1. A multi-shader system in a programmable graphics processing unit (GPU) for processing video data, comprising: a first shader stage configured to receive slice data from a frame buffer and perform variable length decoding (VLD), wherein the first shader stage outputs data to a first buffer within the frame buffer; a second shader stage configured to receive the output data from the first shader stage and perform transformation and motion compensation on the slice data, wherein the second shader stage outputs decoded slice data to a second buffer within the frame buffer; a third shader stage configured to receive the decoded slice data and perform in-loop deblocking filtering (IDF) on the frame buffer; a fourth shader stage configured to perform post-processing on the frame buffer; and a scheduler configured to schedule execution of the shader stages, the scheduler comprising a plurality of counter registers; wherein execution of the shader stages is synchronized utilizing the counter registers.