Systems and methods for efficient spatial intra predictabilty determination (or assessment)
Techniques for efficient determination of a macroblock's spatial predictability quality with respect to the H.264 specification are provided. A device comprises a processor operable to estimate a first subset of spatial prediction modes based on a first pixel subset of a current subblock of an intra-frame. The processor is also operable to estimate a second subset of spatial prediction modes based on a second pixel subset of the current subblock. The first subset of prediction modes is different from the second subset of prediction modes.
1. A device comprising:
a processor operable to determine a first spatial prediction mode from a first subset of spatial prediction modes based on a first pixel subset of a current subblock of an intra-frame, wherein the first subset of spatial prediction modes includes spatial prediction modes with a vertical directivity, a horizontal directivity, and no clear directivity, and to determine a second spatial prediction mode from a second subset of spatial prediction modes based on a second pixel subset of the current subblock in the case that the first spatial prediction mode is unable to be determined, wherein the second subset of spatial prediction modes includes spatial prediction modes with a diagonal directivity, wherein the first pixel subset is selected from said current subblock and pixels of said first pixel subset are arranged in a rectangular grid arrangement such that adjacent selected pixels in the first pixel subset do not touch each other, and wherein the second pixel subset is also selected from said current subblock and pixels of said second pixel subset are in a diagonal grid arrangement such that only two or more corners of adjacent selected pixels touch the corners of other selected pixels in the diagonal grid arrangement; and
a memory coupled to the processor.
2. The device according to claim 1 , wherein the processor is further operable to interpolate a directivity associated with a third subset of spatial prediction modes different from the first subset of spatial prediction modes and the second subset of spatial prediction modes based on the first and second pixel subsets, wherein the third set of spatial prediction modes includes spatial prediction modes with an oblique directivity, and wherein the processor is further operable to determine a third spatial prediction mode from the third subset of spatial prediction modes based on the interpolated directivity in the case that the first spatial prediction mode and the second spatial prediction mode are unable to be determined.
3. The device according to claim 2 , wherein the first subset of spatial prediction modes is based on a first pair of vectors displaced by 90°; the second subset of spatial prediction modes is based on a second pair of vectors displaced by 90°; and the third subset of spatial prediction modes is based on a plurality of vectors displaced by 22.5° from any one of the first pair of vectors and the second pair of vectors.
4. The device according to claim 1 , wherein the processor, when determining the first spatial prediction mode, is operable to perform a first transform operation on the first pixel subset to derive a first resultant matrix having a pattern of coefficients associated with identifying the first spatial prediction mode and, when determining the second spatial prediction mode, is operable to perform a second transform operation on the second pixel subset to derive a second resultant matrix having the pattern of coefficients associated with identifying the second spatial prediction mode.
5. The device according to claim 4 , wherein the first transform operation and the second transform operation use a Hadamard transform.
6. The device according to claim 1 , wherein the first pixel subset is arranged in a rectangular sampling grid arrangement; the second pixel subset is arranged in a diagonal sampling grid arrangement; and the rectangular sampling grid and the diagonal sampling grid arrangement together form an oblique sampling grid arrangement.
7. The device according to claim 1 , where pixels of the first pixel subset and pixels of the second pixel subset are mutually exclusive.
8. The device according to claim 1 , where pixels of the first pixel subset and pixels of the second pixel subset are partially overlapping.
9. A multimedia system comprising:
an encoder operable to determine a first spatial prediction mode from a first subset of spatial prediction modes based on a first pixel subset of a current subblock of an intra-frame, wherein the first subset of spatial prediction modes includes spatial prediction modes with a vertical directivity, a horizontal directivity, and no clear directivity, and to determine a second spatial prediction mode from a second subset of spatial prediction modes based on a second pixel subset of the current subblock in the case that the first spatial prediction mode is unable to be determined, wherein the second subset of spatial prediction modes includes spatial prediction modes with a diagonal directivity, wherein the first pixel subset is selected from said current subblock and pixels of said first pixel subset are arranged in a rectangular grid arrangement such that adjacent selected pixels in the first pixel subset do not touch each other, and wherein the second pixel subset is also selected from said current subblock and pixels of said second pixel subset are in a diagonal grid arrangement such that only two or more corners of adjacent selected pixels touch the corners of other selected pixels in the diagonal grid arrangement; and
a decoder operable to decode the intra-frame based on the first subset of spatial prediction modes and the second subset of spatial prediction modes.
