Sub-prediction unit temporal motion vector prediction (sub-PU TMVP) for video coding
Aspects of the disclosure provide a video coding method for processing a current prediction unit (PU) with a sub-PU temporal motion vector prediction (TMVP) mode. The method can include receiving the current PU including sub-PUs, determining an initial motion vector that is a motion vector of a spatial neighboring block of the current PU, performing a searching process to search for a main collocated picture in a sequence of reference pictures of the current PU based on the initial motion vector, and obtaining collocated motion information in the main collocated picture for the sub-PUs of the current PU. The searching process can include turning on motion vector scaling operation for searching a subset of the sequence of reference pictures, and turning off the motion vector scaling operation for searching the other reference pictures in the sequence of reference pictures.
1. A video coding method for processing a current prediction unit (PU) with a sub-PU temporal motion vector prediction (TMVP) mode, comprising:
receiving the current PU including sub-PUs;
determining a main collocated picture;
determining an initial motion vector for said sub-PUs;
determining collocated sub-PUs in the main collocated picture according to the initial motion vector; and
obtaining collocated motion information of the collocated sub-PUs in the main collocated picture for deriving motion vectors of the sub-PUs of the current PU.
2. The video coding method of claim 1 , wherein the main collocated picture is a temporal collocated picture.
3. The video coding method of claim 1 , wherein said collocated sub-PUs are temporal collocated sub-PUs.
4. The video coding method of claim 1 , wherein the collocated motion information of the collocated sub-PUs comprises motion vectors and associated reference indexes of said collocated sub-PUs.
5. The video coding method of claim 1 , wherein the main collocated picture is determined by an encoder side.
6. The video coding method of claim 1 , wherein the main collocated picture is pre-determined.
7. The video coding method of claim 1 , further comprising signaling or parsing the main collocated picture.
8. The video coding method of claim 7 , wherein the signaling or parsing is in sequence level, picture level, slice level or prediction unit (PU) level.
9. The video coding method of claim 1 , wherein the main collocated picture associates with the initial motion vector.
10. A video coding apparatus for processing a current prediction unit (PU) with a sub-PU temporal motion vector prediction (TMVP) mode, comprising circuitry configured to:
receive the current PU including sub-PUs;
determining a main collocated picture;
determine an initial motion vector for said sub-PUs that is a motion vector of a spatial neighboring block of the current PU;
determine collocated sub-PUs in the main collocated picture according to the initial motion vector; and
obtain collocated motion information of the collocated sub-PUs in the main collocated picture for deriving motion vectors of the sub-PUs of the current PU.
11. The video coding apparatus of claim 10 , wherein the main collocated picture is a temporal collocated picture.
12. The video coding apparatus of claim 10 , wherein said collocated sub-PUs are temporal collocated sub-PUs.
13. The video coding apparatus of claim 10 , wherein the collocated motion information of the collocated sub-PUs comprises motion vectors and associated reference indexes of said collocated sub-PUs.
14. The video coding apparatus of claim 10 , wherein the main collocated picture is determined by an encoder side.
15. The video coding apparatus of claim 10 , wherein the main collocated picture is pre-determined.
16. The video coding apparatus of claim 10 , wherein the circuitry is further configured to:
signal or parse the main collocated picture.
17. The video coding apparatus of claim 16 , wherein the signaling or parsing is in sequence level, picture level, slice level or prediction unit (PU) level.
18. The video coding apparatus of claim 10 , wherein the main collocated picture associates with the initial motion vector.
19. A non-transitory computer-readable medium storing instructions which, when executed by a processor, cause the processor to perform a video coding method for processing a current prediction unit (PU) with a sub-PU temporal motion vector prediction (TMVP) mode, the method comprising:
receiving the current PU including sub-PUs;
determining a main collocated picture;
determining an initial motion vector for said sub-PUs;
determining collocated sub-PUs in the main collocated picture based on the initial motion vector; and
obtaining collocated motion information of the collocated sub-PUs in the main collocated picture for deriving motion vectors of the sub-PUs of the current PU.