Color space conversion for MPEG decoding on FPGA-augmented TriMedia processor

A case study on color space conversion (CSC) for MPEG decoding, carried out on the FPGA-augmented TriMedia processor is presented. That is, a transform from Y'CbCr color space to R'G'B' color space is addressed. First, we outline the extension of TriMedia architecture consisting of FPGA-based reconfigurable functional units (RFU) and associated instructions. Then we analyse a CSC (RFU-specific) instruction which can process four pixels per call, and propose a scheme to implement the CSC operation on RFU(s). When mapped on an ACEX EP1K100 FPGA, the proposed CSC exhibits a latency of 10 and a recovery of 2 TriMedia@200 MHz cycles, and occupies 57% of the device. By configuring the CSC facility on the RFU(s) at application load-time, color space conversion can be computed on FPGA-augmented TriMedia with 40% speed-up over the standard TriMedia.