Ati Technologies Ulc

Advanced Micro Devices Corporation

Shu-Hsien Wu

Edward A Harold

Ying Luo

Gabor Sines

Yang Liu

Wei Gao

Ihab Amer

Feng Pan

Lei Zhang

Haibo Liu

Zhen Biao Chen

Ihab M A Amer

Crystal Yeong-Pian Sau

Jinbo Qiu

Crystal Sau

Ehsan Mirhadi

Zhong Hai Cai

Alvin Duong

An encoder implements a residual-free palette encoding mode in which a block of pixels is used to derive a palette table having a number of palette colors less than a number of pixel colors in the block of pixels, and to derive a color map representing each pixel of the block with a corresponding index number associated with a palette color that most closely matches the pixel's color. The calculations of residuals representing errors between the predicted palette colors and the actual pixel colors are omitted during the encoding process, thereby facilitating implementation of less complex palette mode encoder hardware at the expense of slight loss of color accuracy. Moreover, when multiple encoding modes are available, the encoder can employ the residual-free palette encoding mode when the rate-distortion cost or other cost of using this mode is determined to be the lowest cost of the plurality of encoding modes.

Residual-free palatte mode coding

An encoder encodes an image portion by recursively partitioning the portion into a partitioning hierarchy of levels. The top level has a single block representing the entire portion and each lower level has four smaller blocks representing a corresponding larger block at a higher level. A palette table is generated for each bottom-level block based on the pixels of the associated block. For each successively higher level, the encoder generates a palette table for each current-level block by selecting palette colors based on the palette colors from the four palette tables for the associated four blocks at the next-lowest level. A color index map is then generated based on a final palette table selected from the palette tables generated for the partitioning hierarchy. A representation of the portion is then encoded using the final palette table and the color index map to generate a corresponding segment of an encoded bitstream.

Palette mode video encoding utilizing hierarchical palette table generation

An encoding method is provided which includes receiving a plurality of images, obtaining values of elements in a portion of the images, sorting the elements according to different values of the elements, sorting the elements according to a number of occurrences of the different values and encoding the elements using a subset of the different values having corresponding numbers of occurrences that are higher than corresponding numbers of occurrences of other values. Examples also include a processing device and method for use with palette mode encoding in which the elements are a portion of pixels in images and the values are color values of the portion of pixels in the images.

Top palette colors selection using sorting for palette mode in video encoding

A processing apparatus is provided that includes an encoder configured to encode current frames of video data using previously encoded reference frames and perform motion searches within a search window about each of a plurality of co-located portions of a reference frame. The processing apparatus also includes a processor configured to determine, prior to performing the motion searches, which locations of the reference frame to reload the search window according to a threshold number of search window reloads using predicted motions of portions of the reference frame corresponding to each of the locations. The processor is also configured to cause the encoder to reload the search window at the determined locations of the reference frame and, for each of the remaining locations of the reference frame, slide the search window in a first direction indicated by the location of the next co-located portion of the reference frame.

Dynamic reload of video encoder motion estimation search window under performance/power constraints

Growing community of inventors

Markham, Canada

Shu-Hsien Wu