18 Replies Latest reply on Dec 23, 2010 2:36 AM by Butch2oc

    Title Bug?

    Jim_Simon Level 8

      I'm seeing something weird on my system that I never saw with CS4, and wanted to know if others could reproduce it.

       

      Add a title over a black clip.  Then turn off the black with the track eyeball.  Does your title dim?

        • 1. Re: Title Bug?
          Colin Brougham Level 6

          While I should launch into a diatribe about not providing all the details in the original post, I'll refrain...

           

          Turn off hardware MPE. Do you see it now? Nope. Welcome to the hardware-accelerated Mercury Playback Engine and the glory of linear color processing. Many more joys remain to be found...

           

          The short story is that alpha processing is, in my opinion, really jacked up when using hardware MPE; you'll see things like shaggy text, nasty blurs/glows/shadows, and chunky dissolves. Supposedly, this is a "benefit" but I've had nothing but grief with linear color processing. I've been amassing evidence to take my case to a higher court, so that maybe one day, we'll be able to enjoy the true benefits of hardware MPE, but have the option of disabling this unfortunate side effect. Sadly, the only way around this is to not use hardware MPE.

          • 2. Re: Title Bug?
            Jim_Simon Level 8

            Sure enough, that was it.  Never even occurred to me.

             

            Good investigating.

             

            (I am a little curious about what details you thought might be missing, though.  It was a pretty easy duplication, I thought.)

            • 3. Re: Title Bug?
              shooternz Level 6

              Colin wanted system details and what you had for lunch and what film school you went to

              ...

               

              but he was too polite and respectful to ask.

               

              Unlike me.!

               

              He is a genius and resolved your issue without the detail.

               

              Give him the points.

               

               

              • 4. Re: Title Bug?
                Jim_Simon Level 8

                Well, 'resolved' may be too strong a word.

                 

                It occurs to me that pretty much every video production everywhere will have white titles on a black background.  This is such an industry standard that it's pretty much a given.  But this MPE bug means you can't use MPE if you have such titles.

                 

                It seems like a small thing, but this little bug essentially makes MPE useless for a LOT of productions - the majority, I'd bet.

                 

                Methinks Adobe should release a genuine 5.0.4 fix reeeeeal soon.

                • 5. Re: Title Bug?
                  Colin Brougham Level 6

                  I am a little curious about what details you thought might be missing, though.  It was a pretty easy duplication, I thought.

                   

                  If one knows that you're using a hardware MPE, then it is. Since anyone using software MPE only won't see this, I think that's an important detail.

                   

                  It occurs to me that pretty much every video production everywhere will have white titles on a black background.  This is such an industry standard that it's pretty much a given.  But this MPE bug means you can't use MPE if you have such titles.

                   

                  A workaround--at least with titles--is to include a black "solid" in the title itself. However, since this is not just going to affect white text on a black background, this doesn't solve the issue with graphics supered over a video background.

                   

                  It seems like a small thing, but this little bug essentially makes MPE useless for a LOT of productions - the majority, I'd bet.

                   

                  It'll get worse before it gets better: Battling Hardware MPE, Episode 2: Chunky Blurs

                   

                  Here's a fun one: create a simple cross dissolve between two clips. Step through it frame by frame in software MPE, and you'll see a dissolve as we're accustomed to from Premiere. Now, park the CTI somewhere in the middle of the dissolve, and toggle hardware MPE in. Notice anything? Try stepping through the transition now, and observe what happens especially at the first and last frame of the dissolve. Linear color processing!

                   

                  By the way, any effects that generate particles (I use several Digieffects plug-ins that do this) will generate some truly ugly results in hardware MPE unless you're willing to accept some compromises on designing the particles.

                   

                  Methinks Adobe should release a genuine 5.0.4 fix reeeeeal soon.

