5 Replies Latest reply on Jan 4, 2013 3:50 PM by the_wine_snob

    PE-11/Windows: 1/3-second Narration Delay & Workaround

    ReedWhite Level 1

      My objective was to closely cut video to a music track.  I tried Auto-beat feature, but after experimentation gave that up as useles (at least for the music track I was using).

       

      The workaround:

       

      I tapped the computer's mic in time to the music while recording a Narration track.  Unfortunately, there is a 1/3 second delay between the tap and when it reaches the narration track.  To make matters worse, because you have to listen to the music track, you also have to listen to the delayed thump -- very disconcerting!  Try talking naration with a 1/3 second echo.

       

      After conditioning myself to ignore the "echo," I layed down a thump track.  As expected, it was 1/3 second delayed.  So, I moved the Narration track to the left 10 frames to cancel the delay and achieve proper sync.

       

      The results can be seen at: http://www.youtube.com/watch?v=sgHl4mTKedE

       

      I learned that my Android phone records at 15 fps, and that this can be a problem with PE-11.  So, the above video is sometimes jumpy in some clips with a handheld moving camera -- just think of it as an art effect.  Not sure that PE-11's Stabilization feature actually made an improvement in this case, but I used it.  Also, the 15 fps apparently caused PE-11 to frequently exhibit annoying bugs, like inserting "orphan" frames here and there -- difficult to fix.  (Next time, 30 fps!)

       

      I have experimented on both PE-11 versions for PC and Mac.  I do not recall seeing any significant delay or echo on the Mac when recording a thump trac for synching video tightly to music.  On my PC, I have the latest version of Realtek HD audio drivers, running on a duo-quad Intel processor.

       

      Advice always appreciated.

       

      ... Reed

        • 1. Re: PE-11/Windows: 1/3-second Narration Delay & Workaround
          the_wine_snob Level 9

          Reed,

           

          I find that the use of the * key on the number pad, to be very useful for finding beats, and adding a Marker to edit to. It takes just a bit of practice, but as the Markers can be moved with frame-accurate precision, it's fairly easy to clean them up, and correct for any missed beats. Did you give that a try?

           

          Also, with many mics, and other audio devices, there is a certain latency, but what you describe is beyond what I have ever observed. Did this happen to be a USB mic?

           

          Thanks for sharing, and good luck,

           

          Hunt

          • 2. Re: PE-11/Windows: 1/3-second Narration Delay & Workaround
            ReedWhite Level 1

            The "*" key sounds like a good suggestion.  Thanks!  I had forgotten about that.

             

            The mic I used is just the computer's internal mic.

             

            I get the impression that you have never observed any delay on a PC.  Interesting.

            • 3. Re: PE-11/Windows: 1/3-second Narration Delay & Workaround
              the_wine_snob Level 9

              I see an approximate 8 MS latency delay with my various mics, going direclty into my soundcard, and that is well within the tolerance of the human ear/brain. I have never used my laptop's internal mic, so do not know how good, or how bad, that might be.

               

              Again, thank you for mentioning your workflow, as it might help others.

               

              Good luck,

               

              Hunt

              • 4. Re: PE-11/Windows: 1/3-second Narration Delay & Workaround
                ReedWhite Level 1

                Bill, your comment about seeing no more than 8 ms latency got me digging deeper, eventually to achieve a fix.

                 

                My computer latency is less than 1/30 of a second (not scientifically measured).  Over 90% of the 1/3 second delay (latency to timeline) is apparently introduced by PE-11.

                 

                But, there is good news.  The delay comes from a PE-11 buffer that is adjustable.  Go here:

                 

                     Edit -> Preferences -> Audio -> Audio Hardware -> ASIO Settings

                 

                You will see a Buffer Size slider.  The default size is "2048 Samples," which results in a 1/3 second delay on my computer.  Set the buffer to minimum, resulting in a buffer of "256 Samples."  This removes the lion's share of the delay -- possibly to less than a 30 fps frame.

                 

                There must be some reason why 2048 is default.  Therefore, unless working with Narration, I think that leaving it set at the default "2048 Samples" would be prudent.  Use the minimum only when recording on the Naration track.

                 

                ... Reed

                • 5. Re: PE-11/Windows: 1/3-second Narration Delay & Workaround
                  the_wine_snob Level 9

                  Reed,

                   

                  Great news, and thanks for bringing that setting to my attention.

                   

                  As I normally do narration in PrPro, I will check to see what my ASIO Buffer is set to in that program.

                   

                  Good luck,

                   

                  Hunt