User`s guide

Chapter 3: Pro Tools Concepts 9
chapter 3
Pro Tools Concepts
This chapter is an overview of some essen-
tial concepts related to digital audio, MIDI,
and digital signal processing as they apply
to Pro Tools.
Hard Disk Recording
Tape-based recording is a linear medium—
you need to rewind or fast forward a tape to
hear a particular spot in a recording. To re-
arrange or repeat material in a linear sys-
tem, you need to re-record it.
Hard disk recording is a non-linear (or ran-
dom access) medium—you can go immedi-
ately to any spot in a recording without
having to rewind or fast forward.
Non-linear systems have several advan-
tages. You can easily rearrange or repeat
parts of a recording by making the hard
disk read parts of the recording in a differ-
ent order. In addition, this re-arrangement
is non-destructive, meaning that the original
recorded material is not altered.
Pro Tools is a non-linear recording system
that allows you to rearrange and mix re-
corded material non-destructively.
The Digidesign Audio
Engine
When you start Pro Tools, an application
called DAE automatically launches in the
background. DAE, or the Digidesign Audio
Engine, is Digidesign’s real-time operating
system for digital recording systems. When
you install Pro Tools, DAE is automatically
installed on your system.
In the same way that a computer’s operat-
ing system provides the foundation for
programs that run on the computer, DAE
provides much of the hard disk recording,
digital signal processing, mix automation,
and MIDI functionality required by
Pro Tools and other products from Digide-
sign and its Development Partners.