Video processing methods and apparatuses include receiving input video data associated with a current picture composed of multiple Coding Tree Units (CTUs) for encoding or decoding, determining a number of subpictures, partitioning the current picture into one or more subpictures, and encoding or decoding each subpicture in the current picture. Each subpicture contains multiple complete CTUs and boundaries of each subpicture are aligned with grids of the current picture in units of CTUs. The number of subpictures in the current picture is limited by an allowed maximum number of slices.

Portion- or tile-based video streaming concepts are described.

Portion- or tile-based video streaming concepts are described.

Systems, methods and apparatus for encoding or decoding a file format that stores one or more images are described. One example method includes performing a conversion between a visual media file and a bitstream of a visual media data according to a format rule, where the format rule specifies that a type of a sample entry determines whether decoding capability information network abstraction layer units are included in either the sample entry of a video track in the visual media file or in a sample of the video track and the sample entry of the video track in the visual media file.

Systems, methods and apparatus for encoding or decoding a file format that stores one or more images are described. One example method includes performing a conversion between a visual media file and a bitstream of a visual media data according to a format rule, where the format rule specifies that a type of a sample entry determines whether decoding capability information network abstraction layer units are included in either the sample entry of a video track in the visual media file or in a sample of the video track and the sample entry of the video track in the visual media file.

A moving picture coding apparatus includes an intra-inter prediction unit which calculates a second motion vector by performing a scaling process on a first motion vector of a temporally neighboring corresponding block, when selectively adding, to a list, a motion vector of each of one or more corresponding blocks each of which is either a block included in a current picture to be coded and spatially neighboring a current block to be coded or a block included in a picture other than the current picture and temporally neighboring the current block, determines whether the second motion vector has a magnitude that is within a predetermined magnitude or not within the predetermined magnitude, and adds the second motion vector to the list when the intra-inter prediction unit determines that the second motion vector has a magnitude that is within the predetermined magnitude range.

Techniques and tools for reducing latency in video encoding and decoding by constraining latency due to reordering of video frames, and by indicating the constraint on frame reordering latency with one or more syntax elements that accompany encoded data for the video frames. For example, a real-time communication tool with a video encoder sets a syntax element that indicates a constraint on frame reordering latency, which is consistent with inter-frame dependencies between multiple frames of a video sequence, then outputs the syntax element. A corresponding real-time communication tool with a video decoder receives the syntax element that indicates the constraint on frame reordering latency, determines the constraint on frame reordering latency based on the syntax element, and uses the constraint on frame reordering latency to determine when a reconstructed frame is ready for output (in terms of output order).

Techniques and tools for reducing latency in video encoding and decoding by constraining latency due to reordering of video frames, and by indicating the constraint on frame reordering latency with one or more syntax elements that accompany encoded data for the video frames. For example, a real-time communication tool with a video encoder sets a syntax element that indicates a constraint on frame reordering latency, which is consistent with inter-frame dependencies between multiple frames of a video sequence, then outputs the syntax element. A corresponding real-time communication tool with a video decoder receives the syntax element that indicates the constraint on frame reordering latency, determines the constraint on frame reordering latency based on the syntax element, and uses the constraint on frame reordering latency to determine when a reconstructed frame is ready for output (in terms of output order).

A moving picture coding method includes: making a determination as to whether or not to code all blocks in a current picture in the skip mode; setting, based on a result of the determination, a first flag indicating whether or not a temporally neighboring block is to be referenced, a value of a parameter for determining a total number of merging candidates, and a second flag for each block included in the current picture, the second flag indicating whether or not the block is to be coded in the skip mode; calculating, as a merging candidate, a neighboring block usable for merging; and coding an index which indicates a merging candidate to be used for coding of the current block and attaching the coded index to a bitstream.

A moving picture coding method includes: making a determination as to whether or not to code all blocks in a current picture in the skip mode; setting, based on a result of the determination, a first flag indicating whether or not a temporally neighboring block is to be referenced, a value of a parameter for determining a total number of merging candidates, and a second flag for each block included in the current picture, the second flag indicating whether or not the block is to be coded in the skip mode; calculating, as a merging candidate, a neighboring block usable for merging; and coding an index which indicates a merging candidate to be used for coding of the current block and attaching the coded index to a bitstream.