Video Coding Using Multi-resolution Reference Picture Management

A video encoding apparatus comprising:

• a memory;
• and
• one or more processors coupled with the memory and configured to:
• obtain a list of reference pictures comprising a plurality of pictures stored in a buffer, wherein the plurality of pictures comprising at least a first picture with a first spatial resolution, and a second picture with a second spatial resolution different from the first spatial resolution;
• obtain a reference picture from the list of reference pictures;
• obtain a predicted current picture by using the reference picture with its original spatial resolution without ensuring the reference picture to have a same spatial resolution as the current picture;
• and
• generate a bitstream based on a predicted current picture.

A non-transitory computer readable medium storing a bitstream, wherein the bitstream is generated by performing operations comprising:

• obtaining a list of reference pictures comprising a plurality of pictures stored in a buffer, wherein the plurality of pictures comprising at least a first picture with a first spatial resolution, and a second picture with a second spatial resolution different from the first spatial resolution;
• obtaining a reference picture from the list of reference pictures;
• obtaining a predicted current picture by using the reference picture with its original spatial resolution without ensuring the reference picture to have a same spatial resolution as the current picture;
• and
• generating a bitstream based on a predicted current picture.