Tiling in picture memory mapping to minimize memory bandwidth in compression and decompression of data sequences

• US 6,104,416 A
• Filed: 11/18/1997
• Issued: 08/15/2000
• Est. Priority Date: 11/18/1997
• Status: Expired due to Term

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: McGuinness, Peter J.
• Primary Examiner(s): Chauhan, Ulka J.
• Application Number:
  US08/972,641
• Time in Patent Office: 1,001 Days
• Field of Search: 345/501, 345/520, 345/521, 345/507, 345/516, 345/517, 345/203, 348/714-718
• US Class Current: 345/544
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/4143 embedded in a Personal Computer [PC]

Abstract

A method of storing a picture in a memory such that the latency of the memory can be reduced when retrieving a picture from the memory to be displayed while still reducing the bandwidth when retrieving an array portion of the picture from the memory, and a memory architecture. The memory is subdivided into a plurality of words for storing a picture having rows and columns. The picture is partitioned into one or more tiles each having a predetermined number of rows and columns. The number of bytes in one row of one tile is equal to the number of bytes in one word, for storing the data in one row of a tile in one word. The chrominance Cr and Cb components can be stored in one word, with the first 8 bytes of the word containing one and the next eight containing the other.

Claims

1. A method of mapping of a digital array of data having rows and columns into a memory subdivided into words having a predetermined number of bytes, comprising the steps of:

partitioning the digital array into one or more stripes, each having a predetermined number of columns, each row of each of the stripes having a number of bytes;

partitioning each stripe into two or more tiles, each having a predetermined number of rows and the predetermined number of columns;

storing the data in the first row of one of the tiles in a first word in the memory;

storing the data in each subsequent row of the tile in a word in the memory having a word address adjacent and subsequent to the word storing the data of the directly preceding row, whereby easy retrieval of the subsequent row is accomplished upon the retrieval of the preceding row.

2. The method of claim 1, further comprising the steps of:

storing each data in a first row of a tile of a stripe in a word having a word address adjacent to and subsequent to the word address of last word of an adjacent tile in a directly preceding stripe;

whereby easy retrieval of the words in the tile is accomplished upon the retrieval of the words in the adjacent tile in the directly preceding stripe.

3. The method of claim 1, wherein a first number of bytes of each word contain pixels of Cr chrominance components and a second number of bytes of each word contain pixels of Cb chrominance components, such that the first number and second number of bytes is equal to the number of bytes in one word.

4. The method of claim 1, wherein, the number of bytes in one row of one tile being equal to the number of bytes in one word for storing the data in one row of each tile in one word.

5. The method of claim 1, wherein the predetermined number of rows is 64.

6. The method of claim 1, wherein the memory comprises a burst memory.

7. The method of claim 1, wherein the memory comprises a DRAM.

8. The method of claim 1, wherein the digital array comprises a picture in a video sequence.

9. The method of claim 8, wherein the video sequence comprises an MPEG-2 video sequence.

10. The method of claim 1, wherein the digital array comprises the luminance components of a picture.

11. The method of claim 10, wherein the predetermined number of columns is 16.

12. The method of claim 1, wherein the digital array comprises the chrominance components of a picture.

13. The method of claim 12, wherein the predetermined number of columns is 8.

14. The method of mapping of a digital array of data having even and odd rows and columns into a memory having a first and second memory buffers, each memory buffer subdivided into words having a predetermined number of bytes, comprising the steps of:

partitioning the digital array into one or more stripes, each stripe having a predetermined number of columns, each row of each of the stripes having a number of bytes;

partitioning each stripe into two or more tiles, each having a predetermined number of rows and the predetermined number of columns;

storing the data in the first odd row of one of the tiles in a first word of the first memory buffer;

storing the data in each subsequent odd row of the tile in a word in the first memory buffer having a word address adjacent and subsequent to the word storing the data of the directly preceding odd row, whereby easy retrieval of the subsequent odd row is accomplished upon the retrieval of the preceding odd row;

storing the data in the first even row of the tile in a first word of the second memory buffer;

storing the data in each subsequent even row of the tile in a word in the second memory buffer having a word address adjacent and subsequent to the word storing the data of the directly preceding even row, whereby easy retrieval of the subsequent even row is accomplished upon the retrieval of the preceding even row.

15. The method of claim 14, wherein a first number of bytes of each word contain pixels of Cr chrominance components and a second number of bytes of each word contain pixels of Cb chrominance components, such that the first number and second number of bytes is equal to the number of bytes in one word.

16. The method of claim 14, further comprising the steps of:

storing each data in a first even row of a tile of a stripe in a word having a word address adjacent to and subsequent to the word address of last even word of an adjacent tile in a directly preceding stripe;

whereby easy retrieval of the words in the tile is accomplished upon the retrieval of the words in the adjacent tile in the directly preceding stripe;

storing each data in a first odd row of a tile of a stripe in a word having a word address adjacent to and subsequent to the word address of last odd word of the adjacent tile in the directly preceding stripe;

whereby easy retrieval of the words in the tile is accomplished upon the retrieval of the words in the adjacent tile in the directly preceding stripe.

