System and method for frame buffer decompression and/or compression

Patent metadata

Field	Value
Publication number	US-10043234-B2
Application number	US-201213732286-A
Country	US
Kind code	B2
Filing date	Dec 31, 2012
Priority date	Dec 31, 2012
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

A system and method for decompressing compressed data (e.g., in a frame buffer) and optionally recompressing the data. The method includes determining a portion of an image to be accessed from a memory and sending a conditional read corresponding to the portion of the image. In response to the conditional read, an indicator operable to indicate that the portion of the image is uncompressed may be received. If the portion of the image is compressed, in response to the conditional read, compressed data corresponding to the portion of the image is received. In response to receiving the compressed data, the compressed data is uncompressed into uncompressed data. The uncompressed data may then be written to the memory corresponding to the portion of the image. The uncompressed data may then be in-place compressed for or during subsequent processing.

First claim

What is claimed is:

1. A method of uncompressing data, said method comprising:
determining a portion of an image to be read from a frame buffer memory wherein said frame buffer memory comprises compressed and uncompressed portions;
initiating a conditional read corresponding to said portion of said image, wherein said conditional read initially returns a compressed or uncompressed status indicator concerning said portion based on a data structure comprising a plurality of status indicators for said compressed and uncompressed portions of said frame buffer memory;
further performing said conditional read by reading compressed data if said portion of said image is indicated by said status indicator as compressed and decompressing said compressed data into decompressed data, otherwise skipping over reading said portion of said image if said portion of said image is indicated by said status indicator as uncompressed; and
writing said uncompressed data to said frame buffer memory corresponding to said portion of said image and otherwise skipping over writing said portion of said image if said portion is indicated by said status indicator as uncompressed.

2. The method as described in claim 1 wherein said portion of said image comprises a three dimensional volume.

3. The method as described in claim 2 further comprising:
determining a memory address corresponding to said portion of said image.

4. The method as described in claim 1 wherein said portion of said image comprises a tile of said frame buffer memory.

5. The method as described in claim 4 wherein said frame buffer memory is accessible by a compression unaware client device comprising components unable to process said compressed data.

6. The method as described in claim 1 further wherein said plurality of status indicators are memory resident and comprise a respective status indicator for each portion of said frame buffer memory.

7. The method as described in claim 1 wherein said conditional read is sent to a cache memory.

8. The method as described in claim 1 wherein said status indicator comprises a token.

9. A system for reading a frame buffer memory, said system comprising:
a raster module operable to select a tile of said frame buffer memory to be read, wherein said frame buffer memory comprises compressed and uncompressed tiles;
a conditional read module operable to determine whether said tile of said frame buffer comprises at least one of compressed data and uncompressed data based on a conditional read thereof, wherein said conditional read returns a compressed or uncompressed status indicator concerning said tile, wherein said conditional read module is operable to output compressed data associated with said tile if said tile is indicated as compressed, wherein said conditional read module is operable to skip over said tile if said tile is indicated as uncompressed;
a decompression module operable to generate decompressed data corresponding to said compressed data associated with said tile; and
a data storage module operable to write said decompressed data to said tile of said frame buffer memory, and otherwise to skip over writing said tile of said frame buffer if said tile of said frame buffer is indicated by said status indicator as uncompressed.

10. The system as described in claim 9 wherein said raster module is operable to select a sub-portion of the frame buffer memory in raster scan order.

11. The system as described in claim 9 wherein said raster module is operable to determine an address of said frame buffer memory corresponding to said tile.

12. The system as described in claim 9 wherein said compressed data was compressed by a graphics processing unit (GPU).

13. The system as described in claim 9 wherein said conditional read module is operable to output a token indicating that said tile is one of uncompressed and compressed.

14. The system as described in claim 9 wherein said raster module operable to select said tile of said frame buffer memory based on traversing said frame buffer memory.

15. A graphics processing system comprising:
a frame buffer memory comprising compressed and uncompressed portions, wherein said compressed and uncompressed portions are operable for use in rendering;
a raster module operable to read said frame buffer memory in raster scan order and wherein said raster module is operable to select a portion of said frame buffer memory to be read based on said raster scan order;
a conditional read module operable to determine whether said portion of said frame buffer memory is a compressed portion of an image based on a conditional read thereof, wherein said conditional read returns a compressed or uncompressed status indicator concerning said portion, wherein said conditional read module skips over said portion of said frame buffer memory if said portion of said frame buffer memory is indicated as uncompressed and outputs compressed data is said portion is indicated as compressed; and
a decompression module operable to decompress said compressed data, wherein said decompression module is operable to facilitate said frame buffer memory being read by a compression unaware remote client by decompressing said compressed portions; and
a data storage module operable to write said decompressed data to said portion of said frame buffer memory, and otherwise to skip over writing said portion of said frame buffer memory if said portion of said frame buffer memory is indicated by said status indicator as uncompressed.

16. The graphics processing system as described in claim 15 wherein said portion of said frame buffer memory comprises a tile.

17. The graphics processing system as described in claim 15 wherein said conditional read module is operable to return a token if said portion of said frame buffer memory comprises an uncompressed tile.

18. The graphics processing system as described in claim 15 wherein a cache comprises said conditional read module.

19. The graphics processing system as described in claim 15 wherein said portion of said frame buffer memory corresponds to a 3D volume.

20. The graphics processing system as described in claim 15 wherein said decompression module is operable to decompress said portion of said frame buffer memory in an in-place manner.

Assignees

• Nvidia Corp

Inventors

• Dunaisky Jonathan
• Molnar Steven E
• Amsinck Christian
• Bastos Rui
• Lum Eric B
• Cobb Justin
• Kilgariff Emmett

Classifications

• G06T1/60 Primary

  Memory management · CPC title

• G09G2360/122

  Tiling · CPC title

• G09G5/393

  Arrangements for updating the contents of the bit-mapped memory · CPC title

• G06T9/00

  Image coding (bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00) · CPC title

• H04N19/428

  Recompression, e.g. by spatial or temporal decimation · CPC title