Using Audio Scrubbing

Once you have adjusted the audio you will want to play it back to preview the changes. But sometimes an audio event, like the single click of a camera, is difficult to isolate when it is being played back at normal speed. To get around this, you can scrub the Timeline with the mouse by moving it backward and forward over the sound event until you have found the exact spot you need to change.

However, audio scrubbing is turned off by default. This is set that way so that the majority of editing tasks can be performed while your machine is enjoying the full computer resources available to it.

Once audio scrubbing is turned on, you will see a performance hit, so I recommend that you only turn it on when you need it and then turn it back off again once the audio job is done.

Audio scrubbing in the Source Viewer

This is useful when you're placing makers or setting mark-in and mark-out points for your media clips. Both video and audio tracks can be scrubbed in the Source Viewer.

To activate audio scrubbing in the Source Viewer

1.	Press the Scroll Lock key on your keyboard to activate audio scrubbing. A small A appears over the Audio icon in the Liquid Edition taskbar (Figure 7.34). Figure 7.34. Audio scrubbing activated.
2.	Scrub through the Source Viewer to hear the audio.

Audio scrubbing the Timeline

This type of scrubbing is a little more complex to activate, but it follows the same basic pathyou must press the Scroll Lock key to activate it. However, you then need to make sure the speaker icon on the track you want to hear is hollow, as shown in Figure 7.35. Here, the Name 4 and Name 3 tracks display a hollow speaker icon, and audio scrubbing will be heard on these tracks. Name 5 shows a solid speaker icon, and audio scrubbing will not be heard on this track.

Figure 7.35. The track names showing both examples.

To set a Timeline track for audio scrubbing

• Hold down the Shift key and click once on the speaker representing that Timeline track you want to scrub.
  
  The speaker becomes hollow, indicating that audio scrubbing is active for this track.
  
  

Tip

• Only two Timeline tracks can be activated for audio scrubbing at any one time. Activating a third will turn one of the other two off.

Digital or Analog Output

You have two choices of output when you're using audio scrubbing: digital or analog.

These can be toggled on or off by activating audio scrubbing with the Scroll Lock key and then right-clicking the small A that appears next to the Audio Editor in the Liquid Edition taskbar (Figure 7.36).

• Digital output has one big advantage over analog: its performance is much better.

• Analog output has one big advantage over digital: its audio quality is much clearer and easier to work with.

Figure 7.36. Switching to digital scrubbing.

Which one you use depends on how powerful your computer is and how badly you need the quality offered by analog.