17. The method of claim 14, the number of bytes in one row of one tile being equal to the number of bytes in one word for storing the data in one row of each of the tiles in one word.

18. The method of claim 14, wherein the predetermined number of rows is 64.

19. The method of claim 14, wherein the memory comprises a burst memory.

20. The method of claim 14, wherein the memory comprises a DRAM.

21. The method of claim 14, wherein the digital array comprises a picture in a video sequence.

22. The method of claim 21, wherein the video sequence comprises an MPEG-2 video sequence.

23. The method of claim 14, wherein the digital array comprises the luminance components of a picture.

24. The method of claim 23, wherein the predetermined number of columns 16.

25. The method of claim 14, wherein the digital array comprises the chrominance components of a picture.

26. A method of mapping of a digital array of data into a memory subdivided into words having a predetermined number of bytes, comprising:

storing pixels of Cr chrominance components in a first number of bytes of each word;

storing pixels of Cb chrominance components in a second number of bytes of each word; and

storing pixels of luminance components in a third number of bytes of each word.

27. The method of claim 26, wherein the first number and second number of bytes is equal to the number of bytes in one word.

28. The method of claim 26, wherein the sum of the first, second, and third number of bytes is equal to the number of bytes in one word.

29. The method of claim 26, wherein the memory comprises a DRAM.

30. The method of claim 26, wherein the digital array comprises a picture in a video sequence.

31. The method of claim 30, wherein the video sequence comprises an MPEG-2 video sequence.

32. A method of reading a digital array of data from a burst memory having words with a predetermined number of bytes whereby easy retrieval of the data for display is accomplished, wherein the digital array is partitioned into two or more tiles including a first tile and last tile, each tile having X rows and Y columns including a first and last row and a first and last column, comprising the steps of:

(a) reading data in a word having a word address, the word storing data of one row of one of the tiles;

(b) reading data in a word having a word address equal to the word address read in step (a) plus X; and

(c) repeating step (b) each time incrementing the word address by X until all of the data in one row of the digital array is read.

33. The method of claim 32, further comprising the steps of:

(d) reading data in a word having a word address equal to the word address read in step (a) plus 1;

(e) reading data in a word having a word address equal to the word address read in step (d) plus X; and

(f) repeating step (e) each time incrementing the word address by X until all of the data in one row of the digital array is read; and

(g) repeating step (d), (e), and (f) each time incrementing the word address in step (d) by 1 until all of the data in the digital array is read.

34. The method of claim 32, wherein the tile in step (a) is the first tile of the digital array.

35. The method of claim 32, further comprising the step of sending the data read to the display.

36. The method of claim 32, wherein a first number of bytes of each word contain pixels of Cr chrominance components and a second number of bytes of each word contain pixels of Cb chrominance components, such that the first number and second number of bytes is equal to the number of bytes in one word.

37. The method of claim 32, the number of bytes in one row of one tile being equal to the number of bytes in one word.

38. The method of claim 32, wherein the memory comprises a DRAM.

39. The method of claim 32, wherein the digital array comprises a picture in a video sequence.

40. The method of claim 39, wherein the video sequence comprises an MPEG-2 video sequence.

41. The method of claim 32, wherein the digital array comprises the luminance components of a picture.

42. The method of claim 41, wherein the Y number of columns is 16.

43. The method of claim 32, wherein the digital array comprises the chrominance components of a picture.

44. The method of claim 43, wherein the Y number of columns is 8.

45. The method of claim 32, wherein the X number of rows is 64.

46. A method of reading an array portion of a digital array of data from a burst memory having words with a predetermined number of bytes, the array portion of the digital array having a fixed number of rows and columns, the digital array partitioned into two or more tiles each having a predetermined number of rows and columns including a first and last row and a first and last column, each row of each tile having a number of bytes, comprising the steps of:

determining the word address of the word storing the first row and the first column in the memory, for locating a first byte of data of the array portion;

determining the number of tiles that have data in the array portion;

reading the words storing a part of each tile that has data in the array portion;

selecting the columns in each tile corresponding to the columns in the array portion of the digital array.

47. The method of claim 46, wherein a first number of bytes of each word contain pixels of Cr chrominance components and a second number of bytes of each word contain pixels of Cb chrominance components, such that the first number and second number of bytes is equal to the number of bytes in one word.

48. The method of claim 46, wherein the number of bytes in one row of one tile being equal to the number of bytes in one word.

49. The method of claim 46, wherein the step of determining the number of tiles having data in the array portion of the digital array occurs concurrently with the step of reading a array portion of each tile.

50. The method of claim 46, further comprising the step of storing the selected columns in each tile in a memory buffer.

51. The method of claim 46, wherein the step of selecting the columns in each tile corresponding to the columns in the array portion of the digital array comprises:

rotating each word corresponding to a tile having the first column such that the columns corresponding to the columns in the array portion of the digital array are in the least significant bytes of each word.

