1. A video processing system with reconfigurable computational instructions, the video processing system comprising: a processor operable to execute a set of instructions of a video application comprising a set of computational instructions and at least one instruction extension; a first register file in the processor operable to store first data; an extension adapter coupled to the processor and operable to detect the execution of the instruction extension in the video application; programmable logic coupled to the extension adapter and operable to receive configuration data for defining the instruction extension and execute the instruction extension; a second register file coupled to the programmable logic and the extension adapter and operable to store second data; and a load/store module operable to transfer the first data using the first register file, transfer the second data using the second register file, and transfer the second data directly between the second register file and a system memory.