Abstract: This application provides a media data transmission method and apparatus. The method includes: receiving, by a client, a media presentation description (MPD) file, where the MPD file includes priority indication information, and the priority indication information is used to indicate a priority or priorities of one or more overlays; and processing, by the client, the one or more overlays based on the priority indication information.

Abstract: File formats and parsing and coding of video data are defined to promote more efficient random accessibility of coded video data. Constraints may be imposed on placement of parameter sets and the definition of sync samples in video files. Parameter set data for video data may be coded, for a non-sync sample, only in the sample entry for the sample, the sample, a previous sample in decoding order that is a sync sample, or in a sample occurring in decoding order between the sample and the previous sample in decoding order that is a sync sample.

Abstract: A video coding mechanism for viewpoint dependent video coding is disclosed. The mechanism includes receiving a spherical video signal stitched from multiple directional video streams. The spherical video signal is mapped into a plurality of sub-picture video signals each containing a sequence of sub-pictures. The plurality of sub-picture video signals, are encoded as a plurality of sub-picture bitstreams, such that, when decoded at a decoder, a value of each sample in each sub-picture is identical to a value of a corresponding sample in a decoded entire picture composed from the sub-pictures. The plurality of sub-picture bitstreams are composed into a plurality of sub-picture tracks with an indication that the sub-picture tracks are conforming to a particular video profile. The sub-picture bitstreams are transmitted toward a decoder to support decoding and displaying virtual reality video viewport.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a current picture and a reference picture list syntax structure (ref_pic_list_struct( )) comprising a number of reference entries (num_ref_entries) constrained to a range of zero to a maximum decoded picture buffer size plus an offset. The current picture is decoded based on the ref_pic_list_struct( ) to produce a decoded picture.

Abstract: A method of decoding includes receiving a bitstream having a plurality of layers and a video parameter set (VPS), where the VPS includes a direct reference layer flag, where the direct reference layer flag equal to a first value specifies that a second layer is not a direct reference layer for a first layer, and where the direct reference layer flag equal to a second value specifies that the second layer is the direct reference layer for the first layer; deriving a reference layer flag by: initially setting the reference layer flag to the first value; and updating the reference layer flag to the second value when the direct reference layer flag has the second value; and decoding a picture from the first layer in accordance with the reference layer flag to obtain a decoded picture.

Abstract: A method implemented by a video decoder and comprising: receiving, by the video decoder, a video bitstream comprising a picture and loop_filter_across_subpic_enabled_flag, wherein the picture comprises a subpicture; and applying a deblocking filter process to all subblock edges and transform block edges of the picture except edges that coincide with boundaries of the subpicture when loop_filter_across_subpic_enabled_flag is equal to 0. A method implemented by a video decoder and comprising: receiving, by the video decoder, a video bitstream comprising a picture, EDGE_VER, and loop_filter_across_subpic_enabled_flag, wherein the picture comprises a subpicture; and setting filterEdgeFlag to 0 if edgeType is equal to the EDGE_VER, a left boundary of a current coding block is a left boundary of the subpicture, and the loop_filter_across_subpic_enabled_flag is equal to 0.

Abstract: An apparatus comprises an encoder configured to obtain point clouds, generate a first field that implements prediction type signaling of the point clouds, generate a second field that implements temporal order signaling of the point clouds, and encode the first field and the second field into an encoded bitstream; and an output interface coupled to the encoder and configured to transmit the encoded bitstream. An apparatus comprises a receiver configured to receive an encoded bitstream; and a processor coupled to the encoded bitstream and configured to decode the encoded bitstream to obtain a first field and second field, wherein the first field implements prediction type signaling of point clouds, and wherein the second field implements temporal order signaling of the point clouds, and generate the point clouds based on the first field and the second field.

Abstract: A mechanism for processing video data is disclosed. Video decoder initialization information (DII) is determined. The DII includes data describing a maximum level (MaxLevel) to which all coded video sequences (CVSs) of the bitstream conform and a maximum format that comprises one or more parameters. The MaxLevel indicates a first maximum DPB size needed for decoding the bitstream. The maximum format indicates a second maximum DPB size, denoted as DPB memory for as maximum format (DpbMemory4MaxFormat), determined by simultaneously setting all parameters of the maximum format to largest values. The DII further comprises a first indication of whether the DpbMemory4MaxFormat exceeds the first maximum DPB size. A conversion is performed between a visual media data and a bitstream based on the indication.

Abstract: A method is implemented by a PCC decoder and comprises: receiving, by the PCC decoder, a point cloud bitstream; performing, by the PCC decoder, buffering of the point cloud bitstream based on a time, the performing comprising determining the time based on a delay and a delay offset; and decoding, by the PCC decoder, the point cloud bitstream based on the buffering. A method is implemented by a PCC decoder and comprises: receiving, by the PCC decoder, a point cloud bitstream; performing, by the PCC decoder, buffering of the point cloud bitstream based on a delay, the delay is based on a first delay and a second delay; and decoding, by the PCC decoder, the point cloud bitstream based on the buffering.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a plurality of layers having sublayers and a video parameter set (VPS) including a first flag having a first value, wherein the first flag having the first value specifies that temporal identifiers (IDs) of a highest sublayer representation for level information, decoded picture buffer (DPB) parameters, and hypothetical decoder refresh (HRD) parameters are not present in the VPS and are inferred to be equal to a maximum number of the sublayers that may be present in a layer of the plurality of layers specified by the VPS; obtaining the level information, the HRD parameters, and the DPB parameters corresponding to the temporal ID of the highest sublayer representation from the VPS; and decoding a picture from one of the plurality of layers to obtain a decoded picture. A corresponding method of encoding is also provided.

