Osprey 800e Series User Guide
Osprey Video
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Decide what type of pin to select based on several criteria. Software applications that use Osprey
video capture cards and AV stream drivers communicate with the hardware via a Microsoft
developed software layer named DirectShow®.
DirectShow is a collection of software objects, or object library, for working with video, audio, and
other multimedia data. The object library primarily consists of
filters
–
objects that process video
and audio data and are connected or chained together into
filter graphs
.
For example, Osprey designs filters that are included in all Osprey AV stream drivers and interface
with the capture hardware to grab-digitized frames of video. These filters then process video
streams and pass them to target software applications like Windows Media Encoder. Other filters
are associated with previewing or displaying video that decode video and render video to the
screen.
Filters usually have inputs and outputs and are interconnected programmatically as needed. The
input and output connections are referred to as pins. The pins most important to you are the
Capture Output pin and the Preview Output pin. Generally, captured audio and video to be fed to
the encoder is taken from the Capture pin, while video for local preview, such as the Input Video
window in the Windows Media Controller dashboard, will usually use the Preview pin.
In most cases, the Preview pin has a lower priority in the video processing engine. If the host PC is
nearing its upper performance margin where video quality could be compromised, it is preferable to
sacrifice quality or drop frames in the Preview output in favor of sustaining quality of the Capture
pin’s output. Exposing thes
e pins separately in Osprey drivers allows you to balance your needs with
the host computer’s performance and the video application’s features. You may apply a low
-effort
de-interlacing process to a preview window to save CPU cycle, and apply a more CPU intensive
Advanced Motion Adaptive De-interlacing process to the captured stream for maximum video
quality.
Like other Osprey cards, the Osprey 800 series enables you to define various setups for the two pins.
For example, you can choose to include a logo i
n the capture pin’s video, but not in the Preview
output. When you click
Capture
, the current logo settings for the Capture pin are loaded, and the
changes you make apply only to the Capture pin, not to the Preview pin. The Preview button works
in the same manner.
Common buttons
The following information applies to controls that are not interactive.
OK
Commits the changes you have made on the currently displayed
page, and exits the dialog.
Cancel
Exits the window without committing the changes you have made
on the currently displayed page. Changes made before the most
recent click of Apply are not cancelled.
Apply
Commits the changes you have made on the currently displayed
page, without exiting the dialog.