Abstract: Devices, systems, methods, and other embodiments associated with block type selection are described. In one embodiment, a method calculates for each block from a set of M×N blocks that form a macroblock of image data, a first set of data. Adjacent blocks of the set of M×N blocks are combined into composite blocks. Data of the first set of data is selectively forwarded to composite blocks. For each composited block, a second set of data is calculated based, at least in part, on the forwarded data. A participation block is selected from one of the set of M×N blocks and the set of composite blocks based, at least in part, on the first set of data and the second set of data. The macroblock is compressed based on the participation block.

Abstract: Systems and methods are provided for calculating a motion vector for a macroblock between a reference frame and a current frame. The system includes a main processor. The system further includes a programmable video accelerator configured to receive a linked list of variable length descriptor inputs at the direction of the main processor. The descriptor inputs include the macroblock for which the motion vector is to be calculated. The video accelerator is further configured to calculate a motion vector identifying motion of the identified macroblock from the reference frame to the current frame.

Abstract: In accordance with the teachings described herein, systems and methods are provided for identifying a block of pixel data in a reference frame. The system may include a data fetch, a shift register, and one or more processing blocks. The data fetch may receive a best fit integer block, where the best fit integer block is identified by comparing the current block of pixel data to a search area within a reference block of pixel data. The shift register may be configured to load pixel data to be used for performing a fractional pixel expansion for one quadrant corresponding to each integer pixel in a block of pixel data, the block of pixel data including the best fit integer block plus one additional row of integer pixels and one additional column of integer pixels, wherein a combination of all of the one quadrant fractional expansions provides a plurality of fractional blocks for the best fit integer block.

Abstract: In accordance with the teachings described herein, systems and methods are provided for scanning a search area of reference pixel data to identify a reference macroblock of pixels with a closest pixel fit to a current macroblock of pixels. An example system may include a local memory array (e.g., a shift register), a processing block and a scan sequencer. The local memory array may include a plurality of rows and columns, with N extra rows or columns in addition to a number of rows or columns necessary to store N reference macroblocks of pixels The processing block may be used to compare reference macroblocks of pixels with the current macroblock of pixels to identify the reference macroblock of pixels with the closest pixel fit to the current macroblock of pixels. The scan sequencer may be used to load reference pixel data into the local memory array and present reference macroblocks of pixels from the local memory array to the processing block according to a scan pattern.