Size based transform unit context derivation

1. An apparatus, comprising:

circuitry to:

determine a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame,

determine a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein to determine a context index value, the circuitry is to determine a value of 5−log 2(TU size); and

determine a transform split flag based at least in part on the determined context index value.

2. The apparatus of claim 1 , wherein the determination of the context index value is performed as part of a context adaptive entropy coding operation to determine one or more transform split flags.

3. The apparatus of claim 1 , wherein the determination of the context index value is performed as part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

4. The apparatus of claim 1 , wherein the context index value comprises one of three potential values.

5. The apparatus of claim 1 , wherein the circuitry is to:

determine a split flag of 1 when the transform unit has a size in excess of 32×32, and wherein the split flag of 1 is not explicitly provided in a bitstream; and

determine a split flag of 0 when the transform unit has a size of 4×4, and wherein the split flag of 0 is not explicitly provided in a bitstream.

6. The apparatus of claim 1 , wherein the circuitry is to:

determine a split flag of 1 when the transform unit has a size in excess of a first size, and wherein the split flag of 1 is not explicitly provided in a bitstream; and

determine a split flag of 0 when the transform unit has a second size, and wherein the split flag of 0 is not explicitly provided in a bitstream.

7. The apparatus of claim 1 , wherein the circuitry is to:

determine a context index value of 0 when the transform unit has a size of 32×32;

determine a context index value of 1 when the transform unit has a size of 16×16; and

determine a context index value of 2 when the transform unit has a size of 8×8.

8. The apparatus of claim 1 , wherein the circuitry is to:

determine a split flag of 1 when the transform unit has a size in excess of 32×32, and wherein the split flag of 1 is not explicitly provided in a bitstream;

determine a split flag of 0 when the transform unit has a size of 4×4, and wherein the split flag of 0 is not explicitly provided in a bitstream;

determine a context index value of 0 when the transform unit has a size of 32×32;

determine a context index value of 1 when the transform unit has a size of 16×16; and

determine a context index value of 2 when the transform unit has a size of 8×8.

9. The apparatus of claim 1 , wherein circuitry comprises hardware, firmware, software executed by a processor, or any combination thereof.

10. The apparatus of claim 1 , further comprising a video encoder and wherein the circuitry is part of the video encoder.

11. The apparatus of claim 1 , further comprising a video decoder and wherein the circuitry is part of the video decoder.

12. The apparatus of claim 1 , wherein:

the CU comprises a partition of a picture and

the TU comprises a whole or part of the CU.

13. The apparatus of claim 12 , wherein:

the TU comprises a square shaped region.

14. A system comprising:

a display;

an antenna configured to receive an encoded bitstream of video data;

a memory to store the bitstream;

a processor communicatively coupled to the display, antenna, and memory; and

decoder circuitry to:

determine a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame,

determine a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein to determine a context index value, the circuitry is to determine a value of 5−log 2(TU size); and

determine a transform split flag based at least in part on the determined context index value.

15. The system of claim 14 , wherein the determination of the context index value is performed as part of a context adaptive entropy coding operation to determine one or more transform split flags.

16. The system of claim 14 , wherein the determination of the context index value is performed as part of an entropy Context-adaptive binary arithmetic coding (CABAC) of transform split flags to determine one or more transform split flags.

17. The system of claim 14 , wherein the context index value comprises one of three potential values.

18. The system of claim 14 , wherein the circuitry is to:

determine a split flag of a value of 1 when the transform unit has a size in excess of a first size, and wherein the split flag of 1 is not explicitly provided in the bitstream and

determine a split flag value of 0 when the transform unit has a second size, and wherein the split flag value of 0 is not explicitly provided in the bitstream.

19. The system of claim 14 , wherein the circuitry is to:

determine a context index value of 0 when the transform unit has a size of 32×32;

determine a context index value of 1 when the transform unit has a size of 16×16; and

determine a context index value of 2 when the transform unit has a size of 8×8.

20. The system of claim 14 , wherein the circuitry is to:

determine a split flag of 1 when the transform unit has a size in excess of 32×32, and wherein the split flag of 1 is not explicitly provided in the bitstream;

determine a split flag of 0 when the transform unit has a size of 4×4, and wherein the split flag of 0 is not explicitly provided in the bitstream;

determine a context index value of 0 when the transform unit has a size of 32×32;

determine a context index value of 1 when the transform unit has a size of 16×16; and

determine a context index value of 2 when the transform unit has a size of 8×8,

wherein the determination of the context index value is performed as part of a context adaptive entropy coding operation to determine one or more transform split flags, and

wherein the context index value comprises one of three potential values.

