MIRRORING GRAPHICS CONTENT TO AN EXTERNAL DISPLAY

• US 20120176396A1
• Filed: 06/06/2011
• Published: 07/12/2012
• Est. Priority Date: 01/11/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Dyke, Kenneth C., Sandmel, Jeremy, Harper, John S.
• Granted Patent: US 8,963,799 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G06F 2200/1614 Image rotation following screen orientation, e.g. switching from landscape to portrait mode
• CPC Class Codes: G06F 3/1431 using a single graphics controller
• CPC Class Codes: G09G 2340/04 Changes in size, position or resolution of an image
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 2340/0485 Centering horizontally or vertically
• CPC Class Codes: G09G 2360/04 Display device controller operating with a plurality of display units
• CPC Class Codes: G09G 5/12 Synchronisation between the display unit and other units, e.g. other display units, video-disc players
• CPC Class Codes: G09G 5/373 for modifying the size of the graphic pattern
• CPC Class Codes: G09G 5/377 for mixing or overlaying two or more graphic patterns G09G5/02, G09G5/397 take precedence

Abstract

A data processing system composites graphics content, generated by an application program running on the data processing system, to generate image data. The data processing system stores the image data in a first framebuffer and displays an image generated from the image data in the first framebuffer on an internal display device of the data processing system. A scaler in the data processing system performs scaling operations on the image data in the first framebuffer, stores the scaled image data in a second framebuffer and displays an image generated from the scaled image data in the second framebuffer on an external display device coupled to the data processing system. The scaler performs the scaling operations asynchronously with respect to the compositing of the graphics content. The data processing system automatically mirrors the image on the external display device unless the application program is publishing additional graphics content for display on the external display device.

Claims

1. A method, comprising:

compositing, by a data processing system, graphics content to generate image data;

storing the image data in a first framebuffer;

displaying an image generated from the image data in the first framebuffer on an internal display of the data processing system;

performing, by a scaler, scaling operations on the image data in the first framebuffer, wherein the scaler performs the scaling operations asynchronously with respect to the compositing of the graphics content;

storing scaled image data in a second framebuffer; and

sending data for displaying an image generated from the scaled image data in the second framebuffer to an external display coupled to the data processing system.

2. The method of claim 1, wherein the scaled image data comprises data associated with a first image frame.

3. The method of claim 2, further comprising:

compositing graphics content to generate image data associated with a subsequent image frame before the scaling operations are complete for the image data associated with the first image frame.

4. The method of claim 2, further comprising:

determining if an image generated from scaled image data associated with a previous frame has completed displaying on the external display.

5. The method of claim 4, further comprising:

dropping the scaled image data associated with the first frame if the image generated from scaled image data associated with the previous frame has not completed displaying on the external display.

6. The method of claim 1, further comprising:

receiving graphics content from a computer application program.

7. The method of claim 1, wherein the scaling operations comprise adjusting at least one of the size, resolution, orientation and color of the image data.

8. An apparatus comprising:

a processing device configured to generate a list of compositing commands for graphics content;

a graphics processing unit, coupled to the processing device, configured to execute the list of compositing commands to generate image data based on the graphics content;

an internal display, coupled to the graphics processing unit, configured to display an image generated from the image; and

a scaler unit, coupled to the graphics processing unit, configured to perform scaling operations on the image data to generate scaled image data for an image to be displayed on an external display, wherein the scaler unit performs the scaling operations asynchronously with respect to operations of the processing device and the graphics processing unit.

9. The apparatus of claim 8, wherein the scaled image data comprises data associated with a first image frame.

10. The apparatus of claim 9, wherein the graphics processing unit is further configured to execute compositing commands to generate image data associated with a subsequent image frame before the scaler unit completes the scaling operations for the image data associated with the first image frame.

11. The apparatus of claim 9, wherein the processing device is further configured to determine if an image generated from scaled image data associated with a previous frame has completed displaying on the external display.

12. The apparatus of claim 11, wherein the processing device is further configured to drop the scaled image data associated with the first frame if the image generated from scaled image data associated with the previous frame has not completed displaying on the external display.

13. The apparatus of claim 8, wherein the processing device is further configured to receive graphics content from a computer application program.

14. The apparatus of claim 8, wherein the scaling operations comprise adjusting at least one of the size, resolution, orientation and color of the image data.

15. A non-transitory machine readable storage medium storing instructions which when executed cause a data processing system to perform a method comprising:

compositing graphics content to generate image data;

storing the image data in a first framebuffer;

displaying an image generated from the image data in the first framebuffer on an internal display of the data processing system;

performing, by a scaler, scaling operations on the image data in the first framebuffer, wherein the scaler performs the scaling operations asynchronously with respect to the compositing of the graphics content;

storing scaled image data in a second framebuffer; and

sending data for displaying an image generated fro the scaled image data in the second framebuffer to an external display.

16. The storage medium of claim 15, wherein the scaled image data comprises data associated with a first image frame.

17. The storage medium of claim 16, wherein the method further comprises:

compositing graphics content to generate image data associated with a subsequent image frame before the scaling operations are complete for the image data associated with the first image frame.

18. The storage medium of claim 16, wherein the method further comprises:

determining if an image generated from scaled image data associated with a previous frame has completed displaying on the external display.

19. The storage medium of claim 18, wherein the method further comprises:

dropping the scaled image data associated with the first frame if the image generated from scaled image data associated with the previous frame has not completed displaying on the external display.

20. The storage medium of claim 15, wherein the scaling operations comprise adjusting at least one of the size, resolution, orientation and color of the image data.

21. A method comprising:

receiving, by a data processing system, a first graphics content for a first image to display on an internal display device of the data processing system, wherein the first graphics content is generated by an application program running on the data processing system;

automatically mirroring the first image on an external display device coupled to the data processing system;

determining whether the application program is publishing a second graphics content for a second image to display on the external display device; and

if the application program is publishing a second graphics content, disabling the automatic mirroring.

22. The method of claim 21, further comprising:

if the application program is publishing a second graphics content, sending image data for the second image to the external display device.

23. The method of claim 21, wherein automatically mirroring the first image on the external display device comprises:

performing, by a scaler, scaling operations on image data for the first image to generate scaled image data, wherein the scaler performs the scaling operations asynchronously with respect to a compositing of the first graphics content.

24. The method of claim 23, wherein the scaled image data comprises data associated with a first image frame.

25. The method of claim 24, further comprising:

compositing graphics content to generate image data associated with a subsequent image frame before the scaling operations are complete for the image data associated with the first image frame.

26. A method comprising:

receiving, by a data processing system, a first graphics content for a first image to display on an internal display device of the data processing system, wherein the first graphics content is generated by an application program running on the data processing system;

determining whether the application program is publishing a second graphics content for a second image to display on an external display device coupled to the data processing system;

if the application program is not publishing the second graphics content, automatically mirroring the first image on the external display; and

if the application program is publishing the second graphics content, disabling the automatic mirroring and sending image data for the second image to the external display device.

27. The method of claim 26, wherein automatically mirroring the first image on the external display device comprises:

performing, by a scaler, scaling operations on image data for the first image to generate scaled image data, wherein the scaler performs the scaling operations asynchronously with respect to a compositing of the first graphics content.

28. The method of claim 27, wherein the scaled image data comprises data associated with a first image frame.

29. The method of claim 28, further comprising:

compositing graphics content to generate image data associated with a subsequent image frame before the scaling operations are complete for the image data associated with the first image frame.