System and method for intra prediction in video coding

1. A user equipment, comprising:

a transceiver configured to receive an encoded bitstream of video; and

a decoder comprising processing circuitry configured to:

identify a first intra mode associated with a top prediction unit (PU) in relation to a current PU of the encoded bitstream of video;

identify a second intra mode associated with a left PU in relation to the current PU; and

determine a plurality of most probable modes (MPMs) based on the first intra mode and the second intra mode,

wherein a number of modes is greater than thirty-five;

wherein the first or second intra mode is greater than two, and

wherein the plurality of MPMs is given by:

MPM[0]=a selected mode of one of the first or second intra modes that is greater than two;

MPM[1]=2+(the selected mode+61) % 64); and

MPM[2]=2+(the selected mode−1) % 64).

2. The user equipment of claim 1 , wherein the number of the MPMs is sixty-five.

3. The user equipment of claim 1 , wherein the decoder is further configured to:

decode information indicating whether an intra mode of the current PU is equal to one of the MPMs; and

when the intra mode of the current PU is not equal to any of the plurality of MPMs, determine a remaining intra mode by comparing the intra mode of the current PU to the plurality of MPMs, wherein the remaining intra mode is coded using six bits.

4. The user equipment of claim 3 , wherein the decoder is further configured to:

determine a new remaining intra mode, wherein the new remaining intra mode is given by:

new_rem_intra_luma_pred_mode=(rem_intra_luma_pred_mode−MPM[2]+16) & 0x3F,

where new_rem_intra_luma_pred_mode is the new remaining intra mode, where rem_intra_luma_pred_mode is the remaining intra mode, and where MPM[2] is a one of the plurality of MPMs, and

wherein at least one bin of the new_rem_intra_luma_pred_mode is coded using Context-adaptive binary arithmetic coding (CABAC).

5. The user equipment of claim 1 , wherein the decoder is further configured to:

determine a block size of the current PU;

when the block size is 8, perform intra smoothing using a [1 2 1]/4 filter; and

when the block size is 16 or 32, perform intra smoothing using a [1 2 2 2 1]/8 filter or [1 2 3 4 3 2 1]/16 filter.

6. The user equipment of claim 5 , wherein the [1 2 2 2 1]/8 filter is given by:

y ( n )=(1* x ( n− 2)+2* x ( n− 1)+2* x ( n )++2* x ( n+ 1)+1* x ( n+ 2)+4)>>3.

7. The user equipment of claim 5 , wherein the [1 2 3 4 3 2 1]/16 filter is given by:

y ( n )=(1* x ( n− 3)+2* x ( n− 2)+3* x ( n− 1)+4* x ( n )++3* x ( n+ 1)+2* x ( n+ 2)+1* x ( n+ 3)+8)>>4.

8. The user equipment of claim 1 , wherein the transceiver is further configured to receive a set of angles, where the set of angles is one of a set of all new angles or a set of partially new angles.

9. The user equipment of claim 1 , wherein the decoder is further configured to:

perform intra smoothing using two levels of reference samples.

10. A method for decoding a bitstream of video, comprising:

receiving an encoded bitstream of video; and

identifying a first intra mode associated with a top prediction unit (PU) in relation to a current PU of the encoded bitstream of video;

identifying a second intra mode associated with a left PU in relation to the current PU; and

determining a plurality of most probable modes (MPMs) based on the first intra mode and the second intra mode,

wherein a number of modes is greater than thirty-five;

wherein the first or second intra mode is greater than two, and

wherein the plurality of MPMs is given by:

MPM[0]=a selected mode of one of the first or second intra modes that is greater than two;

MPM[1]=2+(the selected mode+61) % 64); and

MPM[2]=2+(the selected mode−1) % 64).

11. The method of claim 10 , wherein the number of the MPMs is sixty-five.

12. The method of claim 10 , further comprising:

decoding information indicating whether an intra mode of the current PU is equal to one of the MPMs; and

when the intra mode of the current PU is not equal to any of the plurality of MPMs, determining a remaining intra mode by comparing the intra mode of the current PU to the plurality of MPMs, wherein the remaining intra mode is coded using six bits.

13. The method of claim 12 , further comprising:

determining a new remaining intra mode, wherein the new remaining intra mode is given by:

new_rem_intra_luma_pred_mode=(rem_intra_luma_pred_mode−MPM[2]+16) & 0x3F,

where new_rem_intra_luma_pred_mode is the new remaining intra mode, where rem_intra_luma_pred_mode is the remaining intra mode, and where MPM[2] is a one of the plurality of MPMs, and

wherein at least one bin of the new_rem_intra_luma_pred_mode is coded using Context-adaptive binary arithmetic coding (CABAC).

14. The method of claim 10 , further comprising:

determining a block size of the current PU;

when the block size is 8, perform intra smoothing using a [1 2 1]/4 filter; and

when the block size is 16 or 32, perform intra smoothing using a [1 2 2 2 1]/8 filter or [1 2 3 4 3 2 1]/16 filter.

15. The method of claim 14 , wherein the [1 2 2 2 1]/8 filter is given by:

y ( n )=(1* x ( n− 2)+2* x ( n− 1)+2* x ( n )++2* x ( n+ 1)+1* x ( n+ 2)+4)>>3.

16. The method of claim 14 , wherein the [1 2 3 4 3 2 1]/16 filter is given by:

y ( n )=(1* x ( n− 3)+2* x ( n− 2)+3* x ( n− 1)+4* x ( n )++3* x ( n+ 1)+2* x ( n+ 2)+1* x ( n+ 3)+8)>>4.

17. The method of claim 10 , further comprising:

receiving a set of angles, where the set of angles is one of a set of all new angles or a set of partially new angles.

18. The method of claim 10 , further comprising:

performing intra smoothing using two levels of reference samples.