Video prediction cache indexing systems and methods

Abstract

In some embodiments, a video prediction (reference block) cache includes multiple (e.g. 4) independently-addressable subcaches, each storing a predetermined part of a cache back-end (memory subsystem) word. For example, a 16-byte word received by the cache from memory may be split between four 4-byte subcaches. Each subcache line/block stores the data of a 2-D pixel array. Retrieving a cached prediction may be performed by accessing different subcaches synchronously (on the same clock cycle) to assemble the prediction from parts stored in different subcaches. A cache tag may be defined by a 4-D vector having x-position, y-position, frame ID, and color component (luma/chroma) fields. Using sub-word, independently-addressable subcaches allows increasing the efficiency of cache access and allows addressing memory bandwidth limitations facing emerging video coding standards and applications, which employ relatively large and varied prediction sizes.