Intra filtering flag in video coding

1. A method of decoding video data, the method comprising:

receiving a first block of video data, the first block being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

receiving a first syntax element indicating whether a position dependent intra prediction combination (PDPC) coding mode is to be used for the first block of video data;

explicitly decoding a value of the received first syntax element;

applying the PDPC coding mode to the first block of video data in accordance with the value of the first syntax element;

receiving a second block of video data, the second block being associated with a second number of non-zero transform coefficients less than the threshold;

inferring a value of a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data; and

applying the PDPC coding mode in accordance with the inferred value of the second syntax element.

2. The method of claim 1 , wherein receiving the first syntax element further comprises receiving the first syntax element based on an intra prediction mode used to encode the first block of video data.

3. The method of claim 1 , wherein receiving the first syntax element further comprises receiving the first syntax element in the case that the first block of video data is larger than or equal to a predetermined size.

4. The method of claim 1 , wherein the threshold is one of 1, 2, or 3 non-zero coefficients.

5. The method of claim 1 , wherein the first number of non-zero transform coefficients includes the first number of non-zero transform coefficients for both luma and chroma components of the first block of video data.

6. The method of claim 1 , wherein the first block of video data includes a luma block of video data, and wherein the first number of non-zero transform coefficients include the first number of non-zero transform coefficients for the luma block of video data.

7. The method of claim 1 , wherein the first block of video data is not a transform skip block.

8. The method of claim 1 , further comprising:

determining a context for decoding the first syntax element based on an intra prediction mode used to encode the first block of video data; and

decoding the first syntax element using the determined context.

9. A method of encoding video data, the method comprising:

determining whether to use a position dependent intra prediction combination (PDPC) coding mode for encoding a first block of video data;

explicitly encoding a first syntax element indicating whether the PDPC coding mode is to be used for the first block of video data based on the first block of video data being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

signaling the first syntax element in an encoded video bitstream;

determining whether to use the PDPC coding mode for encoding a second block of video data; and

not encoding a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data based on the second block of video data being associated with a second number of non-zero transform coefficients less than the threshold.

10. The method of claim 9 , wherein explicitly encoding the first syntax element further comprises explicitly encoding the first syntax element based on an intra prediction mode used to encode the first block of video data.

11. The method of claim 9 , wherein explicitly encoding the first syntax element further comprises explicitly encoding the first syntax element in the case that the first block of video data is larger than or equal to a predetermined size.

12. The method of claim 9 , wherein the threshold is one of 1, 2, or 3 non-zero coefficients.

13. The method of claim 9 , wherein the first number of non-zero transform coefficients includes the first number of non-zero transform coefficients for both luma and chroma components of the first block of video data.

14. The method of claim 9 , wherein the first block of video data includes a luma block of video data, and wherein the first number of non-zero transform coefficients include the first number of non-zero transform coefficients for the luma block of video data.

15. The method of claim 9 , wherein the first block of video data is not a transform skip block.

16. The method of claim 9 , further comprising:

determining a context for encoding the first syntax element based on an intra prediction mode used to encode the first block of video data; and

encoding the first syntax element using the determined context.

17. An apparatus configured to decode video data, the apparatus comprising:

a memory configured to store the video data; and

one or more processors in communication with the memory, the one or more processors configured to:

receive a first block of the video data, the first block being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

receive a first syntax element indicating whether a position dependent intra prediction combination (PDPC) coding mode is to be used for the first block of video data;

explicitly decode a value of the received first syntax element;

apply the PDPC coding mode to the first block of the video data in accordance with the value of the first syntax element;

receive a second block of video data, the second block being associated with a second number of non-zero transform coefficients less than the threshold;

infer a value of a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data; and

apply the PDPC coding mode in accordance with the inferred value of the second syntax element.

18. The apparatus of claim 17 , wherein to receive the first syntax element, the one or more processors are further configured to receive the first syntax element based on an intra prediction mode used to encode the first block of the video data.

19. The apparatus of claim 17 , wherein to receive the first syntax element, the one or more processors are further configured to receive the first syntax element in the case that the first block of the video data is larger than or equal to a predetermined size.

20. The apparatus of claim 17 , wherein the threshold is one of 1, 2, or 3 non-zero coefficients.

21. The apparatus of claim 17 , wherein the first number of non-zero transform coefficients includes the first number of non-zero transform coefficients for both luma and chroma components of the first block of video data.

