Synchronizing video and audio clips in multi-camera projects
You can synchronize your video and audio clips so that they are all aligned to the same moment in time. The easiest way to do this is to let the Multi-Camera Editor analyze the audio for each of the clips and sync the clips automatically. If your recordings are planned, you can use a special audio signal, such as clapping your hands (similar function to using a clapper board in professional shoots). Some events have natural audio cues that help the sync process, such as music performances or sporting events with a start signal.
You can also synchronize the clips by using markers, shooting time, or you can adjust them manually by dragging the clips in the timeline to the timecode you want. For example, you could use a common visual element, such as a flash to sync videos manually. These methods are helpful if your video footage doesn’t include audio or the audio waveforms within the clips are difficult to sync, or you simply prefer to align the clips manually.
In some cases you might need to use a combination of the synchronization options, depending on your source footage.
* To synchronize video and audio clips in the Multi-Camera Editor
1 After importing your clips to the Multi-Camera Editor, choose one of the following options from the Source Sync Type drop-list on the toolbar:
Audio — Click the Sync button next to the drop-list to synchronize the clips in the timeline. Note: Your video clips must include audio to use this option.
Marker — Select a clip in the timeline, play the clip or scrub to the position you want by using a visual cue, and click the Set/Remove Marker button  on the toolbar to add a marker. After a marker has been added to each clip, click the Sync button on the toolbar to align the clips according to the markers.
Shooting Date/Time — Click the Sync button to synchronize the clips according the shooting date and time as indicated by the metadata recorded by the camera. Note: The clocks must be in sync on the cameras to get accurate results.
Manual — In the timeline, drag each clip to the position you want by using a visual cue.
 
Note: If there are clips that you want to exclude from the synchronization process, click the Exclude from Synchronization button on the corresponding track. Click the button again (Enable for Synchronization ) to include the track.
 
Tip: After you synchronize your clips, you can use the Lock buttons on the individual tracks to ensure that the tracks stay synchronized during the editing process.