|This was added in version 112 of the firmware to the 'Lock/overlay' menu.|
It allows digital mixing of an RGB Lock source (ie. RGB1/2/3) with a CV/YC/SDI Program source when using PIP, overlay or underlay.
Normally, any RGB Lock source remains as an unprocessed signal with any Program source simply inserted into it. Eg. With 'PIP' as the Lock method, the scaled Program source image (eg. CV1) would just be inserted into the RGB Lock source. Underlay would thus be impossible, since the RGB source's signal is not processed and therefore cannot be compared to any key levels.
When 'Dig RGB Lock source' is active, and the Program source is a CV, YC or SDI input, the RGB Lock source IS processed and mixed digitally. Thus switching Program sources would cause the scaled Program source to fade into the Lock source (instead of fading to black).
It also means that underlay now becomes possible with an RGB Lock source - ie. with the Program source being scaled and locked to the RGB Lock source's resolution, but with the (unscaled) RGB Lock source appearing 'in front' of the Program source (in other words, the Program source is underneath - hence the term Underlay).
1. This setting defaults to Off to preserve the same functionality as earlier firmware versions.
2. The On state has no effect when the Program source is an RGB or YUV input.
3. When On and Locking to an RGB connector source, seamless switching between RGB and non-RGB inputs will have glitches (as the unit needs to switch between two very different operating modes).