Abstract:
Systems, methods, and devices for coding video data are described herein. In some aspects, a memory is configured to store the video data associated with a base layer and an enhancement layer. The base layer may comprise a reference block and base layer motion information associated with the reference block. The enhancement layer may comprise a current block. A processor operationally coupled to the memory is configured to determine a position of the base layer motion information in a candidate list based on a prediction mode in a plurality of prediction modes used at the enhancement layer. The processor is further configured to perform a prediction of the current block based at least in part on the candidate list.
Abstract:
In one example, an apparatus is configured to code video data. The apparatus comprises a processor configured to determine a base layer reference block for a current block. The base layer reference block may be located in the base layer. The processor is further configured to determine an enhancement layer reference block for the current block. The enhancement layer reference block may comprise a weighted sum of a first reference block located in the enhancement layer and a second reference block located in the enhancement layer. The processor is further configured to determine a reference block from the base layer reference block and the enhancement layer reference block.
Abstract:
An apparatus for coding video data according to certain aspects includes a memory and a processor in communication with the memory. The memory stores the video data. The video data may include a base layer and an enhancement layer, the base layer including a base layer block and the enhancement layer including an enhancement layer block. The base layer block may be located at a position in the base layer corresponding to a position of the enhancement layer block in the enhancement layer. The processor determines, based on information associated with the base layer block, a partitioning mode of the enhancement layer block. The partitioning mode may indicate that the enhancement layer block is to be partitioned into a first partition and a second partition. The processor further performs motion compensation for the first partition and the second partition of the enhancement layer block.
Abstract:
This disclosure pertains to video coding. Prediction information for a current block in an enhancement layer may be determined based at least in part on base layer information obtained by coding a base block in a base layer beneath the enhancement layer. This base block may occur in a position in the base layer such that it is co-located with a non-causal block in the enhancement layer (e.g., a block that occurs after the current block in the coding order of the enhancement layer). The prediction information determined for the current block may be used to code the current block (e.g., encoding or decoding the current block).
Abstract:
Techniques for encoding and decoding video data are described. A method of coding video may include determining a plurality of motion vector candidates for a block of video data for use in a motion vector prediction process, wherein each of the motion vector candidates points to a respective reference frame index, performing the motion vector prediction process using the motion vector candidates to determine a motion vector for the block of video data, and performing motion compensation for the block of video data using the motion vector and a common reference frame index, wherein the common reference frame index is used regardless of the respective reference frame index associated with the determined motion vector.
Abstract:
In an example, aspects of this disclosure relate to a method for decoding a reference index syntax element in a video decoding process that includes decoding at least one bin of a reference index value with a context coding mode of a context-adaptive binary arithmetic coding (CABAC) process. The method also includes decoding, when the reference index value comprises more bins than the at least one bin coded with the context coded mode, at least another bin of the reference index value with a bypass coding mode of the CABAC process, and binarizing the reference index value.
Abstract:
An apparatus for coding video information according to certain aspects is disclosed. Multi-layer video steams including a base layer and an enhancement layer can be coded. Predictors generated for the base layer and the enhancement layer can be combined to form a final predictor of the enhancement layer. Each predictor can be weighted such that those predictors which are more likely to produce high quality results can be factored more heavily in the final predictor. The conditions upon which the respective weights for enhancement layer predictors and base layer predictors are determined may be implicitly derived from the predictors or characteristics thereof. Alternatively, data may be generated explicating indicating the weights or providing information from which the weights can be determined.
Abstract:
Systems and methods for low complexity forward transforms using zeroed-out coefficients are described herein. One aspect of the subject matter described in the disclosure provides a video encoder comprising a memory configured to store a video block. The video encoder further comprises a processor in communication with the memory. The processor is configured to determine a full power value of the video block. The processor is further configured to determine a reduced transform coefficient matrix, wherein the reduced transform coefficient matrix comprises an inner region of zero or non-zero values of the same inner region of a full transform coefficient matrix and an outer region of zero values, wherein the reduced transform coefficient matrix and the full transform coefficient matrix have the same size. The processor is further configured to determine a partial power value of the video block using the reduced transform coefficient matrix. The processor is further configured to transform the video block from a pixel domain to a coefficient domain using the reduced transform coefficient matrix based on the full power value and partial power value. The processor is further configured to encode the transformed video block.
Abstract:
In general, techniques are described for reducing the space required to store rate distortion values when selecting from multiple, different prediction modes. A video coding device comprising a processor may perform the techniques. The processor may determine first and second sets of intra-prediction modes for a current block of video data. The first and second sets of intra-prediction modes may include less intra-prediction modes, collectively, than a total number of intra-prediction modes. The processor may compute an approximate cost for each intra-prediction mode included in the first and second sets of intra-prediction modes. The processor may store the approximate cost for each intra-prediction mode identified in the first and second sets of intra-prediction modes to a memory. The processor may perform intra-prediction to encode the current block using a mode identified in at least one of the first or second set.
Abstract:
In one embodiment, a video coder for processing video data includes a processor and a memory. The processor is configured to downsample at least prediction mode information of a reference layer block. In addition, the processor is configured to predict at least one of an enhancement layer block or prediction mode information of the enhancement layer block based at least on the prediction mode information of the reference layer block before the processor downsamples the prediction mode information of the reference layer block. The memory is configured to store the prediction mode information of the reference layer block. The prediction mode information of the reference layer block, for example, includes an inter-prediction mode, an intra-prediction mode, or a motion vector of the reference layer block.