Method and system for single loop multilayer coding with subpicture partitioning

1. A versatile video coding (VVC) method, comprising:

obtaining a plurality of video sources;

encoding a bitstream of the plurality of video sources, the bitstream including a plurality of independent layers corresponding to the plurality of video sources;

generating signaling information on the plurality of independent layers and integrating the signaling information with the bitstream; and

transferring the bitstream for decoding processing, wherein the signaling information is to be used in the decoding process to enable a single decoder instance to decode the plurality of independent layers, wherein the signaling information includes at least a video parameter set (VPS), and the VPS includes:

a parameter vps_max_layers_minus1 greater than 0, which specifies a number of the layers in the plurality of independent layers;

a flag vps_all_independent_layers_flag equal to 1, which specifies that the plurality of independent layers are independently coded; and

a flag inbl_one_pic_per_poc_flag equal to 1, which specifies that the bitstream comprises independent layers and there is one and only one coded picture with a particular picture order count (POC) value in a same coded video sequence (CVS) among all layers, and indicates that a profile-tier-level and hypothetical-reference-decoder (HRD) parameters apply collectively to the plurality of independent layers.

2. The method according to claim 1 , wherein: the plurality of independent layers are independently coded region layers; the signaling information further includes an independently-coded-region-layer supplemental-enhancement-information (SEI) message, a parameter set or a metadata track; and the independently-coded-region-layer SEI message, the parameter set or the metadata track includes layout information of independently coded region layers.

3. The method according to claim 2 , wherein the layout information in the independently-coded-region-layer SEI message, the parameter set, or the metadata track includes: a parameter composed_pic_width_in_luma samples specifying a width of a picture composed by one or more independently coded regions in units of luma samples, a parameter composed_pic_height_in_luma samples specifying a height of a picture composed by one or more independently coded regions in units of luma samples, and a parameter num_independent_regions_in_pic_minus1 indicating a number of the independently coded regions in a picture.

4. The method according to claim 2 , wherein the layout information in the independently-coded-region-layer SEI message, the parameter set, or the metadata track includes: parameters boundary_identifier_north, boundary_identifier_east, boundary_identifier_south, and boundary_identifier_west specifying for each layer a identifier respectively at a north, east, south, and west boundary of a decoded picture of each layer within an output picture.

5. The method according to claim 1 , wherein: the plurality of independent layers are independently coded region layers; the signaling information further includes an independently-coded-region-layer supplemental-enhancement-information (SEI) message; and the independently-coded-region-layer SEI message includes mapping information to connect each independently coded region to each layer.

6. The method according to claim 1 , wherein: the signaling information includes an independent layer set nesting SEI message; and the independent layer set nesting SEI message is for carrying SEI messages that apply collectively to the plurality of independent layers of the bitstream, including a buffering period SEI message and a picture timing SEI message that apply to the bitstream.

7. The method according to claim 1 , wherein: the signaling information includes a picture parameter set (PPS); and the PPS includes a conformance window parameters SEI message for each subpicture corresponding to the plurality of independent layers and for specifying a size and a location of a decoded picture of each subpicture.

8. The method according to claim 7 , wherein the conformance window parameters SEI message includes: a flag subpic conformance_window_flag equal to 1, indicating that subpicture conformance cropping window offset parameters follow next in the SEI message; and parameters subpic_conf_win_left_offset, subpic_conf_win_right_offset, subpic_conf_win_top_offset, and subpic_conf_win_bottom_offset for each subpicture to specify coordinates of a rectangular region of each subpicture or cropped from each subpicture.

9. The method according to claim 1 , wherein: the signaling information includes a picture parameter set (PPS); and the PPS includes a subpicture-level output window SEI message for each subpicture corresponding to the plurality of independent layers and for specifying a location of a subpicture output cropping window of each subpicture.

10. The method according to claim 9 , wherein the subpicture-level output window SEI message includes: a flag subpic output window flag equal to 1 indicating that subpicture output cropping window offset parameters follow next in the SEI message; and parameters subpic_conf_win_left_offset, subpic_conf_win_right_offset, subpic_conf_win_top_offset, and subpic_conf_win_bottom_offset for each subpicture to specify coordinates of a rectangular region of the subpicture output cropping window of each subpicture.

