Sensoray 2253 Windows - Manual (Page 11)

3. Select Sensoray.
4. Select 2253.
5. Click on 2253 Demo.
The demo application by default is set up to preview the stream under Stream
A and record to file in Stream B. The user may change the settings to record
both streams (to separate files). Note that due to USB bandwidth constraints,
previewing 2 streams in full color at full size is not supported.
Before starting any of the streams, it is necessary to set the video system, PAL
or NTSC. Customers in North America will generally leave the setting as NTSC.
The next step is to select the video preview type. The options are UYVY, MJPG,
or Y800. UYVY would be the most common setting. UYVY is an uncompressed
color preview. MJPG is less efficient because the JPEGs must be decoded prior
to display, but requires less USB bandwidth. MJPG preview is useful to see the
effects of changing the JPEG Quality. Y800 is black and white preview and is
the most efficient transfer of uncompressed video.
To get the lowest possible preview latency ensure the following parameters are
configured (see Ultra-low Preview Latency below for details). Stream
type:UYVY, Size :704x480 or 704x576, Flip: off (unchecked), Mirror: off
(unchecked), Interpolate: off(unchecked) and Low latency: on (checked).
To start preview, press the Start button under StreamA->Control. A window
will pop up with the stream.
The 2253 allows simultaneous recording while previewing uncompressed
streams. Stream B in the demo app is set up to record by default to an H.264
encoded file. Press “Start” under Stream B to start recording to file. This can
be done independently of the preview stream A.
DirectShow API
The driver supports the DirectShow API. DirectShow is well documented at
MSDN (http://msdn.microsoft.com/en-us/default.aspx). The proxy file
s2253proxy.h may be used to control the bitrate and some additional features
of the 2253 through a COM interface. The operation of the 2253 proxy is
shown in the DLL source code, which is also available with the full application
source code. Please see the FAQ for an example of using the 2253 with a third
party DirectShow program called VideoLan.
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