this dialog allows you to select between "standard" (also called a square aspect ratio) and "ccir601" aspect ratio.

    the maximum resolution of the ccir601 mode is 720 pixels for both ntsc and pal. the standard/square aspect ratio mode has a maximum resolution of 640 pixels for ntsc and 768 pixels for pal. however, the inputs to the osprey-500 all operate in the ccir601 mode. the ccir601 format is true of the analog inputs as well unless the osprey-100 analog mode is selected. thus, it is recommended that only the ccir601 mode be used on the osprey-500.

    note that since the sources are processed in a ccir601 format, the full 768 pixels of the standard/square aspect ratio mode of pal is not available. only 720 maximum pixels are available. if the standard/square aspect ratio mode is selected for pal, the osprey-500 drivers limit the maximum resolution to only 720 pixels.

    also, many digital sources provide only 704 true pixels and not 720 pixels per line. because of this, the osprey-500 scales down from 704 pixels (i.e., a crop of 720 to 704) to the desired size. if 720 pixels are desired, for example, the result is an unscaled 720 pixels in width. if 704 pixels are desired, the result is an unscaled 704 pixels in width. if 352 pixels are desired, the result is a scaling from 704 down to 352 pixels in width (and not 720 down to 352).