Abstract: A method of decoding is provided. The method includes receiving a sub-bitstream having a sequence parameter set (SPS) with a profile tier level (PTL) syntax structure for an output layer set (OLS) with only one layer; setting a number of layers in the OLS equal to one based on the OLS having the only one layer; obtaining the PTL syntax structure for the OLS with the only one layer from the SPS when the number of layers in the OLS has been set equal to one; and decoding a picture from the only one layer using the PTL syntax structure to obtain a decoded picture. A corresponding method of encoding is also provided.

Abstract: A method of decoding is provided. The method includes receiving a sub-bitstream having a sequence parameter set (SPS) with a decoded picture buffer (DPB) syntax structure for an output layer set (OLS) with only one layer; setting a number of layers in the OLS equal to one based on the OLS having the only one layer; obtaining the DPB syntax structure for the OLS with the one layer from the SPS when the number of layers in the OLS has been set equal to one; and decoding a picture from the only one layer using the DPB syntax structure to obtain a decoded picture. A corresponding method of encoding is also provided.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding a coded layer video sequence (CLVS) for a layer in a bitstream. A sequence parameter set (SPS) referred to by the CLVS is also encoded into the bitstream. The SPS is constrained to have a network abstraction layer (NAL) unit header layer identifier (nuh_layer_id) value equal to a nuh_layer_id value of the CLVS when the layer does not use inter-layer prediction. The bitstream is stored for communication toward a decoder.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a sequence parameter set (SPS) including a SPS video parameter set identifier (sps_video_parameter_set_id). The bitstream also comprises a coded picture in a set of video coding layer (VCL) network abstraction layer (NAL) units associated with a layer having a NAL unit header layer identifier (nuh_layer_id). A general layer index corresponding to the nuh_layer_id (GeneralLayerIdx[nuh_layer_id]) is set equal to zero when the sps_video_parameter_set_id is equal to zero. The coded picture is decoded from the VCL NAL units based on the GeneralLayerIdx[nuh_layer_id] to produce a decoded picture The decoded picture is forwarded for display as part of a decoded video sequence.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), where the PU includes a picture header (PH) network abstraction layer (NAL) unit preceding a first video coding layer (VCL) NAL unit, and decoding a coded picture from the PU to obtain a decoded picture.

Abstract: According to certain aspects, an apparatus for coding video information includes a memory and a processor configured to determine whether a first syntax element is present in a bitstream, the first syntax element associated with a sequence parameter set (SPS) and a first flag indicative of whether a temporal identifier (ID) of a reference picture for pictures that refer to the SPS can be nested; and in response to determining that the first syntax element is not present in the bitstream: obtain a second syntax element indicative of a maximum number of temporal sub-layers in a particular layer of the plurality of layers; and determine whether to set the first flag equal to a second flag indicative of whether a temporal ID of a reference picture for any pictures can be nested based at least in part on a value of the second syntax element.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding a plurality of sublayer representations into a bitstream. Hypothetical reference decoder (HRD) parameters and a sublayer coding picture buffer (CPB) parameters present flag (sublayer_cpb_params_present_flag) are also encoded into the bitstream. The HRD parameters for all sublayer representations with temporal identifiers (TemporalIds) less than a maximum TemporalId are inferred to be equal to the HRD parameters for a maximum sublayer representation with the maximum TemporalId when the sublayer_cpb_params_present_flag is set to zero. A set of bitstream conformance tests is performed on the bitstream based on the HRD parameters. The bitstream is stored for communication toward a decoder.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), where any decoding capability information (DCI) network abstraction layer (NAL) unit, video parameter set (VPS) NAL unit, sequence parameter set (SPS) NAL unit, or picture parameter set (PPS) NAL unit referred to by the PU precedes a picture header (PH) NAL unit of the PU and a first video coding layer (VCL) NAL unit of the PU; and decoding a coded picture from the PU to obtain a decoded picture.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding a bitstream comprising one or more output layer sets (OLSs). A video parameter set (VPS) specifying the OLS is also encoded into the bitstream. The VPS comprises sequence-level hypothetical reference decoder (HRD) parameters that apply to all OLSs specified by the VPS. A set of bitstream conformance tests are performed based on the sequence-level HRD parameters. The bitstream is stored for communication toward a decoder.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), where a gradual decoding refresh (GDR) flag in a picture header (PH) of the PU has a first value to specify that a picture associated with the PH is a GDR picture; and decoding the GDR picture from the PU to obtain a decoded picture.