Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to select an intra-prediction mode to use to encode a block of video data, determine whether the block includes a sub-block of a size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, when the block includes the sub-block of the size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, select one of the multiple possible transforms, transform the sub-block using the selected one of the multiple possible transforms, and provide an indication of the selected one of the multiple possible transforms for the size of the block.

Abstract: In one example, an apparatus includes a processor configured to receive video data for two or more views of a scene, determine horizontal locations of camera perspectives for each of the two or more views, assign view identifiers to the two or more views such that the view identifiers correspond to the relative horizontal locations of the camera perspectives, form a representation comprising a subset of the two or more views, and, in response to a request from a client device, send information indicative of a maximum view identifier and a minimum view identifier for the representation to the client device.

Abstract: In one example, an apparatus includes a video encoder configured to partition a block of video data into a first geometric partition and a second geometric partition using a geometric motion partition line, wherein the block comprises N×N pixels, divide the block of video data into four equally-sized, non-overlapping (N/2)×(N/2) sub-blocks, and encode at least one of the sub-blocks through which the geometric motion partition line passes using a transform size smaller than (N/2)×(N/2). The video encoder may determine transform sizes for the sub-blocks based on whether the geometric motion partition line passes through the sub-blocks. In one example, a video decoder may inverse transform the sub-blocks, and may determine transform sizes for the sub-blocks based on whether the geometric motion partition line passes through the sub-blocks.

Abstract: In general, this disclosure describes techniques for coding video data for random access. In particular, this disclosure proposes to code a syntax element that indicates if a dependent picture may be successfully decoded in the event of a random access request to a clean decoding refresh (CDR) picture and may be required for decoding the pictures following the clean decoding refresh (CDR) picture in display order.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to scan a two-dimensional block of transform coefficients to produce a one-dimensional vector of the transform coefficients, determine values indicative of whether the transform coefficients in the one-dimensional vector are significant; and entropy encode at least one of the values using a context model selected based on at least a percentage of significant coefficients in a predetermined number of the values encoded before the at least one of the values.

Abstract: In one example, an apparatus includes a video encoder configured to partition a block of video data into a first geometric partition and a second geometric partition using a geometric motion partition line, wherein the block comprises N×N pixels, divide the block of video data into four equally-sized, non-overlapping (N/2)×(N/2) sub-blocks, and encode at least one of the sub-blocks through which the geometric motion partition line passes using a transform size smaller than (N/2)×(N/2). The video encoder may determine transform sizes for the sub-blocks based on whether the geometric motion partition line passes through the sub-blocks. In one example, a video decoder may inverse transform the sub-blocks, and may determine transform sizes for the sub-blocks based on whether the geometric motion partition line passes through the sub-blocks.

Abstract: Systems and methods are disclosed for video coding using signaling syntax and pixel predictions. The signaling syntax used for encoding and decoding video data is organized into multiple syntax groups based at least in part on the syntax type. The video data is coded plane by plane. The video data in each plane is coded in an order such that processing inter-prediction is prior to intra-prediction.

Abstract: In one aspect of this disclosure, rounding adjustments to bi-directional predictive data may be purposely eliminated to provide predictive data that lacks any rounding bias. In this case, rounded and unrounded predictive data may both be considered in a rate-distortion analysis to identify the best data for prediction of a given video block. In another aspect of this disclosure, techniques are described for selecting among default weighted prediction, implicit weighted prediction, and explicit weighted prediction. In this context, techniques are also described for adding offset to prediction data, e.g., using the format of explicit weighted prediction to allow for offsets to predictive data that is otherwise determined by implicit or default weighted prediction.

Abstract: Aspects of this disclosure relate to, in an example, a method that includes identifying a first block of video data in a first temporal location from a first view, wherein the first block is associated with a first disparity motion vector. The method also includes determining a motion vector predictor for a second motion vector associated with a second block of video data, wherein the motion vector predictor is based on the first disparity motion vector. When the second motion vector comprises a disparity motion vector, the method includes determining the motion vector predictor comprises scaling the first disparity motion vector to generate a scaled motion vector predictor, wherein scaling the first disparity motion vector comprises applying a scaling factor comprising a view distance of the second disparity motion vector divided by a view distance of the first motion vector to the first disparity motion vector.

Abstract: A method for color blending prevention in video coding may include selecting, in a mode decision phase of an encoding of a current video frame, to encode an output bitstream in skip mode, wherein the skip mode includes altering encoding of the coding unit by setting luma component transform coefficients for the coding unit to zero, revaluating the selection of the skip mode based on quantized chroma coefficients, the quantized chroma coefficients generated from transformed and quantized residual chroma components, confirming the selection of the skip mode when there are no non-zero quantized chroma coefficients, and revoking the selection of the skip mode when there are non-zero quantized chroma coefficients, wherein the non-zero quantized chroma coefficients are transmitted when the selection of the skip mode is revoked.

Abstract: A method of coding video data includes determining a candidate motion vector for each of one or more candidate portions of a video frame and determining a current motion vector for a current portion of a current frame. The current motion vector identifies a portion of a reference frame that at least partially matches the current portion of the current frame. The method also includes calculating a motion vector difference between the current motion vector and each of the candidate motion vectors, selecting one of the candidate motion vectors based on the calculated motion vector differences, signaling an index identifying the candidate portion having the selected one of the candidate motion vectors, and signaling the corresponding motion vector difference calculated with respect to the selected one of the candidate motion vectors.

