Abstract: A method and apparatus for coding video information are disclosed. In one example, the method may involve: identifying one or more prediction modes for a fixed-rate codec, each prediction mode having a rate-distortion cost; and selecting, for a current block, a prediction mode that has the lowest rate-distortion cost from among the one more prediction modes not previously selected. The method may involve: (i) determining whether the selected prediction mode would result in overflow or underflow of a buffer of the fixed-rate codec; and (ii) determining whether the selected prediction mode would result in remaining bits in the slice being insufficient to code remaining blocks of the slice. The method may involve utilizing a fallback mode to code the current block in response to each of the selected one or more prediction modes resulting in at least one of conditions (i) and (ii) being true.

Abstract: A method and apparatus for detecting a complex region of an image are disclosed. In one example, the method may involve calculating complexity values for a current block, a next block, and a previous block. The method may involve: (i) detecting that the previous complexity value is less than a first threshold value, and that the next complexity value is greater than a second threshold value; and (ii) determining that neither a transition to the current block nor a transition to the previous block is a flat-to-complex region transition. The method may involve detecting a flat-to-complex region transition when transitioning to the next block in response to (i) and (ii).

Abstract: Certain aspects relate to systems and techniques for compressing image data using pattern mode compression schemes. A pattern mode compression scheme can reduce the amount of data stored in a frame buffer to reduce power costs of an image display system. In some implementations, pattern mode compression can be suitable for compression of pixel blocks having a limited color palette with one or more pixels of a different foreground color, and a slope-enabled pattern compression can be suitable for compression of pixel blocks having a gradient. Input pixel values can be compared against a dynamically-populated, fixed size pattern entry database to determine whether pattern mode compression or slope-enabled pattern mode compression should be used to compress the image block.

Abstract: A system and method for display stream compression is disclosed. In one example, there is provided a method that includes coding a block within a slice of video data. The slice may comprise one or more blocks of the video data. The method further includes storing bits corresponding to the block in a buffer, determining information indicative of a position of the block within the slice, and determining fullness of the buffer based at least in part on the position of the block within the slice.

Abstract: A method and apparatus for video coding with spatial prediction mode for multi-mode video coding is disclosed. In one aspect, the method includes coding a slice of video data, the slice including a plurality of pixels organized into a first line and a plurality of non-first lines. The coding of the slice further includes coding a current pixel of the first line in a spatial prediction mode using a previous pixel of the first line as a predictor and coding another pixel of a non-first line in a coding mode other than the spatial prediction mode.

Abstract: Entropy coding techniques for display stream compression (DSC) are disclosed. In one aspect, a method of entropy coding video data includes partitioning a block of the video data into a plurality of groups of samples based at least in part on a coding mode of the block. The method further includes entropy coding the block via performing a group-wise skip on at least one of the groups in response to all of the samples in the at least one group being equal to a predetermined value.

Abstract: Certain aspects relate to systems and techniques for compressing image data using mixed mode compression schemes. A mixed mode compression scheme can reduce the amount of data stored in a frame buffer to reduce power costs of an image display system. In some implementations, mixed mode compression can be suitable for compression of pixel blocks having one or two color channels exhibiting a relatively low variation in pixel intensity with the remaining channel or channels exhibiting a relatively high variation. The pixel values in each color channel of an RGB or YCoCg image can be analyzed to determine how many channels are a smooth component and how many channels are a variant component, and mixed mode compression can be selected and implemented based on the color channel analysis to adaptively and individually compress the color channels.

Abstract: A system and method for coding a block of video data in block prediction mode for display stream compression (DSC) is disclosed. In one aspect, the method includes determining a candidate block to be used for predicting a current block in a current slice. The candidate block may be within a range of locations defined by one or more block prediction parameters. The method further includes determining, based on the candidate block and the current block, a prediction vector identifying a location of the candidate block with respect to the current block, and coding the current block in block prediction mode at least in part via signaling the prediction vector identifying the location of the candidate block with respect to the current block.

Abstract: A system and method for coding video data in pattern mode for display stream compression (DSC) is disclosed. In one aspect, the method includes determining that a first pattern in a current block of video data is not in a pattern database comprising a plurality of patterns, and adding the first pattern to the pattern database. The first pattern may be associated with a first index identifying a location of the first pattern in the pattern database. The method further includes coding the current block in pattern mode at least in part via signaling (i) the first pattern determined not to be in the pattern database and (ii) the first index identifying the location of the first pattern in the first database.

Abstract: A system and method for flatness detection for display stream compression (DSC) is disclosed. In one aspect, the method includes determining a first complexity value for a previous block of video data, a second complexity value for a current block of the video data, and a third complexity value for a next block of the video data. The method also includes determining whether the current block includes a transition from a complex region to a flat region based at least in part on the first, second, and third complexity values.

Abstract: According to certain aspects, an apparatus for coding video data includes a memory for storing the video data and a processor. The memory includes a buffer. The processor is configured to receive the video data to be coded. The processor is further configured to determine a Lagrangian parameter for a coding mode based at least in part on a bit rate of the coding mode and a fullness of the buffer.

Abstract: An apparatus for coding video data according to certain aspects includes a memory for storing the video data and a processor. The memory includes a buffer. The processor is configured to receive the video data to be coded. The processor is further configured to determine a quantization parameter (QP) of a current block of the video data without considering a type of content of the video data and a rate-distortion model associated with the type of content. The processor is also configured to code the current block in a bitstream using the determined QP.

Abstract: Certain aspects relate to systems and techniques for compressing image data using pattern mode compression schemes. A pattern mode compression scheme can reduce the amount of data stored in a frame buffer to reduce power costs of an image display system. In some implementations, pattern mode compression can be suitable for compression of pixel blocks having a limited color palette with one or more pixels of a different foreground color, and a slope-enabled pattern compression can be suitable for compression of pixel blocks having a gradient. Input pixel values can be compared against a dynamically-populated, fixed size pattern entry database to determine whether pattern mode compression or slope-enabled pattern mode compression should be used to compress the image block.

Abstract: Certain aspects relate to systems and techniques for compressing image data using mixed mode compression schemes. A mixed mode compression scheme can reduce the amount of data stored in a frame buffer to reduce power costs of an image display system. In some implementations, mixed mode compression can be suitable for compression of pixel blocks having one or two color channels exhibiting a relatively low variation in pixel intensity with the remaining channel or channels exhibiting a relatively high variation. The pixel values in each color channel of an RGB or YCoCg image can be analyzed to determine how many channels are a smooth component and how many channels are a variant component, and mixed mode compression can be selected and implemented based on the color channel analysis to adaptively and individually compress the color channels.