8 Replies Latest reply on Dec 15, 2010 1:40 PM by Todd_Kopriva

    Anti-aliasing with CS5 and Blackmagic Multibridge Pro

    James P. Brady Level 1

      To anyone else using a Blackmagic Multibridge Pro card:

       

      I am experiencing bad aliasing on scaled video in a Blackmagic Adobe  Premiere timeline.

      With Adobe Premiere's GPU acceleration turned on, scaled video looks  great, but the GPU setting introuces too many other bugs to be reliable  (unpredictable cross dissolves, alpha channel misinterpretation, etc.).

      When I turn GPU acceleration off, cross dissolves and titles act as they  should, but scaled and time-altered video looks quite bad.

      I'm working in Blackmagic native timelines (pick any--it's the same for  all) and have Adobe Premiere's Preview File Format set to "Uncompressed  10-bit YUV" with "Maximum Bit Depth" and "Maximum Render Quality"  checked... but the effected video still looks aliased.   Anyone else out there with this configuration having the same issue?

      Best,
      James

      Windows Vista Ultimate 64-bit SP2
      16GB RAM
      24GHz Intel Xeon (dual quad-core E5450 @ 3GHz)
      CalDigit 2TB Raid
      NVIDIA Quadro CX v258.49
      Blackmagic Multibridge Pro v7.7.2
      Premiere Pro CS5 v5.0.1

        • 1. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
          dradeke Adobe Employee

          Can you say what kind of source footage you're using and what kind of frame size you're inserting it into?

           

          Dennis

          • 2. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
            James P. Brady Level 1

            Yes, Dennis.  Our studio uses a variety of source video:  Sony PDW-F350 HD 1080i 59.94, HDV shot on a Sony HVR-Z1U (both digitized as Blackmagic 10-bit YUV AVI files), and lately HD MOV files from the Canon EOS 5D Mark II.

             

            All of these source formats encounter the same aliasing issue when scaled to any frame size other than 100%.   Literally, 99% and 8% both look equally as rough.

             

            I made a splitscreen render of the issue to submit to Blackmagic, but have not heard back yet from them on my initial inquiry.

             

            Thank you for your attention.

            -James

            • 3. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
              dradeke Adobe Employee

              Checking the obvious, but you do know there is a playback resolution control in CS5 and it could be set to something other than 'full' resolution?

               

              you're using the latest on both Adobe and BMD, but there is a slightly newer driver on nvidia.  Another thing to try is to uninstall nvidia drivers altogether to see if its related to the graphics card.

               

              Also, I'm unclear if this is just a preview issue or is it affecting the output as well?

               

              Thanks

              Dennis

              • 4. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
                James P. Brady Level 1

                Dennis,

                 

                Both playback and paused resolutions are both locked to full when using a Blackmagic sequence.  Although this brings up a good point--the issue may not lie with Blackmagic's playback.

                 

                To test this, I started a new NTSC-DV sequence (which doesn't employ the Blackmagic video card) and made the following observation: I can see the video in the program monitor change when I switch between "GPU acceleration" and "software only"--the same change that was visible through Blackmagic playback.  So, I rendered a few files:

                 

                Render 1:  Mercury Playback Engine Software Only + "use previews" checked

                Render 2:  Mercury Playback Engine Software Only + "use previews" unchecked

                Render 3:  Mercury Playback Engine GPU Acceleration + "use previews" checked

                Render 4:  Mercury Playback Engine GPU Acceleration + "use previews"  unchecked

                 

                From the four renders, I get three distinct looks.  Renders 3 and 4 are the same and all video looks good (but there are unpredictable transition omissions and incorrect overlay handling issues using GPU).  Render 2 is almost the same as 3 & 4, but with some minor aliasing to the video (and of course, none of the unpredictable GPU quirks).  Render 1 is the most unique... very aliased video, slowed video jitters, drop-shadows appear darker and strokes thicker.

                 

                I'll try uninstalling and/or upgrading the NVIDIA driver... but on paper, this should only affect the GPU Accelerated settings, correct?

                I'd like to fix the "software only" so that what I see while editing is what the rendered file looks like afterward.

                 

                Thanks again for the ideas ...off to troubleshoot!

                James

                • 5. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
                  James P. Brady Level 1

                  More information: I upgraded the NVIDIA driver to the most current available (v258.96).  No difference.

                   

                  I did, however, notice something else very important.  I started a new sequence with the following settings:

                   

                  Editing Mode: Desktop

                  Preview File Format: Microsoft AVI

                  Codec: Uncompressed UYVY 422 8bit

                  Renderer: Mercury Playback Engine Software Only

                   

                  With these settings, a timeline with a red-render-bar (no preview files built) played smooth, but looked aliased and generally degraded.  No surprise here, this is the same result I've been getting in any of the Blackmagic timeline presets.  BUT in this editing mode, once preview files were built, the built 'green-render-bar' sections look sharp and clean.  So it would seem that the Blackmagic timeline presets are simply not building uncompressed preview files unless the Adobe Renderer is set to "GPU Acceleration" (even with the preview file codec set to uncompressed 8bit or 10 bit YUV).

                   

                  Not an Adobe Issue after all!   Thanks for your input ...off to write Blackmagic!

                  • 6. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
                    Todd_Kopriva Level 8

                    The Premiere Pro CS5 (5.0.3) update fixes some issues regarding dissolves/transitions processed by CUDA not  behaving properly when Opacity keyframes were present. Let us  know how things  work after you've installed the update.

                    1 person found this helpful
                    • 7. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
                      James P. Brady Level 1

                      Thanks for the heads-up on Adobe's update, Todd.  I have installed 5.0.3 and it has solved many of the undesirable GPU-related issues.  I am now satisfied with the way GPU acceleration handles cross dissolves and alpha channels.  I feel like I'm now moving in the right direction, working with GPU-acceleration enabled for all projects.

                       

                      That said, and in confirmation of my previous post, the only remaining issue seems to lie with how Blacmagic-native timelines interpret renders and preview files differently between a project with GPU acceleration enabled versus disabled.  Take, for example my previous list of renders from a Blackmagic-native timeline...

                       

                      Render 1:  Mercury Playback Engine Software Only + "use previews" checked

                      Render 2:  Mercury Playback Engine Software Only + "use previews" unchecked

                      Render 3:  Mercury Playback Engine GPU Acceleration + "use previews" checked

                      Render 4:  Mercury Playback Engine GPU Acceleration + "use previews"  unchecked

                       

                      With the 5.0.3 update, renders 3 and 4 are still the same as each other (no change here), but now all transitions and alpha composites look as expected (fixed!). Next up, renders 1 and 2 are now also the same as each other (fixed! A predictable result, unlike in v5.0.2).  The video is still aliased as before--but the fact that these two renders are now the same helps pinpoint the aliasing issue to Blackmagic's handling of GPU disabled renders.

                       

                      In short, the Adobe Premiere update 5.0.3 addresses and corrects all known GPU-related rendering issues within Premiere-native timelines.  And, because of this, any distinction seen between "GPU Acceleration" and "Software Only" renders from a Blackmagic-native timeline have been reduced to a mere curiosity.

                       

                      My thanks to Adobe and everyone who posted here to help solve such a convoluted issue!

                       

                      Best,
                      James

                      • 8. Re: Anti-aliasing with CS5 and Blackmagic Multibridge Pro
                        Todd_Kopriva Level 8

                        Thanks for reporting back with your results. That helps.