Abstract: A three-dimensional data encoding method includes: (i) in a first case where a layered structure is generated by classifying three-dimensional points into layers: encoding attribute information for the three-dimensional points based on the layered structure; and generating a bitstream including layer information utilized for the generation of the layered structure; and (ii) in a second case where the three-dimensional points are not classified: encoding attribute information for the three-dimensional points; and generating a bitstream not including the layer information.

Abstract: A three-dimensional data encoding method includes: calculating coefficient values from pieces of attribute information of three-dimensional points included in point cloud data; quantizing the coefficient values individually to generate quantized values; and generating a bitstream including the quantized values. Each of the coefficient values belongs to any one of layers. In the quantizing, each of the coefficient values is quantized using a quantization parameter for a layer to which the coefficient value belongs among the layers, and the bitstream includes first information and pieces of second information, the first information indicating a reference quantization parameter, the pieces of second information being for calculating quantization parameters for the layers from the reference quantization parameter.

Abstract: A data transmission method according to one aspect of the present disclosure includes: generating a plurality of MPUs, reference clock time information, and leading clock time information indicating a leading PTS that is a clock time at which a leading access unit in the MPU is presented, transmitting the generated plurality of MPUs, reference clock time information, and leading clock time information, wherein the leading clock time information indicates the leading PTS of the plurality of MPUs of which presentation is started after the leading clock time information is transmitted in the generated plurality of MPUs, and each of the generated plurality of MPUs indicates a time point at which each access unit that does not exist in a head of the MPU is presented as a relative value to a time point of another access unit in the MPU.

Abstract: A three-dimensional data encoding method includes: determining, by a first method, a first prediction value of a distance component included in position information of a three-dimensional point; and determining, by a second method, a second prediction value of a direction component included in the position information, the second method being different from the first method. For example, the first method may be inter prediction, and the second method may be intra prediction.

Abstract: Provided is a video reception method performed by a video reception apparatus including a display. The video reception method includes: receiving a reception signal multiplexed from a video signal and an audio signal; obtaining the video signal and first transfer characteristics information by demultiplexing the reception signal, the first transfer characteristics information being information for specifying, per random access unit, a transfer function corresponding to a luminance dynamic range of the video signal; obtaining video data by decoding the video signal obtained; and displaying the video data while controlling a luminance dynamic range of the display per random access unit according to the first transfer characteristics information.

Abstract: A three-dimensional data encoding method includes: classifying three-dimensional points included in point cloud data into layers, based on geometry information of the three-dimensional points; generating first information indicating whether to permit referring to, for a current three-dimensional point included in the three-dimensional points, attribute information of another three-dimensional point belonging to a same layer as the current three-dimensional point; and encoding attribute information of the current three-dimensional point to generate a bitstream, by or without referring to the attribute information of the other three-dimensional point according to the first information. The bitstream includes the first information.

Abstract: A three-dimensional data decoding method includes: performing at least one of: a first process including: determining a first context based on first information identifying a first point cloud including a first prediction point that is referred to for calculating a predicted value of a first three-dimensional point according to inter prediction; and arithmetic-decoding, using the first context determined, second information identifying the first prediction point; or a second process including: determining a second context based on at least one of the first information or the second information; and arithmetic-decoding, using the second context determined, a prediction residual of the first three-dimensional point.

Abstract: A three-dimensional data decoding method includes: selecting, from among contexts, a first context for an encoded first information item to be processed; and arithmetic-decoding the encoded first information item to be processed, using the first context, to generate a first information item to be processed. Encoded first information items including the encoded first information item to be processed are included in a bitstream generated by encoding an information item about positions of three-dimensional points. The encoded first information items are generated by arithmetic-encoding first information items including the first information item to be processed. The first information items each correspond to a different one of reference positions and indicate whether a three-dimensional point corresponding to a reference position corresponding to the first information item is present.

Abstract: A three-dimensional data encoding method includes: obtaining geometry information which includes first three-dimensional positions on a measurement target, and is generated by a measurer that radially emits an electromagnetic wave in different directions and obtains a reflected wave which is the electromagnetic wave that is reflected by the measurement target; generating a two-dimensional image including first pixels corresponding to the directions, based on the geometry information; and encoding the two-dimensional image to generate a bitstream. Each of the first pixels has a pixel value indicating a first three-dimensional position or attribute information of a three-dimensional point which is included in a three-dimensional point cloud and corresponds to a direction to which the first pixel corresponds among the directions.

Abstract: An encoding method for encoding three-dimensional points each having a position represented by a distance and an angle, the encoding method comprising: identifying three-dimensional points that belong to a second processing unit and have been encoded, for inter prediction of a first three-dimensional point belonging to a first processing unit; and selecting a reference three-dimensional point from the three-dimensional points identified to calculate an inter predicted value of the first three-dimensional point. The three-dimensional points identified include a second three-dimensional point and a third three-dimensional point, the second three-dimensional point having a second angle corresponding to a first angle of the first three-dimensional point, the third three-dimensional point having a third angle greater than the second angle.

