ViewCast Osprey-450e - Manual (Page 82)

The Audio Driver
76 ViewCast
Audio formats
The Osprey hardware supports sampling of analog audio at 32, 44.1 and 48 kHz in 16-bit PCM
format. Captured audio data is down-sampled and reformatted if necessary by Microsoft system
audio components, allowing an application to capture audio data in 8-bit and 16-bit mono or stereo
formats at any of the following data rates:

8 kHz

11.025 kHz

16 kHz

22.05 kHz

32 kHz

44.1 kHz

48 kHz
Audio playback
Osprey cards provides audio capture only, not audio playback. Continue to play back captured audio
using your system soundcard.
Audio configuration
The OspreyConfig applet is included as part of the Osprey AVStream driver package. It is also
provided in source form in the Osprey AVStream SDK. It provides supplementary controls that are
not available via the standard system properties.
OspreyConfig’s controls are device-specific and apply only to Osprey audio capture devices. Use the
Device menu list at the top of the applet’s window to select which device you are controlling.
Mono Source Mode
If set to Use Left Channel, then left channel audio data is copied to the right channel.
If set to Use Right Channel, then right channel audio data is copied to the left channel.
If set to Average Left and Right, no copying is done.
The Microsoft mixer component always averages both channels when converting to mono. If a
signal is present on, say, the left channel only, the Average mode will average the left channel with
the silent right channel, effectively halving the signal amplitude. Setting this control to Left results in
only left channel data in the mono capture, with no amplitude drop.
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 update to refresh the settings.