Join Angie Taylor for an in-depth discussion in this video Editing and looping audio, part of After Effects: Kinetic Typography Techniques (2011).
After Effects isn't really an audio application, but you can do a certain amount of editing in After Effects, for example, create loops from audio. And that's what we're going to have a look at here. I'm in O3 Loop Audio Project, which you can find within the O1 working with Audio folder, which is in your Project files folder. And in there, I have the 01B Loop Audio Composition open. And you can see that within that I have my thatday mp3 file, which I'm using to create my kinetic animation. It's going to be the inspiration for the kinetic typography that I'm going to be working on.
Now, what I want to do is I want to use this audio to control an effect. The problem is the audio already has the vocals on top of the music and I really would like to have the music separate from the vocals. And it's not always possible to do this, and I approached the artist and asked them, but they didn't have the original files. So, what I have to do here is just separate it by creating a loop of the introduction. And if we just have a little preview of that, I'm going to use the period key on the number pad to preview it. (music playing) So you can see that the vocals come in at around about this point here. So what I really want to do is create a copy of that track without the vocals. Now, if you'll listen to the rest of it, you'll see that there's an underlying, looping piece of music that goes on underneath the vocals, which is basically just that first section repeated, so if you have a listen to that. (music playing) So my idea was just to take this section and loop it. So what I'm going to do is, first of all, duplicate my layer. I want to keep the layer with the vocals on, so I'm going to go to Edit menu, and choose Duplicate, or I can use Command+D or Ctrl+D on Windows to duplicate the layer (UNKNOWN) in the timeline.
Now, I'm going to take a minute just to rename this new layer, so I'm going to select the Layer, and hit the Return key on the keyboard which makes names editable in After Effects. And I'm going to call this Loop Section. Okay? And the next thing I'm going to do is just trim this. Now, I'm going to trim it roughly to begin with. We've got the time marker on the first marker, so that's a good enough place for me to start. So I'm going to trim that now. I can either do it manually just by clicking and dragging the end of the clip.
It makes it a bit tricky cuz you can't really see where the end is because of the labels I've attached to the markers. So instead of doing that, I'm going to use keyboard shortcut. And the keyboard shortcut to trim the endpoint of a layer is to hold down the Alt key and hit the right square bracket. You may not have seen that happen. If we zoom in, you'll see that that layer is now trimmed at this point, okay? So, right square bracket will trim the end of a layer, left square bracket with the Alt key held down will trim the endpoint of the layer. So we've trimmed our audio quite successfully.
What I want to do now is create my loop and I don't really want to do it within this comp, because I've got, already got my main piece of footage within this comp. So really, I want to create a new composition with just the loop section within it. So to do that, I'm going to go to the Layer menu, and choose Precompose, and precompose is just like nesting backwards. It's going to allow me to create a new composition containing only that looped section of footage. So we'll call this Loop Audio Comp.
Okay, and this is where we're going to loop the audio. So we've named it Loop Audio Comp. Makes sense. Now, you have two choices when you're precomposing one layer. You can leave all the attributes in this composition or you can move them to a new composition. Let's just choose Move to new composition and click on OK. And you'll see that, basically, what it's done is it's replaced my layer with a composition named Loop Audio Comp. If I double-click that, I can open it up, and in there, you can see my looped section of audio.
Now, just to make it easier to see what's going on, what I'm going to do is delete my markers. So I'm going to right-click on here, and choose Delete All Markers, cuz we don't really need to see them for this section. I'm then going to duplicate this looped section and create two that run back-to-back. And the reason that I'm doing that is, if we have a look at the waveform by double-licking the L key, we see that we get a sudden end to the audio. If I preview that, (music playing) that's not really what we want. So what we want to do is create a smoother transition.
So I'm going to duplicate this and create a transition between the two clips, which will kind of hide our transition a little bit. So I'm going to duplicate the layer, Command+D or Ctrl+D if you're on the PC. I'm also going to make the waveform bigger just by expanding it. And then, I'm also going to zoom in to my timeline by hitting the Plus key on the main keyboard, so that I can see the audio. And this is the section that really is creating the problem, okay? There's a bit of noise starting around about here, so what I really want to do is trim both of these layers to that point instead.
So, select them both, hold down the Alt key and hit right bracket to trim them to that point. Again, we'll have a little listen. (music playing) Okay, we still got a little bit on there. With them both selected, you can also just trim by moving the endpoint using the Regular Selection tool, will allow you to trim that manually, and you'll see that both get trimmed. (music playing) Okay. So that's going to be okay, I think. What we're going to do though is just keyframe that last little section out using the Audio Levels Keyframes.
So I'm going to move to the beginning where we just want to start fading the audio out. And then I'm going to hit the L key once and that will open up my Audio Levels properties for both layers. If I click on the stopwatch for one of them, that will enable the stopwatch for both of them, which means that I'm starting to animate this property. So I'm going to go from 0 decibels, and then I'm going to jump to the outpoint of the layers by hitting the O key on the keyboard. And at this point, I'm going to take that value down to about, let's say about minus 15. And let's just have a little preview of that.
(music playing) Okay? So that just softens that little edge, brings that edge down. So we're going to zoom back out again in the timeline by hitting the Minus key on the keyboard. So I can see my entire section. I'm going to jump to the first keyframe in my Keyframe section, and again, hitting K on the keyboard will jump to the next keyframe, hitting J on the keyboard will jump to the previous keyframe. So you can use J and K to jump between these keyframes. Alternatively, if you don't like remembering keyboard shortcuts, you can use these little buttons here to jump to the previous or next keyframe.
So at the first keyframe what we want to do is create an overlap. Again, I'm going to zoom in so you can see what's happened here. What I really want to happen now is for this layer to begin at this point. Okay? So what I'm going to do is just quickly deselect the layers and make sure I only have this one selected. Now, to move a layer, rather than trim a layer, at the position of the time marker, you hit the left bracket key, but without the Alt key held down. So no Alt key held down this time, just left bracket will move the start point of my layer to the current time marker. If I zoom out again using Minus on the keyboard, I can see that I've now got an overlap between those two clips.
So let's just play that and see how it sounds. (music playing) Okay, so I'm happy with that. And I'm going to keep that as my looped section and just very quickly trim the comp to this duration by moving the time marker to the end. Hitting the End key to set the end of my work area, and then right-clicking and saying Trim Comp to Work Area. So, I've got a nice little looped section of audio now that I can use in my final composition.
So, that's a little bit about how you can use different tools and shortcuts to edit and animate footage in terms of audio.
- Working with audio
- Preparing source files
- Structuring your After Effects project
- Working with shapes and effects
- Optimizing performance
- Animating text
- Creating 3D animation
- Using expressions to create motion
- Rendering your final movie