Data path and instruction set for packed pixel operations for video processing

One embodiment of the present invention discloses a method for processing video data within a video data processing path of a processing unit. The video data processing path includes three stages. In the first stage, source operands are extracted from a local register file and are ordered to map efficiently onto the downstream data path. In the second stage, arithmetic operations are performed on the source operands based on video processing instructions to generate intermediate results. In the third stage, additional operations are performed on the intermediate results based on the video processing instructions. In some embodiment, the intermediate results are combined with additional operands retrieved from the local register file.