Demonstrate simple use of built-in video capture engine.
VideoCaptureDemo([fullscreen=0][, fullsize=0][, roi][, depth][, fps=realmax][,deviceId=0][, cameraname][, bpc=8])
VideoCaptureDemo initializes the first attached and supported camera on
your computer (e.g, the built-in iSight of Apple Macintosh computers),
then shows its video image in a Psychtoolbox window.
By default, a capture rate of 30 frames per second is requested, and the
timecode and interframe interval of each captured image is displayed in
the top-left corner of the display. A press of the ESCape key ends the
‘fullscreen’ If set to non-zero value, the image is displayed in a
fullscreen window, as usual, otherwise a normal GUI window is used.
‘fullsize’ If set to 1, the cameras image is scaled up to full screen
resolution, ie. so it fills the maximum amount of display area, but
preserving the original aspect ratio.
‘roi’ Selects a rectangular subregion of the camera for display. By
default, it selects the full area of the camera, if possible. This
parameter may need tweaking for some cameras, as some drivers have
bugs and don’t work well with all settings.
‘depth’ Number of color channels 1 = grayscale, 3 = rgb, 4 = rgba etc.
‘fps’ Target capture framerate. Maximum for given resolution and color depth
‘deviceId’ Device index of video capture device. Defaults to system default.
‘cameraname’ Name string for selection of video capture device. This is
only honored if ‘deviceId’ is a negative number, and only for certain
video capture plugins. Defaults to none.
‘bpc’ Optional bit depth in bits per channel. Defaults to classic 8 bpc, but
some cameras support up to 16 bpc. Setting 16 bpc will try to coerce those into
providing “HDR” data. Usually this works with higher end firewire cameras and
the dc1394 capture engine. Your mileage with standard consumer cameras and the
default [GStreamer](GStreamer) capture engine will likely be less great. If at all, it would
probably only work on Linux or on OSX with [GStreamer](GStreamer) built from source, so you
have the camerabin1 plugin available.