Abstract: A block processing pipeline in which macroblocks are input to and processed according to row groups so that adjacent macroblocks on a row are not concurrently at adjacent stages of the pipeline. The input method may allow chroma processing to be postponed until after luma processing. One or more upstream stages of the pipeline may process luma elements of each macroblock to generate luma results such as a best mode for processing the luma elements. Luma results may be provided to one or more downstream stages of the pipeline that process chroma elements of each macroblock. The luma results may be used to determine processing of the chroma elements. For example, if the best mode for luma is an intra-frame mode, then a chroma processing stage may determine a best intra-frame mode for chroma and reconstruct the chroma elements according to the best chroma intra-frame mode.

Abstract: A block input component of a video encoding pipeline may, for a block of pixels in a video frame, compute gradients in multiple directions, and may accumulate counts of the computed gradients in one or more histograms. The block input component may analyze the histogram(s) to compute block-level statistics and determine whether a dominant gradient direction exists in the block, indicating the likelihood that it represents an image containing text. If text is likely, various encoding parameter values may be selected to improve the quality of encoding for the block (e.g., by lowering a quantization parameter value). The computed statistics or selected encoding parameter values may be passed to other stages of the pipeline, and used to bias or control selection of a prediction mode, an encoding mode, or a motion vector. Frame-level or slice-level parameter values may be generated from gradient histograms of multiple blocks.

Abstract: The video encoders described herein may determine an initial designation of a mode in which to encode a block of pixels in an early stage of a block processing pipeline. A component of a late stage of the block processing pipeline (one that precedes the transcoder) may determine a different mode designation for the block of pixels based on coded block pattern information, motion vector information, the position of the block in a row of such blocks, the order in which such blocks are processed in the pipeline, or other encoding related syntax elements. The component in the late stage may communicate information to the transcoder usable in coding the block of pixels, such as modified syntax elements or an end of row marker. The transcoder may encode the block of pixels in accordance with the different mode designation or may change the mode again, dependent on the communicated information.

Abstract: Memory latency tolerance methods and apparatus for maintaining an overall level of performance in block processing pipelines that prefetch reference data into a search window. In a general memory latency tolerance method, search window processing in the pipeline may be monitored. If status of search window processing changes in a way that affects pipeline throughput, then pipeline processing may be modified. The modification may be performed according to no stall methods, stall recovery methods, and/or stall prevention methods. In no stall methods, a block may be processed using the data present in the search window without waiting for the missing reference data. In stall recovery methods, the pipeline is allowed to stall, and processing is modified for subsequent blocks to speed up the pipeline and catch up in throughput. In stall prevention methods, processing is adjusted in advance of the pipeline encountering a stall condition.

Abstract: Blocks of pixels from a video frame may be encoded in a block processing pipeline using wavefront ordering, e.g. according to knight's order. Each of the encoded blocks may be written to a particular one of multiple buffers such that the blocks written to each of the buffers represent consecutive blocks of the frame in scan order. Stitching information may be written to the buffers at the end of each row. A stitcher may read the rows from the buffers in order and generate a scan order output stream for the frame. The stitcher component may read the stitching information at the end of each row and apply the stitching information to one or more blocks at the beginning of a next row to stitch the next row to the previous row. Stitching may involve modifying pixel(s) of the blocks and/or modifying metadata for the blocks.

Abstract: A knight's order processing method for block processing pipelines in which the next block input to the pipeline is taken from the row below and one or more columns to the left in the frame. The knight's order method may provide spacing between adjacent blocks in the pipeline to facilitate feedback of data from a downstream stage to an upstream stage. The rows of blocks in the input frame may be divided into sets of rows that constrain the knight's order method to maintain locality of neighbor block data. Invalid blocks may be input to the pipeline at the left of the first set of rows and at the right of the last set of rows, and the sets of rows may be treated as if they are horizontally arranged rather than vertically arranged, to maintain continuity of the knight's order algorithm.

Abstract: A block processing pipeline that includes a software pipeline and a hardware pipeline that run in parallel. The software pipeline runs at least one block ahead of the hardware pipeline. The stages of the pipeline may each include a hardware pipeline component that performs one or more operations on a current block at the stage. At least one stage of the pipeline may also include a software pipeline component that determines a configuration for the hardware component at the stage of the pipeline for processing a next block while the hardware component is processing the current block. The software pipeline component may determine the configuration according to information related to the next block obtained from an upstream stage of the pipeline. The software pipeline component may also obtain and use information related to a block that was previously processed at the stage.

Abstract: Systems and methods for local tone mapping are provided. In one example, an electronic device includes an electronic display, an imaging device, and an image signal processor. The electronic display may display images of a first bit depth, and the imaging device may include an image sensor that obtains image data of a higher bit depth than the first bit depth. The image signal processor may process the image data, and may include local tone mapping logic that may apply a spatially varying local tone curve to a pixel of the image data to preserve local contrast when displayed on the display. The local tone mapping logic may smooth the local tone curve applied to the intensity difference between the pixel and another nearby pixel exceeds a threshold.

Abstract: Systems and methods for down-scaling are provided. In one example, a method for processing image data includes determining a plurality of output pixel locations using a position value stored by a position register, using the current position value to select a center input pixel from the image data and selecting an index value, selecting a set of input pixels adjacent to the center input pixel, selecting a set of filtering coefficients from a filter coefficient lookup table using the index value, filtering the set of source input pixels to apply a respective one of the set of filtering coefficients to each of the set of source input pixels to determine an output value for the current output pixel at the current position value, and correcting chromatic aberrations in the set of source input pixels.

