Psychtoolbox>Datapixx.{mex*} subfunction

pixels = Datapixx(‘GetVideoLine’ [, nPixels=HORIZONTAL_RESOLUTION]);

Upload pixels from Datapixx internal video receiver line buffer to local host.
The pixels uploaded are from the start of the top raster line of the most recent
video frame.
-“nPixels” specifies the number of pixels to be uploaded. The default value is
the horizontal resolution of the display. If nPixels is greater than the
horizontal resolution of the display, then the returned pixels will include the
digital video data received during the horizontal blanking interval, and
possibly into the next raster line. The maximum number of pixels which can be
requested is 2048.
-“pixels” is returned as a 2D array with one column for each pixel, and one row
for each of the red/green/blue components. Each datum is an 8-bit unsigned pixel
component value.
Note that GetVideoLine is asynchronous w.r.t. internal line buffer writes. If
the top raster line is modified between two video frames, and GetVideoLine
executes while the new top raster line is being received, then the returned data
could be a combination of the old and new data.

###See also: