About Mixer Automation and Keyframe Recording

Whenever you play back a sequence, the audio level and pan keyframes in the clips control the mix automatically. This is called mixer automation and is especially important when you have a lot of tracks in a long sequence. Audio level and pan keyframes allow you to build up a complete audio mix by recording keyframes on just one track at a time. With keyframes, you can orchestrate a complete mix of audio tracks by yourself, a task that once required several people, with each person focused on a group of tracks.

There are several ways to add audio level keyframes to your clip items and modify them in the Timeline or Viewer. You can:

Note: Although the steps described above generally refer to using the controls in the Audio Mixer to automate your mix one track at a time, these steps can also apply to using a control surface. For more information about using a control surface, see Using a Control Surface with the Audio Mixer.

Specifying Audio Keyframe Recording Resolution

Before you start recording keyframes using the Audio Mixer, you must define the frequency with which Final Cut Pro records audio level and pan keyframes. Final Cut Pro can record every subtle movement of an audio fader and panning slider or a reduced (“thinned”) number of those keyframes.

To choose the resolution for audio keyframe recording
  1. Choose Final Cut Pro > User Preferences.

  2. In the Editing tab of the User Preferences window, choose an option from the Record Audio Keyframes pop-up menu:

    • All: Records the maximum number of keyframes possible while you move a track strip’s fader or panning slider. The end result is an ultra-precise re-creation of the levels you set using the Audio Mixer. The drawback to this option is that you might end up with an extremely dense cluster of keyframes in the audio level overlays of the affected clips that can be difficult to edit later. Unless you are doing very fast, precise audio mixing, you may want to avoid this option.
    • Reduced: Records only a subset of keyframe information created when you move a track strip’s fader or panning slider. The resulting audio level or pan overlay in the Timeline or Viewer is still a fairly accurate reproduction of the levels you set, but the number of keyframes recorded is much smaller than when the All option is chosen.
    • Peaks Only: Records only the minimum number of keyframes necessary to approximate the levels you recorded when moving a track strip’s fader or panning slider. Keyframes recorded using the Peaks Only option reflect only the highest and lowest levels that were recorded. This is primarily useful when you want to record a minimum number of keyframes to edit later in the Timeline or Viewer.

Recording Audio Level and Pan Keyframes

As long as the Record Audio Keyframes button at the top of the Audio Mixer is selected, audio level and pan keyframes are recorded whenever a fader or panning slider is adjusted. Keyframes can be recorded both during playback and when playback is paused.

During playback, keyframe recording begins when you position the pointer on a fader or panning slider and press the mouse button, and recording continues until you release the mouse button. The density of recorded keyframes depends on what you specified in the Record Audio Keyframes pop-up menu in the Editing tab of the User Preferences window.

Note: Instead of using the mouse to adjust your faders, you can also use a supported control surface to adjust multiple faders and panning sliders simultaneously.

Keyframe recording continues as long as the mouse button is held down, so it’s best to mix groups of short, consecutive clips in a track all at once. For example, suppose you’ve edited a dialogue sequence with multiple angles of coverage so that the dialogue spoken by a single character is broken up into six different clips on tracks A1 and A2.

Figure. Timeline window showing audio clip items for six different clips on tracks A1 and A2.

Because each clip has its own independent audio levels, to use the Audio Mixer to set the levels for the entire group, you need to keep the mouse button held down continuously to record keyframes as you play back all six clips. If you stop halfway through clip 4, the audio level overlays for these clips look like this:

Figure. Timeline window showing clip audio  levels adjusted up to the playhead position in clip 4, but no level changes thereafter.

This is because no fader movement was detected in either clip 5 or clip 6, so the levels were not adjusted for these clips. If this happens, it’s easy to move the playhead back to the beginning of the section you’re working on and record any additional keyframes.

When you release the mouse button, keyframe recording ends and the fader for that track goes back to displaying the previously set levels. The same rules apply to recording pan information.

Important: If the Record Audio Keyframes button is not selected, no keyframes are recorded when you move faders or panning sliders. However, you can still modify keyframes and levels between any two keyframes.

To record audio level or pan keyframes
  1. Click the Record Audio Keyframes button in the button bar at the top of the Audio Mixer to turn on keyframe recording.

    Tip: You can click the Record Audio Keyframes button to turn keyframe recording on or off during playback, if necessary.

  2. In the Viewer or Timeline, move the playhead to the area of your sequence where you want to begin recording keyframes.

    It’s a good idea to start a few seconds before the section you’ll actually be mixing, to give yourself time to get ready.

    Figure. Timeline window showing the playhead positioned a few seconds before a clip begins.
  3. Begin playback of your sequence.

  4. As your sequence plays, position the pointer over the fader or panning slider in the relevant track strip, then hold down the mouse button to begin recording keyframes for clips playing back in that track.

    Figure. Pointer positioned over a fader slider in the Audio Mixer to start recording keyframes.
  5. Hold down the mouse button to continue recording keyframes, and move the fader or panning slider to adjust the clip’s audio or pan levels in real time while playback continues.

  6. When you’ve finished, release the mouse button to stop recording keyframes.

    The sequence continues to play, and the fader and pan controls return to the previously set levels.

  7. If there are any other Audio Mixer controls you want to adjust at this time, repeat steps 4 through 6.

  8. When you’ve finished making adjustments, stop playback.

After you finish recording automation for a track, you can move the playhead back to the beginning to record keyframes for additional tracks. This way, you can create your audio mix one track at a time, adding keyframes for each track until you’ve set levels for all the clips in your sequence. Ultimately, it doesn’t matter whether you use the Audio Mixer in real time or set levels directly in the Timeline or Viewer. You can choose whatever method works for a particular track or clip.

