220 LESSON 12
Acquiring and Editing Audio
Creating a high-quality aural experience Adobe Premiere Pro offers professional-quality audio-editing tools that rival
many stand-alone audio-mixing and editing products. For example, it includes
the following:
t Sample-specific edits : Video typically has between 24 and 30 frames per
second. Edits fall between frames at intervals of roughly 1/30 second. Audio
typically has thousands of samples per second; for example, CD audio is
44,100 samples per second (44.1 kHz). Adobe Premiere Pro lets you edit
between audio samples.
t Three types of audio tracks : The three categories of audio tracks are mono,
stereo, and 5.1 (six-channel surround). You can have any or all of these track
types in a sequence.
t Submix tracks : You can assign selected audio tracks to a submix track. That lets
you apply one instance of audio and affect the settings of several tracks at once.
t Channel editing : You can split out individual audio channels from stereo and
5.1 surround sound files and apply effects only to them. For example, you can
select the two rear channels in a 5.1 track and add reverb to them.
t Recording studio : Adobe Premiere Pro lets you record any instrument or
microphone you can connect to an ASIO-compliant sound card. You can
record directly to a track on an existing sequence or to a new sequence.
t Audio conforming : Adobe Premiere Pro up-converts audio to match your
project’s audio settings. It also converts so-called fixed-point (integer) data to
32-bit floating-point data. Floating-point data allows for much more realistic
audio effects and transitions.
Camcorder kHz and bit-rate settings Many DV camcorders give you two audio quality options: 16-bit audio recorded at
48 kHz (16 bits of data per sample at 48,000 samples per second) or lower-quality
12-bit audio recorded at 32 kHz. The latter option lays down two stereo tracks on
your DV tape: one with audio recorded by the on-camera microphone, and the
other giving you an option to insert narration or some other audio. If you recorded
at 32 kHz and set your project to 48 kHz, you shouldn’t have a problem. Adobe
Premiere Pro CS5 will up-convert your audio during the conforming process.
#
Note: Floating-
point data has no
fixed number of digits
before and after the
decimal point; that is,
the decimal point can
float. This leads to more
accurate calculations.
