An image decoding method includes obtaining, from a bitstream, first information indicating a motion vector resolution of a current unit among plural motion vector resolutions including a first motion vector resolution and a second motion vector resolution, and obtaining, from the bitstream, second information indicating whether a merge mode is applied to the current unit or not when the first information indicates the first motion vector resolution. The current unit is decoded based on the merge mode when the second information indicates that the merge mode is applied to the current unit. When the first information indicates the second motion vector resolution, the second information is not obtained from the bitstream. A picture is split into one or more largest coding units, and a largest coding unit among the one or more largest coding units is split into one or more coding units including the current unit.

Video signal coding and decoding functions can generate lists of potential candidates to use in coding and decoding, for example, predictors. Video signal coding component candidate undergo operations before potential inclusion in candidate lists. The candidates are checked after being modified by the operations to see if other equal candidates are already in the candidate list. If equal candidates are not in the list, the modified candidates are added to the candidate list. If equal candidates are already in the list, the modified candidates are not added to the list. Operations that can be performed comprise rounding and clipping.

A method for adaptive MV precision is disclosed. According to one embodiment, whether to use or not to use the adaptive MV precision for a current block is determined according to a prediction mode/partition type of the current block. If the adaptive MV precision is used, a current MV precision is determined for a current MV of the current block, and the current MV is encoded or decoded at the current MV precision. If the adaptive MV precision is not used, the current MV is encoded or decoded at a finer MV precision. In another embodiment, a value of a current adaptive MV precision flag is selected for a current block to indicate whether to use or not to use the adaptive MV precision for a current block according to a prediction mode/partition type of the current block.

A method for adaptive MV precision is disclosed. According to one embodiment, whether to use or not to use the adaptive MV precision for a current block is determined according to a prediction mode/partition type of the current block. If the adaptive MV precision is used, a current MV precision is determined for a current MV of the current block, and the current MV is encoded or decoded at the current MV precision. If the adaptive MV precision is not used, the current MV is encoded or decoded at a finer MV precision. In another embodiment, a value of a current adaptive MV precision flag is selected for a current block to indicate whether to use or not to use the adaptive MV precision for a current block according to a prediction mode/partition type of the current block.

A format for use in encoding moving image data, comprising: a sequence of frames including plurality of the frames in which at least a region is encoded using motion estimation; a respective set of motion vector values representing motion vectors of the motion estimation for each respective one of these frames or each respective one of one or more regions within each of such frames; and at least one respective indicator associated with each of the respective frames or regions, indicating whether the respective motion vector values of the respective frame or region are encoded at a first resolution or a second resolution.

A format for use in encoding moving image data, comprising: a sequence of frames including plurality of the frames in which at least a region is encoded using motion estimation; a respective set of motion vector values representing motion vectors of the motion estimation for each respective one of these frames or each respective one of one or more regions within each of such frames; and at least one respective indicator associated with each of the respective frames or regions, indicating whether the respective motion vector values of the respective frame or region are encoded at a first resolution or a second resolution.

A video processing apparatus may comprise one or more processors that are configured to determine an interpolation filter length for an interpolation filter associated with a coding unit (CU) based on a size of the CU. The one or more processor may be configured to determine an interpolated reference sample based on the determined interpolation filter length for the interpolation filter and a reference sample for the CU. The one or more processor may be configured to predict the CU based on the interpolated reference sample. For example, if a first CU has a size that is greater than the size of a second CU, the one or more processors may be configured to use a shorter interpolation filter for the first CU than for the second CU.

Methods and apparatus for video coding are disclosed. According to this method, a bitstream corresponding to encoded data of the video sequence is generated at an encoder side or received at a decoder side, where the bitstream comprises a first syntax related to AMVR precision, and wherein the syntax related to the AMVR precision is coded by context coding bins with at least two contexts. One or motion vectors for the target block are encoded, at the encoder side, or decoded, at the decoder side, utilizing information comprising the AMVR precision.

Aspects of the disclosure provide methods and apparatuses for video decoding. In some examples, an apparatus includes processing circuitry. The processing circuitry decodes prediction information of a current block from a coded video bitstream. The prediction information is indicative of an intra block copy mode. Then, the processing circuitry determines, according to the intra block copy mode, a first portion of a resolution syntax. The resolution syntax is unified of a same semantic for block vectors in the intra block copy mode and motion vectors in an inter picture merge mode. Further, the processing circuitry decodes a second portion of the resolution syntax from the coded video bitstream, and determines a block vector according to a resolution that is indicated by a combination of the first portion and the second portion. Then, the processing circuitry reconstructs at least one sample of the current block according the block vector.

A method and apparatus for encoding of a video sequence in an encoder or decoding of the video sequence in a decoder includes parsing an initial motion vector from the video sequence associated with a block. A plurality of samples are determined and pre-fetched to permit both motion vector refinement and motion compensation based on parsing the initial motion vector. Motion vector refinement is performed to determine a final motion vector using a first subset of the plurality of samples, and motion compensation is performed using a second subset of the plurality of samples.