DigiDesign Digidesign Pro Tools 8.0, Reference Manual

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Pro Tools Reference Guide 690
Identifying Beats
Identifying the beat of a one-bar drum loop and
creating Bar|Beat Markers for it:
1
Place a one-bar drum loop at the beginning of
an audio track.
2
Select
View > Rulers > Samples
. This ensures
that the selected audio material will be sample-
accurate.
3
Select the audio region with the Time Grabber
tool and choose
Event > Identify Beat
.
4
In the Bar|Beat Markers dialog, specify the
start and end locations for the inserted Bar|Beat
Markers. Since this example deals with a one-bar
loop, enter 1|1|000 and 2|1|000.
5
If necessary, specify a time signature for the
start and end range.
6
Click
OK
to automatically calculate the new
tempo and insert the necessary Bar|Beat Markers
and meter events. Any existing tempo and
meter events residing within the selection are
deleted.
When working with a selection, the Identify Beat
command only calculates a single tempo for the
selected range. If the tempo varies from measure
to measure, or beat to beat, you’ll need to use
the
Identify Beat
command for each tempo vari-
ance (making sure to accurately define a precise
selection range or beat location for the tempo
change).
To accurately define tempos for a range of audio
with the
Identify Beat
command, make certain
that the initial selection represents an accurate
length of bars and beats. You may want to first
loop the selection on playback to see if it plays
accurately (see “Loop Playback Mode” on
page 338). To avoid drift, and remain sample-ac-
curate, select the audio material with the Time
Scale set to Samples rather than Bars|Beats.
Identify Beat dialog
Bar|Beat Markers inserted
When identifying beats, select as large an
area as possible. For example, if you
have a four-bar-long audio file you want to
identify, select the entire four bars instead
of just one bar, in order to minimize round-
ing errors (see “Sample Rounding and Edit
Operations” on page 670).