Multiversion Low-Power Hardware Accelerator for the AV1 Interpolation Filters

One of the new tools included in the AV1 video codec is the adaptive filtering scheme used in the sample interpolation process. This scheme includes three different filter families called Regular, Sharp and Smooth, offering high flexibility for motion estimation (ME) and motion compensation (MC). However, the high number of interpolation filters also leads to greater complexity and energy consumption, since the generation of samples at sub-pixel position is a costly process. This paper proposes a low-power and high-throughput hardware accelerator focused on the AV1 interpolation filters called Multiversion Interpolation Processor (MVIP). The accelerator includes the three AV1 interpolation filter families, with versions that employ operand isolation for power reduction in unused filters. The accelerator also includes a precise MVIP assuming the MC scenario, besides two approximate versions to reduce the cost on the ME scenario. The proposed design is able to process 8K video at 50fps in MC and 2,656.14 Msamples/sec in ME, with a power dissipation of 41.30mW.