摘要:
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.
摘要:
Source and destination video devices may use data structures that signal details of an operation point for an MPEG-2 (Motion Picture Experts Group) System bitstream. In one example, an apparatus includes a multiplexer that constructs a data structure corresponding to a multiview video coding (MVC) operation point of an MPEG-2 (Motion Picture Experts Group) System standard bitstream, wherein the data structure signals a rendering capability value that describes a rendering capability to be satisfied by a receiving device to use the MVC operation point, a decoding capability value that describes a decoding capability to be satisfied by the receiving device to use the MVC operation point, and a bitrate value that describes a bitrate of the MVC operation point, and that includes the data structure as part of the bitstream, and an output interface that outputs the bitstream comprising the data structure.
摘要:
A demultiplexer may assemble view components of sub-bitstreams. In one example, an apparatus comprises a demultiplexer that produces a multiview video coding (MVC) standard compliant bitstream from a received bitstream comprising a primary sub-bitstream and an embedded sub-bitstream. To produce the MVC standard compliant bitstream, the demultiplexer determines whether a view component of the primary sub-bitstream has a view order index that is greater than a view order index of a view component of the embedded sub-bitstream, and to add the view component from the sub-bitstream for which the view order index is lower to the produced bitstream. The received bitstream may comprise delimiter network abstraction layer (NAL) units between each view component to differentiate the view components. The apparatus may further comprise a video decoder to decode the bitstream produced by the demultiplexer.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
This disclosure describes rules that may be applied during block-based video coding to ensure that quantization parameter selections for luma blocks will not adversely affect the quality of chroma blocks. In accordance with this disclosure, rate-controlled video encoding occurs in which quantization parameter changes in luma blocks are pre-evaluated to determine whether such quantization parameter changes in luma blocks will also cause quantization changes for chroma blocks. If quantization parameter changes in the luma blocks will also cause quantization changes for chroma blocks, then that quantization parameter change for luma blocks may be skipped and not evaluated. In this way, secondary effects of quantization parameter changes in the luma blocks (with respect to the chroma blocks) can be avoided.
摘要:
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.
摘要:
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.