Video coding and decoding methods and devices using a library picture bitstream

A method, comprising:

• encoding a video picture by referencing a library picture corresponding to a library picture bitstream to obtain encoded data, wherein the video picture is allowed to be encoded by referencing the library picture;
• and
• adding a first flag to the encoded data to obtain a video bitstream;
• wherein the first flag is set to a first value and indicates that a value of a target parameter in a sequence header of the video bitstream is used as a value of a target parameter of the library picture bitstream;
• wherein the video bitstream references the library picture bitstream;
• wherein the target parameter in the sequence header of the video bitstream comprises first decoding capability information of the video bitstream, wherein the first decoding capability information comprises a profile flag indicating a profile that comprises the video bitstream and a level flag indicating a level that comprises the video bitstream;
• and
• wherein the library picture bitstream comprises second decoding capability information corresponding to the profile flag and the level flag.

A device, comprising:

• a memory configured to store instructions;
• and
• a processor coupled to the memory, wherein the processor is configured to execute the instructions to facilitate the following being performed by the device:
• obtaining a library picture flag from a current bitstream;
• setting the current bitstream as a video bitstream based on the library picture flag indicating that the video bitstream is not a library picture bitstream;
• parsing, from the video bitstream, a library picture reference flag that indicates whether the video bitstream is allowed to be decoded by referencing a library picture corresponding to the library picture bitstream;
• based on the library picture reference flag indicating that the video bitstream is allowed to be decoded by referencing the library picture, parsing a first flag from the video bitstream;
• and
• based on the first flag having a first value:
• setting a value of a target parameter in a sequence header of the video bitstream as a value of a second target parameter of the library picture bitstream, and reconstructing the library picture based on the value of the target parameter of the library picture bitstream.

A device, comprising:

• a memory configured to store instructions;
• and
• a processor coupled to the memory, wherein the processor is configured to execute the instructions to facilitate the following being performed by the device:
• encoding a video picture by referencing a library picture corresponding to a library picture bitstream to obtain encoded data, wherein the video picture is allowed to be encoded by referencing the library picture;
• and
• adding a first flag to the encoded data to obtain a video bitstream,
• wherein the first flag is set to a first value and indicates that a value of a target parameter in a sequence header of the video bitstream is used as a value of a target parameter of the library picture bitstream;
• wherein the video bitstream references the library picture bitstream;
• wherein the target parameter in the sequence header of the video bitstream comprises first decoding capability information of the video bitstream, wherein the first decoding capability information comprises a profile flag indicating a profile that comprises the video bitstream and a level flag indicating a level that comprises the video bitstream;
• and
• wherein the library picture bitstream comprises second decoding capability information corresponding to the profile flag and the level flag.