Abstract: A transmission method includes: generating a frame for transfer which stores one or more first internet protocol (IP) packets storing content, and one or more second IP packets each including reference clock information which indicates a time for a playback of the content; and transmitting the generated frame through broadcasting. In the generating, header compression is performed on the one or more first IP packets and the header compression is not performed on the one or more second IP packets.

Abstract: A three-dimensional data encoding method uses a first encoding scheme and a second encoding scheme different from the first encoding scheme, and includes: (i) transforming a first quantization parameter to a first scale value or (ii) transforming the first scale value to the first quantization parameter, based on a first table indicating a correspondence between values of the first quantization parameter and values of the first scale value and being shared between the first encoding scheme and the second encoding scheme; performing encoding including a first quantization process to generate encoded attribute information, the first quantization process being a process of dividing, by the first scale value, each of first coefficient values based on items of attribute information of three-dimensional points included in point cloud data; and generating a bitstream including the encoded attribute information and the first quantization parameter.

Abstract: A three-dimensional data encoding method includes: (i) in a first case where a layered structure is generated by classifying three-dimensional points into layers: encoding attribute information for the three-dimensional points based on the layered structure; and generating a bitstream including layer information utilized for the generation of the layered structure; and (ii) in a second case where the three-dimensional points are not classified: encoding attribute information for the three-dimensional points; and generating a bitstream not including the layer information.

Abstract: A three-dimensional data encoding method includes: encoding, for each of second units, information about positions of three-dimensional points included in a first unit, to generate encoded data items, the second units being smaller than the first unit that is an encoding unit; and outputting the encoded data items. Each of the encoded data items includes no individual additional information. The encoded data items include common additional information. The common additional information includes first information indicating a size of a first encoded data item included in the encoded data items.

Abstract: A three-dimensional data encoding method includes: combining first point cloud data and second point cloud data to generate third point cloud data; and encoding the third point cloud data to generate encoded data. The encoded data includes identification information indicating whether each of three-dimensional points included in the third point cloud data belongs to the first point cloud data or the second point cloud data.

Abstract: A three-dimensional data encoding method includes: determining whether a first valid node count is greater than or equal to a first threshold value predetermined, the first valid node count being a total number of valid nodes that are nodes each including a three-dimensional point, the valid nodes being included in first nodes belonging to a layer higher than a layer of a current node in an N-ary tree structure of three-dimensional points included in point cloud data, N being an integer greater than or equal to 2; and, when the first valid node count is greater than or equal to the first threshold value, performing first encoding on attribute information of the current node, the first encoding including a prediction process in which second nodes are used, the second nodes including a parent node of the current node and belonging to a same layer as the parent node.

Abstract: A three-dimensional data encoding method includes: encoding a first flag indicating whether a node having a parent node different from a parent node of a current node is to be referred to in encoding of the current node included in an n-ary tree structure of three-dimensional points included in three-dimensional data; selecting a coding table from N coding tables according to occupancy states of neighboring nodes of the current node, and performing arithmetic encoding on information of the current node using the coding table selected, when the first flag indicates that the node is to be referred to; and selecting a coding table from M coding tables according to the occupancy states of the neighboring nodes of the current node, and performing arithmetic encoding on information of the current node using the coding table selected, when the first flag indicates that the node is not to be referred to.

Abstract: A three-dimensional data encoding method includes: when combine coding including (i) combining pieces of point cloud data to generate combined point cloud data and (ii) encoding the combined point cloud data is performed: setting first information to a first value, and generating a bitstream including the first information set, the first information indicating whether there is a possibility that each leaf node includes three-dimensional points, the first value indicating that there is the possibility that the leaf node includes the three-dimensional points; and when the combine coding is not performed: setting the first information to the first value or a second value, and generating a bitstream including the first information set, the second value indicating that there is no possibility that the leaf node includes the three-dimensional points.

Abstract: A three-dimensional data encoding method includes: encoding geometry information of each of three-dimensional points based on one of a first geometry information encoding method of encoding using octree division and a second geometry information encoding method of encoding without using octree division; and generating a bitstream including the geometry information encoded and a geometry information flag indicating whether the encoding was performed based on the first geometry information encoding method or the second geometry information encoding method. In the generating of the bitstream: when the encoding is performed based on the first geometry information encoding method, the bitstream including a parameter set used in octree division is generated; and when the encoding is performed based on the second geometry information encoding method, the bitstream not including the parameter set used for octree division is generated.

Abstract: A transmitting method according to one aspect of the present disclosure includes transmitting a first stream, the first stream including: timing update identification information id1 indicating whether or not a correspondence relationship between a first reference clock and a second reference clock has been updated, the first reference clock being used to transmit and receive the first stream, and the second reference clock being used to transmit and receive a second stream related to another content to be reproduced in synchronization with the content related to the first stream; a first time according to the first reference clock; and a second time according to the second reference clock, the second time being associated with the first time based on the updated correspondence relationship.