                   

                  You probably shouldn't hold your breath for this. Despite this truly crippling and ugly side-effect, this won't be considered a bug--the linear color processing is endemic to hardware MPE, and is the cause of this issue. It is a conscious design decision that has negative consequences in almost every circumstance that I use; I'm sure there are benefits for others, but I've not discovered them. That's why I'm putting together evidence for, if nothing else, the ability to toggle between linear color processing and "the old way" when using hardware MPE. As it is, I have Project Settings tied to a keyboard shortcut so that I can toggle hardware MPE on and off. I almost always export with hardware MPE turned off.

                  • 6. Re: Title Bug?
                    Jeff Bellune Adobe Community Professional

                    But this MPE bug means you can't use MPE if you have such titles.

                     

                    It seems like a small thing, but this little bug essentially makes MPE useless for a LOT of productions

                    In the interest of keeping Todd and Dennis happy, I have to correct your use of the term MPE.

                     

                    Premiere Pro CS5 *always* uses the new Mercury Playback Engine for playback.  The only difference is whether you're using the software version of the engine, or the hardware version of it.

                     

                    The hardware version is accelerated by CUDA with certain nVidia graphics adapters.  The software version is always available no matter what graphics adapter you have.

                     

                    There are real-world differences between how the hardware and software versions of the MPE behave.

                     

                    -Jeff

                     

                    EDIT: Please notice Colin's careful use of the terms "hardware MPE" and "software MPE".  That's how it's done, folks.

                    • 7. Re: Title Bug?
                      Colin Brougham Level 6

                      Please notice Colin's careful use of the terms "hardware MPE" and "software MPE".  That's how it's done, folks.

                       

                      I have keyboard macros set up for those

                      • 8. Re: Title Bug?
                        Todd_Kopriva Level 8

                        I think that a great feature request would be to have an option in Premiere Pro that allowed the user to choose between blending in a linear color space (gamma=1.0) versus blending in a perceptual color space (gamma=something else, higher than 1.0). There is such an option in After Effects.

                        • 9. Re: Title Bug?
                          Colin Brougham Level 6

                          *head smack*

                           

                          Nice one, Todd--I forgot about that. I'm going to request just that.

                           

                          For what it's worth, the benefits of hardware MPE are many and wonderful, but this is a major oversight, in my opinion. Unfortunately, one of my clients noticed this--he complained that all dissolves looked "[self-edited for content]" in the spots I'd finished for him. That was the genesis of my campaign against linear color processing in hardware MPE; I've found others since then, but that got the ball rolling. However, your suggestion about this as a preference in AE is the catalyst for a better-formed feature request--thanks.

                          • 10. Re: Title Bug?
                            acgold777 Level 1

                            So is this an issue for timeline playback while editing only or does it actually affect the final rendered file?  If the latter, can't you just turn Hardware MPE off before exporting?

                            • 11. Re: Title Bug?
                              Colin Brougham Level 6

                              So is this an issue for timeline playback while editing only or does it actually affect the final rendered file?

                               

                              Technically speaking, it doesn't affect playback--at least not playback of unrendered video. That's because MPE--software or hardware--does not use linear color processing when Premiere is playing back from a sequence/in the Program Monitor; the system overhead to process in linear color would negatively affect realtime playback. When you stop playback with hardware MPE enabled, or you render previews with your sequence set to Maximum Render Quality and summarily playback those previews, you will see the "fringing" around alpha elements.

                               

                              On the other hand, exporting with hardware MPE enabled, or exporting with software MPE enabled along with Maximum Render Quality toggled on, forces linear color processing--this means a gamma curve of 1.0 and 32-bit color. While perhaps technically desirable (and aesthetic desirable in some circumstances, I suppose), it has this negative impact on the edges defined by an alpha channel. In Todd's blog post, "some details about scaling in Premiere Pro CS5," the following is said regarding linear color processing:

                               

                              When rendering is done on the CPU with Maximum Render Quality enabled, processing is done in a linear color space (i.e., gamma = 1.0) at 32 bits per channel (bpc), which results in more realistic results, finer gradations in color, and better results for midtones. CUDA-accelerated processing is always performed in a 32-bpc linear color space. To have results match between CPU rendering and GPU rendering, enable Maximum Render Quality.

