Abstract:
A video decoder determines, based at least in part on a size of a prediction unit (PU), whether to round either or both a horizontal or a vertical component of a motion vector of the PU from sub-pixel accuracy to integer-pixel accuracy. The video decoder generates, based at least in part on the motion vector, a predictive sample block for the PU and generates, based in part on the predictive sample block for the PU, a reconstructed sample 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 video block information. The video block information includes reference layer block information. The processor determines, based on a parameter of the video block information, a transform function that may be used to code the video block information. The processor may encode or decode the video block information. The transform function may be an alternative transform when the parameter is a predetermined value and a primary transform when the parameter is not the predetermined value. The alternative transform includes one of: a discrete-sine-transform (DST), a Type-I DST, a Type-III DST, a Type-IV DST, a Type-VII DST, a discrete-cosine-transform (DCT), a DCT of different types, and a Karhunen-Loeve transform (KLT).
Abstract:
This disclosure proposes various techniques for limiting the number of bins that are coded using an adaptive context model with context adaptive binary arithmetic coding (CABAC). In particular, this disclosure proposes to limit the number of bins that use CABAC for coding level information of transform coefficients in a video coding process.
Abstract:
A system and method for coding a picture in a multi-layer bitstream is disclosed. In one aspect, the method includes encoding at least one layer of the multi-layer bitstream in accordance with a first coding scheme. The multi-layer bitstream may comprise a base layer. The method further includes encoding a conformance window flag and at least one position offset for the picture in a Video Parameter Set (VPS) of the base layer. The conformance window flag may indicate that the VPS comprises the at least one position offset.
Abstract:
A method of decoding video data includes decoding a first block of video data to produce a block of reconstructed luma residual values and a block of predicted chroma residual values, wherein the block of video data has one of a 4:2:0 or a 4:2:2 chroma sub-sampling format. The method further includes performing a color residual prediction process to reconstruct a block of chroma residual values for the first block of video data using a subset of the reconstructed luma residual values as luma predictors for the block of predicted chroma residual values.
Abstract:
A device for decoding video data includes a memory configured to store video data, and at least one processor. The at least one processor is configured to: determine a first bit-depth of luma residual samples for a block of video data, determine a second bit-depth of predicted chroma residual samples for the block of video data, adjust the luma residual samples based on the first bit-depth and the second bit-depth to produce bit-depth adjusted luma residual samples, determine chroma residual samples for the block of video data based on the bit-depth adjusted luma residual samples and the predicted chroma residual samples, and decode the block of video data based on the luma residual samples and the chroma residual samples.
Abstract:
A method of coding video data includes receiving one or more layers of video information. Each layer may include at least one picture. The method can include processing an indicator within at least one of a video parameter set (VPS), a sequence parameter set (SPS), or a picture parameter set (PPS) that indicates whether all direct reference layer pictures associated with the at least one of the video parameter set (VPS), the sequence parameter set (SPS), or the picture parameter set (PPS) are added to an inter-layer reference picture set. Based on the indicator, the method can further include refraining from further signaling inter-layer reference picture information in any video slice associated with the at least one of the video parameter set (VPS), the sequence parameter set (SPS), or the picture parameter set (PPS). Alternatively, based on the indicator, the method can further include adding to the inter-layer reference picture set all direct reference layer pictures for any video slice associated with the at least one of the video parameter set (VPS), the sequence parameter set (SPS), or the picture parameter set (PPS).
Abstract:
An apparatus for coding video information according to certain aspects includes a memory unit and a video processor in communication with the memory unit. The video processor is configured to identify a first picture included in the first set of pictures, wherein pictures within the first set of pictures having an output position after the output position of the first picture also have a decoding position after the decoding position of the first picture. The video processor is further configured to identify a second picture included in the second set of pictures, wherein pictures within the second set of pictures having an output position after the output position of the second pictures also have a decoding position after the decoding position of the second picture. The video processor is also configured to code the identified first picture and the identified second picture via one syntax element into one access unit.
Abstract:
In one example, a device includes a video coder configured to code a first set of syntax elements for the coefficients of a residual block of video data, and code, using at least a portion of the first set of syntax elements as context data, a second set of syntax elements for the coefficients, wherein the first set of syntax elements each correspond to a first type of syntax element for the coefficients, and wherein the second set of syntax elements each correspond to a second, different type of syntax element for the coefficients. For example, the first set of syntax elements may comprise values indicating whether the coefficients are significant (that is, have non-zero level values), and the second set of syntax elements may comprise values indicating whether level values for the coefficients have absolute values greater than one.
Abstract:
A video encoder generates a first and a second candidate list. The first candidate list includes a plurality of motion vector (MV) candidates. The video encoder selects, from the first candidate list, a MV candidate for a first prediction unit (PU) of a coding unit (CU). The second MV candidate list includes each of the MV candidates of the first MV candidate list except the MV candidate selected for the first PU. The video encoder selects, from the second MV candidate list, a MV candidate for a second PU of the CU. A video decoder generates the first and second MV candidate lists in a similar way and generates predictive sample blocks for the first and second PUs based on motion information of the selected MV candidates.