Securing protected content during video playback
AssigneeApple Inc.
InventorIan C. Hendry
Life of this patent
Estimating the term…
Abstract
The disclosed embodiments provide a system that drives a display from a computer system. During operation, the system writes graphical output to protected memory and drives the display from the protected memory. If the graphical output lacks protection, the system discontinues the driving of the display from the protected memory. In particular, upon detecting a lack of protection in the graphical output, the system continues to drive the display from the protected memory during a grace period associated with the lack of protection in the graphical output. The system then discontinues driving of the display from the protected memory if protection of the graphical output does not resume during the grace period.
Claims22
A method for driving a display from a computer system, comprising:
- storing display content in protected memory;
- determining an operating state of a display pipe that couples the protected memory to an external display, the display pipe being external to the display;
- when the display pipe is operating in a protected mode, driving, by the display pipe, the display content to the external display from the protected memory;
- and
- when the display pipe is operating in an unprotected mode:
- determining whether the display pipe has been operating in the unprotected mode for a period at least equal to a grace period;
- when the display pipe has been operating in the unprotected mode for a period less than the grace period, driving, by the display pipe, the display content to the external display from the protected memory;
- and
- when the display pipe has been operating in the unprotected mode for a period longer than the grace period, preventing driving of the display content to the external display from the protected memory.
A system for driving an external display from a computer system, comprising:
- a graphics-processing unit (GPU) configured to write display content to protected memory;
- a processor configured to determine whether a display pipe is operating in a protected mode;
- and
- the display pipe coupled to the external display, the display pipe configured to:
- when the display pipe is operating in a protected mode, drive the display content to the display from the protected memory;
- and
- when the display pipe is operating in an unprotected mode and when the display pipe is actively transmitting date to the display:
- determine whether the display pipe has been operating in the unprotected mode for a period at least equal to a grace period;
- when the display pipe has been operating in the unprotected mode for a period less than the grace period, drive, by the display pipe, the display content to the display from the protected memory;
- and
- when the display pipe has been operating in the unprotected mode for a period longer than the grace period, prevent driving of the display content to the display from the protected memory.
A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for driving a display from a computer system, the method comprising:
- storing display content in protected memory;
- determining an operating state of a display pipe that couples the protected memory to an external display;
- when the operating state of the display pipe indicates the display pipe is operating in a protected mode, driving, by the display pipe, the display content to the display from the protected memory;
- and
- when the operating state of the display pipe indicates the display pipe is operating in an unprotected mode:
- determining whether the display pipe has been operating in the unprotected mode for a period at least equal to a grace period;
- when the display pipe has been operating in the unprotected mode for a period less than the grace period, driving, by the display pipe, the display content to the display from the protected memory;
- and
- when the display pipe has been operating in unprotected mode for a period longer than the grace period, preventing driving of the display content to the display from the protected memory.
A method for driving a display from a computer system, comprising:
- storing display content in protected memory;
- determining an operating state of a display pipe that couples the protected memory to an external display;
- when the operating state indicates the display pipe is driving an allowed display type, driving, by the display pipe, the display content to the display from the protected memory;
- when the operating state of the display pipe indicates the display pipe is operating in a protected mode, driving, by the display pipe, the display content to the display from the protected memory;
- and
- when the operating state of the display pipe indicates the display pipe is operating in an unprotected mode, preventing driving of the display content to the display from the protected memory.
Dependencies are inferred from the claim text.