At this time, iMovie 1.4 for iOS allows you to do "audio splits" also known as J-cut or L-cuts.
This feature is available only on iPads because Audio Waveforms are also only available on iPad.
In order to extend audio from clip 1 do the following:
- Create a New Project and turn Audio Waveforms ON (unless you already have them on and visible)
NOTE: if you don't know where to find the button for Audio Waveforms, tap the yellow question mark button, which is known as Coaching Tips. These tips will display the name of each button in the UI. You can easily dismiss them by tapping the question mark button again.
- Add two video clips to Timeline, one with clear audio, second without. Make sure they have enough "handles" or room.
NOTE: this means that when you go in your Video Bin and you click on a clip to select a portion of it to add it to Timeline, make sure that selection is in the middle of the clip, so that you have more video/audio to play with at the beginning and at the end of the clip selection.
- Open Precision Editor by tapping beneath the transition or by using the two finger gesture to expand Timeline
- In Precision Editor you will be able to see blue and yellow dots alligned with your clips
- In order to extend the audio of 1st clip (on the top layer in Precision Editor) do the following:
- Drag the upper blue dot to the right of your clip
This will result in audio of 1st clip continuing to playback over your 2nd clip. You just performed an L-cut.
You can also extend audio contained in 2nd clip (if any), by dragging bottom blue dot to the left of clip.
For more info regarding Audio Split go here:
http://help.apple.com/imovie/ipad/1.4/index.html?lang=en-us#kna7dd3f29
Good luck!