Image data transfer

• US 6,337,691 B1
• Filed: 07/29/1998
• Issued: 01/08/2002
• Est. Priority Date: 07/29/1997
• Status: Expired due to Fees

• Current Assignee: Autodesk, Inc.
• Original Assignee: Discreet Logic, Inc. (Autodesk, Inc.)
• Inventors: Trainor, James
• Primary Examiner(s): Chauhan, Ulka J.
• Application Number:
  US09/126,039
• Time in Patent Office: 1,259 Days
• Field of Search: 345/501-503, 345/516, 345/505, 345/511, 345/328, 345/536, 345/537, 345/547, 345/723, 725/38, 725/46, 725/87-89, 725/92
• US Class Current: 345/537
• CPC Class Codes: G11B 2220/415 Redundant array of inexpensive disks [RAID] systems
• CPC Class Codes: G11B 27/034 on discs G11B27/036, G11B27/038 take precedence
• CPC Class Codes: H04N 5/262 Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects

Abstract

Image data (derived from film or video clips) is transferred from storage to high speed memory. After a transfer has taken place, a prediction is made as to subsequent image frames that will need to be transferred. The predicted images are transferred from storage to high speed memory while previously transferred data held in memory is processed.

Claims

1. A method of transferring image data describing sequences of images representing a plurality of clips from a storage device to a high speed memory for image processing, comprising the steps of:

predicting which image data from a plurality of clips will be required by an image processing application that combines the image data from the plurality of clips, after processing image data currently in said high speed memory including the substeps of;

creating a look-ahead map having data describing said plurality of clips;

creating a history table of requested images; and

searching for patterns in said look-ahead map and said history table to predict images which will be required by said image processing application; and

transferring said predicted image data from said storage device to said high speed memory while processing said image data currently in said high speed memory.

2. A method according to claim 1, wherein indications of said predicted images are stored in a prediction table.

3. A method according to claim 1, wherein said data describing each image in said look-ahead map comprises physical storage address on said storage device of the next image in one of said clips.

4. A method according to claim 1, wherein said searching for patterns comprises the steps of:

calculating the number of individual ones of said clips are stored in said history table;

using said calculated number to identify an entry in said history table; and

addressing history table entries from said identified entry in order to address said look-ahead map to obtain physical storage addresses of said predicted images.

5. A computer-readable medium having computer-executable instructions for performing steps comprising:

predicting which image data from a plurality of clips will be required by an image data processing application that combines the image data from the plurality of clips including the substeps of;

creating a look-ahead map having data describing said plurality of clips,

creating a history table of requested images; and

searching for patterns in said look-ahead map and said history table to predict images which will be required by said image processing application; and

transferring said predicted image data from a storage device to a high speed memory device while processing current image data.

6. A computer-readable medium according to claim 5, wherein said computer-executable instructions include instructions for storing an indication of predicted images in a prediction table.

7. A computer-readable medium according to claim 6, wherein said computer-executable instructions include instructions for relating an indication of predicted images to image data.

8. A computer-readable medium according to claim 5, wherein said computer-executable instructions include instructions for performing said search for patterns, comprising the steps of calculating the number of individual ones of said clips in said history table, using said calculated number to identify an entry in said history table, and addressing said history table entries from said identified entry in order to address said look-ahead map to obtain indications of said predicted images.

9. Image data transfer apparatus, comprising processing means including a processor executing one or more image processing application(s) that combines images from a plurality of clips, a high speed memory and a storage device,

wherein said processor is arranged to transfer image data describing sequences of images representing a plurality of clips from said storage device to said high speed memory by predicting image data which will be required by said image processing application(s) after processing image data currently in said high speed memory, and predicting image data is performed by:

storing a look-ahead map comprising data describing said plurality of clips;

storing a history table of requested images; and

searching for patterns in said look-ahead map and said history table to predict images which will be required by said image processing application(s); and

transferring said predicted image data from said storage device to said high speed memory while processing said current image data.

10. Apparatus according to claim 9, wherein said predicted images are written to a prediction table.

11. Apparatus according to claim 10, wherein said processor is arranged to perform said prediction and said transferring of predicted image data each time image data is requested from said storage device.

12. Apparatus according to claim 10, wherein said high speed memory comprises a cache.

13. Apparatus according to claim 9, wherein said data describing each image in said look-ahead map comprises physical storage addresses on said storage device of next image in said clips.

14. Apparatus according to claim 13, wherein said processor is arranged to perform said prediction and said transferring of predicted image data each time image data is requested from said storage device.

15. Apparatus according to claim 13, wherein said high speed memory comprises a cache.

16. Apparatus according to claim 9, wherein said processor is arranged to search for patterns by calculating the number of individual clips in said history table;

using said calculated number to identify an entry in said history table; and

addressing history table entries from said identified entry in order to address said look-ahead map to obtain physical storage address of said predicted images.

17. Apparatus according to claim 16, wherein said processor is arranged to perform said prediction and said transferring of predicted image data each time image data is requested from said storage device.

18. Apparatus according to claim 16, wherein said high speed memory comprises a cache.

19. Apparatus according to any of claim 11, wherein said processor is arranged to perform said prediction and said transferring of predicted image data each time image data is requested from said storage device.

20. Apparatus according to claim 19, wherein said high speed memory comprises a cache.

21. Apparatus according to claim 11, wherein said high speed memory comprises a cache.

22. Apparatus according to claim 9, wherein said processor is arranged to perform said prediction and said transferring of predicted image data each time image data is requested from said storage device.

23. Apparatus according to claim 9, wherein said high speed memory comprises a cache.