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. Video blocks of a GPB frame may, therefore, be encoded using a bidirectional prediction mode with a first motion vector from a reference picture in a first reference picture list and a second motion vector from the same or substantially similar reference picture in a second reference picture list. The techniques include jointly coding the first and second motion vectors for a video block of a GPB frame. The techniques include coding the first motion vector relative to a first motion predictor generated from a motion vector of a neighboring block, and coding the second motion vector relative to the first motion vector.

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: An example video coding system may include a processor and memory. The processor may determine sets of parameters for slices that correspond to a picture of a video sequence, and determine, and store in overhead information, the set of parameters that has the highest commonality. The processor may determine for each slice whether the set of parameters determined for the slice is equivalent to the set of parameters stored in overhead information. If the set of parameters for the slice is equivalent to the set of parameters stored in overhead information, the processor may store an indication in a slice header of the slice that indicates that the set of parameters stored in overhead information applies to the slice, otherwise the processor may store in the slice header of the slice the determined set of parameters for the slice. The processor may transmit the overhead information and the slices.

Abstract: Signaling of prediction size unit in accordance with video coding. In accordance with video coding, various binarization may be performed. In accordance with coding related to different types of slices (e.g., I, P, B slices), one or more binary trees may be employed for performing various respective operations (e.g., coding unit (CU) prediction and prediction unit (PU) partition mode operations). In one implementation, a common or singular binary tree is employed to encode jointly CU prediction and PU partition mode in a single syntax element for both P slices and B slices. That is to say, in such an implementation, instead of employing different respective binary trees for at least these different respective processes/operations, a common or single binary tree may be employed for them both. Appropriate coordination between and encoder/transmitter device and a decoder/receiver device may be performed to ensure appropriate handling of different respective phases of video coding.

Abstract: In general, techniques are described for performing motion vector prediction for video coding. An apparatus comprising a motion compensation unit may implement the techniques. The motion compensation unit determines spatial candidate motion vectors (MVPs) associated with a current portion of a video frame and prunes the spatial candidate motion vectors to remove duplicates without removing a temporal candidate motion vector. The motion compensation unit selects one of the temporal candidate motion vector or one of the spatial candidate motion vectors remaining after pruning as a selected candidate motion vector based on a motion vector predictor (MVP) index signaled in a bitstream and performs motion compensation based on the selected candidate motion vector.

Abstract: A system may receive an input stream for a coding operation. The system may determine available coding modes for the coding operation. The system may include coding selection logic that may determine a coding mode in response to the based on the available selection of coding modes. The coding selection logic may use the selected coding mode to determine a coding strategy. The selection logic may send an indication of the selected coding mode and coding strategy to coding logic to support execution of the coding operation, which may use the selected coding mode and coding strategy.

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.

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 a method of coding video data. In an example, the method includes identifying a first block of video data in a first temporal location from a first view, wherein the first block of video data is associated with a first temporal motion vector. The method also includes determining, when a second motion vector associated with a second block of video data comprises a temporal motion vector and the second block is from a second view, a motion vector predictor for the second motion vector based on the first temporal motion vector. The method also includes coding prediction data for the second block using the motion vector predictor.

Abstract: A video encoder may encode video data by adaptively selecting between one-eighth-pixel and one-quarter-pixel precision motion vectors, and signal the selected precision. In one example, an apparatus includes a video encoder to encode a block of video data using a one-eighth-pixel precision motion vector when use of the one-eighth-pixel precision motion vector is determined to be preferable for the block over a one-quarter-pixel precision motion vector, and to generate a signal value indicative of the use of the one-eighth-pixel precision motion vector for the block, and an output interface to output the encoded block and the signal value. A video decoder may be configured to receive the signal value and the encoded block, analyze the signal value to determine whether the block was encoded using one-eighth-pixel precision or one-quarter-pixel precision, and decode the block based on the determination.

