also indicated as '24fps' in the processing information below. I choose 'Export video file', set to MP4, filename - and it works. The result is a 2D-MP4 file at 24fps.

When I set the DCP to '3D' under the DCP tab, the export will create two separate MP4 files for left and right.

When I add just the MXF file of the same trailer, it is indicated as 48fps - that way, I would be able to export it as a 48fps L/R sequential MP4 - depending on what I set for framerate under DCP. Note, the export is always formatted as the DCP project settings, not according to source file settings.

So, at least in 2.16.9, it looks as if DCP-o-matic is behaving as intended.


- Carsten
martianmaine
Posts: 2
Joined: Mon May 09, 2022 3:15 pm

Re: Can't Convert 3D DCP to 2D ProRes

Post by martianmaine »

Hey,

So I downloaded the updated version and everything seems to work, but unfortunately, the app itself will crash midway during conversion for unexplained reasons. I just exported a regular 2D DCP to ProRes to make sure and that worked perfectly. It only crashes when I'm exporting the 3D DCP. Also, the options to change the overall framerate of a DCP are gone if that's something I wanted to do, as is the option to change the container to 4096x2160. All it offers now is either the Flat option or the Scope option. Any idea how to fix any of this? Thank you for your help regardless.
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Can't Convert 3D DCP to 2D ProRes

Post by Carsten »

Some of these settings options now need to be enabled in advanced preferences.

You may try an MP4 export as well. Maybe something is broken in the ProRes encoding.
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