Using high-level synthesis for rapid design of video processing pipes

In this work, we share our experience in using High-Level Synthesis (HLS) for rapid development of an optical flow design on FPGA. We have performed HLS using Vivado HLS as well as a HLS tool we have developed for the optical flow design at hand and similar video processing problems. The paper first describes the design problem we have and then discusses our own HLS tool. The tool we developed has turned out to be pretty general-purpose except for the ability to handle cyclic inter-iteration dependencies. It also introduces some novel concepts to HLS, such as “pipelined multiplexers”. The synthesis results show that we can achieve better timing or better area results compared to Vivado HLS. Furthermore, the Verilog RTL our HLS tool outputs is much more readable than the one from Vivado HLS. This makes it much easier for the designer to debug and modify the RTL.