11 Replies Latest reply on Dec 16, 2014 10:25 AM by Tim Kurkoski

    Multiprocessing color space render issue

    SOhare Level 1

      After installing the newest update of After Effects CC 2014 I am having troubles with my renders while using multiprocessing.

      The color space I'm working in is a linearized 32bpc sRGB IEC61966-2.1  When I render without multiprocessing turned on, the render turns out fine, but with it turned on the resulting render is way too bright, as though the gamma has been lifted way too high. I would really like to be able to use multi-processing, since it cuts my render times down to a fifth of what they would be otherwise. Any advice would be much appreciated.

       

      Also, just for fun I took my file back into After Effects CC (12.2)  and tried rendering it with multiprocessing without changing any settings and the render turned out just fine, making me think that this is specifically a CC 2014 problem.

        • 1. Re: Multiprocessing color space render issue
          Dave LaRonde Level 6

          Perhaps an accurate diagnosis, cn gbe made with the information at hand, but just to be on the safe side I would include version numbers of your OS & AE, right down to the last decimal point.  Who know?  You could be missing a bug fix.

          • 2. Re: Multiprocessing color space render issue
            Tim Kurkoski Adobe Employee

            This is a bug that was introduced in After Effects CC 2014.1 (13.1). My apologies about this.

             

            First things first: to work around this bug you will need to disable multiprocessing in order to get a color-accurate render, via either RAM preview or via the Render Queue. Alternately, you can use multiprocessing but to get expected colors you must disable color management (set the project's working space to None), or if using Rec. 709 or sRGB you can leave the working space enabled and disable only the Linearize Working Space option.

             

            If you choose to leave multiprocessing enabled and disable color management, you can create the same color transform by applying the Color Profile Converter effect. For example, before rendering via the render queue, pre-compose your final comp and apply the effect to the pre-comp.

             

            We will evaluate a fix for this bug for a future update to After Effects CC 2014. An update is scheduled to release soon (this week or next), but a fix for this bug won't be included; this will have to wait for the next update.

             

            Under the hood, here's what happened to cause this bug:

             

            In After Effects CC 2014.1 (13.1), a color transform to Rec. 709 is automatically added to frames delivered via Dynamic Link when color management is enabled in the project. This is a new behavior in this version, which solved a problem with gamma and/or color shifts when sending frames to Premiere Pro or Adobe Media Encoder, which assume that all incoming Dynamic Link frames are Rec. 709.


            When multiprocessing is enabled in After Effects, it uses Dynamic Link to communicate with the subprocesses. In this case, After Effects knows what color profile is being used; no additional color correction is necessary.


            Combining these two behaviors we get this bug: an unnecessary color transform to Rec. 709 is being applied to frames rendered when multiprocessing is enabled. We failed to take the multiprocessing case into account when we added the new behavior.


            If your project's working space is already Rec. 709 or sRGB (which are functionally the same), you wouldn't notice a difference, since the additional color transform results in no change. Using any other profile would cause a color shift. Enabling the Linearize Working Space option with any profile will introduce a gamma shift.


            Again, my apologies about this bug.

            • 3. Re: Multiprocessing color space render issue
              tombo Level 1

              Hi Tim. I seem to be having trouble with Multiprocessing as well... but with RAM previews not keeping the render.

              Running AE CC 2014.1.

              If I disable multiprocessing, then do a ram preview, the "Green" progress bar in the timeline progresses along till my out point, than plays back in real time.

              When I stop preview the green indicators stay there and I can scroll along the timeline very quickly as per normal.

               

              If I I turn on Multiprocessing, and I do a RAM preview, it progresses much quicker obviously and the green bar gets to the end point, then plays back in real time... as expected...

              However when you stop the preview, almost all the Green bar disappears. So I need to again do another RAM preview to again see the play back.

               

              When I say almost all the green disappears, the are a few "Dots" of green still visible in the timeline and this seems to be random as to which very small parts of the timeline stay green.

              In AE CC I used to see a dark blue line in the timeline RAM progress bar. I have not seen this in AE CC 2014.1?