52. The method of claim 46, wherein the step of selecting the columns in each tile corresponding to the columns in the array portion of the digital array comprises:

rotating each word corresponding to a tile having the last column such that the columns corresponding to the columns in the array portion of the digital array are in the most significant bytes of each word.

53. The method of claim 46, wherein the array portion of the digital array comprises a macroblock.

54. The method of claim 46, wherein the array portion of the digital array comprises a block.

55. The method of claim 46, wherein the memory comprises a DRAM.

56. The method of claim 46, wherein the digital array comprises a picture in a video sequence.

57. The method of claim 56, wherein the video sequence comprises an MPEG-2 video sequence.

58. The method of claim 46, wherein the digital array comprises the luminance components of a picture.

59. The method of claim 58, wherein the predetermined number of columns is 16.

60. The method of claim 46, wherein the digital array comprises the chrominance components of a picture.

61. The method of claim 60, wherein the predetermined number of columns is 8.

62. The method of claim 46, wherein the predetermined number of rows is 64.

63. A memory for storing a digital array of data having rows and columns partitioned into two or more tiles each having a predetermined number of rows and a predetermined number of columns, comprising:

a plurality of words, including a first word, each having a predetermined number of bytes such that a number of bytes in one row of one tile being equal to the number of bytes in one word for storing the data in one row of a tile in one word;

the data in the first row of one of the tiles is in a first word;

the data in each subsequent row of the tile is in a word having a word address adjacent and subsequent to the word storing the data of the directly preceding row, hereby easy retrieval of the subsequent row is accomplished upon the retrieval of the preceding row;

a plurality of memory rows, each row having one or more of the plurality of words; and

a plurality of memory columns.

64. The memory of claim 63, wherein a first number of bytes of each word contain pixels of Cr chrominance components and a second number of bytes of each word contain pixels of Cb chrominance components, such that the first number and second number of bytes is equal to the number of bytes in one word.

65. The memory of claim 63, wherein each data in a first row of a tile of a stripe is in a word having a word address adjacent to and subsequent to the word address of a last word of an adjacent tile in a directly preceding stripe;

whereby easy retrieval of the words in the tile is accomplished upon the retrieval of the words in the adjacent tile in the directly preceding stripe.

66. The memory of claim 63, wherein the number of bytes in one row of one stripe being equal to the number of bytes in one word for storing the data in one row of a stripe in one word.

67. The memory of claim 63, wherein the memory comprises a burst member.

68. The memory of claim 63, wherein the memory comprises a DRAM.

69. The memory of claim 63, wherein the digital array comprises a picture in a video sequence.

70. The memory of claim 69, wherein the video sequence comprises an MPEG-2 video sequence.

71. The memory of claim 63, wherein the digital array comprises the luminance components of a picture.

72. The memory of claim 71, wherein the predetermined number of columns is 16.

73. The memory of claim 63, wherein the digital array comprises the chrominance components of a picture.

74. The memory of claim 73, wherein the predetermined number of columns is 8.

75. The memory of claim 63, wherein the predetermined number of rows is 64.

76. A computer comprising:

an input device;

an output device;

a memory for storing a digital array of data having rows and columns partitioned into two or more tiles each having a predetermined number of rows and a predetermined number of columns, including;

a plurality of words, including a first word, each having a predetermined number of bytes such that a number of bytes in one row of one tile being equal to the number of bytes in one word for storing the data in one row of a tile in one word;

the data in the first row of one of the tiles is in a first word;

the data in each subsequent row of the tile is in a word having a word address adjacent and subsequent to the word storing the data of the directly preceding row, whereby easy retrieval of the subsequent row is accomplished upon the retrieval of the preceding row;

a plurality of memory rows, each row having one or more of the plurality of words; and

a plurality of memory columns.

77. The computer of claim 76, wherein a first number of bytes of each word contain pixels of Cr chrominance components and a second number of bytes of each word contain pixels of Cb chrominance components, such that the first number and second number of bytes is equal to the number of bytes in one word.

78. The computer of claim 76, wherein each data in a first row of a tile of a stripe is in a word having a word address adjacent to and subsequent to the word address of a last word of an adjacent tile in a directly preceding stripe;

whereby easy retrieval of the words in the tile is accomplished upon the retrieval of the words in the adjacent tile in the directly preceding stripe.

79. The computer of claim 76, wherein the number of bytes in one row of one stripe being equal to the number of bytes in one word for storing the data in one row of a stripe in one word.

80. The computer of claim 76, wherein the memory comprises a burst memory.

81. The computer of claim 76, wherein the memory comprises a DRAM.

82. The computer of claim 76, wherein the digital array comprises a picture in a video sequence.

83. The computer of claim 82, wherein the video sequence comprises an MPEG-2 video sequence.

84. The computer of claim 76, wherein the digital array comprises the luminance components of a picture.

85. The computer of claim 84, wherein the predetermined number of columns is 16.

86. The computer of claim 76, wherein the digital array comprises the chrominance components of a picture.

87. The computer of claim 86, wherein the predetermined number of columns is 8.

88. The computer of claim 76, wherein the predetermined number of rows is 64.