Prioritizing tile-based virtual reality video streaming using adaptive rate allocation

A system for streaming virtual reality videos, the system comprising:

• one or more computer-readable memories comprising a spherical video;
• and
• at least one computing device configured to cause the system to:
• receive viewport information from a client device comprising a current viewport location;
• partition a three-dimensional (3D) sphere mesh into a plurality of 3D mesh segments that comprises a 3D top spherical cap, a 3D bottom spherical cap, and a set of 3D middle mesh segments;
• partition, based on the plurality of 3D mesh segments, a spherical video into a plurality of 3D tiles by dividing the spherical video into a 3D top spherical cap tile, a 3D bottom spherical cap tile, and a set of four 3D middle tiles;
• determine an available bandwidth to stream the plurality of 3D tiles;
• assign the plurality of 3D tiles to priority levels based on a distance from each tile to the current viewport location;
• and
• stream the plurality of 3D tiles to the client device by streaming:
• 3D tiles at a lowest priority level at, at least, a minimum bit rate to provide a predetermined minimum video quality, and
• 3D tiles at a highest priority level at a maximum bit rate determined by a difference between the available bandwidth and a minimum bandwidth required to stream the plurality of 3D tiles at the minimum bit rate.

A system for streaming virtual reality videos, the system comprising:

• one or more computer-readable memories comprising a panorama video;
• and
• at least one computing device configured to cause the system to:
• receive a current viewport location of a client device;
• partition a three-dimensional (3D) sphere mesh into a plurality of 3D mesh segments that comprises a 3D top spherical cap, a 3D bottom spherical cap, and a set of 3D middle mesh segments;
• partition, based on the plurality of 3D mesh segments, a panorama video into a plurality of 3D tiles by dividing the panorama video into a hexaface sphere comprising a 3D top spherical cap tile, a 3D bottom spherical cap tile, and a set of four 3D middle tiles;
• determine an available bandwidth to stream the plurality of 3D tiles;
• assign the plurality of 3D tiles to priority levels based on a distance from each 3D tile to the current viewport location;
• and
• stream the plurality of 3D tiles to the client device by streaming:
• 3D tiles at a lowest priority level at, at least, a minimum bit rate to provide a predetermined minimum video quality, and
• 3D tiles at a highest priority level at a maximum bit rate determined by a difference between the available bandwidth and a minimum bandwidth required to stream the plurality of 3D tiles at the minimum bit rate.