the pixel clock pclk 113 the vga signal 107 comprises a vga signal filling a rectilinear window on the display screen this vga signal is uniformly black in color thus it has zero red green and blue components the second video signal 123 comprises an mpeg video signal which is also uniformly black in color as used herein the term u201c window u201d includes any set of vga or video data sized to fit in a selected set of pixels on the screen video data includes any stream of selected pixel data such as a pixel stream in the mpeg format in the preferred embodiment the following steps are performed as part of the fine adjustment of the pixel clock frequency using pclk 113 at a step 801 a uniformly black vga image is selected for input as the vga signal 107 for filling a first window 810 and a uniformly white mpeg image is selected for input as the video signal for filling a second window 812 at a step 802 the left border is offset by the number of pixels determined by the previous calibration steps 701 through 708 601 through 611 at a step 802 the top border is offset by the number of pixels determined in the previous calibration steps 701 through 706 705 at a step 803 a first.