7 Replies Latest reply on Apr 2, 2015 6:44 AM by Szalam

    Working with 60fps clips in 24fps Linked Comp

    Interobang Level 1

      I am trying to use the time warp effect in Ae to alter the speed of the clip at different points in the clip.  So going from normal 100% down to 40% then back up to 100%, with a nice smooth gradation/ramping between speeds. 

       

      This is easy enough to achieve, I know how to do this, but the problem I am experiencing is bringing the clip from a 24fps timeline in Pr into a linked comp in Ae.  The clip is 60fps, and is not conformed in Pr to 24fps.  But when I bring it into the 24fps Ae comp it is slowing the clip down, conforming it to the comps setting, i guess.  I just want it to play back in real time in Ae so that I can edit the time warp myself. 


      It is especially a problem because now the comp length is way shorter than the clip, which makes working with it an absolute nightmare.

        • 1. Re: Working with 60fps clips in 24fps Linked Comp
          Interobang Level 1

          Right, so I figured out what my problem is but have now encountered another, even more annoying problem.

          My computer is not actually playing the comp back in real time.  So the box above the RAM preview panel is saying in red that it's playing back at a varying speed between 15 and 18 fps.  Even though the RAM preview frame rate is set to 24fps.  Fine, I'll get a graphics card to fix this problem.

          The problem I am having now, is that when I slow my clip down to 40% speed, it is using frame blending to create the extra frames instead of the actually frames that exist in the 60fps footage!  So I am getting horrific blending artefacts on my slow mo.  Whole frame blending is way too choppy.  What the hell happened to my extra frames?

          • 2. Re: Working with 60fps clips in 24fps Linked Comp
            Szalam Adobe Community Professional & MVP

            How is After Effects interpreting the footage?

             

            Interobang wrote:

             

            My computer is not actually playing the comp back in real time.

            ...

              Fine, I'll get a graphics card to fix this problem.

            That might not help as AE uses the GPU for very little. How are you doing your RAM preview? What are your computer specs? What exact version number of AE are you using? What happens if you RAM preview in a comp without time remapping or time warping? Etc. FAQ: What information should I provide?

            • 3. Re: Working with 60fps clips in 24fps Linked Comp
              Interobang Level 1

              I've not asked After Effects to interpret the footage.  I have gotten past that.  As I mentioned in the update, it was looking like it had interpreted the footage, because it was playing back slowly.  The footage in the project window is saying that it's 60fps.

              I am using Ae CC 2014, monthly subscription, so it would have to be the most up-to-date version.

              I have a pretty powerful computer.  It's a Hackintosh.  Core i7 4790, 16GB RAM, 250GD SSD for the system drive.  Currently no graphics card, which Yosemite does not like too much, so I have a Gigabyte GTX 760 on it's way.

              But none of the above is dealing with my most pressing problem, which is the missing frames and the clip length.  Can you help with this

              • 4. Re: Working with 60fps clips in 24fps Linked Comp
                Szalam Adobe Community Professional & MVP

                Interobang wrote:

                 

                I've not asked After Effects to interpret the footage.  I have gotten past that.  As I mentioned in the update, it was looking like it had interpreted the footage, because it was playing back slowly.  The footage in the project window is saying that it's 60fps.

                AE is interpreting it some way whether you asked it to or not. Any software that works with video files interprets every bit of footage. For troubleshooting reasons, I was asking how AE is interpreting it.

                 

                How were you playing it back in AE when it played slow? With the spacebar?

                • 5. Re: Working with 60fps clips in 24fps Linked Comp
                  Rick Gerard Adobe Community Professional & MVP

                  It is very easy to get confused with frame rates. First, the only way to show all of your frames is to have the comp and the footage at the same frame rate. The speed of the playback as it relates to the clock on the wall depends on the frame rate used to record the original footage. If you want to slow down 60fps footage so that is plays at half speed then put your 60fps footage in a 30 fps comp and interpret the footage as 30 fps. Now the every frame of the footage will play back but it will take 20 seconds for the clock in the shot to show 10 seconds.

                   

                  Most folks have a hard time figuring out how to look at time changes in footage and they make incorrect assumptions. If you want to play your footage at normal speed then slow down the footage, then return to normal speed and your original footage is 60 fps and the final video will be 24 fps then you have to Interpret the footage at it's original frame rate, bring it into After Effects, then enable time remapping. Time remapping will set a keyframe at the start and at the end of the clip. The clip will play back in real time but frames will either be blended or dropped. There is no way around this.

                   

                  You go to the point in the time line where you want to start slowing down the clip and you set a keyframe, then you go to the part of the clip where you want the footage to play slowly and set another, then you go to the part of the clip where you want to start returning to real time and set another, then you go to the part of the clip where you want to return to real time.

                   

                  Now comes the fun part. You select all of the keyframes except the first two and drag them to the right. so that keyframe number 3, the point where you want the footage to be at it's constant slow motion part is where you want to have this happen according to the clock on the wall. IOW if you want the first 2 seconds to play in real time then the second keyframe is at 2 seconds, then at 3 seconds you want to clip to start playing back at 1/4 speed you would select all of the keyframes except the first two and drag the third keyframe to the 3 second mark.

                   

                  Now you select all of the keyframes but the first three and drag them to the right. You need to move the 4th keyframe far enough to the right so that the footage will be playing at 1/4 speed. If you want the original footage from two and a half seconds to 10 and a half seconds to play at 1/4 speed then that's 40 seconds according to the clock on the wall so you would slide all of the keyframes except the first 4 to the right until the 4th keyframe came to the 40 second mark.

                   

                  You repeat the process for all of the keyframes except the first 4 and move them to the right until you get to the point where you want the clip to return to normal time. Then you go into the graph editor and adjust the curves of the value graph until you get the timing you want with a constant angle between the first two keyframes, a curve between the second and third, a straight line that has 1/4 the slope of the first section between 3 and 4, then a curve between 4 and 5 and the same slope between 5 and 6 that you have between 1 and 2.

                   

                  I think I already went through this for you in another thread. Maybe it was for someone else.

                   

                  If you use Twixtor to do this the theory is exactly the same. It just takes a while to get used to thinking in time.

                  • 6. Re: Working with 60fps clips in 24fps Linked Comp
                    Interobang Level 1

                    If I use either the spacebar or the "play" button in the RAM preview window, the result is the same.

                     

                    What do you mean by your question: "how is AE interpreting the footage?"  How do I tell how AE is interpreting the footage?

                    • 7. Re: Working with 60fps clips in 24fps Linked Comp
                      Szalam Adobe Community Professional & MVP

                      Interobang wrote:

                       

                      How do I tell how AE is interpreting the footage?

                      After Effects Help | Importing and interpreting footage items