10. The system according to claim 9 , wherein the encoder is further operable to interpolate a directivity associated with a third subset of spatial prediction modes different from the first subset of spatial prediction modes and the second subset of spatial prediction modes based on the first and second pixel subsets, wherein the third set of spatial prediction modes includes spatial prediction modes with an oblique directivity, and wherein the processor is further operable to determine a third spatial prediction mode from the third subset of spatial prediction modes based on the interpolated directivity in the case that the first spatial prediction mode and the second spatial prediction mode are unable to be determined.
11. The system according to claim 10 , wherein the first subset of spatial prediction modes is based on a first pair of vectors displaced by 90°; the second subset of spatial prediction modes is based on a second pair of vectors displaced by 90°; and the third subset of spatial prediction modes is based on a plurality of vectors displaced by 22.5° from any one of the first pair of vectors and the second pair of vectors.
12. The system according to claim 9 , wherein the encoder, when determining the first spatial prediction mode, is operable to perform a first transform operation on the first pixel subset to derive a first resultant matrix having a pattern of coefficients associated with identifying the first spatial prediction mode and, when determining the second spatial prediction mode, is operable to perform a second transform operation on the second pixel subset to derive a second resultant matrix having the pattern of coefficients associated with identifying the second spatial prediction mode.
13. The system according to claim 12 , wherein the first transform operation and the second transform operation use a Hadamard transform.
14. The system according to claim 9 , wherein the first pixel subset is arranged in a rectangular sampling grid arrangement; the second pixel subset is arranged in a diagonal sampling grid arrangement; and the rectangular sampling grid and the diagonal sampling grid arrangement together form an oblique sampling grid arrangement.
15. The system according to claim 9 , where pixels of the first pixel subset and pixels of the second pixel subset are mutually exclusive.
16. The system according to claim 9 , where pixels of the first pixel subset and pixels of the second pixel subset are partially overlapping.
17. A multimedia system comprising:
means for determining a first spatial prediction mode from a first subset of spatial prediction modes based on a first pixel subset of a current subblock of an intra-frame, wherein the first subset of spatial prediction modes includes spatial prediction modes with a vertical directivity, a horizontal directivity, and no clear directivity;
means for determining a second spatial prediction mode from a second subset of spatial prediction modes based on a second pixel subset of the current subblock in the case that the first spatial prediction mode is unable to be determined, wherein the second subset of spatial prediction modes includes spatial prediction modes with a diagonal directivity, wherein the first pixel subset is selected from said current subblock and pixels of said first pixel subset are arranged in a rectangular grid arrangement such that adjacent selected pixels in the first pixel subset do not touch each other, and wherein the second pixel subset is also selected from said current subblock and pixels of said second pixel subset are arranged in a diagonal grid arrangement such that only two or more corners of adjacent selected pixels touch the corners of other selected pixels in the diagonal grid arrangement; and
means for encoding the intra-frame based on the first spatial prediction mode or, in the case that the first spatial prediction mode is unable to be determined, based on the second spatial prediction mode.
18. The system according to claim 17 , further comprising:
means for interpolating a directivity associated with a third subset of spatial prediction modes different from the first subset of spatial prediction modes and the second subset of spatial prediction modes based on the first and second pixel subsets, wherein the third set of spatial prediction modes includes spatial prediction modes with an oblique directivity; and
means for determining a third spatial prediction mode from the third subset of spatial prediction modes based on the interpolated directivity in the case that the first spatial prediction mode and the second spatial prediction mode are unable to be determined.
19. The system according to claim 18 , wherein the first subset of spatial prediction modes is based on a first pair of vectors displaced by 90°; the second subset of spatial prediction modes is based on a second pair of vectors displaced by 90°; and the third subset of spatial prediction modes is based on a plurality of vectors displaced by 22.5° from any one of the first pair of vectors and the second pair of vectors.
20. The system according to claim 17 , wherein the means for determining the first spatial prediction mode includes means for performing a first transform operation on the first pixel subset to derive a first resultant matrix having a pattern of coefficients associated with identifying the first spatial prediction mode, and wherein the means for determining the second spatial prediction mode is operable to perform a second transform operation on the second pixel subset to derive a second resultant matrix having the pattern of coefficients associated with identifying the second spatial prediction mode.
21. The system according to claim 20 , wherein the first transform operation and the second transform operation use a Hadamard transform.
