Abstract: A device for encoding video data may be configured to encode video data according to a set of sample adaptive offset (SAO) types; perform a plurality of coding passes to test a subset of the SAO types for a first block of video data, wherein the subset is smaller than the set; select from the subset of SAO types an SAO type for the first block of video data; and generate for inclusion in an encoded bitstream, information for identifying the selected SAO type for the first block.

Abstract: A device for encoding video data may be configured to encode video data according to a set of sample adaptive offset (SAO) types; perform a plurality of coding passes to test a subset of the SAO types for a first block of video data, wherein the subset is smaller than the set; select from the subset of SAO types an SAO type for the first block of video data; and generate for inclusion in an encoded bitstream, information for identifying the selected SAO type for the first block.

Abstract: In an example, aspects of this disclosure relate to a method of coding video data that includes determining a quantization parameter (QP) for coding residual video data, where the QP is indexed to a quantizer step size. The method also includes determining a quantization scaling value for scaling the quantizer step size, and applying the quantization scaling value scaling to the quantizer step size. The method also includes coding the residual video data using the scaled quantizer step size.

Abstract: In one example, a video coding device is configured to intra-predict a block of video data, using values of pixels along a primary boundary of the block, to form a predicted block, determine whether to filter the predicted block using data of a secondary boundary of the block, and filter the predicted block using data of the secondary boundary in response to determining to filter the predicted block. The video coding device may determine whether to filter the predicted block based on a comparison of a Laplacian value or a gradient difference value to a threshold. The determination of whether to filter the predicted block may be based at least in part on a boundary relationship, e.g., the relationship of one boundary to another, or of a boundary to pixel values of the predicted block.

Abstract: In various implementations, provided are systems and methods for correcting the distortion present in a fisheye image, and rendering the image for display as 360-degree video. In various implementations, a computing device can receive 2-dimensional video data captured by an omnidirectional camera. The computing device can map an image from each video frame to a 3-dimensional hemispherical representation. In various implementations, this mapping can be executed using a polynomial model. The 3-dimensional hemispherical representation can then be used in a 360-degree video presentation, to provide a virtual reality experience.

Abstract: Techniques and systems are described for mapping 360-degree video data to a truncated square pyramid shape. A 360-degree video frame can include 360-degrees' worth of pixel data, and thus be spherical in shape. By mapping the spherical video data to the planes provided by a truncated square pyramid, the total size of the 360-degree video frame can be reduced. The planes of the truncated square pyramid can be oriented such that the base of the truncated square pyramid represents a front view and the top of the truncated square pyramid represents a back view. In this way, the front view can be captured at full resolution, the back view can be captured at reduced resolution, and the left, right, up, and bottom views can be captured at decreasing resolutions. Frame packing structures can also be defined for 360-degree video data that has been mapped to a truncated square pyramid shape.

Abstract: An apparatus configured to filter video information according to certain aspects includes a memory unit and a processor in communication with the memory unit. The memory unit stores video information comprising at least two adjacent video blocks, each video block comprising a plurality of video samples, and each video sample having a bit depth. The processor determines a filtered video sample based at least in part on a video sample and an adjustment value. The processor determines the adjustment value at least in part from an input with a limited bit depth. The input is determined from a set of one or more video samples, and its bit depth is limited such that it is less than the bit depth of the one or more video samples.

Abstract: A device may include a video coder to determine an equivalent quantization parameter (QP) for a decoded block of video data using a quantization matrix for the decoded block of video data, determine deblocking parameters based on the determined equivalent QP, and deblock an edge of the decoded block based on the determined deblocking parameters. In particular, the video coder may determine equivalent QPs for two neighboring blocks defining a common edge, and deblock the common edge based on the equivalent QPs. The video coder may determine deblocking parameters, such as ? and tc values, based on the equivalent QPs. The video coder may then deblock the common edge based on the deblocking parameters, e.g., determine whether to deblock the common edge, determine whether to apply a strong or a weak filter to the common edge, and determine a width (in number of pixels) for a weak filter.

Abstract: This disclosure describes techniques for signaling deblocking filter parameters for a current slice of video data with reduced bitstream overhead. Deblocking filter parameters may be coded in one or more of a picture layer parameter set and a slice header. The techniques reduce a number of bits used to signal the deblocking filter parameters by coding a first syntax element that indicates whether deblocking filter parameters are present in both the picture layer parameter set and the slice header, and only coding a second syntax element in the slice header when both sets of deblocking filter parameters are present. Coding the second syntax element is eliminated when deblocking filter parameters are present in only one of the picture layer parameter set or the slice header. The second syntax element indicates which set of deblocking filter parameters to use to define a deblocking filter applied to a current slice.

Abstract: The present disclosure describes a method, an apparatus, and a computer readable medium for congestion control in wireless communications. For example, the example method may include determining a plurality of picture transmission deltas, wherein a picture transmission delta is a difference between transmission times of two consecutive pictures. The example method further includes determining whether congestion associated with receiving real-time transport protocol (RTP) packets is present based on a picture transmission delta jitter, determining a new maximum bit rate based on a current maximum bit rate and a determination that congestion is present, and transmitting the new maximum bit rate to a sending device.

Abstract: Techniques described herein are related to harmonizing the signaling of coding modes and filtering in video coding. In one example, a method of decoding video data is provided that includes decoding a first syntax element to determine whether PCM coding mode is used for one or more video blocks, wherein the PCM coding mode refers to a mode that codes pixel values as PCM samples. The method further includes decoding a second syntax element to determine whether in-loop filtering is applied to the one or more video blocks. Responsive to the first syntax element indicating that the PCM coding mode is used, the method further includes applying in-loop filtering to the one or more video blocks based at least in part on the second syntax element and decoding the one or more video blocks based at least in part on the first and second syntax elements.

