Dynamic frame repetition in a variable refresh rate system
A method, computer program product, and system for adjusting a dynamic refresh frequency of a display device are disclosed. The method includes the steps of obtaining a current frame duration associated with a first image, computing, based on the current frame duration, a repetition value for a second image, and repeating presentation of the second image on a display device based on the repetition value. The logic for implementing the method may be included in a graphics processing unit or within the display device itself.
1. A method, comprising:
presenting a first frame of image data on a display device utilizing a dynamic refresh frequency, the display device configured to operate synchronously with a processing unit configured to generate image data for presentation on the display device;
calculating an estimate for a current frame duration, wherein the current frame duration represents a time required to render, by the processing unit, a second frame of image data into a frame buffer;
determining a repetition value based on the current frame duration, a minimum allowed frame duration for the display device, and a maximum allowed frame duration for the display device; and
repeating presentation of the first frame of image data on the display device based on the repetition value.
2. The method of claim 1 , wherein the display device is one of a liquid crystal display (LCD), a light emitting diode (LED) display, an organic light emitting diode (OLED) display, and an active-matrix OLED (AMOLED) display.
3. The method of claim 2 , wherein presenting the first frame of image data on the display device comprises refreshing a plurality of pixels in response to receiving the first frame of image data via a video interface, and wherein repeating presentation of the first frame of image data on the display device comprises refreshing the plurality of pixels with the first frame of image data a number of times equal to the repetition value.
4. The method of claim 1 , wherein calculating an estimate for the current frame duration comprises calculating a rendering time associated with the second frame of image data.
5. The method of claim 1 , wherein calculating an estimate for the current frame duration comprises calculating an average rendering time associated with N previous frames of image data.
6. The method of claim 1 , wherein determining the repetition value comprises calculating a maximum repetition value by dividing the current frame duration by the minimum allowed frame duration for the display device to generate a first intermediate result, rounding the first intermediate result down to the nearest integer value to generate a first rounded result, and subtracting one from the first rounded result to generate the maximum repetition value.
7. The method of claim 6 , wherein determining the repetition value comprises calculating a minimum repetition value by dividing the current frame duration by the maximum allowed frame duration for the display device to generate a second intermediate result, rounding the second intermediate result up to the nearest integer value to generate a second rounded result, and subtracting one from the second rounded result to generate the minimum repetition value.
8. The method of claim 7 , wherein determining the repetition value comprises selecting the repetition value as an integer greater than or equal to the minimum repetition value and less than or equal to the maximum repetition value.
9. The method of claim 1 , wherein the processing unit is a graphics processing unit (GPU) configured to:
calculate the estimate for the current frame duration; and
determine the repetition value.
10. The method of claim 9 , wherein the GPU is further configured to cause the presentation of the first frame of image data to be repeated on the display device by re-encoding the first frame of image data in a video signal transmitted to the display device via an interface.
11. The method of claim 1 , wherein a scaling unit of the display device is configured to:
calculate the estimate for the current frame duration; and
determine the repetition value.
12. The method of claim 1 , wherein a timing controller of the display device is configured to:
calculate the estimate for the current frame duration; and
determine the repetition value.
13. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform steps comprising:
presenting a first frame of image data on a display device utilizing a dynamic refresh frequency, the display device configured to operate synchronously with a processing unit configured to generate image data for presentation on the display device;
calculating an estimate for a current frame duration, wherein the current frame duration represents a time required to render, by the processing unit, a second frame of image data into a frame buffer;
determining a repetition value based on the current frame duration, a minimum allowed frame duration for the display device, and a maximum allowed frame duration for the display device; and
repeating presentation of the first frame of image data on the display device based on the repetition value.
14. The non-transitory computer-readable storage medium of claim 13 , wherein calculating an estimate for the current frame duration comprises calculating a rendering time associated with the second frame of image data.
15. The non-transitory computer-readable storage medium of claim 13 , wherein determining the repetition value comprises calculating a maximum repetition value by dividing the current frame duration by the minimum allowed frame duration for the display device to generate a first intermediate result, rounding the first intermediate result down to the nearest integer value to generate a first rounded result, and subtracting one from the first rounded result to generate the maximum repetition value.
16. The non-transitory computer-readable storage medium of claim 15 , wherein determining the repetition value comprises:
calculating a minimum repetition value by dividing the current frame duration by the maximum allowed frame duration for the display device to generate a second intermediate result, rounding the second intermediate result up to the nearest integer value to generate a second rounded result, and subtracting one from the second rounded result to generate the minimum repetition value; and
selecting the repetition value as an integer greater than or equal to the minimum repetition value and less than or equal to the maximum repetition value.
17. A system, comprising:
a processor configured to:
present a first frame of image data on a display device utilizing a dynamic refresh frequency, the display device configured to operate synchronously with a processing unit configured to generate image data for presentation on the display device;
calculate an estimate for a current frame duration, wherein the current frame duration represents a time required to render, by the processing unit, a second frame of image data into a frame buffer,
determine a repetition value based on the current frame duration, a minimum allowed frame duration for the display device, and a maximum allowed frame duration for the display device, and
repeat presentation of the first frame of image data on the display device based on the repetition value.
18. The system of claim 17 , wherein calculating an estimate for the current frame duration comprises calculating a rendering time associated with the second frame of image data.
19. The system of claim 17 , wherein the processing unit is a graphics processing unit (GPU).
20. The system of claim 17 , wherein the processor is one of a scaling unit included in the display device and a timing controller included in the display device.