VID SCALE, INC.

Embodiments of video coding systems and methods are described for reducing coding latency introduced by decoder-side motion vector refinement (DMVR). In one example, two non-refined motion vectors are identified for coding of a first block of samples (e.g. a first coding unit) using bi-prediction. One or both of the non-refined motion vectors are used to predict motion information for a second block of samples (e.g. a second coding unit). The two non-refined motion vectors are refined using DMVR, and the refined motion vectors are used to generate a prediction signal of the first block of samples. Such embodiments allow the second block of samples to be coded substantially in parallel with the first block without waiting for completion of DMVR on the first block. In additional embodiments, optical-flow-based techniques are described for motion vector refinement.

Systems and methods are described for reducing the complexity of using bi-directional optical flow (BIO) in video coding. In some embodiments, bit-width reduction steps are introduced in the BIO motion refinement process to reduce the maximum bit-width used for BIO calculations. In some embodiments, simplified interpolation filters are used to generate predicted samples in an extended region around a current coding unit. In some embodiments, different interpolation filters are used for vertical versus horizontal interpolation. In some embodiments, BIO is disabled for coding units with small heights and/or for coding units that are predicted using a sub-block level inter prediction technique, such as advanced temporal motion vector prediction (ATMVP) or affine prediction.

A method for receiving and displaying media content may be provided. The method may include requesting a set of DASH video segments that are associated with various viewports and qualities. The method may include displaying the DASH video segments. The method may include determining a latency metric based on a time difference between the display of a DASH video segment and one of: a device beginning to move, the device ceasing to move, the device determining that the device has begun to move, the device determining that the device has stopped moving, or the display of a different DASH video segment. The different DASH video segment may be associated with one or more of a different quality or a different viewport.

Systems, methods, and instrumentalities are described herein for calculating local illumination compensation (LIC) parameters for bi-predicted coding unit (CU). The LIC parameters may be used to generate adjusted samples for the current CU and to address local illumination changes that may exist among temporal neighboring pictures. LIC parameters may be calculated based on bi-predicted reference template samples and template samples for a current CU. Bi-predicted reference template samples may be generated based on reference template samples neighboring temporal reference CUs. For example, the bi-predicted reference template samples may be generated based on averaging the reference template samples. The reference template samples may correspond to template samples for the current CU. A CU may be or may include a coding block and/or a sub-block that may be derived by dividing the coding block.

Systems and methods are described for video coding using affine motion prediction. In an example method, motion vector gradients are determined from respective motion vectors of a plurality of neighboring sub-blocks neighboring a current block. An estimate of at least one affine parameter for the current block is determined based on the motion vector gradients. An affine motion model is determined based at least in part on the estimated affine parameter(s), and a prediction of the current block is generated using the affine motion model. The estimated parameter(s) may be used in the affine motion model itself. Alternatively, the estimated parameter(s) may be used in a prediction of the affine motion model. In some embodiments, only neighboring sub-blocks above and/or to the left of the current block are used in estimating the affine parameter(s).

Systems, methods, and instrumentalities for affine motion estimation for affine model-based video coding may be disclosed herein. A first motion vector (MV) set including one or more MVs may be derived for a first coding block. The MVs may be control point MVs (CPMVs) and the MVs may be derived by performing affine motion estimation (ME) associated with the first coding block. The first MV set may be added to a recently-estimated MV list. A head of the recently-estimated MV list may be set to the first MV set. The recently-estimated MV list may be empty or may contain one or more previously-added MV sets.

Systems, methods, and instrumentalities are disclosed for processing history-based motion vector prediction (HMVP). A video coding device may generate a history-based motion vector prediction (HMVP) list for a current block. The video coding device derive an HMVP candidate from a previously coded block. The HMVP candidate may include motion information associated with a neighboring block of the current block, one or more reference indices, and a bi-prediction weight index. The video coding device may add the HMVP candidate to the HMVP list for motion compensated prediction of a motion vector associated with the current block. The video coding device use one HMVP selected from the HMVP list to perform motion compensated prediction of the current block. The motion compensated prediction may be performed using the motion information associated with the neighboring block of the current block, the one or more reference indices, and the bi-prediction weight index.

A media content processing device may decode visual volumetric content based on one or more messages, which may indicate which attribute sub-bitstream of one or more attribute sub-bitstreams indicated in a parameter set is active, The parameter set may include a visual volumetric video-based parameter set. The message indicating one or more active attribute sub-bitstreams may be received by the decoder, A decoder may perform decoding, such as determining which attribute sub-bitstream to use for decoding visual media content, based on the one or more messages, The one or more messages may be generated and sent to a decoder, for example, to indicate the deactivation of the one or more attribute sub-bitstreams. The decoder may determine an inactive attribute sub-bitstream and skip the inactive attribute sub-bitstream for decoding the visual media content based on the one or more messages.

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products directed to improved linear model estimation for template-based video coding are provided. Included therein is a method comprising determining minimum and maximum (“min/max”) values of luma and chroma samples neighboring a coding block, wherein the min/max chroma values correspond to the min/max luma values; determining a first linear model parameter of a template-based video coding technique (i) based on a single look-up table and the min/max chroma values and (ii) at a precision no greater than 16 bits; determining a second linear model parameter of the template-based video coding technique (i) based on the first linear model parameter and the minimum chroma and luma values and (ii) at a precision no greater than 16 bits; and predicting chroma samples of the coding block based on reconstructed luma samples of the coding block and the first and second linear model parameters.

Video data may be palette decoded. Data defining a palette table may be received. The palette table may comprise index values corresponding to respective colors. Palette index prediction data may be received and may comprise data indicating index values for at least a portion of a palette index map mapping pixels of the video data to color indices in the palette table. The palette index prediction data may comprise run value data associating run values with index values for at least a portion of a palette index map. A run value may be associated with an escape color index. The palette index map may be generated from the palette index prediction data at least in part by determining whether to adjust an index value of the palette index prediction data based on a last index value. The video data may be reconstructed in accordance with the palette index map.