Hardware assist for YUV data format conversion to software MPEG decoder

• US 6,353,440 B1
• Filed: 10/29/1999
• Issued: 03/05/2002
• Est. Priority Date: 03/21/1996
• Status: Expired due to Term

• Current Assignee: S3 Graphics Co., Ltd. (HTC Corporation)
• Original Assignee: S3 Graphics Co., Ltd. (HTC Corporation)
• Inventors: Keene, David
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): NGUYEN, FRANCIS N
• Application Number:
  US09/430,370
• Time in Patent Office: 858 Days
• Field of Search: 345/154, 345/186, 345/501, 345/523-525, 345/155, 345/434, 345/203, 345/530-535, 345/547, 345/545, 345/572, 345/603-604, 345/520, 345/562, 348/453, 348/717, 348/384
• US Class Current: 345/603
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory

Abstract

A display controller assists a host processor in decoding MPEG data. The display controller receives YUV data in non-pixel video format from a host CPU and perform the otherwise CPU intensive task of rasterization within the display controller. In addition, the display controller may use its internal BITBLIT engine to copy U and V data from one line in a BITBLIT operation to adjacent lines, so as to replicate U and V data. A byte mask preserves Y data on the adjacent lines from being overwritten. At the end of the BITBLIT operation, the display controller generates a signal indicating that the frame buffer has been filled with new data, and thus display controller automatically switches to reading from the newly written frame buffer.

Claims

1. A display controller for receiving video data from a data bus in a component YUV format and storing the video data to a display memory in a pixel video format, the display controller comprising:

a bus interface, coupled to the data bus, for receiving video data in a component YUV format and corresponding video data addresses within a predetermined address range;

a display memory controller, coupled to said bus interface, for receiving video data in a component YUV format in contiguous successive streams of luminance and chrominance difference data and corresponding video data addresses within a predetermined address range and for storing said video data by directing separate luminance and chrominance difference data into predetermined memory portions according to a predetermined memory aperture so as to store said video data in a pixel video format in a display memory; and

a memory configuration-register coupled to the bus interface and the display memory controller and configured to set addresses for the predetermined memory aperture.

2. The display controller of claim 1 wherein said video data comprises luminance and chrominance difference data and said component YUV format comprises a first contiguous block of luminance data and at least a second contiguous block of chrominance difference data.

3. The display controller of claim 2 wherein said display memory controller receives the first contiguous block of luminance data and stores the first contiguous block of luminance data in at least one byte lane within the display memory.

4. The display controller of claim 3 wherein said display memory controller receives the at least a second contiguous block of chrominance difference data and stores the at least a second contiguous block of chrominance difference data in at least another byte lane within the display memory.

5. The display controller of claim 4, wherein said first contiguous block of luminance data comprises one frame of luminance data.

6. The display controller of claim 5, wherein said at least a second contiguous block of chrominance difference data comprises one frame of chrominance difference data.

7. The display controller of claim 6 wherein said at least one byte lane comprises a plurality of pairs of adjacent byte lanes, each pair of the plurality of pairs of byte lanes for storing pairs of luminance data for one line of one frame of video data.

8. The display controller of claim 7 wherein said at least one byte lane comprises a plurality of pairs of adjacent byte lanes, each pair of the plurality of pairs of byte lanes for storing pairs of chrominance difference data for one line of one frame of video data.

9. The display controller of claim 8, wherein said chrominance difference data is stored in every other line of each of said plurality of pairs of byte lanes and said display controller further comprises a bit block transfer engine, coupled to the bus interface and to the display memory controller, for transferring blocks of data within the display memory, wherein said bit block transfer engine replicates chrominance data from every other line of said plurality of pairs of byte lanes to a corresponding adjacent line within said plurality of pairs of byte lanes.

10. The display controller of claim 9 wherein said bit block transfer engine replicates chrominance data after said display memory controller has completed storing one frame of video data in the display memory.

11. The display controller of claim 10 wherein said display controller outputs a signal through said bus interface to a host processor indicating completion of a bit block transfer operation.

