Efficiency evaluation and architecture design of SSD unities for the H.264/AVC standard

This paper presents the design and evaluation of architectures that performs the SSD (Sum of Squared Differences) similarity criterion calculation. The comparison was made with other widely used criterion: the SAD (Sum of Absolute Differences). In order to compare the impact of both criteria in the coding process, a set of executions using the JM 16.0 reference software were performed. In these tests, SSD almost ever got a better video quality than SAD. Three architectures are proposed to perform SSD: (a) the first one uses a multiplexer, (b) the second uses a memory and (c) the last one uses a dedicated multiplier. One architecture to perform SAD is proposed to be compared with the architectures using SSD. Each solution was described in VHDL and synthesized to an Altera Stratix II FPGA. The video quality gain using SSD over the SAD encourages the use of SSD calculators even with a lower operation frequency when compared with an SAD implementation. In the best case and considering HDTV 1080p videos (1920 × 1080 pixels), it is possible to reach real time processing (30 frames per second) by putting 12 SSD calculators working in parallel.