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Chapter 7: The Osprey-300 Audio Driver
Note that in order to get mono audio you have
to select mono mode in your application. For
example, in SwiftCap you have to select mono
8-bit or mono 16-bit in the Capture Settings ->
Audio -> Format control group.
Because of the way DirectShow chooses audio
modes, mono mode only works correctly when
the sample rate you select is an exact match for
an available hardware sample rate. That is, the
sample rate must be 32, 44.1, or 48 kHz in most
cases, and may be further restricted when SDI
or DV1394 is selected (Refer to the explanation
of Preferred Audio Sample Rate, above).
Audio Level
This control sets the hardware Input Reference
level and software-based Boost factor. The
settings are separate for each input of each
device, and are applied to whichever input is
selected in the current application or in the
system mixer. The settings displayed do NOT
automatically update when you change inputs
in the application or mixer – click the “update”
button to refresh the settings.
The Input Reference level is meaningful only
on the analog unbalanced and balanced inputs;
when a digital input is selected this control is
disabled. The default level is chosen such that
the expected amplitude of a full volume input
signal will have adequate headroom without
clipping. If you do experience clipping, or are
working with very low-level signals, you can
adjust this level. On this control, a higher
reference level results in lower gain, so the
quietest setting is at the top of the scale.
The units, default value and range are different
for unbalanced and balanced signals (figure 4).
Click the “Dflt” button to restore the default
value. The Boost setting can be set individually
for each input. It supplements the system
mixer volume controls by providing a very wide
adjustment range. You can use it to calibrate or
normalize input levels across multiple inputs; or
to accomodate microphones or other non-line
inputs that have nonstandard signal levels.
Balanced and Unbalanced Audio
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Summary of Contents for Osprey-300
Page 1: ...Osprey 300 User s Guide...
