Arri Mscope Challenge

[Kevin Camp]

this sounds really interesting… can we get a sample of the two 1920×720(1080) images that make up the 1920×1440 frame?

i’m kind of wondering if the 3d glasses effect might be useful… what you essentially will have is a stereo pair of frames, which is what the 3d glasses effect is designed to combine into one frame. it’s just that your frames come from the same camera (rather than two separate cameras).

my concern is that the 3d glasses effect is expecting two frames that are the same size as the final frame, so it may do some vertical scaling with interpolation, which is not what you want. you want to separate each line and insert lines from the other image… or possibly scale it vertically by means of line duplication (no interpolation) and replace every other line with lines from the other image.

you may be able to use draft settings to prevent ae from interpolating when scaling and then combine the lines…

but these are all things that would need to be tested.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Sacha Sojic]

Hi Kevin,

I’ll try to get clearance to post 2 frames from our camera tests. However, the best way to test a solution is to use 2 colored frames (a blue and a red one, for instance). A successful merge is then plainly obvious, much more so than using actual footage in my opinion.

Thanks for the 3D glasses suggestion. I hadn’t thought of giving that effect a shot. I’ll try and see if it leads anywhere.

Best,

Sacha Sojic

[Kevin Camp]

[Sacha Sojic] “the best way to test a solution is to use 2 colored frames (a blue and a red one, for instance). A successful merge is then plainly obvious, much more so than using actual footage in my opinion.”

3d glasses does well with this test, if you compensate for the 720 lines in a 1080 frame of the original footages…

there are two ways that can work:

method 1:

create two comps, one for even lines and one for odd that are 1920×720 (square px, since it sounds like the footage will be square px). this will crop out the black letter boxing. drop the appropriate footage into each and then bring those comps into a 1920×1440 comp (anamorphic px).

then create a new layer (comp size) and add the 3d glasses effect. set the left view to the odd comp and the right view to the even comp, then set the 3d view to ‘interlace upper L lower R’ — note, i’m assuming that the odd lines footage relates to the upper field and even lines footage is the lower field with this mscope footage splitting technique, but that may not be the case…

method 2:

drop the two pieces of footage into a 1920×1440 anamorphic comp, create a new comp sized solid and add the transform effect. uncheck the uniform scale option and set the scale height to 150. this is to effectively crop the 120 pixels off the top and bottom of the frames when they get re-interlaced.

then add the 3d glasses effect after the transform effect. use the same settings as above.

using 2 colored solids in as the test, both methods produce perfectly interlaced, 1920×1440 anamorphic final frames…

what this test doesn’t show is if there is any interpolated scaling to the original frames that would degrade the final frame. that’s where actual footage/frames would be most helpful. obviously, you can create either method above and test it with real footage. if it doesn’t work, there are some other ways that might work…

the real trick is to figure out how not to have ae do interpolated scaling, and, not be to difficult to do. you can definitely avoid the scaling issue, by creating 720 precomps (one for each line) for both the even and odd line footage, then put those 1440 comps into a final comp all spaced out and in the right order, but that’s a lot of work, and it would be nice to not have to do that…

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Sacha Sojic]

That’s very cool, Kevin. I’ll give it a try. I’ll get back to you regarding the interpolation issue once I’ve tested it with actual footage.

Sacha Sojic

[Sacha Sojic]

Kevin,

Just ran a pair of shots through 3D glasses. It turns out the plugin is, in fact, interpolating. My first hint came when I tried the method with 2 the colored frames. Although it seemed to be interlacing properly, the topmost and bottommost lines of the comp were of a darker hue, indicating that the colored solids had in fact been stretched to 1440 pixels (producing an anti-aliasing effect along those edges) before half of their lines were dropped and interlaced together.

Performing the test with footage confirms this. The resulting image is blocky and is identical in appearance to a single channel being stretched vertically to 1440 pixels.

Great try though. Do you have anything else in mind? And given the fact that this thread is taking a “Non-Expressionist” tangent, should I cross-post it to the other AE forums?

Sacha Sojic

[Kevin Camp]

you might move post this in the ae forum too… you may get more responses.

but you may be able to get the 3d glasses to work by setting the 3d layer’s layer quality to ‘draft’ rather than best — the quality setting looks like a diagonal line in the switches panel, click it to make it look like a jaggy line to set it to draft.

if it does work, you’ll need to set the ‘best settings’ to use draft quality in the render settings. don’t use the ‘draft’ preset, it changes other settings, like resolution and such… if it does work you could create you own ‘mscope’ preset with the settings that work.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Sacha Sojic]

Hi Kevin,

Sorry for the late reply. Access to the net here in Cuba is spotty at best, courtesy of uncles Raul and Fidel…

I had already thought of giving the draft setting a try, as you suggested in your original post. It was a success. The plugin does stretch each frame vertically 200% before it interlaces both channels, but in draft mode it effectively doubles each line without interpolating. That’s perfect.

I conformed a small part of the edit and combined the channels using this method and I obtained a perfect Mscope anamorphic sequence. Wow.

We were already in awe of our great AJA KiPro and Final Cut workflow. Thanks for your help in bringing AE into the fold.

Best,

Sacha Sojic