Reference data buffer for intra-prediction of digital video

• US 20060222080A1
• Filed: 03/31/2005
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wang, Wen-Shan
• Granted Patent: US 7,684,491 B2
• Time in Patent Office: Days
• US Class Current: 375/240.240
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

Encoding or decoding digital video frames in intra-prediction mode by selecting column reference data locations for blocks adjacent a current block from a column reference data buffer storing column reference data samples for no more than two macro blocks of the frame. In some cases, the column reference data buffer may include a storage size for samples of a first column of data of blocks of one macro block of luminance samples. Encoding and decoding may also include selecting row reference data locations for blocks adjacent a current block from a row reference data buffer storing row reference data samples for at least one row of macro blocks of the frame. In some cases, the row reference data buffer may include storage for samples of a first row of data of fourteen successive blocks spanning two rows. The concept can be applied to various video processing components and standards.

Claims

1. A method comprising:

completing one of prediction direction determination and intra prediction coding for a current block of a digital video frame, wherein completing comprises;

storing a plurality of a type of reference data samples from a plurality of blocks of no more than two macro blocks of the digital video frame in a plurality of reference data locations, during completing.

2. The method of claim 1, wherein the no more than two macro-blocks include samples from one of not more than two blocks of chrominance samples and not more than four blocks of luminance samples.

3. The method of claim 1, wherein the no more than two macro-blocks include a sample size of no more than one macro block of luminance column reference data samples;

and

further comprising storing two blocks of chrominance column reference data samples of the digital video frame in a plurality of reference data locations, during completing.

4. The method of claim 3, wherein the macro block of luminance column reference data samples are equal to a number of luminance blocks of one macro block multiplied by a number of luminance data samples in one column of each of the luminance blocks, and the two blocks of chrominance column reference data samples are equal to a number of chrominance data samples in one column of one chrominance block of Cr and in one column of one chrominance block of Cb.

5. The method of claim 1, wherein the type of reference data samples are column reference data samples, and further comprising:

selecting a current location from the plurality of blocks;

selecting a reference data location to a left of the current location.

6. The method of claim 1, wherein the reference data locations comprise at least two column reference data locations, and further comprising:

storing a plurality of samples from the plurality of blocks in each of a plurality of row reference data locations, wherein the row reference data locations comprises locations for at least four macro-blocks in the frame;

pointing a column write pointer to a column reference data location corresponding to a current location of the plurality of blocks;

pointing a row write pointer to a row reference data location corresponding to the current location;

pointing a column read pointer to a location to a left of the column write pointer in the column reference data locations; and

pointing a plurality of row read pointers to locations of at least two of a left and above, above, and a right and above the row write pointer in the row reference data locations.

7. The method of claim 6, further comprising:

incrementing the column write pointer and a row write pointer by a number equal to the number of samples of reference data from one block;

resetting the column write pointer after the samples have been pointed to by the column write pointer for the up to one macro-block in the frame.

8. A method comprising:

one of selecting a direction for intra-prediction direction determination and producing code for intra-prediction coding of a current block of a digital video frame, wherein selecting or completing comprises;

selecting a current location from a plurality of reference data locations of the digital video frame, wherein the reference data locations include one of an even row of macro block locations and an odd row of macro block locations for column reference data; and

storing column reference data for no more than two of the even row of locations during selecting or producing when the current location is in the even row, and no more than two of the odd row of locations during selecting or producing when the current location is in the odd row.

9. The method of claim 8, wherein the reference data locations include an even row of macro block locations and an odd row of macro block locations for row reference data;

and further comprising;

selecting row reference data from the even row of locations when the current location is in the odd row, or from the odd row of locations when the current location is in the even row.

10. The method of claim 9, wherein selecting column reference data comprises selecting column data from a location to a left of the current location, and wherein selecting row reference data comprises selecting row data from a location of at least one of to a left and above, above, and to a right and above the current location.

11. The method of claim 9, further comprising completing direction determination and intra-prediction coding using samples stored in buffers corresponding to the selected row reference data and the selected column reference data.

12. The method of claim 11, where completing direction determination and intra-prediction coding includes comparing the samples stored in buffers corresponding to the selected row reference data and the selected column reference data with a plurality of reference data samples corresponding to the current location.