22. The apparatus of claim 17 , wherein the first block of video data includes a luma block of video data, and wherein the first number of non-zero transform coefficients include the first number of non-zero transform coefficients for the luma block of video data.

23. The apparatus of claim 17 , wherein the first block of the video data is not a transform skip block.

24. The apparatus of claim 17 , wherein the one or more processors are further configured to:

determine a context for decoding the first syntax element based on an intra prediction mode used to encode the first block of the video data; and

decode the first syntax element using the determined context.

25. An apparatus configured to encode video data, the apparatus comprising:

a memory configured to store the video data; and

one or more processors in communication with the memory, the one or more processors configured to:

determine whether to use a position dependent intra prediction combination (PDPC) coding mode for encoding a first block of video data;

explicitly encode a first syntax element indicating whether the PDPC coding mode is to be used for the first block of video data based on the first block of video data being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

signal the first syntax element in an encoded video bitstream;

determine whether to use the PDPC coding mode for encoding a second block of video data; and

not encode a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data based on the second block of video data being associated with a second number of non-zero transform coefficients less than the threshold.

26. The apparatus of claim 25 , wherein to explicitly encode the first syntax element, the one or more processors are further configured to explicitly encode the first syntax element based on an intra prediction mode used to encode the first block of the video data.

27. The apparatus of claim 25 , wherein to explicitly encode the first syntax element, the one or more processors are further configured to explicitly encode the first syntax element in the case that the first block of the video data is larger than or equal to a predetermined size.

28. The apparatus of claim 25 , wherein the threshold is one of 1, 2, or 3 non-zero coefficients.

29. The apparatus of claim 25 , wherein the first number of non-zero transform coefficients includes the first number of non-zero transform coefficients for both luma and chroma components of the first block of video data.

30. The apparatus of claim 25 , wherein the first block of video data includes a luma block of video data, and wherein the first number of non-zero transform coefficients include the first number of non-zero transform coefficients for the luma block of video data.

31. The apparatus of claim 25 , wherein the first block of the video data is not a transform skip block.

32. The apparatus of claim 25 , wherein the one or more processors are further configured to:

determine a context for encoding the first syntax element based on an intra prediction mode used to encode the first block of the video data; and

encode the first syntax element using the determined context.

33. An apparatus configured to decode video data, the apparatus comprising:

means for receiving a first block of video data, the first block being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

means for receiving a first syntax element indicating whether a position dependent intra prediction combination (PDPC) coding mode is to be used for the first block of video data;

means for explicitly decoding a value of the received first syntax element;

means for applying the PDPC coding mode to the first block of video data in accordance with the value of the first syntax element;

means for receiving a second block of video data, the second block being associated with a second number of non-zero transform coefficients less than the threshold;

means for inferring a value of a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data; and

means for applying the PDPC coding mode in accordance with the inferred value of the second syntax element.

34. An apparatus configured to encode video data, the apparatus comprising:

means for determining whether to use a position dependent intra prediction combination (PDPC) coding mode for encoding a first block of video data;

means for explicitly encoding a first syntax element indicating whether the PDPC coding mode is to be used for the first block of video data based on the first block of video data being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

means for signaling the first syntax element in an encoded video bitstream;

means for determining whether to use the PDPC coding mode for encoding a second block of video data; and

means for not encoding a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data based on the second block of video data being associated with a second number of non-zero transform coefficients less than the threshold.

35. A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to decode video data to:

receive a first block of video data, the first block being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

receive a first syntax element indicating whether a position dependent intra prediction combination (PDPC) coding mode is to be used for the first block of video data;

explicitly decode a value of the received first syntax element;

apply the PDPC coding mode to the first block of the video data in accordance with the value of the first syntax element;

receive a second block of video data, the second block being associated with a second number of non-zero transform coefficients less than the threshold;

infer a value of a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data; and

apply the PDPC coding mode in accordance with the inferred value of the second syntax element.

36. A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to encode video data to:

determine whether to use a position dependent intra prediction combination (PDPC) coding mode for encoding a first block of video data;

explicitly encode a first syntax element indicating whether the PDPC coding mode is to be used for the first block of video data based on the first block of video data being associated with a first number of non-zero transform coefficients greater than or equal to a threshold;

signal the first syntax element in an encoded video bitstream;

determine whether to use the PDPC coding mode for encoding a second block of video data; and

not encode a second syntax element indicating whether the PDPC coding mode is to be used for the second block of video data based on the second block of video data being associated with a second number of non-zero transform coefficients less than the threshold.