23. The display controller of claim 1 wherein the display memory controller is further configured to switch between a first video buffer and a second video buffer in the display memory.

24. The display controller of claim 23 wherein the memory configuration register includes data values indicating locations of the first video buffer and the second video buffer, and wherein the display memory controller utilizes the data values to translate X and Y coordinate of a bit block transfer into memory addresses of the display memory.

25. The display controller of claim 24 wherein the data values in the memory configuration register are programmed from a central processing unit and, alternatively, the data values are programmed from a basic input/output system read-only memory (BIOS ROM).

12. A method for assisting decoding of video data partially decoded in a host processor, said method comprising the steps of:

receiving, in a display controller, video data in a component YUV format and corresponding video data addresses within a predetermined address range, and

storing the video data in a pixel video format in a display memory.

13. The method of claim 12 wherein the video data comprises luminance and chrominance difference data and the component YUV format comprises a first contiguous block of luminance data and at least a second contiguous block of chrominance difference data.

14. The method of claim 13 wherein the step of storing comprises the step of storing the first contiguous block of luminance data in at least one byte lane within the display memory.

15. The method of claim 14 wherein the step of storing further comprises the step of storing the at least a second contiguous block of chrominance difference data in at least another byte lane within the display memory.

16. The method of claim 15, wherein the first contiguous block of luminance data comprises one frame of luminance data.

17. The method of claim 16, wherein the at least a second contiguous block of chrominance difference data comprises one frame of chrominance difference data.

18. The method of claim 17 wherein the at least one byte lane comprises a plurality of pairs of adjacent byte lanes, each pair of the plurality of pairs of byte lanes for storing pairs of luminance data for one line of one frame of video data.

19. The method of claim 18 wherein the at least one byte lane comprises a plurality of pairs of adjacent byte lanes, each pair of the plurality of pairs of byte lanes for storing pairs of chrominance difference data for one line of one frame of video data.

20. The method of claim 19, wherein the step of storing further comprises the steps of:

storing chrominance difference data in every other line of each of the plurality of pairs of byte lanes, and

replicating, in a bit block transfer engine within the display controller, chrominance data from every other line of the plurality of pairs of byte lanes to a corresponding adjacent line within the plurality of pairs of byte lanes.

21. The method of claim 20 wherein the bit block transfer engine replicates chrominance data after the display memory controller has completed storing one frame of video data in the display memory.

22. The method of claim 21 further comprising the step of outputting a signal to a host processor indicating completion of a bit block transfer operation.

26. An electronically-readable medium storing a program for permitting a computer to perform a method of assisting decoding of video data partially decoded in a host processor, the method comprising the steps of:

receiving, in a desplay controller, video data in a component YUV format in contiguous successive streams of luminance and chrominance difference data and corresponding video data addresses within a predetermined address range,

setting addresses for a predetermined memory aperture by use of a memory configuration register, and

storing the video data by directing separate luminance and chrominance difference data into predetermined memory portions according to the predetermined memory aperture so as to store said video data in a pixel video format in a display memory.

27. A display system for receiving video data from a data bus in a component YUV format and storing the video data to a display memory in a pixel video format, comprising:

a data bus to supply video data in a component YUV format;

a display memory to store the video data in a pixel video format;

a bus interface, coupled to the data bus, for receiving the video data in a component YUV format and corresponding video data addresses within a predetermined address range;

a display memory controller, coupled to the bus interface, for receiving the video data in a component YUV format in contiguous successive streams of luminance and chrominance difference data and corresponding video data addresses within a predetermined address range and for storing said video data by directing separate luminance and chrominance difference data into predetermined memory portions according to a predetermined memory aperture so as to store the video data in a pixel video format in a display memory, the display memory controller storing Y data in consecutive odd byte locations on succeeding lines in the display memory by performing an address translation on the Y data, the display memory controller further storing U data in every fourth byte location starting with a second byte location and storing V data in every fourth byte location starting with a fourth byte location;

a memory configuration register coupled to the bus interface and the display memory controller and configured to set addresses for the predetermined memory aperture; and

a display to display the video data.