ADV7181D VGA decoding to 8-bit YUV422


I plan to use ADV7181D to decode RGB signal (VGA 640x480 and XGA 1024x768)...however because of hardware constrains we can only use 8-bit SDR...From the specification for RGB signals we need to use CP (components processor) but the CP output format only support 16 and 20 bits SDR mode. So my questions are:

1)  Is it able to configure ADV7181D to capture RGB signals and output 8-bit YUV422?

2) If it is able, will the AV code insertion work? so we can ignore HSYNC & VSYNC