22. A computer program product that includes a non-transitory computer readable medium comprising instructions for processing multimedia data, wherein the instructions cause a computer to:
determine a first spatial prediction mode from a first subset of spatial prediction modes based on a first pixel subset of a current subblock of an intra-frame, wherein the first subset of spatial prediction modes includes spatial prediction modes with a vertical directivity, a horizontal directivity, and no clear directivity;
determine a second spatial prediction mode from a second subset of spatial prediction modes based on a second pixel subset of the current subblock in the case that the first spatial prediction mode is unable to be determined, wherein the second subset of spatial prediction modes includes spatial prediction modes with a diagonal directivity, wherein the first pixel subset is selected from said current subblock and pixels of said first pixel subset are arranged in a rectangular grid arrangement such that adjacent selected pixels in the first pixel subset do not touch each other, and wherein the second pixel subset is also selected from said current subblock and pixels of said second pixel subset are arranged in a diagonal grid arrangement such that only two or more corners of adjacent selected pixels touch the corners of other selected pixels in the diagonal grid arrangement; and
encode the intra-frame based on the first spatial prediction mode or, in the case that the first spatial prediction mode is unable to be determined, based on the second spatial prediction mode.
23. The computer program product according to claim 22 , further comprising instructions to cause the computer to:
interpolate a directivity associated with a third subset of spatial prediction modes different from the first subset of spatial prediction modes and the second subset of spatial prediction modes based on the first and second pixel subsets, wherein the third set of spatial prediction modes includes spatial prediction modes with an oblique directivity; and
determine a third spatial prediction mode from the third subset of spatial prediction modes based on the interpolated directivity in the case that the first spatial prediction mode and the second spatial prediction mode are unable to be determined.
24. The computer program product according to claim 23 , wherein the first subset of spatial prediction modes is based on a first pair of vectors displaced by 90°; the second subset of spatial prediction modes is based on a second pair of vectors displaced by 90°; and the third subset of spatial prediction modes is based on a plurality of vectors displaced by 22.5° from any one of the first pair of vectors and the second pair of vectors.
25. The computer program product according to claim 22 , wherein the instructions to cause the computer to determine the first spatial prediction mode include instructions to cause the computer to perform a first transform operation on the first pixel subset to derive a first resultant matrix having a pattern of coefficients associated with identifying the first spatial prediction mode.
26. The computer program product according to claim 25 , wherein the first transform operation uses a Hadamard transform.
27. The computer program product according to claim 25 , wherein the instructions to cause the computer to determine the second spatial prediction mode include instructions to cause the computer to perform a second transform operation on the second pixel subset to derive a second resultant matrix having the pattern of coefficients associated with identifying the second spatial prediction mode.
28. The computer program product according to claim 27 , wherein the second transform operation uses a Hadamard transform.
29. A method comprising:
determining, with a processor, a first spatial prediction mode from a first subset of spatial prediction modes based on a first pixel subset of a current subblock of an intra-frame, wherein the first subset of spatial prediction modes includes spatial prediction modes with a vertical directivity, a horizontal directivity, and no clear directivity;
determining, with the processor, a second spatial prediction mode from a second subset of spatial prediction modes based on a second pixel subset of the current subblock in the case that the first spatial prediction mode is unable to be determined, wherein the second subset of spatial prediction modes includes spatial prediction modes with a diagonal directivity, wherein the first pixel subset is selected from said current subblock and pixels of said first pixel subset are arranged in a rectangular grid arrangement such that adjacent selected pixels in the first pixel subset do not touch each other, and wherein the second pixel subset is also selected from said current subblock and pixels of said second pixel subset are arranged in a diagonal grid arrangement such that only two or more corners of adjacent selected pixels touch the corners of other selected pixels in the diagonal grid arrangement; and
encoding, with the processor, the intra-frame based on the first spatial prediction mode or, in the case that the first spatial prediction mode is unable to be determined, based on the second spatial prediction mode.
30. The method according to claim 29 , further comprising:
interpolating, with the processor, a directivity associated with a third subset of spatial prediction modes different from the first subset of spatial prediction modes and the second subset of spatial prediction modes based on the first and second pixel subsets, wherein the third set of spatial prediction modes includes spatial prediction modes with an oblique directivity; and
determining a third spatial prediction mode from the third subset of spatial prediction modes based on the interpolated directivity in the case that the first spatial prediction mode and the second spatial prediction mode are unable to be determined.
31. The method according to claim 29 , wherein determining the first spatial prediction mode includes: performing, with the processor, a first transform operation on the first pixel subset; and further comprising: deriving, with the processor, a first resultant matrix having a pattern of coefficients associated with identifying the first spatial prediction mode.
32. The method according to claim 31 , wherein the first transform operation uses a Hadamard transform.
33. The method according to claim 31 , wherein determining the second spatial prediction mode includes: performing, with the processor, a second transform operation on the second pixel subset; and further comprising: deriving, with the processor, a second resultant matrix having the pattern of coefficients associated with identifying the second spatial prediction mode.
34. The method according to claim 33 , wherein the second transform operation uses a Hadamard transform.