Retime audio

Motion lets you retime audio tracks in your project, to speed them up, slow them down, or play them at a different speed. There are several ways to retime audio tracks:

  • Adjust the Timing controls in the Properties Inspector to modify an audio track’s playback speed, In and Out points, duration, and end condition (whether the track stops, loops, or “ping-pongs” back and forth).

  • Adjust the green bar in the Audio Timeline to modify an audio track’s duration and playback speed, and to set whether or not the track loops.

Adjust an audio track’s timing parameters in the Properties Inspector

Each audio object in your project has timing parameters in the Properties Inspector.

  1. Select an audio track in the Audio list or Audio Timeline.

  2. Open the Properties Inspector, then click the Show button on the right side of the Timing row.

    The Timing parameters appear.

    Note: The Show button is hidden until you move the pointer over the right side of the Timing row.

  3. Adjust the Timing parameters:

    • Speed: Drag in this value slider to set the speed of the audio track as a percentage. The default is 100%. Values lower than 100 play the audio track more slowly than its original speed, and also extend the Duration of the audio track. Values higher than 100 play the track faster than its original speed, and shorten its duration.

    • In: Click the left or right arrow (or enter a new value in the field) to change the In point of the audio track. Adjusting this parameter moves the audio track In point to the specified frame without affecting track duration.

    • Out: Click the left or right arrow (or enter a new value in the field) to change the Out point of the audio track. Adjusting this parameter moves the audio track Out point to the specified frame without affecting track duration.

    • Duration: Click the left or right arrow (or enter a new value in the field) to set the total duration of the audio track. Adjusting Duration also affects the Speed and the Out point.

    • End Condition: Click the pop-up menu, then choose an option to set how playback continues when audio ends in the track. There are four options:

      • None: The audio track’s duration in your project is equal to the duration of its source media file (the default setting).

      • Loop: When the last frame of the audio track is reached, the track loops back to the first frame and plays again. This can cause a jump in the audio track’s apparent playback unless the track is designed to loop seamlessly. The End Duration value must be greater than 0 for this parameter to have any effect.

      • Ping-Pong: When the last frame of the audio track is reached, the next iteration of track playback is reversed. The End Duration value must be greater than 0 for this parameter to have any effect. (The Ping-Pong option is mainly for reference—the reversed section of the audio track sounds noisy, because Motion does not support true reverse playback.)

      • Hold: The audio stops at the loop point.

    • End Duration: Drag the slider to set the number of frames by which the track is extended at the end of its duration. This control is available only when End Condition is set to a value other than None.

Change the audio track’s duration and playback speed in the Audio Timeline

Motion lets you change the timing of audio tracks in the Audio Timeline.

Important: To affect all channels of a multichannel audio file, select all tracks in the Audio list before making adjustments in the Audio Timeline.

  1. In the Audio Timeline, position the pointer over the end of an audio track’s the green bar.

  2. Do any of the following:

    • Shorten track duration and increase playback speed: Holding down the Option key, drag the end of the green bar to the left.

    • Lengthen track duration and slow playback speed: Holding down the Option key, drag the end of the green bar to the right.

    As you drag, the retiming pointer appears, and a tooltip displays the track’s duration and speed.

    Timeline showing audio clip being shortened with retiming pointer

Loop an audio track

Another way to extend an audio track’s duration is to loop it. You can easily loop a track by adjusting it in the Audio Timeline. When a looped audio track reaches its last frame, the audio starts playing from its first frame.

  1. In the Audio Timeline, position the pointer close to the end of an audio track’s green bar.

  2. Holding down the Option and Shift keys, drag the end of the green bar to the left.

    As you drag, the loop pointer appears, and a tooltip displays the track’s In and Out points, duration, and loop duration.

    Timeline showing audio track being looped

    The Audio Timeline displays looped tracks with barriers to indicate where loops begin and end. The first loop barrier in a track’s bar is interactive. Dragging the barrier left or right changes the point where the track loops.