• Adobe After Effects

  Tempering Audio Keyframes

  Posted by Dolver on February 8, 2007 at 1:02 am

  Hey folks,

  I have converted my audio to keyframes and have linked some motion to the audio. However, the motion is a too jumpy (to be expected since their is a discreet position for EVERY single frame). Is there any way to make the motion smoother? So that my moving object looks less spastic? Thanks in advance.

  Dolver replied 19 years, 3 months ago 3 Members · 6 Replies
• 6 Replies

• 

  Mike Clasby

  February 8, 2007 at 1:38 am

  You can use the Smoother (like the Wiggler) but it to sets keyframes and is not as easy as the Smooth expression to change and see the results (then change again if you don’t like the results). Here is an earlier post for smoothing audio keyframes driving camera position, the principal is the same:

  Name: yikesmikes
  Date: Nov 23, 2006 at 10:08:46 pm
  Subject: Re: audio to camera position

  You can try a smooth expression, they’re easier to change than the smoother. Here’s the typical smooth expression (the flipside of wiggle, eh):

  smooth(2, 5)

  This from AE Help is all I know about the smooth expression, but I do know it’s not as intuitive as wiggle, raising the width smoothes more:

  Number or Array smooth(width=.2, samples=5, t=time) {width, samples, and t are numbers} Applies a box filter to the value of the property at the specified time, and smooths the result over time. Width (in seconds) is the range of time over which the filter is averaged. Samples equals the number of discrete samples evenly spaced over time. Generally, you’ll want samples to be an odd number so that the value at the current time is included in the average. For example, position.smooth(.1, 5).

  smooth (.5, 5)

  Really dampens things.

  Or you could try linear interpolation. Say if you audio ranged from 0 to 20 (and these are the values that are being transferred to the camera position, then you could limit the audio through linear interpolation. The part of your expression that looked like this:

  thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”)

  could be changed to this

  linear (thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”), 0,20,0,5)

  Then when the audio ranges from 0 to 20, the camera changes will be from 0 to 5, making things less violent.
• 

  Colin Braley

  February 8, 2007 at 1:53 am

  Window > The Smoother.
  ~Colin Braley
• 

  Colin Braley

  February 8, 2007 at 1:56 am

  Sorry about that, for some reason I didn’t see Yikesmikes’ post…but anyway if you were going to go the expression route I would use “ease” interpolation. The expression would look something like this:

  ease(thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”), 0,20,0,5)

  ~Colin
• 

  Mike Clasby

  February 8, 2007 at 2:33 am

  Dolver, you probably figuresd it out, but if you use the smooth expression, it goes on the Both Channels>Slider stopwatch, something like

  smooth (.5,5)

  really dampens things.
• 

  Dolver

  February 8, 2007 at 3:00 am

  Thanks folks — I will try these out when I get back in to work tomorrow. I am sure one of these methods will work for me. Thanks again.
• 

  Dolver

  February 9, 2007 at 3:32 pm

  I found another problem with my expression — I have a random number generator in there — I need this randomness, and the ranges that I have are good. But is there any way to make this less jumpy. So if the random range is 10 to 20, I don’t want the computer picking:

  Frame 1: 11
  Frame 2: 19
  Frame 3: 10
  Frame 4: 16, etc.

  But maybe more like:

  Frame 1: 11
  Frame 2: 11.5
  Frame 3: 13
  Frame 4: 13.5
  Frame 5: 13
  Frame 6: 14, etc.

  So that the range is still 10-20, but it doesn’t make drastic jumps. Is there any way to do this? Thanks.

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