PCLK is calculated by the following formula : PCLK = Width x Height x Blanking Period x Frame Rate
For example for a 1920 x 1080 video resolution, for a frame rate of 60Hz and an estimated 20% blanking resulting in a blanking period of 1.2, the PCLK would be
PCLK= 1920 pixels x 1080 pixels x 1.2 x 60Hz = 149MHz.