1. An apparatus comprising: a central processing unit; and a graphics processing unit comprising an array of software-configurable general purpose parallel processors, a globally shared memory, wherein each of the software-configurable general purpose parallel processors in said array of software-configurable general purpose parallel processors has access to said globally shared memory, and a shared memory, wherein (a) said shared memory is accessible by said central processing unit to program said shared memory with computer executable instructions for controlling said graphics processing unit, (b) said computer executable instructions comprise a transform program which, when executed by one or more of said software-configurable general purpose parallel processors of said graphics processing unit, (i) transforms and quantizes each macroblock of a current frame, (ii) inverse-quantizes and inverse-transforms each macroblock, (iii) creates a reconstructed picture, and (iv) outputs coefficients to said central processing unit for encoding into a bitstream, and (c) said current frame and a reference frame are stored in said globally shared memory of the graphics processing unit.