Keyframing in the Audio Editor


You are now familiar with the Audio Editor controls and the Level curve. Your goal in this exercise is to fade in the Bumper Sirens audio at the beginning of the project, and fade it out at the end. You can accomplish this goal by keyframing the Level curve in the Audio Editor. What's keyframing? Great question. Keyframing is the process of assigning a specific parameter value to a specific frame. Why? So that the values can change over time. If the values on the Level curve change, the curve bends to show the different values over time. For example, to fade in an audio track, you can assign the audio level a value of 96 dB (the lowest audio level) at the first frame of the track, and a value of 0 dB 1 second later in the track. The result when you play the track is that it will start silent and gradually fade up to a normal volume level of 0 dB 1 second later. Let's try it.

First, though, you need to learn how to set a keyframe. There are many ways to set keyframes in Motion. For this exercise, you'll set keyframes in the Audio Editor controls and on the curve itself. Let's start with the Audio Editor controls.

1.

In the Audio Editor, move the playhead to the beginning of the project.

The Audio Editor includes a Current Frame field to make it easy to maneuver the playhead within the Audio Editor. The current frame should be 00:00:00;00.

NOTE

The playhead needs to be paused to use this keyframing method.

2.

Drag the Level slider all the way to the left (96).

Now you need to set a keyframe to assign the value of 96 dB to the first frame of audio. To set a keyframe, you click and hold down the keyframe pop-up menu. Where is the pop-up menu? Hidden to the right of the Level value field. The pop-up menu button looks like a dash until you roll over it.

Keyframe pop-up menu hidden

Keyframe pop-up menu showing

3.

Click the Level keyframe pop-up menu and choose Add Keyframe.

A black diamond (a keyframe indicator) appears in place of the dash to show that a keyframe has been added to the frame. The actual keyframe (purple dot) appears at the playhead position on the Level curve.

Now let's set another keyframe 1 second later.

4.

In the Audio Editor Current Frame field, type 1.00 and press Return to move the playhead forward 1 second.

5.

Click the Level keyframe pop-up menu and choose Add Keyframe.

A new keyframe appears on the Level curve at the playhead position (1;00).

Now that you've set the keyframe, you can change its value.

6.

Change the Level control to a value of 0.

The Level curve bends so that the level changes from 96 dB to 0 dB over a 1-second period of time.

7.

Scrub the playhead over the first second of audio in the Audio Editor to hear the value change.

You can also play the audio in the Audio Editor by clicking the Play button located in the upper left of the Audio Editor tab.

8.

Press Cmd-S to save your progress.

That wasn't so difficult. You can also use the keyframe pop-up menu to delete keyframes by choosing Delete Keyframe from the menu.



    Apple Pro Training Series Getting Started with Motion
    Apple Pro Training Series: Getting Started With Motion
    ISBN: 0321305337
    EAN: 2147483647
    Year: 2005
    Pages: 283
    Authors: Mary Plummer

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