Abstract: A video coding mechanism is disclosed. The mechanism includes receiving at a decoder, a bitstream including a video coding layer (VCL) network abstraction layer (NAL) unit containing a slice of image data divided into a plurality of tiles. A number of the tiles in the VCL NAL unit are determined. A number of entry point offsets for the tiles is also determined as one less than the number of the tiles in the VCL NAL unit. Each entry point offset indicates a starting location of a corresponding tile in the VCL NAL unit. The number of entry point offsets is not explicitly signaled in the bitstream. The entry point offsets for the tiles are obtained based on the number of entry point offsets. The tiles are decoded at the entry point offsets to generate a reconstructed image.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising an adaptive loop filter (ALF) adaptation parameter set (APS) including an ALF luma filter signal flag (alf_luma_filter_signal_flag) and a ALF chroma filter signal flag (alf_chroma_filter_signal_flag), wherein at least one of the alf_luma_filter_signal_flag or the alf_chroma_filter_signal_flag is equal to one. A slice is decoded based on ALF parameters in the ALF APS. The slice is forwarded for display as part of a decoded video sequence.

Abstract: A method of decoding a coded video bitstream is provided. The method includes receiving a bitstream containing an external decoder refresh (EDR) picture and a list of pictures for the EDR picture. The list of pictures lists pictures referred to by entries in a first reference picture list, pictures referred to by entries in a second reference picture list, and external pictures in increasing decoding order. A difference between picture order count values for any two consecutive pictures in the list of pictures is greater than one half of a negative of maximum picture order count least significant bits and less than one half of the maximum picture order count least significant bits. The method further includes obtaining an external picture from the the external pictures referred to in the list of pictures and decoding the EDR picture using the external picture that was obtained.

Abstract: A method of decoding includes receiving a first picture parameter set and a second picture parameter set each referring to same sequence parameter set, the first picture parameter set and the second picture parameter set having same values of a conformance window when the first picture parameter set and the second picture parameter set have same values of picture width and picture height, and applying the conformance window to a current picture corresponding to the first picture parameter set or the second picture parameter set.

Abstract: In general, the disclosure to techniques for regional random access within a picture of video data. For example, a video coding device receives a plurality of pictures in a coding order. Each respective picture of the plurality of pictures comprises a plurality of regions. For a first region in a first picture of the plurality of pictures, the video coding device determines that the first region is codable independent from each other region of the first picture and from a first region in a second picture preceding the first picture in the coding order and, responsive to making such a determination, determine that the first region in the first picture has random accessibility. The video coding device codes each video block in the first region independent from any video blocks outside of the first region.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a current picture including a plurality of video coding layer (VCL) network abstraction layer (NAL) units that do not have a same NAL unit type. Active entries of reference picture lists are obtained for slices positioned in a sub-picture A (subpicA) in subsequent pictures following the current picture in decoding order. The active entries do not refer to any reference picture preceding the current picture in decoding order when the subpicA at the current picture is associated with an intra-random access point (IRAP) NAL unit type. The subsequent pictures are decoded based on the reference picture list active entries. The subsequent pictures are forwarded for display as part of a decoded video sequence.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving an extracted bitstream that is a result of a sub-bitstream extraction process from an input bitstream containing a set of sub-pictures. The extracted bitstream contains only a subset of the sub-pictures of the input bitstream to the sub-bitstream extraction process. A flag from the extracted bitstream is set to indicate that sub-picture information related to the subset of the sub-pictures is present in the extracted bitstream. One or more sub-picture identifiers (IDs) for the subset of the sub-pictures are obtained based on the flag. The subset of the sub-pictures is decoded based on the sub-picture IDs.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding a sequence of point cloud compression (PCC) components into a bitstream. A buffering period supplemental enhancement information (SEI) message is also encoded into the bitstream. A hypothetical reference decoder (HRD) is initialized at a coded atlas access unit (AU) associated with the buffering period SEI message. A HRD conformance check of the bitstream is performed starting at the coded atlas AU. The bitstream is stored for communication toward a decoder.

Abstract: A video coding mechanism is disclosed. The mechanism includes partitioning a picture into a plurality of first level tiles. A subset of the first level tiles is partitioned into a plurality of second level tiles. The first level tiles and the second level tiles are assigned into one or more tile groups such that all tiles in an assigned tile group containing the second level tiles are constrained to cover a rectangular region of the picture. The first level tiles and the second level tiles are encoded into a bitstream. The bitstream is stored for communication toward a decoder.

Abstract: A method of decoding includes receiving the coded video bitstream, the coded video bitstream containing reference picture lists; obtaining reference pictures for a current picture from the reference picture lists; setting a motion vector refinement flag to a first value to enable motion vector refinement for a current block of the current picture when the reference pictures are in a same layer as the current picture; setting the motion vector refinement flag to a second value to disable the motion vector refinement for the current block of the current picture when the reference pictures are in a different layer than the current picture; and refining a motion vector corresponding to the current block when the motion vector refinement flag is set to the first value.

