3 Replies Latest reply on Mar 20, 2016 1:20 AM by Rick Gerard

    how to achieve that effect

    007jamesbondb90946478

      hi guys,

       

      maybe someone can help me how to achieve that kind of effect which is seen in that youtube video at 1:19. that "frame jumping" to the beat. At the moment i have no idea THX for any Help!

       

      https://www.youtube.com/watch?v=NY8TBh0cW2M

        • 1. Re: how to achieve that effect
          Rick Gerard Adobe Community Professional & MVP

          Nothing magic here, just cuts and a moving shot.  You just have to have editing skills and I would do it in Premiere Pro instead of After Effects.

          • 2. Re: how to achieve that effect
            007jamesbondb90946478 Level 1

            thank you for your answer @Rick you say just cuts right? But that cuts should be synchronized to the beat. At the moment i do that kind of react to beat with the expression "linear(value,x,x,x,x)" in After Effects.

             

            do you know any tutorials on youtube which could help me out?  

            • 3. Re: how to achieve that effect
              Rick Gerard Adobe Community Professional & MVP

              Trying to write an expression that automatically slices out time segments in a clip in time with the beat of the music assumes that you know exactly what the BBM (beats per minute are) and when in the musical phrase you want to do the effect and you have somehow managed to sync up everything perfectly with the audio track and time and the musical phrases.

               

              A better approach may be to use the * key to add markers where you want the cuts to happen and then write the expression to skip X amount of time every time it comes to a marker.

               

              My suggestion to do that kind of cutting in Premiere Pro would take me just a few minutes to do. I'd pick the phrase I want to jump in time, then expose the waveform and look for beats or mark them with markers, then I'd make some cuts in the video at each point in time that I wanted to see on the beat and then I'd just trim the out points and drag the cuts into place.

               

              If I were to automate the process I'd select the clip I wanted to jump around in the project panel and set an in point and out point, then I'd create a new comp from that selection, then I'd cut the audio in the same way so the in point of the audio matched the shot, then I'd playback the audio using the . key on the numeric keypad and add markers to the beats using the * key, then I'd check the markers, then I would add an expression that looked for markers and every time it found one it skipped forward in time by X number of frames. The expression would look like this:


              s = 2;


              if (marker.numKeys > 0){

                n = marker.nearestKey(time).index;

                if (marker.key(n).time <= time){

                  n++;

                  if (n > marker.numKeys) n = 0;

                }

              }

              if (n > 0){

                 t =  time + n * s

              }

              In this case I want time to jump 2 seconds so the variable s is equal to 2 seconds. If I wanted the video to jump 1 second I'd set the variable to 1 second. The timeline would look like this:

              Screen Shot 2016-03-19 at 11.58.02 PM.png

              If I wanted to jump time in equal amounts and not bother setting markers you could use the an easier expression that defined the interval as a value in seconds and added that interval whenever time could be divided by the interval. For example:

              s = 2;

              i = .5;

              count = Math.floor(time/i);

              time + (count * s)


              This expression skips ahead 2 seconds every half second. You'll have to determine the best way to get your time skips to match the beat of the music. The marker method is as accurate as your sense of music, the second is mathematically accurate but depends on you knowing exactly what the tempo (bbm) of the music is.

               

              One last point. When cutting to music the action and where the eye is looking in the frame has a lot to do with how the brain interprets timing. In some cases the action or cut must lead the beat, in other cases it must follow. That's why I think the marker is a better choice.