               

              I am using the same settings in the multiprocessor panel as I did in AE CC.

               

              As mentioned, turning off multiprocessing fixes the issue albeit a lot slower with RAM previews of course.

               

              Any suggestions?

               

              Setup:

              NEW MAC PRO 2014

              64GB

              OS X 10.9.2

              PROMISE 8TB T2 Raid

              AE CC 2014.1

              • 4. Re: Multiprocessing color space render issue
                SOhare Level 1

                Thank you for your reply, this completely answers my question. The work around you suggest doesn't really seem reasonable, since I have hundreds of renders I need to produce. I guess I will simply have to go back to working in my older CC 12.2 until that fix you mention comes out down the road.

                • 5. Re: Multiprocessing color space render issue
                  Tim Kurkoski Adobe Employee

                  tombo wrote:

                   

                  Hi Tim. I seem to be having trouble with Multiprocessing as well... but with RAM previews not keeping the render.

                  tombo, it would be best if you started a new thread on this topic, with the same detail as your post above. When you do:

                   

                  Are you able to consistently reproduce this problem? Other After Effects users have reported a similar problem, but we are not able to reproduce the issue. We suspect that the cache ID's are getting into an unexpected state, causing After Effects to think that the cache no longer matches the contents of the comp. But until we know how you're getting into that state, we don't have the information we need to investigate. More detail about your comp (frame size, frame rate, source file types and codecs in use, effects used, expressions used) and what you're doing before it happens will be helpful. Posting or sending us a comp that reproduces the problem would help immensely.

                   

                  The blue cache markers indicate frames that have been stored on disk. Assuming that you have disk cache enabled in the preferences, this should happen automatically but it is a slower process and doesn't happen instantaneously; After Effects moves the frames from RAM to disk during idle time. That you are not seeing the blue disk cache markers in After Effects CC 2014.1 (13.1) is probably related to the other problem of the cache being unexpectedly flushed.

                  • 6. Re: Multiprocessing color space render issue
                    tombo Level 1

                    Thanks Tim… I'm away on location atm, but will be back in the office in 3 days and will get you more info.

                    Cheers

                    Tom

                     

                    sent from Toms MacBook Pro

                    tom@2oc.com.au

                    • 7. Re: Multiprocessing color space render issue
                      DG. David Escalante Level 1

                      Is this supposed to be fixed by now? I still having this problem with 13.1.1.3

                      • 8. Re: Multiprocessing color space render issue
                        Tim Kurkoski Adobe Employee

                        DG. David Escalante wrote:

                         

                        Is this supposed to be fixed by now? I still having this problem with 13.1.1.3

                        No, this was not fixed in the 13.1.1 update for After Effects CC 2014.1. We hope to fix this in the near future. We don't yet have a schedule to share on such a release.

                        • 9. Re: Multiprocessing color space render issue
                          ekreidler Level 1

                          Hi Tim -- but if you're working in linear color space, doesn't this affect how effects work and how things are composited? It's more than just a color profile conversion, correct?

                           

                          So basically no MP renders in 13.1 using linear workflow?

                          • 10. Re: Multiprocessing color space render issue
                            Tim Kurkoski Adobe Employee

                            if you're working in linear color space, doesn't this affect how effects work and how things are composited? It's more than just a color profile conversion, correct?

                            Correct that enabling the Linearize Working Space option affects compositing results, but this bug does not interact with the compositing or effects calculations. This bug applies an unnecessary color transformation to Rec. 709 to the entire frame after compositing is complete. But this is non-linear Rec. 709, resulting in the wrong color even when the working space is set to Rec. 709 or sRGB. So, correct, you should not use linear workflows with multiprocessing enabled in After Effects CC 2014.1 (13.1).

                             

                            This bug is fixed in the update to After Effects CC 2014 that we plan to release next week.

                            • 11. Re: Multiprocessing color space render issue
                              Tim Kurkoski Adobe Employee

                              This is fixed in the After Effects 2014.2 (13.2) update, which is now available.

                              Details here: http://adobe.ly/1IVopxh