Layered random access with reference picture resampling

A device for decoding an encoded video bitstream, the device comprising:

• at least one memory configured to store program code;
• and
• at least one processor configured to read the program code and operate as instructed by the program code, the program code including:
• first obtaining code configured to cause the at least one processor to obtain from the encoded video bitstream a coded base layer picture included in a layered random access (LRA) access unit, and a coded enhancement layer picture included in the LRA access unit;
• determining code configured to cause the at least one processor to determine whether a random access occurs at the LRA access unit;
• first generating code configured to cause the at least one processor to, based on the random access not occurring at the LRA access unit, generate a reconstructed base layer picture by reconstructing the coded base layer picture, and generate a reconstructed enhancement layer picture by reconstructing the coded enhancement layer picture using the reconstructed base layer picture and the previously reconstructed picture;
• second generating code configured to cause the at least one processor to, based on the random access occurring at the LRA access unit:
• generate the reconstructed base layer picture by reconstructing the coded base layer picture, and
• based on the coded enhancement layer picture depending on the previously reconstructed picture and the previously reconstructed picture being unavailable, generate the reconstructed enhancement layer picture by upsampling the reconstructed base layer picture;
• and
• output code configured to cause the at least one processor to output the reconstructed enhancement layer picture.

A non-transitory computer-readable medium storing instructions, the instructions comprising:

• one or more instructions that, when executed by one or more processors of a device for decoding an encoded video bitstream, cause the one or more processors to:
• obtain from the encoded video bitstream a coded base layer picture included in a layered random access (LRA) access unit, and a coded enhancement layer picture included in the LRA access unit, wherein the coded enhancement layer picture depends on a previously reconstructed picture;
• determine whether a random access occurs at the LRA access unit;
• based on the random access not occurring at the LRA access unit, generate a reconstructed base layer picture by reconstructing the coded base layer picture, and generate a reconstructed enhancement layer picture by reconstructing the coded enhancement layer picture using the reconstructed base layer picture and the previously reconstructed picture;
• based on the random access occurring at the LRA access unit:
• generate the reconstructed base layer picture by reconstructing the coded base layer picture, and
• based on the coded enhancement layer picture depending on the previously reconstructed picture and the previously reconstructed picture being unavailable, generate the reconstructed enhancement layer picture by upsampling the reconstructed base layer picture;
• and
• output the reconstructed enhancement layer picture.