21. The apparatus of claim 14 , wherein:

the CU comprises a partition of a picture and

the TU comprises a whole or part of the CU.

22. At least one non-transitory article comprising a computer program stored thereon having instructions that, if executed by the computer, cause the computer to: determine a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame; determine a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein to determine a context index value, the computer is to determine a value of 5−log 2(TU size); and determine a transform split flag based at least in part on the determined context index value.

23. The non-transitory article of claim 22 , wherein the determination of the context index value is performed as part of a context adaptive entropy coding operation to determine one or more transform split flags.

24. The non-transitory article of claim 22 , wherein the determination of the context index value is performed as part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

25. The non-transitory article of claim 22 , wherein the context index value comprises one of three potential values.

26. The non-transitory article of claim 22 , further comprising instructions stored thereon, that, if executed by the computer, cause the computer to: determine a split flag of a value of 1 when the transform unit has a size in excess of a first size, and wherein the split flag of 1 is not explicitly provided in a bitstream; and determine a split flag value of 0 when the transform unit has a second size, and wherein the split flag value of 0 is not explicitly provided in a bitstream.

27. The non-transitory article of claim 22 , further comprising instructions stored thereon, that, if executed by the computer, cause the computer to: determine a context index value of 0 when the transform unit has a size of 32.times.32; determine a context index value of 1 when the transform unit has a size of 16.times.16; and determine a context index value of 2 when the transform unit has a size of 8.times.8.

28. The non-transitory article of claim 22 , further comprising instructions stored thereon, that, if executed by the computer, cause the computer to: determine a split flag of 1 when the transform unit has a size in excess of 32.times.32, and wherein the split flag of 1 is not explicitly provided in a bitstream; determine a split flag of 0 when the transform unit has a size of 4.times.4, and wherein the split flag of 0 is not explicitly provided in a bitstream; determine a context index value of 0 when the transform unit has a size of 32.times.32; determine a context index value of 1 when the transform unit has a size of 16.times.16; and determine a context index value of 2 when the transform unit has a size of 8.times.8, wherein the determination of the context index value is performed as part of a context adaptive entropy coding operation to determine one or more transform split flags, and wherein the context index value comprises one of three potential values.

29. The non-transitory article of claim 22 , wherein: the CU comprises a partition of a picture and the TU comprises a whole or part of the CU.

30. A computer-implemented method, the method comprising:

determining a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame,

determining a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein determining a context index value comprises determining a value of 5−log 2(TU size); and

determining a transform split flag based at least in part on the determined context index value.

31. The method of claim 30 , wherein the context index value comprises one of three potential values.

32. The method of claim 30 , wherein determining the context index value is part of a context adaptive entropy coding operation to determine one or more transform split flags.

33. The method of claim 30 , wherein determining the context index value is part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

34. The method of claim 30 , further comprising:

determining a split flag of a value of 1 when the transform unit has a size in excess of a first size, and wherein the split flag of 1 is not explicitly provided in a bitstream; and

determining a split flag value of 0 when the transform unit has a second size, and wherein the split flag value of 0 is not explicitly provided in a bitstream.

35. The method of claim 30 , further comprising:

determining a context index value of 0 when the transform unit has a size of 32×32;

determining a context index value of 1 when the transform unit has a size of 16×16; and

determining a context index value of 2 when the transform unit has a size of 8×8.

36. The method of claim 30 , wherein:

the CU comprises a partition of a picture and

the TU comprises a whole or part of the CU.

37. An apparatus, comprising:

circuitry to:

determine a region size for a node of a region quadtree, the region associated with a second region and the region associated with a video frame,

determine a context index value associated with an individual node of the region quadtree based at least in part on the region size, wherein to determine a context index value, the circuitry is to determine a value of 5−log 2(region size); and

determine a split flag based at least in part on the determined context index value.

38. The apparatus of claim 37 , wherein

the region comprises a transform unit (TU),

the second region comprises a coding unit (CU),

the CU comprises a partition of a picture, and

the TU comprises a whole or part of the CU.

39. The apparatus of claim 37 , wherein the determination of the context index value is performed as part of a context adaptive entropy coding operation to determine one or more transform split flags.

40. The apparatus of claim 37 , wherein the determination of the context index value is performed as part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

41. The apparatus of claim 37 , wherein the context index value comprises one of three potential values.