摘要:
This disclosure describes techniques for coding transform coefficients for a block of video data. According to these techniques, a video coder (a video encoder or video decoder) stores a first VLC table array selection table in memory, and an indication of at least one difference between the first VLC table array selection table and a second VLC table array selection table. The video coder reconstructs at least one entry of the second VLC table array selection table based on the first VLC table array selection table using the stored indication of the difference between the first VLC table array selection table and a second VLC table array selection table. The video coder uses the reconstructed at least one entry of the second VLC table array selection table to code at least one block of video data.
摘要:
Video coding devices and methods use a function-based definition of scan order to scan transform coefficients associated with a block of residual video data. A video coder may define a scan order for coefficients based on a predefined function and one or more parameter values. A video encoder may use a function-based scan order to scan a two-dimensional array of coefficients to produce a one-dimensional array of coefficients for use in producing encoded video data. The video encoder may signal the parameters to a video decoder, or the video decoder may infer one or more of the parameters. The video decoder may use the function-based scan order to scan a one-dimensional array of coefficients to reproduce the two-dimensional array of coefficients for use in producing decoded video data. In each case, the scan order may vary according to the parameter values, which may include block size, orientation, and/or orientation strength.
摘要:
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.
摘要:
An asymmetric frame of a coded video bitstream may include a full resolution picture of a left view and a reduced resolution picture of a right view, where the left and right views form a stereo view pair for three-dimensional video playback. In one example, an apparatus includes a video encoder configured to receive a first picture of a first view of a scene having a first resolution, receive a second picture of a second view of the scene having a reduced resolution relative to the first resolution, form an asymmetric frame including the first picture and the second picture, and encode the asymmetric frame. In this manner, decoders of varying capabilities may receive the same bitstream, and the bitstream may consume less bandwidth than one or more bitstreams having full resolution pictures of a stereo view pair. The bitstream may have better quality than a bitstream having subsampled pictures.
摘要:
During the prediction stage of a video encoding and/or decoding process, a video coder can use relatively longer filters for certain motion vectors pointing to certain sub-pixel positions and relatively shorter filters for motion vectors pointing to other sub-pixel positions, where a longer filter generally refers to an interpolation filter with a greater number of filter coefficients, also called taps, while a shorter filter generally refers to an interpolation filter with fewer taps.
摘要:
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.
摘要:
A video coder determines a deblocking quantization parameter (QP) value based on at least one of a first QP value and a second QP value. Subsequently, the video coder applies a deblocking filter that is based on the deblocking filter to an edge associated with a first video block. The edge occurs at a boundary between the first video block and a second video block. The first video block is associated with a current coding unit (CU) and the second video block is associated with a neighboring CU. The current CU is included in a first quantization group and the neighboring CU is included in a second quantization group. The first QP value is defined for the first quantization group. The second QP value is defined for the second quantization group.
摘要:
In one example, a device for coding video data includes a video coder configured to determine, for a depth block of a depth component of video data, a co-located texture block of a corresponding texture component, and when at least a portion of the texture block corresponds to a prediction unit of the texture component that is not intra-prediction coded: disable an inter-component Wedgelet depth modeling mode for the depth block, select an intra-prediction coding mode for the depth block other than the disabled inter-component Wedgelet depth modeling mode, and code the depth block using the selected intra-prediction coding mode.
摘要:
In one example, an apparatus includes a video encoder configured to partition a block of video data into a first partition and a second partition using a geometric motion partition line, calculate a prediction value of a pixel in a transition region of the block using a filter that applies a value for at least one neighboring pixel from the first partition and a value for at least one neighboring pixel from the second partition, calculate a residual value of the pixel in the transition region of the block based on the prediction value of the pixel in the transition region, and output the residual value of the pixel. In one example, a video decoder may use a similar filter to decode an the encoded block after receiving the residual value for the encoded block, and using a definition of the geometric motion partition line.
摘要:
This disclosure describes techniques for quantizing coefficients of a video block for a video coding process that supports context-based adaptive binary arithmetic coding (CABAC). A method may comprise estimating a last non-zero coefficient of the video block, and generating a set of quantized coefficients for the video block based on an assumption that the estimated last non-zero coefficient is actually the last non-zero coefficient of the video block.