Abstract: A method for decoding a video bitstream. The bitstream comprises coded data for at least one picture, and each picture comprises at least one tile group. The method includes parsing a flag that specifies whether tile information for a coded picture is present in a parameter set or in a tile group header. The tile information indicates which tiles of the picture are included in a tile group. The method parses the tile information from either the parameter set or the tile group header based on the flag. The method obtains the decoded data of the coded picture based on the tile information.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a current picture and a reference picture list structure comprising an inter-layer reference picture flag. The mechanism determines an entry in the reference picture list structure associated with the current picture is an inter-layer reference picture (ILRP) entry based on the inter-layer reference picture flag. The current picture is decoded based on an inter-layer reference picture indicated by the entry in the reference picture list structure when the entry is the ILRP entry. The current picture is forwarded for display as part of a decoded video sequence.

Abstract: A method of decoding includes encountering an end of tile bit with a first value and byte alignment bits in a video bitstream, which indicate that a current coding tree block (CTB) is a last CTB in a tile; encountering an end of CTB row bit with the first value and the byte alignment bits in the video bitstream, which indicate that waveform parallel processing (WPP) is enabled and that the current CTB is the last CTB in a CTB row but not the last CTB in the tile; and reconstructing the plurality of CTBs in the tile based on the end of tile bit with the first value, the end of CTB row bit with the first value, and the byte alignment bits.

Abstract: A method of decoding includes determining, by the video decoder, whether a resolution of a current picture being decoded is the same as the resolution of reference pictures identified by a reference picture list associated with the current picture; enabling, by the video decoder, decoder-side motion vector refinement (DMVR) for a current block of the current picture when the resolution of the current picture is determined to be the same as the resolution of each of the reference pictures; disabling, by the video decoder, the DMVR for the current block of the current picture when the resolution of the current picture is determined to be different than the resolution of either of the reference pictures; and refining, by the video decoder, motion vectors corresponding to the current block using the DMVR when the DMVR flag is enabled for the current block.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a flag and a plurality of coded pictures including an intra random access point (IRAP) picture and one or more non-leading pictures associated with the IRAP picture. When the flag is set to a first value any leading pictures associated with the IRAP picture precede, in decoding order, all non-leading pictures associated with the IRAP picture. When the flag is set to a second value a non-leading picture precedes, in decoding order, an initial leading picture associated with the IRAP picture. The IRAP picture, any leading pictures associated with the IRAP picture, and the one or more non-leading pictures associated with the IRAP picture are decoded in decoding order based on the flag.

Abstract: A method of decoding a coded video bitstream implemented by a video decoder is disclosed. The method includes determining that a coded video sequence (CVS) of the coded video bitstream includes a video coding layer (VCL) network abstraction layer (NAL) unit having a gradual decoding refresh (GDR) network abstraction layer (NAL) unit type (GDR_NUT), the VCL NAL unit having the GDR_NUT containing a GDR picture; initiating decoding of the CVS at the GDR picture; and generating an image according to the CVS as decoded. A corresponding method of encoding is also disclosed.

Abstract: A method of decoding implemented by a video decoder including determining, by the video decoder, whether a resolution of a current picture being decoded is the same as the resolution of reference pictures identified by a reference picture list associated with the current picture; enabling, by the video decoder, bi-direction optical flow (BDOF) for a current block of the current picture when the resolution of the current picture is determined to be the same as the resolution of each of the reference pictures; disabling, by the video decoder, the BDOF for the current block of the current picture when the resolution of the current picture is determined to be different than the resolution of either of the reference pictures; and refining, by the video decoder, motion vectors corresponding to the current block using the BDOF when the BDOF is enabled for the current block.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a flag and a picture including a sub-picture with a sub-picture boundary. The sub-picture is decoded. Filtering operations are performed across the sub-picture boundary when the flag is set to a first value. The filtering operations across the sub-picture boundary are omitted when the flag is set to a second value. The sub-picture is forwarded for display as part of a decoded video sequence.

Abstract: A method of video encoding a sequence of pictures, the method being implemented in an encoding device and comprising: obtaining an intra prediction picture comprising at least two sub-units; obtaining a first encoded other picture, wherein the intra prediction picture and the first encoded other picture have the same Picture Order Count, POC, value; obtaining encoded other pictures different from the intra prediction picture and the first encoded other picture; and distributing the at least two sub-units of the intra prediction picture over one or more sub-units of the encoded other pictures and/or over one or more sub-units of the first encoded other picture.

Abstract: A method of decoding a coded video bitstream implemented by a video decoder is provided. The method includes the video decoder determining whether a value for a first flag is provided by an external input; setting a first flag equal to the value provided by the external input and a second flag equal to the value of the first flag to prevent a gradual decoding refresh (GDR) picture from being output when the value for the first flag is provided by the external input; decoding the GDR picture; and storing the GDR picture in a decoded picture buffer (DPB).