Methods and apparatus to reduce latency during viewport switching in immersive video

A non-transitory computer readable storage medium comprising instructions to cause at least one programmable circuit to at least:

• obtain a first bitstream having a first encoded frame and a second encoded frame encoded at a higher resolution than the first encoded frame, the first encoded frame and the second encoded frame both corresponding to an entire view of an immersive video, the second encoded frame having a coding dependency on the first encoded frame;
• rewrite the first bitstream into a second bitstream based on field of view information, the second bitstream including the first encoded frame and a third encoded frame, the third encoded frame corresponding to a portion of the second encoded frame, the portion of the second encoded frame corresponding to a field of view smaller than the entire view, the field of view specified by the field of view information;
• and
• cause transmission of the second bitstream to a client device to decode and render the portion of the second encoded frame.

A method comprising:

• obtaining a first bitstream having a first encoded frame and a second encoded frame encoded at a higher resolution than the first encoded frame, the first encoded frame and the second encoded frame both corresponding to an entire view of an immersive video, the second encoded frame having a coding dependency on the first encoded frame;
• rewriting the first bitstream into a second bitstream based on field of view information, the second bitstream including the first encoded frame corresponding to the entire view of the immersive video and a third encoded frame corresponding to a portion of the second encoded frame, the portion of the second encoded frame corresponding to a field of view smaller than the entire view, the field of view specified by the field of view information;
• and
• transmitting the second bitstream to a client device for decoding and rendering the portion of the second encoded frame.