• Adobe After Effects

  Creating a video loop synced to music

  Posted by Eric Carl on September 8, 2007 at 8:13 pm

  Hi, first post on the board, looks like there’s a lot of knowledgeable people on here! Awesome!

  I’m pretty new to AE, and am working on a short video loop to be used as a screensaver for my first real project. I’ve got a pretty good handle on what I need to do EXCEPT for actually syncing up my video with the loop.

  First off, the audio loop is 3.745 seconds. It is two measures long. My video will have events that occur on each 8th note, so there will be 16 events across the 2 measures.

  My first question, is what should I set my framerate as for my composition? The default for NTSC is 29.97, but that makes doing the math for this a little difficult and I’m not sure it’s necessary for a screensaver. Can I just use 30 instead?

  Also, how would I set up the length of my composition? I can’t really tell it to just be “3.745” seconds as the Duration field doesn’t allow for entering characters that way.

  So, any ideas how I can come up with the correct duration to enter, and then how to figure out the placement of my events so they sync up with each 8th note? I’m there’s some simple math in there but I’m about the worst mathematician ever. Thanks!

  Mike Clasby replied 19 years ago 2 Members · 2 Replies
• 2 Replies

• 

  Eric Carl

  September 8, 2007 at 9:39 pm

  Here, you can see exactly what I’m trying to accomplish:

  https://www.sans-concept.com/Boards/Deadly_Lights.mp4

  It’s all working except that obviously the lights don’t match the rhythm. The problem I’m finding is that the loop length of the audio and the timing of the notes are not going to divide equally into a specific 30 fps frame rate. My math is telling me they should technically occur like every 5.562 frames (not exact number, but you get the idea).

  Should I just build this at 90 fps or something where I’ll be able to more accurately place the lights and just render it out at 30 hoping it’ll work? Ideas?
• 

  Mike Clasby

  September 9, 2007 at 1:42 am

  Dan has three tuts under “Audio and Expressions” to use Convert Audio to keyframes to animate layers in AE.

  https://www.motionscript.com/design-guide/toc.html

  Trapcode’s SoundKeys is similar but on steroids, where you can pick out frequency ranges for animation reactions.

  https://www.trapcode.com/products_soundkeys.html

  I don’t know if you canget anymore precise… let me think on that, you can always ask over at the Cow AE Expressions page:

  https://forums.creativecow.net/viewforum/227

  Or write Dan an e-mail at his site (first link).

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