|Current versions of the CORIO2 firmware provide far greater Aspect ratio adjustments than before, but their use can be confusing. Here we'll try to explain what is going on.|
In the 'System' menu there's a new option called 'Aspect adjust'. This can be left in the default 'Simple' mode for normal use (and will function as per previous versions). The 'Advanced' mode is detailed here.
In Advanced mode the 'Aspect ratio' options in the 'Setup Program source' and 'Adjust scaler parameters' menus disappear. Instead the Zoom and Shrink menus become more detailed.
Zoom now allows you to control zooming separately in both the horizontal and vertical directions in 1% steps. This is very useful when performing complex Aspect ratio conversion as it lets you define your own source aspect ratio. In effect, if you have a 16:9 widescreen image within a 4:3 source resolution you can Zoom vertically to avoid the black bars top and bottom. The final pixel:line (width:height) ratio is also shown so you know what ratio you're achieving.
As an example, if your source resolution is 800x600 then the new Zoom adjustment will be shown as:
Zoom H/V 100 100 1.333:1
This is because it has calculated the 800:600 ratio as 1.333:1 (which is the same as 4:3). If you have a 16:9 widescreen image within the 4:3 source, then you could Zoom vertically to achieve the 16:9 ratio. 16:9 is the same as 1.777:1 (just divide 16 by 9).
Zoom H/V 100 133 1.772:1
1.772:1 is as close as you can get to 1.777:1 - it's out by less than 0.5%.
Like Zooming, you can now adjust the Shrink values separately for the H & V directions. The menu option is very similar to the Zoom one, as shown below:
ShrnkH/V 100 100 1.333:1
This shows a normal 800x600 aspect ratio (of 4:3). If your source resolution was a widescreen 16:9 image, and you were feeding it to a normal 4:3 SVGA monitor (800x600), then you would of course get the wrong aspect ratio. Reducing the V Shrink value could be done to correct for this:
ShrnkH/V 100 75 1.777:1
Thus the output has been shrunk vertically to achieve the required aspect ratio. If the output was already a 16:9 resolution (eg. 1920x1080), then this would not have been needed - the unit would already have been showing:
ShrnkH/V 100 100 1.777:1
It knows this because it works out the ratio of 1.777:1 from the resolution database in the unit. It knows that 1920:1080 is the same as 1.777:1 (ie. 1920 divided by 1080 = 1.777).