11. A versatile video coding (VVC) method, comprising:

obtaining a bitstream of a plurality of video sources, the bitstream including a plurality of independent layers corresponding to the plurality of video sources, and signaling information on the plurality of independent layers integrated with the bitstream;

decoding the bitstream by using a single decoder instance to decode the plurality of independent layers, based on the signaling information, to generate decoded output video contents integrating the plurality of video sources; and

rendering the decoded output video contents using the signaling information, wherein the signaling information includes at least a video parameter set (VPS), and the VPS includes:

a parameter vps_max_layers_minus1 greater than 0, which specifies a number of the layers in the plurality of independent layers; a flag vps_all_independent_layers_flag equal to 1, which specifies that the plurality of independent layers are independently coded; and

a flag inbl_one_pic_per_poc_flag equal to 1, which specifies that the bitstream contains independent layers and there is one and only one coded picture with a particular picture order count (POC) value in a same coded video sequence (CVS) among all layers, and indicates that a profile-tier-level and hypothetical-reference-decoder (HRD) parameters apply collectively to the plurality of independent layers.

12. The method according to claim 11 , wherein: the plurality of independent layers are independently coded region layers; the signaling information further includes an independently-coded-region-layer supplemental-enhancement-information (SEI) message, a parameter set or a metadata track; and the independently-coded-region-layer SEI message, the parameter set or the metadata track includes layout information of independently coded region layers.

13. The method according to claim 12 , wherein the layout information in the independently-coded-region-layer SEI message, the parameter set, or the metadata track includes: a parameter composed_pic_width_in_luma samples specifying a width of a picture composed by one or more independently coded regions in units of luma samples, a parameter composed_pic_height_in_luma samples specifying a height of a picture composed by one or more independently coded regions in units of luma samples, and a parameter num_independent_regions_in_pic_minus1 indicating a number of the independently coded regions in a picture.

14. The method according to claim 12 , wherein the layout information in the independently-coded-region-layer SEI message, the parameter set, or the metadata track includes: parameters boundary_identifier_north, boundary_identifier_east, boundary_identifier_south, and boundary_identifier_west specifying for each layer a identifier respectively at a north, east, south, and west boundary of a decoded picture of each layer within an output picture.

15. The method according to claim 11 , wherein: the plurality of independent layers are independently coded region layers; the signaling information further includes an independently-coded-region-layer supplemental-enhancement-information (SEI) message; and the independently-coded-region-layer SEI message includes mapping information to connect each independently coded region to each layer.

16. The method according to claim 11 , wherein: the signaling information includes an independent layer set nesting SEI message; and the independent layer set nesting SEI message is for carrying SEI messages that apply collectively to the plurality of independent layers of the bitstream, including a buffering period SEI message and a picture timing SEI message that apply to the bitstream.

17. The method according to claim 11 , wherein: the signaling information includes a picture parameter set (PPS); and the PPS includes a conformance window parameters SEI message for each subpicture corresponding to the plurality of independent layers and for specifying a size and a location of a decoded picture of each subpicture.

18. The method according to claim 17 , wherein the conformance window parameters SEI message includes: a flag subpic conformance_window_flag equal to 1, indicating that subpicture conformance cropping window offset parameters follow next in the SEI message; and parameters subpic_conf_win_left_offset, subpic_conf_win_right_offset, subpic_conf_win_top_offset, and subpic_conf_win_bottom_offset for each subpicture to specify coordinates of a rectangular region of each subpicture or cropped from each subpicture.

19. The method according to claim 11 , wherein: the signaling information includes a picture parameter set (PPS); and the PPS includes a subpicture-level output window SEI message for each subpicture corresponding to the plurality of independent layers and for specifying a location of a subpicture output cropping window of each subpicture.

20. The method according to claim 19 , wherein the subpicture-level output window SEI message includes: a flag subpic output window flag equal to 1 indicating that subpicture output cropping window offset parameters follow next in the SEI message; and parameters subpic_conf_win_left_offset, subpic_conf_win_right_offset, subpic_conf_win_top_offset, and subpic_conf_win_bottom_offset for each subpicture to specify coordinates of a rectangular region of the subpicture output cropping window of each subpicture.