Abstract: Methods are disclosed for supporting stereo 3D video in computing devices. A computing device can receive stereo 3D video data employing a YUV color space and chroma subsampling, and can generate anaglyph video data therefrom. The anaglyph video data can be generated by unpacking the stereo 3D video data to left and right views and combining the left and right views into a single view via matrix transformation. The combining uses transform matrices that correspond to a video pipeline configuration. The transform matrix coefficients can depend on characteristics of the video pipeline components. Modified transform matrix coefficients can be used in response to changes in the video pipeline configuration. Video encoded in stereo 3D video data can be selected to be displayed in stereo 3D, anaglyph or monoscopic form, depending on user input and/or characteristics of video pipeline components.

Abstract: A switching module is adapted to configure switches between source buffers and rendering pipelines. Each of the switches has one or more selection inputs each representing encoded data for a media track from one of the source buffers. Each of the switches also has a selection output associated with one of the rendering pipelines for decoding and rendering. The switching module is further adapted to use the switches to manage which of the media tracks, if any, have encoded data routed to the rendering pipelines during media streaming. The rendering pipelines can include a video rendering pipeline and one or more audio rendering pipelines, where the switching module is part of a media engine adapted to determine a clock source in one of the audio rendering pipeline(s), and the clock source is used to drive synchronization of the media tracks.

Abstract: Techniques and tools for encoding enhancement layer video with quantization that varies spatially and/or between color channels are presented, along with corresponding decoding techniques and tools. For example, an encoding tool determines whether quantization varies spatially over a picture, and the tool also determines whether quantization varies between color channels in the picture. The tool signals quantization parameters for macroblocks in the picture in an encoded bit stream. In some implementations, to signal the quantization parameters, the tool predicts the quantization parameters, and the quantization parameters are signaled with reference to the predicted quantization parameters. A decoding tool receives the encoded bit stream, predicts the quantization parameters, and uses the signaled information to determine the quantization parameters for the macroblocks of the enhancement layer video. The decoding tool performs inverse quantization that can vary spatially and/or between color channels.

Abstract: Techniques and tools are described for scalable video encoding and decoding. In some embodiments, an encoding tool encodes base layer video and outputs encoded base layer video in a base layer bit stream. The encoding tool encodes inter-layer residual video (representing differences between input video and reconstructed base layer video) using motion compensation relative to previously reconstructed inter-layer residual video. For the inter-layer residual video, the encoding tool outputs motion information and motion-compensated prediction residuals in an enhancement layer bit stream. A decoding tool receives the base layer bit stream and enhancement layer bit stream, reconstructs base layer video, reconstructs inter-layer residual video, and combines the reconstructed base layer video and reconstructed inter-layer residual video.

Abstract: Adjacent regions are identified in an image. Coding parameters for the adjacent regions are identified. Selective filtering is performed at the region between the identified adjacent regions.

Abstract: Techniques and tools are presented for controlling artifacts such as banding artifacts, ringing artifacts and film scan artifacts in video. For example, before encoding, a pre-processor performs combined filtering and dithering on video such that the weight of dithering at a location depends on the results of filtering at the location. For the combined filtering and dithering, the pre-processor can determine a lowpass signal and highpass residual, weight dithering based on local characteristics of the highpass residual, and then combine the lowpass signal with the weighted dithering. Or, to determine the relative weight, the pre-processor can use a filter whose normalization factor varies depending on how many sample values around a location are within a threshold of similarity to a current sample value at the location. The filtering and dithering can use different strengths for luma and chroma channels.

Abstract: In certain embodiments, to eliminate DC leakage into surrounding AC values, scaling stage within a photo overlap transform operator is modified such that the off-diagonal elements of the associated scaling matrix have the values of 0. In certain embodiments, the on-diagonal scaling matrix are given the values (0.5, 2). In some embodiments, the scaling is performed using a combination of reversible modulo arithmetic and lifting steps. In yet other embodiments, amount of DC leakage is estimated at the encoder, and preprocessing occurs to mitigate amount of leakage, with the bitstream signaling that preprocessing has occurred. A decoder may then read the signal and use the information to mitigate DC leakage.

Abstract: Techniques and tools for high dynamic range (“HDR”) image generation and rendering are described herein. In several described embodiments, images having distinct exposure levels are aligned. In particular embodiments, the alignment of a reference image to a non-reference image is based at least in part on motion vectors that are determined using covariance computations. Furthermore, in certain embodiments, saturated areas, underexposed areas, and/or moving objects are ignored or substantially ignored during the image alignment process. Moreover, in certain embodiments, a hierarchical pyramid block-based scheme is used to perform local motion estimation between the reference image and the non-reference image.

Abstract: Techniques and tools are described for scalable video encoding and decoding. In some embodiments, an encoding tool encodes base layer video and outputs encoded base layer video in a base layer bit stream. The encoding tool encodes inter-layer residual video (representing differences between input video and reconstructed base layer video) using motion compensation relative to previously reconstructed inter-layer residual video. For the inter-layer residual video, the encoding tool outputs motion information and motion-compensated prediction residuals in an enhancement layer bit stream. A decoding tool receives the base layer bit stream and enhancement layer bit stream, reconstructs base layer video, reconstructs inter-layer residual video, and combines the reconstructed base layer video and reconstructed inter-layer residual video.

