Avid Technology Car Video System PT User Manual

Page of 154
Media Station|PT Guide
10
Frame-Rate Accurate Video 
Editing and Sample-Rate Accurate 
Audio Editing
Media Station|PT edits with frame accuracy. 
This means that in a 30-fps project, you can edit 
at 30 different locations for every one second of 
video. Pro Tools edits with sample rate accuracy. 
In a 48-kHz session, there are potentially 48000 
locations to edit for every second of audio. 
When Pro Tools exports an AAF or OMF compo-
sition destined for an Avid application, it must 
ensure that the audio files line up on frame 
boundaries. To do this, it might have to split an 
existing audio region into three clips. For exam-
ple, the following illustration shows a 5-frame 
video clip and a corresponding audio region. In 
Pro Tools, the audio regions might not line up 
on video frame boundaries.
In order to export frame accurate audio regions, 
Pro Tools splits the audio media on frame 
boundaries and fills any gaps with silence. The 
following illustration shows the resulting audio 
regions that are exported to Media Station|PT.
When you use Export Selected Tracks as 
OMF/AFF to export tracks from Pro Tools with 
Enforce Avid Compatibility enabled, a number 
of additional media files labeled Sample Accu-
rate Edit appear in the Avid bins. These are the 
additional media files that Pro Tools creates to 
ensure that Media Station|PT receives frame-ac-
curate audio. You also see the sample-accurate 
edit media files if you zoom in on the imported 
audio in the Timeline.
Figure 1.  Original audio region
One Pro Tools audio region
5 frame video clip
The original audio region does not line up on video frame boundaries
Figure 2.  Exported audio region
Three exported audio regions
5 frame video clip
Exported audio regions line up on video frame boundaries
New audio region 
with padded silence
New audio region 
with padded silence