This application discloses a motion vector obtaining method and apparatus, a computer device, and a storage medium. In the method, an initial motion vector of a to-be-processed picture block is determined by using a location relationship between a reference block and the to-be-processed picture block. When the reference block and the to-be-processed picture block are located in a same coding tree block, a decoder uses an initial motion vector of the reference block as the initial motion vector of the to-be-processed picture block. When the reference block and the to-be-processed picture block are located in different coding tree blocks, the decoder uses a final motion vector of the reference block as the initial motion vector of the to-be-processed picture block.

A system comprises an encoder configured to compress attribute and/or spatial information for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. To compress the attribute and/or spatial information, the encoder is configured to convert a point cloud into an image based representation. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud. In some embodiments, an encoder generates time-consistent patches for multiple version of the point cloud at multiple moments in time and uses the time-consistent patches to generate image based representations of the point cloud at the multiple moments in time.

A point cloud coding method includes obtaining description information of a bounding box size of a to-be-encoded point cloud and a normal axis of a to-be-encoded patch in the to-be-encoded point cloud, where the description information of the bounding box size of the to-be-encoded point cloud and the normal axis of the to-be-encoded patch are used to determine a tangent axis of the to-be-encoded patch and a bitangent axis of the to-be-encoded patch. The point cloud encoding method further includes encoding a syntax element into a bitstream, where the syntax element includes an index of the normal axis of the to-be-encoded patch and information for indicating the description information of the bounding box size of the to-be-encoded point cloud, and the syntax element is used to indicate the tangent axis of the to-be-encoded patch and the bitangent axis of the to-be-encoded patch.

A point cloud coding method includes obtaining description information of a bounding box size of a to-be-encoded point cloud and a normal axis of a to-be-encoded patch in the to-be-encoded point cloud, where the description information of the bounding box size of the to-be-encoded point cloud and the normal axis of the to-be-encoded patch are used to determine a tangent axis of the to-be-encoded patch and a bitangent axis of the to-be-encoded patch. The point cloud encoding method further includes encoding a syntax element into a bitstream, where the syntax element includes an index of the normal axis of the to-be-encoded patch and information for indicating the description information of the bounding box size of the to-be-encoded point cloud, and the syntax element is used to indicate the tangent axis of the to-be-encoded patch and the bitangent axis of the to-be-encoded patch.

Techniques are disclosed for the creation of multi-codec encoding profiles (or encoding ladders), which define quality and bitrate for each of the streams made available to clients for streaming a video. In particular, optimization techniques may take into account a quality rate function of each of the codecs when determining the encoding ladder. Additional considerations may include a network bandwidth distribution and/or a distribution of client types.

Techniques are disclosed for the creation of multi-codec encoding profiles (or encoding ladders), which define quality and bitrate for each of the streams made available to clients for streaming a video. In particular, optimization techniques may take into account a quality rate function of each of the codecs when determining the encoding ladder. Additional considerations may include a network bandwidth distribution and/or a distribution of client types.

A video codec can involve encoding and decoding picture information and first and second flags, wherein the encoding or decoding of the picture information is based on a coding mode indicated by the first flag or the second flag, and the first flag indicates a subblock merge mode and the second flag indicates an inter affine prediction mode, and the encoding or decoding of the first flag uses CABAC coding based on a first probability model and encoding or decoding of the second flag uses CABAC coding based on a second probability model.

Still frame detection for single pass video data, including: determining that an average quantization parameter of a frame of video data falls below a quantization parameter threshold; determining whether an amount of skipped macroblocks in the frame meets a skipped macroblock threshold; and responsive to the amount of skipped macroblocks exceeding the skipped macroblock threshold, identifying the frame as a still frame.

A prediction method for an image block comprising a first prediction sub-block and a second prediction sub-block, the prediction method comprising: parsing a first index from a bitstream, wherein the first index is used to obtain prediction information of the first prediction sub-block; parsing a second index from the bitstream; comparing the first index with the second index; adjusting the second index in the event that the second index is equal to or greater than the first index; and obtaining prediction information of the second prediction sub-block according to the adjusted second index.

There are provided mechanisms for methods and apparatuses for transform selection in encoding and decoding of video blocks.