Abstract: Techniques and tools for high dynamic range (HDR) image rendering and generation. An HDR image generating system performs motion analysis on a set of lower dynamic range (LDR) images and derives relative exposure levels for the images based on information obtained in the motion analysis. These relative exposure levels are used when integrating the LDR images to form an HDR image. An HDR image rendering system tone maps sample values in an HDR image to a respective lower dynamic range value, and calculates local contrast values. Residual signals are derived based on local contrast, and sample values for an LDR image are calculated based on the tone-mapped sample values and the residual signals. User preference information can be used during various stages of HDR image generation or rendering.

Abstract: Aspects of the present invention relate to systems and methods for picture up-sampling using direct interpolation. Some aspects of the present invention provide an up-sampling procedure designed for the Scalable Video Coding extension of H.264/MPEG-4 AVC.

Abstract: Aspects of the present invention relate to systems, methods and devices for upsampling images and design of upsampling filters. Some aspects relate to a determination of a phase offset position in a higher resolution picture relative to a lower resolution picture. Interpolation filter coefficients for some filters may then be selected based on the filter offset. Other aspects relate to selection of coefficients for filters that are not dependent on the phase offset. In certain implementations, a weighting factor may be used to combine the effects of a phase-offset-dependent filter and an independent filter.

Abstract: Techniques and tools for high dynamic range (HDR) image rendering and generation. An HDR image generating system performs motion analysis on a set of lower dynamic range (LDR) images and derives relative exposure levels for the images based on information obtained in the motion analysis. These relative exposure levels are used when integrating the LDR images to form an HDR image. An HDR image rendering system tone maps sample values in an HDR image to a respective lower dynamic range value, and calculates local contrast values. Residual signals are derived based on local contrast, and sample values for an LDR image are calculated based on the tone-mapped sample values and the residual signals. User preference information can be used during various stages of HDR image generation or rendering.

Abstract: Techniques and tools for encoding and decoding data values that are hierarchically organized are presented. For example, an encoder encodes data as a set that has a hierarchy of subsets with set symbols. In the encoding, the encoder evaluates the data values of the set and selectively encodes a symbol combination code that indicates the set symbols of multiple subsets of the set. Then, for each of the multiple subsets considered as a new set, the encoder selectively repeats the evaluating, selective encoding and selective repetition for the new set. In corresponding decoding, a decoder decodes data encoded as a set that has a hierarchy of subsets with set symbols. In some implementations, the encoding and decoding are adaptive and use a symbol alphabet with nested elements.

Abstract: In certain embodiments, to eliminate DC leakage into surrounding AC values, scaling stage within a photo overlap transform operator is modified such that the off-diagonal elements of the associated scaling matrix have the values of 0. In certain embodiments, the on-diagonal scaling matrix are given the values (0.5, 2). In some embodiments, the scaling is performed using a combination of reversible modulo arithmetic and lifting steps. In yet other embodiments, amount of DC leakage is estimated at the encoder, and preprocessing occurs to mitigate amount of leakage, with the bitstream signaling that preprocessing has occurred. A decoder may then read the signal and use the information to mitigate DC leakage.

Abstract: Embodiments of the present invention relate to methods and systems for ordering, communicating and applying pixel intra-prediction modes.

Abstract: An encoder is disclosed that is partitioned into discrete hardware modules. The discrete modules include multiple re-entry and exit points that allow enhanced control by software. The software can control the discrete modules during the encoding process and make adjustments according to CPU bandwidth and/or user requirements allowing for enhanced quality control and seamless hardware/software operations. In one embodiment, a media stream is received into an encoder that includes a pipeline of multiple hardware stages for encoding. An intermediate result is provided from at least one of the hardware stages to an encoding control module that processes the intermediate result to determine configuration instructions for a next hardware stage in the pipeline. Thus, the encoding process can be modified dynamically through hardware and software interactions as the media stream progresses through the pipeline of the encoder.

Abstract: Embodiments of the present invention relate to methods and systems for ordering, communicating and applying pixel intra-prediction modes.

Abstract: Techniques and tools for encoding and decoding a block of frequency coefficients are presented. An encoder selects a scan order from multiple available scan orders and then applies the selected scan order to a two-dimensional matrix of transform coefficients, grouping non-zero values of the frequency coefficients together in a one-dimensional string. The encoder entropy encodes the one-dimensional string of coefficient values according to a multi-level nested set representation. In decoding, a decoder entropy decodes the one-dimensional string of coefficient values from the multi-level nested set representation. The decoder selects the scan order from among multiple available scan orders and then reorders the coefficients back into a two-dimensional matrix using the selected scan order.

Abstract: Adjacent blocks are identified in an image. Coding parameters for the adjacent blocks are identified. Deblock filtering between the identified adjacent blocks is skipped if the coding parameters for the identified adjacent blocks are similar and not skipped if the coding parameters for the identified adjacent blocks are substantially different.