1. A weighted prediction module for use in a video encoder that processes a video signal including a sequence of pictures, the weighted prediction module comprising: processing hardware that includes: a weighted prediction parameter generation module configured to generate a plurality of initial weighted prediction parameters, to analyze the plurality of initial weighted prediction parameters, and to generate a refinement flag that indicates one of: enable parameter refinement or disable parameter refinement, wherein the plurality of initial weighted prediction parameters include: a first parameter generated based on a first sum of absolute differences between pixel data and pixel mean data for a first picture and a second sum of absolute differences between the pixel data and the pixel mean data for a second picture; and a second parameter generated based on a third sum of gray-level data for the first picture and a fourth sum of gray-level data for the second picture; a weighted prediction parameter refinement module, coupled to the weighted prediction parameter generation module, that, when the refinement flag indicates that the parameter refinement is enabled, is configured to generate a plurality of refined weighted prediction parameters by refining the plurality of initial weighted prediction parameters; and a weighted prediction flag generation module, coupled to the weighted predication parameter generation module and the weighted prediction parameter refinement module configured to generate a weighted prediction flag that indicates one of: enable weighted prediction or disable weighted prediction, based on the refinement flag.