Coding MCTS-nested SEI messages to exclude other SEI messages that are not MCTS-nested

A device for decoding video data, the device comprising:

• a memory configured to store video data;
• and
• one or more processors implemented in circuitry and configured to:
• decode a received supplemental enhancement information (SEI) network abstraction layer (NAL) unit of a video bitstream including the video data, the SEI NAL unit, as received by the device, containing a motion constrained tile sets (MCTS) nesting SEI message, the video bitstream conforming to a video coding standard, the video coding standard imposing a restriction on the video bitstream that the video bitstream as received by the device will not contain any non-MCTS-nesting SEI messages when the video bitstream as received by the device contains a respective MCTS nesting SEI message;
• determine, based on the restriction imposed on the video bitstream by the video coding standard, that the SEI NAL unit, as received by the device, does not contain any non-MCTS-nesting SEI messages in response to the SEI NAL unit containing the MCTS nesting SEI message;
• and
• decode subsequent SEI messages of the received SEI NAL unit as MCTS nesting SEI messages in response to the determination.

A device for decoding video data, the device comprising:

• means for decoding a received supplemental enhancement information (SEI) network abstraction layer (NAL) unit of a video bitstream, the SEI NAL unit, as received by the device, containing a motion constrained tile sets (MCTS) nesting SEI message, the video bitstream conforming to a video coding standard, the video coding standard imposing a restriction on the video bitstream that the video bitstream as received by the device will not contain any non-MCTS-nesting SEI messages when the video bitstream as received by the device contains a respective MCTS nesting SEI message;
• means for determining, based on the restriction imposed on the video bitstream by the video coding standard, that the SEI NAL unit, as received by the device, does not contain any non-MCTS-nesting SEI messages in response to the SEI NAL unit containing the MCTS nesting SEI message;
• and
• means for decoding subsequent SEI messages of the received SEI NAL unit as MCTS nesting SEI messages in response to the determination.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause a processor of a device to:

• decode a received supplemental enhancement information (SEI) network abstraction layer (NAL) unit of a video bitstream, the SEI NAL unit, as received by the device, containing a motion constrained tile sets (MCTS) nesting SEI message, the video bitstream conforming to a video coding standard, the video coding standard imposing a restriction on the video bitstream that the video bitstream as received by the device will not contain any non-MCTS-nesting SEI messages when the video bitstream as received by the device contains a respective MCTS nesting SEI message;
• determine, based on the restriction imposed on the video bitstream by the video coding standard, that the SEI NAL unit, as received by the device, does not contain any non-MCTS-nesting SEI messages in response to the SEI NAL unit containing the MCTS nesting SEI message;
• and
• decode subsequent SEI messages of the received SEI NAL unit as MCTS nesting SEI messages in response to the determination.