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 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: 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 storage method includes: acquiring one or more units in which an encoded stream generated by encoding point cloud data is stored; and storing the one or more units into a file. The storing includes storing, in control information for the file, information indicating that data stored in the file is data generated by encoding the point cloud data.

Abstract: A three-dimensional data encoding method includes: calculating a predicted value of a position of a three-dimensional point according to one of inter prediction and intra prediction; calculating a residual between the predicted value and the position; arithmetic-encoding the residual using a first context when the predicted value is calculated according to the inter prediction; and arithmetic-encoding the residual using a second context different from the first context when the predicted value is calculated according to the intra prediction. The residual is expressed by third residual information indicating a bit count of the residual.

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: performing motion compensation on a plurality of encoded point clouds; merging the plurality of encoded point clouds that have been motion compensated to generate a reference point cloud; generating an N-ary tree structure of a current point cloud, where N is an integer greater than or equal to 2; and encoding the N-ary tree structure of the current point cloud using the reference point cloud.

Abstract: A transmitting method stores data making up a coded stream into a predetermined data unit and transmits the stored data in the predetermined data unit. The transmitting method further generates presentation time information indicating a presentation time of the predetermined data unit, based on reference time information received from an external source; and transmits the predetermined data unit, first control information which includes the generated presentation time information, and second control information which includes leap second information indicating whether or not the presentation time information is a time that is before a leap second adjustment. A receiving method receives the predetermined data unit, first control information, and second control information; and reproduces the received predetermined data unit based on the first and second control information that are received.

Abstract: A three-dimensional data encoding method includes: determining a first three-dimensional point that is encoded and has a position represented by a first polar coordinate system having a first position as a reference; and determining (i) a distance between the first position and a second position, (ii) a first angle formed by a first line connecting the first position and the second position and a second line connecting the first position and the first three-dimensional point, and (iii) a first distance from the first position to the first three-dimensional point in the first polar coordinate system, to calculate a prediction value of a second distance from the second position to a second three-dimensional point that is not yet encoded and has a position represented by a second polar coordinate system having the second position as a reference.

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: obtaining second attribute information obtained by transforming first attribute information of a three-dimensional point in at least one frame among frames, the frames constituting a sequence; and encoding the second attribute information to generate a bitstream. The transforming is different from quantization, and the bitstream further includes: at least one first parameter provided for the sequence for the transforming; and at least one second parameter provided for each of the at least one frame for the transforming.

Abstract: A three-dimensional data storage method includes: acquiring one or more units in which an encoded stream generated by encoding point cloud data is stored; and storing the one or more units into a file. The storing includes storing, in control information for the file, information indicating that data stored in the file is data generated by encoding the point cloud data.

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.

Abstract: A transmitting method according to one aspect of the present disclosure includes transmitting video control information for reproduction of video data having an individually reproducible unit, transmitting the video data, determining a transmission order of audio control information for reproduction of audio data in a reproduction interval corresponding to a reproduction interval of the video data in such a way that the audio control information is transmitted after the video control information, and transmitting the audio control information according to the determined transmission order, and transmitting the audio data. Thus, in the receiving apparatus, a delay time from reception of data to reproduction of video and audio is shortened.

Abstract: A three-dimensional data encoding method includes: encoding first information of a first current node or second information of a second current node, the first current node being included in an N-ary tree structure of first three-dimensional points included in a first three-dimensional point cloud, N being 2 or 4, the second current node being included in an octree structure of second three-dimensional points included in a second three-dimensional point cloud The encoding of the first information or the second information includes encoding the first information using a first encoding pattern including a pattern common to a second encoding pattern used in encoding the second information.

Abstract: A transmitting method for transmitting contents using a broadcast wave and a communication path comprises: including content information in application control information when transmitting the contents using both the broadcast wave and the communication path, the content information being information for synchronizing a content transmitted by using the broadcast wave with a content transmitted by using the communication path at a reception side that receives the contents and being related to the content transmitted by using the communication path; and transmitting the application control information by using at least the broadcast wave in the broadcast wave and the communication path. As a result, a contents transmitting method is provided for enabling a quick access to contents through communication when the contents are reproduced by a combination of broadcast and communication on the receiving side.

Abstract: A three-dimensional data encoding method includes: obtaining third point cloud data that is a combination of first point cloud data and second point cloud data, and includes geometry information of each of three-dimensional points included in the third point cloud data, and identification information indicating which of the first point cloud data and the second point cloud data each of the three-dimensional points belongs to; and generating encoded data by encoding the third point cloud data obtained. In the generating, identification information of each of the three-dimensional points is encoded as attribute information.

Abstract: A three-dimensional data encodes method of encoding three-dimensional data items in time series. Each of the three-dimensional data items includes a geometry information item and an attribute information item in association with a same time point. The three-dimensional data encoding method includes: first encoding of encoding the geometry information item; and second encoding of encoding the attribute information item with reference to the geometry information item associated with the same time point. The geometry information item and the attribute information item that are in association with the same time point are included in an access unit.

Abstract: A three-dimensional data encoding method includes: encoding divided data items to generate encoded data items each corresponding to a respective one of the divided data items, the divided data items being included in subspaces obtained by dividing a current space including three-dimensional points, the divided data items each including one or more three-dimensional points among the three-dimensional points; and generating a bitstream including the encoded data items and control information items each corresponding to a respective one of the encoded data items. Each of the control information items includes a first identifier and a second identifier. The first identifier indicates a subspace corresponding to an encoded data item corresponding to the control information item, and the second identifier indicates a divided data item corresponding to the encoded data item corresponding to the control information item.

Abstract: A three-dimensional data encoding method includes: encoding pieces of attribute information of respective three-dimensional points, using parameters; and generating a bitstream including the pieces of attribute information encoded, control information, and pieces of first attribute control information. The control information corresponds to the pieces of attribute information and includes pieces of type information each indicating a type of different attribute information, the pieces of first attribute control information correspond one-to-one with the pieces of attribute information, and each of the pieces of first attribute control information includes first identification information indicating that the first attribute control information is associated with one of the pieces of type information.