It's important to notice that the AE Projekt Color Depth is 16 bits but rendering is done to only millions of colors (8 bit). I rendered the test file with RGB+Alpha Premultiplied and Color Depth = Millions of Colors (8bit) The composition settings for background color was pure black RGB. This ProRes4444 test file was created with AE Project settings: I still need to do some more tests to find out what's really going on but I already found some more interesting things I want to share:įor one of my rendered ProRes4444 test files I recognized something strange: That proofs it's a ProRes4444 footage interpretation or a footage unpremultiplication bug! They also import and look correct in Premiere Pro.īut if these correctly rendered files are imported back into AE for comparison, the alpha channel values for Straight and Premultiplied Alpha channels are still correct and identical but for the Premultiplied Alpha test file the unpremultiplied RGB values are wrong a bit off and darker compared to the original AE composition and the Alpha Straight test file!!! I strongly believe that's bug.ĭoing exactly the same test but rendering with GoPro Cineform Codec instead of ProRes4444 does not have the described issue (wrong unpremultiplied RGB values) from above.

I double checked the rendered alpha channels Straight and Premultiplied and compared them mathematically by difference and they null/zero out so that proofs they are identical and the rendered alpha channel is correct for both Straight and Premultiplied. It's a ProRes4444 footage interpretation or an footage unpremultiplication bug of After Effects. Regarding the second issue I raised (Alpha Premuliplied bug), I did some more tests and have to admit that it's not a rendering bug how it looked at first.

Ffmpeg mp4 to prores