Systems, methods and apparatus for processing visual media data are described. One example method includes performing a conversion between visual media data and a visual media file including one or more tracks storing one or more bitstreams of the visual media data according to a format rule; wherein the format rule specifies whether a first element indicative of whether a track contains a bitstream corresponding to a specific output layer set controls whether a second element indicative of a chroma format of the track and/or a third element indictive of a bit depth information of the track is included in a configuration record of the track.

A media stream receiver is provided for scalable physical layer flow of packetized media streams. The media stream receiver replicates the processing block in time, rather than in hardware, through the use of a single shared memory and pointer alignment calculations, which combines multiple buffering stages as the single, shared memory buffer to offer redundancy and alignment, while acting as a receiver buffer to account for packet delay variations. By doing so the media stream receiver can perform a vertical interval switch between received media streams.

Disclosed are multiple methods and multiple apparatus e media data, and multiple methods and multiple apparatus for media data transmitting, media data processing, reference picture request processing and reference picture specifying. By means of the method to produce media data, the method for media data transmitting, and the method for media data processing, the synchronization and correct processing and transmission of bitstreams are ensured on the basis of dependency relation between video layer bitstream and library layer bitstream, and correct bitstream is highly efficiently provided to a decoder. By means of the method for reference picture request processing and reference picture specifying, a current picture is provided with a library picture set in which the library picture does not belong to the random access segment to which the current picture belongs and the previously most adjacent random access segment, and correct decoding of the current picture is ensured and repeated downloading of library pictures is avoided, thus ensuring the correct decoding and highly efficient transmission of a bitstream produced by library-based video coding method, and increasing transmission efficiency and storage efficiency.

Generating a media file, by generating a first data structure assigning a subset of samples of a track to one or more sample groups, each sample of the subset comprising one or more network abstraction layer (NAL) units; generating a second data structure for describing each of the one or more sample groups, the first and second data structures comprising a first grouping type indicating a mapping between NAL units and the one or more sample groups, the second data structure associating a sample group identifier to a NAL unit; generating a third data structure for describing a tile region, the third data structure comprising a second grouping type indicating that the samples of the track comprise one or more tile regions; and, generating a media file including the samples and including a metadata part, the metadata part comprising the first, second and third data structures, and the metadata part comprising a reference grouping type for linking the second and third data structures.

A block-request streaming system provides for improvements in the user experience and bandwidth efficiency of such systems, typically using an ingestion system that generates data in a form to be served by a conventional file server (HTTP, FTP, or the like), wherein the ingestion system intakes content and prepares it as files or data elements to be served by the file server. A client device can be adapted to take advantage of the ingestion process. The client device might be configured to optimize use of resources, given the information available to it from the ingestion system. This may include configurations to determine the sequence, timing and construction of block requests based on monitoring buffer size and rate of change of buffer size, use of variable sized requests, mapping of block requests to underlying transport connections, flexible pipelining of requests, and/or use of whole file requests based on statistical considerations.

A media stream receiver is provided for scalable physical layer flow of packetized media streams. The media stream receiver replicates the processing block in time, rather than in hardware, through the use of a single shared memory and pointer alignment calculations, which combines multiple buffering stages as the single, shared memory buffer to offer redundancy and alignment, while acting as a receiver buffer to account for packet delay variations. By doing so the media stream receiver can perform a vertical interval switch between received media streams.

Playing video in a format that matches user device includes downloading a video from a server; loading the video into a player; checking if the video contains metadata specifying resolution and crop parameters that matches user device; if metadata is found, then identifying a frame from the video and define a focus point in center of frame; limiting view of the frame and reduce/enlarge video resolution inside viewzone based on the metadata or data; displaying viewzone so that vertical dimension of the viewzone matches a vertical dimension of the user device, and the focus point remains in the center of the frame and in the center of the user device; upon user rotation of the user device, re-displaying the frame such that the focus point remains in the center of the device, and a horizontal dimension of the viewzone matches a horizontal dimension of user device; and continuing rendering subsequent frames of the video, layers and effects.

A system and method are provided of minimizing network bandwidth used from an external network by client peers in a local network. The method can include the operation of organizing a plurality of clients each having media streamlets and a client parent in a structure within the local network. Mapping information propagates through the structure. The mapping information represents local streamlet locations as stored by the plurality of clients. Another operation is retrieving a local streamlet from a client identified in the mapping information as having the local streamlet for the requesting client.

A method for encapsulating encoded media data corresponding to a wide view of a scene, the method comprising:

obtaining a projected picture from the wide view of the scene;

splitting the projected picture into at least one sub-picture;

encoding the at least one sub-picture into a plurality of tracks;

generating descriptive metadata associated with the encoded tracks, the descriptive metadata comprise a first information associated with each track being indicative of a spatial relationship between the at least one sub-picture encoded in the track and a reference picture;

wherein the descriptive metadata further comprises a second information indicating the reference picture.

A video decoder may be configured to output layers of video data according to layers specified in an output layer set mode as well as based on the actual layers received in an access unit. Accordingly, the video coder may be configured to output layers actually received rather than restart a video bitstream in situations where the layers actually received do not match the layers specified in the output layer set mode. In another example, a video encoder may disable inter prediction when the sub-picture ID of a sub-picture in a currently coded picture does not match the sub-picture ID of a sub-picture in a reference picture.