Abstract: This disclosure describes video encoding and decoding techniques in which a first order prediction process and a second order prediction process are used in combination to generate predictive video blocks for video coding. First order prediction may be similar to conventional motion estimation and motion compensation that generates residual video blocks. The second order prediction may involve a process similar to conventional intra-prediction, but is performed on the residual video blocks. The techniques of this disclosure may pre-define the second order prediction to a specific mode, such as a mode similar to the intra-DC mode used in intra coding. In addition, the techniques of this disclosure may combine aspects of the first order and second order prediction into a single process so that the effects of second order prediction on the residuals are taken into account during the first order prediction process, which may improve compression.

Abstract: In an example aspects of this disclosure generally relate to a method of coding video data that includes determining a first bit depth for outputting video data and a second bit depth for coding the video data, wherein the first bit depth is less than the second bit depth. The method also includes determining whether the video data will be used as reference data when coding other video data. The method also includes storing, based on the determination, the video data at the first bit depth when the video data is not used as reference data, and the video data at the second bit depth when the video data is used as reference data.

Abstract: Aspects of this disclosure relate to, in an example, a method that includes identifying a first block of video data in a first temporal location from a first view, wherein the first block is associated with a first disparity motion vector. The method also includes determining a motion vector predictor for a second motion vector associated with a second block of video data, wherein the motion vector predictor is based on the first disparity motion vector. When the second motion vector comprises a disparity motion vector, the method includes determining the motion vector predictor comprises scaling the first disparity motion vector to generate a scaled motion vector predictor, wherein scaling the first disparity motion vector comprises applying a scaling factor comprising a view distance of the second disparity motion vector divided by a view distance of the first motion vector to the first disparity motion vector.

Abstract: Adaptive loop filtering in accordance with video coding. An adaptive loop filter (ALF) and/or other in-loop filters (e.g., sample adaptive offset (SAO) filter, etc.) may be implemented within various video coding architectures (e.g., encoding and/or decoding architectures) to perform both offset and scaling processing, only scaling processing, and/or only offset processing. Operation of such an ALF may be selective in accordance with any of multiple respective operational modes at any given time and may be adaptive based upon various consideration(s) (e.g., desired complexity level, processing type, local and/or remote operational conditions, etc.). For example, an ALF may be applied to a decoded picture before it is stored in a picture buffer (or digital teacher buffer (DPB)). An ALF can provide for coding noise reduction of a decoded picture, and the filtering operations performed thereby may be selective (e.g., on a slice by slice basis, block by block basis, etc.).

Abstract: The disclosure relates to techniques for switching between channels of digital multimedia content. In particular, a decoding device decodes and renders to a display at least one frame of a segment of data prior to receiving the entire segment. In certain aspects, the decoding device may render one of the frames of the segment and freeze the rendered frame until the decoding device receives all of the frames of the segment. In other aspects, the decoding device may render frames of one or more segments at a reduced rendering rate until the receiving and rendering operations of decoding device are synchronized such that the rendering of the current segment occurs at substantially the same time as the receiving of the next segment. By rendering at least frame prior to receiving the entire segment the decoding device more quickly displays content to a user during a channel switching event.

Abstract: A system may receive an input stream for a coding operation by a coding device. The system may determine a processing device to assist the coding device with the coding operation. The processing device may generate an indicator containing coding information or other coding assistance by processing the input stream. The processing device may send the indicator to the coding device. In some cases, the indicator may be embedded in the metadata of the stream by the processing device. The indicator may be extracted by the coding device. After reception of the indicator, the coding device may execute the coding task while using the information in the indicator to assist.

Abstract: This disclosure relates to techniques for reducing a cost of coding prediction information in video coding. Video blocks in a generalized P/B (GPB) frame are encoded using up to two motion vectors calculated from reference pictures in two separate reference picture lists that are identical. When one of the reference picture lists is preferred over the other reference picture list, the preferred reference picture list may be used for unidirectional prediction, by default. When a GPB frame is enabled such that the first and second reference picture lists are identical, either of the first and second reference picture lists may be used for unidirectional prediction. The techniques include coding one or more syntax elements indicating that a video block is coded using one of the unidirectional prediction mode with respect to a reference picture in a reference picture list and the bidirectional prediction mode using less than two bits.

Abstract: Frequency domain sample adaptive offset (SAO). Video processing of a first signal operates to generate a second video signal such that at least one characteristic of a first portion of video information of the first video signal is replicated in generating a second portion of video information, such that the first portion of video information and the second portion of video information undergo combination to generate the second video signal. Such use of the first video signal may involve replication and scaling of the first video information to generate the second portion of video information. One possible characteristic of the first portion of video information may correspond to an energy profile as a function of frequency. One or more portions of the first video signal may be employed to generate different respective portions of the second signal. Such video processing operations may be performed on a block by block basis.

Abstract: Sample adaptive offset (SAO) in accordance with video coding. SAO filtering may be performed before de-blocking processing (e.g., in accordance with video signal decoding and/or encoding). For example, a receiver and/or decoder communication device may receive signaling from a transmitter and/or encoder communication device that includes various band offsets. Corresponding band indices may be determined via analysis of the received video signal (e.g., received from the transmitter and/or encoder communication device), inferentially without requiring signaling of such band indices from the transmitter and/or encoder communication device. Upon appropriate analysis of one or more largest coding units (LCUs) generated from the video signal to determine a pixel value distribution (e.g., which may be using a histogram in one instance), then based on that pixel value distribution, the band indices are identified and the band offsets applied thereto.