AJA IO LA, Инструкция по установке и эксплуатации, Страница: 47 / 76

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Chapter 5:
Final Cut Pro and Other Software
5
Final Cut Pro
Final Cut Pro 4 ships with information already configured for most common system
configurations. After you install the AJA software on your Power Mac or Xserve, all
you need to do to begin using Final Cut is to run it and choose the proper setups
from the canned ones provided. These canned setups are called “Easy Setups” in
Final Cut Pro and are available to use and edit under Audio/Video Settings in the
“Final Cut Pro” menu (next to the apple menu).
The manual you are reading does not provide operational information about Final
Cut Pro 4. Please read the Final Cut Pro user documentation provided with it for
information on learning to use it and how to configure it. The chapter you are
reading addresses the configuration and setup unique to use of Io with Final Cut
Pro.
A Note About Io
Audio Levels and
Final Cut There are many different conventions for representing audio levels in professional
audio/video equipment. In the analog world, the “VU” meter has been the standard
for representing audio levels within the available dynamic range. A zero (“0”) VU is
considered the nominal “peak.” The “red” area above zero VU represents
“headroom” for occasional instantaneous “hot” peak levels. It is important to
support headroom, otherwise the instantaneous peaks are hard-clipped resulting in
distortion. In the digital world, the digital numeric range is fixed. To support
“headroom”, the equivalent zero VU point is most often defined as 20db below full
scale digital.
Io supports the most common industry standards for analog levels: nominal or “0
VU” is 20db below full scale digital, and full scale digital represents
an analog level of +24dbu. This means a nominal tone outputs at +4dbu.
In order to meet the above professional digital levels in Final Cut Pro,
audio levels should peak at –20db. In other words, you should adjust
the audio levels in Final Cut so that peaks hitting 0 VU on an analog
meter, hit –20db on Final Cut Pro’s meter. For a nominal tone level,
set the tone to –20 db.
For example, if Io’s Balanced Audio Outputs are connected to a
Sony Betacam SP deck, an audio level of –20db on Final Cut Pro’s
level meter will indicate 0 VU on the deck.