A high throughput two-dimensional discrete cosine transform and MPEG4 motion estimation using vector coprocessor

摘要

In this work a configurable and scalable vector coprocessor for real time processing of MPEG4 motion estimation (ME) and two-dimensional DCT (2D DCT) is presented. A sequential DSP processor based on a reduced instruction set computer (RISC) processor architecture would require a frequency of 15 GHz for the real time processing of these two processes for a common intermediate format (CIF) sized sequence at 25 frames per second (fps). This frequency requirement will increase further if the image dimensions are increased. On the other hand our architecture on FPGA can achieve the real time processing rate at low frequency for CIF sized sequence and at higher frequency for full high definition (FHD) sequence for combined ME and 2D DCT. Due to configurable nature of the architecture and FPGA, this can be extended to higher dimensional image sequences. An important aspect of the architecture is that same datapath that is used for ME is also used for 2D DCT, with minor modification, leading to saving in area and time consumption. In addition the processor-coprocessor architecture has lower energy consumption and cost than the sequential processor.