Abstract: Techniques are described for sub-prediction unit (PU) based motion prediction for video coding in HEVC and 3D-HEVC. In one example, the techniques include an advanced temporal motion vector prediction (TMVP) mode to predict sub-PUs of a PU in single layer coding for which motion vector refinement may be allowed. The advanced TMVP mode includes determining motion vectors for the PU in at least two stages to derive motion information for the PU that includes different motion vectors and reference indices for each of the sub-PUs of the PU. In another example, the techniques include storing separate motion information derived for each sub-PU of a current PU predicted using a sub-PU backward view synthesis prediction (BVSP) mode even after motion compensation is performed. The additional motion information stored for the current PU may be used to predict subsequent PUs for which the current PU is a neighboring block.

Abstract: In general, techniques are described for applying partition-based filters when coding video data. A device comprising at least one processor may be configured to implement the techniques. The processor selects a filter to apply near a boundary of a first portion of the video data and determines at least one of the plurality of filter coefficients of the selected filter for which the video data will not be available to be filtered. Based on the determination, the processor determines a partial filter that does not include the at least one of the plurality of filter coefficients for which the video data will not be available to be filtered. The processor renormalizes the plurality of filter coefficients included within the partial filter and applies the renormalized partial filter near the boundary of the first portion of the video data to generate a filtered first portion of the video data.

Abstract: This disclosure describes techniques for signaling deblocking filter parameters for a current slice of video data with reduced bitstream overhead. Deblocking filter parameters may be coded in one or more of a picture layer parameter set and a slice header. The techniques reduce a number of bits used to signal the deblocking filter parameters by coding a first syntax element that indicates whether deblocking filter parameters are present in both the picture layer parameter set and the slice header, and only coding a second syntax element in the slice header when both sets of deblocking filter parameters are present. Coding the second syntax element is eliminated when deblocking filter parameters are present in only one of the picture layer parameter set or the slice header. The second syntax element indicates which set of deblocking filter parameters to use to define a deblocking filter applied to a current slice.

Abstract: Techniques for coding video data include coding a plurality of blocks of video data, wherein at least one block of the plurality of blocks of video data is coded using a coding mode that is one of an intra pulse code modulation (IPCM) coding mode and a lossless coding mode. In some examples, the lossless coding mode may use prediction. The techniques further include assigning a non-zero quantization parameter (QP) value for the at least one block coded using the coding mode. The techniques also include performing deblocking filtering on one or more of the plurality of blocks of video data based on the coding mode used to code the at least one block and the assigned non-zero QP value for the at least one block.

Abstract: This disclosure describes techniques for signaling deblocking filter parameters for a current slice of video data with reduced bitstream overhead. Deblocking filter parameters may be coded in one or more of a picture layer parameter set and a slice header. The techniques reduce a number of bits used to signal the deblocking filter parameters by coding a first syntax element that indicates whether deblocking filter parameters are present in both the picture layer parameter set and the slice header, and only coding a second syntax element in the slice header when both sets of deblocking filter parameters are present. Coding the second syntax element is eliminated when deblocking filter parameters are present in only one of the picture layer parameter set or the slice header. The second syntax element indicates which set of deblocking filter parameters to use to define a deblocking filter applied to a current slice.

Abstract: An apparatus for coding video data according to certain aspects includes a memory unit and a processor in communication with the memory unit. The memory unit stores video data. The video data may include a base layer comprising samples with a lower bit depth and an enhancement layer comprising samples with a higher bit depth. The processor predicts the values of samples in the enhancement layer based on the values of samples in the base layer. The prediction performed by the processor includes applying a preliminary mapping to the base layer samples to obtain preliminary predictions, and then applying adaptive adjustments to the preliminary predictions to obtain refined predictions. Parameters used for the adaptive adjustments may depend on the values and distribution of base layer samples. The processor may encode or decode the video data.

Abstract: Techniques for coding video data include coding a plurality of blocks of video data, wherein at least one block of the plurality of blocks of video data is coded using a coding mode that is one of an intra pulse code modulation (IPCM) coding mode and a lossless coding mode. In some examples, the lossless coding mode may use prediction. The techniques further include assigning a non-zero quantization parameter (QP) value for the at least one block coded using the coding mode. The techniques also include performing deblocking filtering on one or more of the plurality of blocks of video data based on the coding mode used to code the at least one block and the assigned non-zero QP value for the at least one block.

Abstract: This disclosure describes techniques for performing sample adaptive offset signaling and coding in a video coding process. Techniques of the disclosure include both a merge-based and prediction-based signaling process for sample adaptive offset information (i.e., offset values and offset type). The techniques includes determining offset information for a current partition, comparing the offset information of the current partition with offset information of one or more neighbor partitions, coding a merge instruction in the case that the offset information of one of the one or more neighbor partitions is the same as the offset information of the current partition, and coding one of a plurality of prediction instructions in the case that the offset information of the one or more neighbor partitions is not the same as the offset information of the current partition.

Abstract: In one example, an apparatus for processing video data comprises a video coder configured to, for each of the one or more chrominance components, calculate a chrominance quantization parameter for a common edge between two blocks of video data based on a first luminance quantization parameter for the first block of video data, a second luminance quantization parameter for the second block of video data, and a chrominance quantization parameter offset value for the chrominance component. The video coder is further configured to determine a strength for a deblocking filter for the common edge based on the chrominance quantization parameter for the chrominance component, and apply the deblocking filter according to the determined strength to deblock the common edge.