Abstract: Systems and methods for processing image data in RGB format are provided. In one example, an electronic device includes memory to store image data in raw or RGB format, or both, and an RGB image processing pipeline to process the image data. Specifically, the RGB image processing pipeline may process the image data regardless of whether the image data is of raw or RGB format. The RGB image processing pipeline may include receiving logic to receive the image data in raw or RGB format and demosaicing logic to, when the receiving logic receives the image data in raw format, convert the image data into RGB format. The logic may include local tone mapping logic configured to apply spatially varying tone curves to the image data, a color correction matrix configured to correct color in the image data, and gamma logic configured to transform the image data into gamma space.

Abstract: In an embodiment, a system includes a display processing unit configured to process a video sequence for a target display. In some embodiments, the display processing unit is configured to composite the frames from frames of the video sequence and one or more other image sources. The display processing unit may be configured to write the processed/composited frames to memory, and may also be configured to generate statistics over the frame data, where the generated statistics are usable to encode the frame in a video encoder. The display processing unit may be configured to write the generated statistics to memory, and the video encoder may be configured to read the statistics and the frames. The video encoder may be configured to encode the frame responsive to the statistics.

Abstract: Embodiments of the present invention may provide a video coder. The video coder may include an encoder to perform coding operations on a video signal in a first format to generate coded video data, and a decoder to decode the coded video data. The video coder may also include an inverse format converter to convert the decoded video data to second format that is different than the first format and an estimator to generate a distortion metric using the decoded video data in the second format and the video signal in the second format. The encoder may adjust the coding operations based on the distortion metric.

Abstract: Adaptive video processing for a target display panel may be implemented in or by a decoding/display pipeline associated with the target display panel. The adaptive video processing methods may take into account video content, display characteristics, and environmental conditions including but not limited to ambient lighting and viewer location when processing and rendering video content for a target display panel in an ambient setting or environment. The display-side adaptive video processing methods may use this information to adjust one or more video processing functions as applied to the video data to render video for the target display panel that is adapted to the display panel according to the ambient viewing conditions.

Abstract: Video processing techniques and pipelines that support capture, distribution, and display of high dynamic range (HDR) image data to both HDR-enabled display devices and display devices that do not support HDR imaging. A sensor pipeline may generate standard dynamic range (SDR) data from HDR data captured by a sensor using tone mapping, for example local tone mapping. Information used to generate the SDR data may be provided to a display pipeline as metadata with the generated SDR data. If a target display does not support HDR imaging, the SDR data may be directly rendered by the display pipeline. If the target display does support HDR imaging, then an inverse mapping technique may be applied to the SDR data according to the metadata to render HDR data for display. Information used in performing color gamut mapping may also be provided in the metadata and used to recover clipped colors for display.

Abstract: Adaptive video processing for a target display panel may be implemented in or by a server/encoding pipeline. The adaptive video processing methods may obtain and take into account video content and display panel-specific information including display characteristics and environmental conditions (e.g., ambient lighting and viewer location) when processing and encoding video content to be streamed to the target display panel in an ambient setting or environment. The server-side adaptive video processing methods may use this information to adjust one or more video processing functions as applied to the video data to generate video content in the color gamut and dynamic range of the target display panel that is adapted to the display panel characteristics and ambient viewing conditions.

Abstract: A method and system for adaptively mixing video components with graphics/UI components, where the video components and graphics/UI components may be of different types, e.g., different dynamic ranges (such as HDR, SDR) and/or color gamut (such as WCG). The mixing may result in a frame optimized for a display device's color space, ambient conditions, viewing distance and angle, etc., while accounting for characteristics of the received data. The methods include receiving video and graphics/UI elements, converting the video to HDR and/or WCG, performing statistical analysis of received data and any additional applicable rendering information, and assembling a video frame with the received components based on the statistical analysis. The assembled video frame may be matched to a color space and displayed. The video data and graphics/UI data may have or be adjusted to have the same white point and/or primaries.

Abstract: Systems and methods for correcting green channel non-uniformity (GNU) are provided. In one example, GNU may be corrected using energies between the two green channels (Gb and Gr) during green interpolation processes for red and green pixels. Accordingly, the processes may be efficiently employed through implementation using demosaic logic hardware. In addition, the green values may be corrected based on low-pass-filtered values of the green pixels (Gb and Gr). Additionally, green post-processing may provide some defective pixel correction on interpolated greens by correcting artifacts generated through enhancement algorithms.

Abstract: Systems and methods for local tone mapping are provided. In one example, an electronic device includes an electronic display, an imaging device, and an image signal processor. The electronic display may display images of a first bit depth, and the imaging device may include an image sensor that obtains image data of a higher bit depth than the first bit depth. The image signal processor may process the image data, and may include local tone mapping logic that may apply a spatially varying local tone curve to a pixel of the image data to preserve local contrast when displayed on the display. The local tone mapping logic may smooth the local tone curve applied to the intensity difference between the pixel and another nearby pixel exceeds a threshold.

Abstract: Systems and methods for generating local image statistics are provided. In one example, an image signal processing system may include a statistics pipeline with image processing logic and local image statistics collection logic. The image processing logic may receive and process pixels of raw image data. The local image statistics collection logic may generate a local histogram associated with a luminance of the pixels of a first block of pixels of the raw image data or a thumbnail in which a pixel of the thumbnail represents a downscaled version of the luminance of the pixels of the first block of the pixel. The raw image data may include many other blocks of pixels of the same size as the first block of pixels.

Abstract: A method for coding video is disclosed. The method generally includes the steps of (A) receiving a video signal having a series of pictures, each of the pictures having a plurality of blocks, (B) analyzing the blocks to forecast if coding the blocks in a zero-residual coding mode would generate a plurality of artifacts, (C) disabling the zero-residual coding mode for the blocks forecasted to generate at least one of the artifacts and (D) enabling the zero-residual coding mode for the blocks forecasted to generate none of the artifacts.