13. An apparatus comprising:

an intra-predictor to perform direction determination and intra-prediction coding comprising;

a buffer comprising;

a plurality of reference data locations to store a plurality of a type of reference data samples from a plurality of blocks of a digital video frame of data;

wherein the reference data locations comprise locations for no more than two macro blocks in the frame.

14. The apparatus claim 13, wherein the samples are samples of column reference data, the blocks are macro-blocks, and the plurality of reference data locations are three or four buffers each storing reference data samples from one column of a block.

15. The apparatus of claim 13, wherein the buffer is a column reference buffer and the reference data locations are up to four column reference data locations for column reference data samples of up to four blocks of one row of macro blocks of the frame;

and the intra-predictor further comprises;

a row reference buffer comprising;

a plurality of row reference data locations to store a plurality of row reference data samples from the plurality of blocks,

wherein the row reference data locations comprise locations from at least one row of blocks in the frame.

16. The apparatus of claim 15, wherein the column reference data locations comprise one of an even row of macro block locations and an odd row of macro block locations for the frame, and wherein the row reference data locations comprise an even row of macro block locations and an odd row of macro block locations for the frame.

17. The apparatus of claim 15, wherein the reference data locations comprise locations for no more than two macro-blocks in the frame and each reference data location stores eight samples from a first column of a block.

18. The apparatus of claim 15, further comprising:

a column buffer write pointer storage to store a column buffer write pointer to point to a current location of the video frame in the plurality of column reference data locations;

a column buffer read pointer storage to store a column buffer read pointer to point to a column reference data location located to a left of the column buffer write pointer;

a row buffer write pointer storage to store a row buffer write pointer to point to a current location of the video frame in the plurality of row reference data locations;

a row buffer read pointer storage to store a row buffer read pointer to point to a row reference data location located one of to a left and above, above, and to a right and above the row buffer write pointer,

wherein the current location of the video frame in the plurality of column reference data is the same location in the frame as the current location of the video frame in the plurality of row reference data.

19. The apparatus of claim 15, wherein the intra-predictor further comprises:

a selector to select a selected reference data location from the plurality of column reference data locations and the plurality of row reference data locations, and

a comparator to compare samples of the selected reference data location with samples of a current location located in the frame abutting the selected reference data location.

20. The apparatus of claim 13, wherein each block comprises one of:

an 8×

8 block of blue chrominance samples (Cb),

an 8×

8 block of red chrominance samples (Cr), and

a 16×

16 block comprising four 8×

8 blocks of luminance samples (Y0, Y1, Y2, and Y3).

21. A system comprising;

a computing device with a video input to receive a frame of digital video;

an intra-predictor to perform direction determination and intra-prediction coding comprising;

a column reference data buffer to store eight samples of column reference data for each 8×

8 block of one of;

no more than two adjacent 8×

8 macro blocks of blue chrominance samples (Cb);

no more than two adjacent 8×

8 macro blocks of red chrominance samples (Cr); and

no more than four 8×

8 blocks of luminance samples (Y0, Y1, Y2, and Y3) of no more than two adjacent 16×

16 macro blocks of luminance samples.

22. The system of claim 21, wherein the intra-predictor further comprises:

a row reference data buffer to store eight samples of row reference data for each 8×

8 block of one of;

no more than six 8×

8 blocks of blue chrominance samples (Cb);

no more than six 8×

8 blocks of red chrominance samples (Cr); and

no more than eighteen 8×

8 blocks of luminance samples (Y0, Y1, Y2, and Y3) of no more than six 16×

16 macro blocks of luminance samples.

23. The system of claim 21, wherein the column reference data buffers are to each store eight samples of a first column of each of the four 8×

8 blocks of no more than two 16×

16 macro blocks of luminance samples.

24. An apparatus comprising:

an intra-predictor to perform one of direction determination and intra-prediction coding comprising;

a column reference data buffer storing no more than 32 samples of column reference data of a frame of digital video,

wherein a comparison of samples of a column of a current block of the frame to a subset of the samples column reference data is used to provide intra-prediction code for the frame.

25. The apparatus of claim 24, wherein the intra-predictor further comprises:

a row reference data buffer to store a number of samples of row reference data of the frame,

wherein the number of samples of row reference data is at least four times the number of samples of column reference data.

26. The apparatus of claim 24, wherein the samples of column reference data include samples from no more than two macro blocks of the frame, and the samples of row reference data include samples from at least two macro block rows of the frame.