Note: You can also make changes to levels in tracks you’ve already mixed. New changes made to the fader and pan automation overwrite previously set keyframes.

Looping Playback to Mix Each Track

You can set a section of your sequence to loop so that you can mix each track without stopping playback. As the section of your sequence loops, you can go from one track strip fader to the next, adjusting (or overwriting) keyframes until your mix is perfect.

To record automation while your program is looping
  1. Click the Record Audio Keyframes button in the button bar at the top of the Audio Mixer to turn on keyframe recording.

    Tip: You can click the Record Audio Keyframes button to turn keyframe recording on or off during playback, if necessary.

  2. In the Timeline or Canvas, set In and Out points.

    It’s a good idea to place In and Out points several seconds earlier and later than you need, to give yourself time to manipulate the controls before reaching the boundaries of the loop. Otherwise, you may overwrite keyframes you previously set when playback resets to the In point.

    Figure. Timeline window showing sequence In and Out points set a few seconds before and after a clip.
  3. Choose View > Loop Playback to turn on looped playback.

  4. To begin looped playback, choose Mark > Play > In to Out, or press Shift-Backslash (\).

  5. Position the pointer over any fader or panning slider you want to adjust, then press and hold down the mouse button to begin recording keyframes.

  6. Hold down the mouse button to continue recording keyframes, and move the control you’ve selected to adjust the clip’s audio or pan levels in real time while playback continues.

  7. When you’ve finished, release the mouse button to stop keyframe recording.

    The sequence continues to play, and the fader and pan controls return to previously set levels. When playback loops, you can click another control to continue making adjustments to clips in other tracks. You can also make changes to clips in tracks you’ve already mixed.

    Note: New changes made using a track’s fader and panning slider overwrite any previous levels.

  8. When you’ve finished making adjustments, stop playback.

    If keyframe recording stops before the end of a clip, the audio or pan level of the remaining duration of that clip depends on whether or not there were already keyframes in the clip.

    • If there were no keyframes in the clip prior to recording keyframes: The audio level or pan overlay remains at the level of the last recorded keyframe for the remaining duration of that clip.
      Figure. Timeline window showing where playback stopped and the audio level stopped being adjusted.
    • If there were keyframes in the clip prior to recording keyframes: The audio level or pan values are interpolated from the level of the last recorded keyframe to the level of the next keyframe.
      Figure. Timeline window showing where playback stopped in an audio clip that had keyframes already in it.

Modifying Recorded Keyframes

After you’ve recorded keyframes for a series of clips on a particular track, there are two ways you can make modifications to the levels you’ve set with the Audio Mixer: by using the Audio Mixer or by modifying keyframes in the Viewer or Timeline.

Using the Audio Mixer to Record over Previously Existing Automation

You can use the Audio Mixer to make further changes to audio clips in your sequence that already have audio level and pan keyframes applied. How these changes are made depends on whether or not keyframe recording is turned on.

  • If the Record Audio Keyframes button is selected: Changes you make with the Audio Mixer during playback create a new set of keyframes, completely overwriting any previously existing keyframes. Changes you make while playback is paused insert new keyframes at the position of the playhead.
  • If the Record Audio Keyframes button is not selected: Changes you make with the Audio Mixer during playback do not create new keyframes. Instead, existing keyframes are modified to match the levels set when the playhead passes over them.

    Individual keyframes can be adjusted if the playhead is directly over them. If the playhead is between two keyframes, the level of both keyframes is changed to adjust that entire section of the overlay.

During playback, every fader and panning slider in the Audio Mixer animates, displaying the current levels in your sequence. At any time during playback, you can adjust a fader or panning slider to begin recording new automation or modifying existing automation. This helps you to maintain a smooth transition from any previously recorded levels to the new levels you’re setting.

Modifying Keyframes in the Timeline and Viewer

You can also make changes to the audio level and pan keyframes in the Timeline. By displaying level overlays in the Timeline (click the Clip Overlays control), you can modify the keyframes you recorded, using the Selection and Pen tools to make precise adjustments. For more information on adjusting audio level and pan keyframes in the Timeline, see Adjusting Audio Levels in the Timeline and Panning Audio in the Timeline.

To modify pan keyframes you’ve added using the panning sliders in the Audio Mixer
Do one of the following:
  • Open the clip in the Viewer. Stereo pan keyframes appear on their own overlay in the clip’s Audio tab. For more information on adjusting stereo pan keyframes in the Viewer, see Changing the Pan of Audio in the Viewer.

  • In the Timeline, click the Clip Keyframes control, then Control-click in the keyframe editor area of an audio track and choose Pan from the shortcut menu. Pan keyframes are now displayed in the keyframe editor for the audio tracks in the Timeline, and you can adjust them with the Pen tool.

Deleting Audio Level and Pan Keyframes

You can easily remove level and pan automation from clips in a sequence using the Remove Attributes command. Audio level and pan keyframes can be removed separately or together.

To remove keyframes using the Remove Attributes command
  1. Do one of the following:

    • Select one or more clips in the Timeline, then choose Edit > Remove Attributes.

    • Select one or more clips in the Timeline, Control-click one of the selected clips, then choose Remove Attributes from the shortcut menu.

  2. In the Remove Attributes dialog, select Levels or Pan to delete keyframes from those overlays.

    Figure. Remove Attributes dialog showing the Levels and Pan checkboxes selected.
  3. When you’ve finished, click OK.

    All audio level and pan keyframes are removed from the selected clip, and the audio level is reset to 0 dB.