Settings that affect scaling:

• H_WIDTH
  • Defines the size of the horizontal part of the input signal that will be processed
  • Can be used to crop the input signal (in combination with H_POS)
• V_WIDTH
  • Defines the size of the vertical part of the input signal that will be processed
  • Can be used to crop the input signal (in combination with V_POS)
• ZOOM_SIZE
  • Zooms uniformely, keeps aspect ratio
  • Does not affect the black bars to the left and right
• ZOOM_WIDTH
  • Zooms only in horizontal direction, modifies aspect ratio
  • Changes the size of the black bars the left and right
  • Since it scales only in one direction, it can be used to "restore" can be used to restore an aspect ratio that was manipulated by cropping the picture using H_WIDTH and/or V_WIDTH
• ZOOM_OVERSCAN
  • Shrinks the picture uniformely
  • Introduces a black "letterbox" around the shrunk picture
  • Think of it as the inverse of ZOOM_SIZE

Scaling to full height:

• (+)
  • Uses as much screen space as possible
  • (Relatively) easy to setup
• (-)
  • Non-integer scale - pixels are not exactly represented
  • Scanlines look bad (at least on 1080p)

1. ZOOM ON
2. set ZOOM_SIZE to 100%
3. vertical scaling:
   • reduce ZOOM_SIZE until picture fills vertical space
   • modify ZOOM_V_POS to align vertically
4. horizontal scaling:
   • use H_WIDTH and ZOOM_H_POS until picture is cropped correctly
   • modify ZOOM_WIDTH until aspect ratio is restored (calculate/measure manually, keep non-square pixels of some systems in mind)

Integer scaling:

• (+)
  • Integer scale - pixels are exactly represented
  • Scanlines look good
• (-)
  • Either loses some lines in the top/bottom area or has to use a letterbox
  • Hard to setup

1. Modify VISUAL_SET until picture is cropped correctly
2. Modify ZOOM_SET and/or ZOOM_OVERSCAN until vertical scale is integer
   • Can use scanlines to verify this
   • May need to go back and slightly modify V_WIDTH to get perfect results
3. Align picture vertically using ZOOM_V_POS
4. Modify ZOOM_SIZE until horizontal scale is integer
   • No method to verify this
   • Simply try to achieve the desired aspect ratio (calculate/measure manually, keep non-square pixels of some systems in mind)
5. Align picture horizontally using ZOOM_H_POS