Abstract: In one example, an apparatus for signaling information for video data includes a processor configured to receive video data for two or more views of a scene, form a representation comprising a subset of the two or more views, and send, to a client device, as a part of a manifest of the representation, information indicative of a maximum number of views in the representation that can be targeted for output. An apparatus for receiving information for video data may receive the manifest including the information indicating the maximum number of views and request at least a portion of the video data of the representation based at least in part on a maximum number of views that can be output by the apparatus and the information indicative of the maximum number of views in the representation that can be targeted for output.

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: This disclosure describes techniques for mitigating rounding errors in a fixed-point transform associated with video coding by applying a variable localized bit-depth increase at the transform. More specifically, the techniques include selecting a constant value based on a size of a fixed-point transform in a video coding device and applying a variable localized bit-depth increase at the transform with a value equal to the constant value. Applying the variable localized bit-depth increase includes left-shifting a transform input signal by a number of bits equal to the constant value before the fixed-point transform, and right-shifting a transform output signal by a number of bits equal to the constant value after the fixed-point transform. The constant value is selected from a plurality of constant values stored on the video coding device. Each of the constant values is pre-calculated for one of a plurality of different transform sizes supported by the video coding.

Abstract: In one example, a video decoder is configured to determine whether a component of a transform unit of a coding unit of video data includes at least one non-zero coefficient based on a codeword for the transform unit, determine whether the transform unit is split into sub-transform units based on the codeword, and decode the transform unit based on the determinations. In another example, a video encoder is configured to determine whether a component of a transform unit of a coding unit of video data includes at least one non-zero coefficient, determine whether the transform unit is split into sub-transform units, select a codeword from a variable length code table, wherein the variable length code table provides an indication that the codeword corresponds to the determinations, and provide the codeword for the transform unit.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to calculate a residual block for a block of video data based on a predicted block formed using an intra-prediction mode, and transform the residual block using a transform mapped from the intra-prediction mode. In another example, an apparatus includes video encoder configured to receive an indication of a first intra-prediction mode in a first set of intra-prediction modes for a block of video data, determine a second intra-prediction mode from a second set of intra-prediction modes, smaller than the first set of intra-prediction modes, to which the first intra-prediction mode is mapped, determine a directional transform to which the second intra-prediction mode is mapped, and apply the directional transform to residual data of the block.

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: This disclosure describes techniques associated with filtering of video data in a video encoding and/or decoding process. In accordance with this disclosure, filtering is applied at an encoder, and filter information is encoded in the bitstream to identify the filtering that was applied at the encoder. Different types of filtering may be applied based on an activity metric determined for the video data. Moreover, in accordance with this disclosure, the manner in which the filter information is encoded into the bitstream may be dependent on the activity metric. In particular, for a first range of the activity metric, one or more filters are encoded directly, and for a second range of the activity metric, one or more filters are predictively encoded.

Abstract: Methods and apparatus to process multimedia data enabling efficient partial decoding of transform coded data are described. A decoder device receives transform coefficients, where the transform coefficients are associated with multimedia data. The decoder device determines a set of multimedia samples to be reconstructed. In one aspect, the set of samples to be reconstructed is a subset of a matrix of transformed multimedia samples. The decoder device determines a set of transform coefficients to be used to reconstruct the multimedia samples. In one aspect, the transform coefficients are used to scale partial basis images associated with the encoding method used to generate the transform coefficients, resulting in reconstructed multimedia samples.

Abstract: Apparatus and methods of using content information for encoding multimedia data are described. A method of processing multimedia data includes classifying content of multimedia data, and encoding the multimedia data in a first data group and in a second data group based on the content classification, wherein the first data group comprises a coefficient and the second data group comprises a first differential refinement associated with the first data group coefficient. An apparatus for using content information for encoding multimedia data includes a content classifying module configured to classify content of multimedia data and provide content classification data, and an encoder configured to encode the multimedia data in a first data group and in a second data group based on the content classification, wherein the first data group comprises a coefficient and the second data group comprises a first differential refinement associated with the first data group coefficient.

Abstract: Apparatus and methods of using content information for encoding multimedia data are described. A method of processing multimedia data includes classifying content of multimedia data, and encoding the multimedia data in a first data group and in a second data group based on the content classification. The first and second groups are associated with quality levels. A user can request a target quality level.