The first step is to review the documentation here:
The second step would be to get an evaluation board and begin working with it.
The link has various scripts to program the ADV7181 with depending on the input and output formats you want. The output pins P19-P0 will have the digital data and HS, VS, FIELD/DE pins will have the timing information.
To understand the various formats I'd suggest the book, "Video Demystified" and the appropriate stands for VESA and NTSC/PAL.