                               

                              The rest of that post is also helpful for understanding a bit more about what is going on under the hood in regard to software vs. hardware MPE.

                               

                              If the latter, can't you just turn Hardware MPE off before exporting?

                               

                              Absolutely, but you'll lose the benefit of hardware acceleration for transforms and effects that are thus enabled. Depending on the nature of the footage you're editing with, the effects you're using, and the processing power of your computer, this can have a significant impact on your export time. No, hardware MPE has no bearing on the actual encoding to your destination file, but the frames handed off to the CPU-based encoder either come from the GPU (hardware MPE on) or the CPU (hardware MPE off); if the CPU is doing double-duty, your total export time goes up.

                               

                              Ain't no free lunch

                              • 12. Re: Title Bug?
                                shooternz Level 6
                                Ain't no free lunch

                                 

                                 

                                At least Jim could have given you the points ...instead of taking you to lunch!

                                 

                                Tough audience tonite huh!

                                • 13. Re: Title Bug?
                                  Colin Brougham Level 6

                                  Tough audience tonite huh!

                                   

                                  Just tonight? No sir...

                                  • 14. Re: Title Bug?
                                    the_wine_snob Level 9
                                    Tough audience tonite huh!

                                    Sometimes it IS that way.

                                     

                                    Now, Todd, Jeremy and the rest of the team probably always get the Friday, Maine Lobster lunch, in the Official Adobe Cafeteria, so points do not matter so much. For the "unwashed," they hold out a hope - and I will bring the wine.

                                     

                                    Hunt

                                    • 15. Re: Title Bug?
                                      shooternz Level 6

                                      with my thanx.Forget the Lobster...I thought we were going to get Adobe Shares based on points.

                                       

                                      Hear that  Adobe made a bit of profit recently.

                                       

                                      Did we help or not?

                                       

                                      Give mine to Todd and the Adobe employees

                                      • 16. Re: Title Bug?
                                        jeremy d. Level 3
                                        Now, Todd, Jeremy and the rest of the team probably always get the Friday, Maine Lobster lunch, in the Official Adobe Cafeteria, so points do not matter so much. For the "unwashed," they hold out a hope - and I will bring the wine.

                                         


                                        There's still a chair waiting for you

                                        • 17. Re: Title Bug?
                                          Jim_Simon Level 8
                                          MPE--software or hardware--does not use linear color processing when Premiere is playing back from a sequence/in the Program Monitor

                                           

                                          Then perhaps linear color processing is not to blame here, because I very much see the bug in unrendered playback with hardware MPE on, but I do not see it in software mode.  I also see it in exports with CUDA off but MRQ on.

                                           

                                          Further (and the reason I discovered this little moth), the expanded brightness of the title does NOT occur over a video clip in either hardware or software mode.  It only occurs over a Premiere generated black clip.  Place a title over a video clip, continue it over a black clip.  When the CTI goes from the end of the video to the black clip, you can clearly see an unnatural brightening of the title.  (I should try importing a Photoshop generated black still to see of the issue exists there as well.)

                                          • 18. Re: Title Bug?
                                            Butch2oc Level 1

                                            I get the same results Jim, and thanks to you guys I think I may understand what's going on with some other issues I have noticed, but not explained or questioned correctly.

                                            In my blog "moving graphic when adding filters" I asked the below but got no reply....

                                             

                                            Have any of you noticed very slight noise or instability in graphics when the background has a lot of movement & contrast under graphic.

                                            Ever noticed when a small graphic, lets say at disclaimer size dissolves up... that you get noise introduced for the duration of the dissolve?

                                             

                                            Is this associated with the linear color processing you are talking about?

                                             

                                            Is the workaround to turn off Hardware MPE before exporting ?

                                             

                                            In my laymans terms, to me, it appears to be contrast sensitive alpha processing i.e. If you have a background with alot of motion and contrast... I find it's only when the darker areas travel behind the graphic that you notice the artifacting. So not just over black for me.

                                            I also see it alot more after a bottle of fine south aussie red