WO2024041047A1

WO2024041047A1 - Screen refresh rate switching method and electronic device

Info

Publication number: WO2024041047A1
Application number: PCT/CN2023/094624
Authority: WO
Inventors: 李时进; 周健
Original assignee: 荣耀终端有限公司
Priority date: 2022-08-24
Filing date: 2023-05-16
Publication date: 2024-02-29
Also published as: CN116052618A; CN117711356A; CN116052618B; CN117711355A

Abstract

The present application relates to the technical field of image processing and display, and provides a screen refresh rate switching method and an electronic device, capable of quickly switching the screen refresh rate of a display screen from a low refresh rate to a high refresh rate. A SurfaceFlinger of an electronic device receives a first refresh rate switching instruction, wherein the first refresh rate switching instruction is used for instructing a screen refresh rate to be switched from a first refresh rate to a second refresh rate, the first refresh rate is less than or equal to a preset threshold, and the second refresh rate is greater than the preset threshold; the SurfaceFlinger sends the first refresh rate switching instruction to a display driver in response to the end of a signal period of a current first Vsync signal, wherein the signal period of the first Vsync signal is set to be a preset period under the condition that the screen refresh rate of the display screen is the first refresh rate, and the preset period is less than the reciprocal of the first refresh rate; the display driver switches the screen refresh rate from the first refresh rate to the second refresh rate in response to the first refresh rate switching instruction.

Description

Screen refresh rate switching method and electronic device

This application claims priority for the Chinese patent application submitted to the State Intellectual Property Office on August 24, 2022, with application number 202211021875.0 and the invention title "A screen refresh rate switching method and electronic device", the entire content of which is incorporated by reference. in this application.

Technical field

The present application relates to the field of image processing and display technology, and in particular to a screen refresh rate switching method and electronic equipment.

Background technique

In terms of the processing mechanism for switching the screen refresh rate of the display from a low refresh rate back to a high refresh rate, according to the native mechanism of the Android system, at least two signal periods need to pass at the initial screen refresh rate of the display, for example If the initial screen refresh rate of the display screen is 10Hz and the corresponding signal period is 100ms, it will take at least 200ms to switch the screen refresh rate of the display screen from the low refresh rate of 10Hz back to the high refresh rate of 60Hz, 90Hz or 120Hz. Rate. Under such a mechanism, lag may occur when the screen refresh rate of the display is switched from a low refresh rate back to a high refresh rate.

Contents of the invention

In view of this, this application provides a screen refresh rate switching method and electronic device, which can quickly switch the screen refresh rate of the display screen from a low refresh rate to a high refresh rate and optimize the switching performance.

In a first aspect, this application provides a screen refresh rate switching method, which method can be applied to electronic equipment, where the electronic equipment includes a display screen. The method includes: when the screen refresh rate of the display screen is a third refresh rate, in response to the electronic device switching from displaying dynamic images to displaying static images, switching the screen refresh rate of the display screen from the third refresh rate to the first refresh rate rate, and set the signal period of the first Vsync signal to the preset period. Wherein, the third refresh rate is greater than the first refresh rate, and the first refresh rate is less than or equal to the preset threshold, and the preset period is less than the reciprocal of the first refresh rate. In response to the electronic device switching from displaying static images to displaying dynamic images, the SurfaceFlinger of the electronic device receives the first refresh rate switching instruction. The first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. The second refresh rate is greater than the preset threshold. In response to the current signal period of the first Vsync signal ending, SurfaceFlinger sends a first refresh rate switching instruction to the display driver of the electronic device. Among them, the first Vsync signal is used to trigger SurfaceFlinger for layer synthesis. In response to the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate.

In the above technical solution, when the electronic device switches from displaying dynamic images to displaying static images, the screen refresh rate of the display screen is switched from the third refresh rate to the first refresh rate, because the first refresh rate is less than or equal to the preset refresh rate. Set the threshold to a low refresh rate, so this can reduce the power consumption of electronic devices when displaying static images. Moreover, the signal period of the first Vsync signal is set to a preset period. In this way, after the electronic device switches from displaying static images to displaying dynamic images, the screen refresh rate of the display screen needs to be switched from the first refresh rate to the second refresh rate. (High refresh rate), the electronic device can be in the current signal period of the first Vsync signal (i.e., the preset period) At the end, the corresponding first refresh rate switching command is issued. Since the preset period is less than the reciprocal of the first refresh rate, compared to the native mechanism of the Android system, SurfaceFlinger needs to wait until a cycle whose length is the reciprocal of the first refresh rate ends before downloading. By issuing the first refresh rate switching command, the timeliness of SurfaceFlinger's issuance of the first refresh rate switching command is improved, so that the display screen can receive and respond to the first refresh rate switching command in a timely manner and quickly complete the screen refresh rate switching.

In a second aspect, this application provides a screen refresh rate switching method, which method can be applied to an electronic device, where the electronic device includes a display screen. The method includes: SurfaceFlinger of the electronic device receives a first refresh rate switching instruction from an upper layer. The first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. Wherein, the first refresh rate is less than or equal to the preset threshold, and the second refresh rate is greater than the preset threshold. In response to the end of the signal period of the current first vertical synchronization Vsync signal, SurfaceFlinger sends a first refresh rate switching instruction to the display driver of the electronic device. Among them, the first Vsync signal is used to trigger SurfaceFlinger for layer synthesis. The signal period of the first Vsync signal is set to a preset period when the screen refresh rate of the display screen is the first refresh rate. The preset period is less than the reciprocal of the first refresh rate. In response to the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate.

It should be understood that the above-mentioned first refresh rate is less than or equal to the preset threshold, which is a low refresh rate, and the second refresh rate is greater than the preset threshold, which is a high refresh rate.

In the above technical solution, when the screen refresh rate of the display screen of the electronic device is the first refresh rate (low refresh rate), the signal period of the first Vsync signal is set to the preset period. In this way, when it is necessary to switch the screen refresh rate of the display screen from the first refresh rate (low refresh rate) to the second refresh rate (high refresh rate), SurfaceFlinger can switch the signal period of the current first Vsync signal (preset period). ) ends, the first refresh rate switching command is issued. Since the preset period is less than the reciprocal of the first refresh rate, compared to the native mechanism of the Android system, SurfaceFlinger needs to wait until a cycle whose length is the reciprocal of the first refresh rate ends before it can be issued. First refresh rate switching command, the timeliness of SurfaceFlinger issuing the first refresh rate switching command is improved, so that the display screen can also receive the first refresh rate switching command in time, and respond to the first refresh rate switching command in a timely manner to refresh the screen. rate switching, thus reducing the switching time of the screen refresh rate of the display screen, avoiding lagging, improving the chirality of the electronic device, and improving the user experience.

In a possible implementation of the second aspect, after the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate in response to the first refresh rate switching instruction, the above method further includes: The display driver sends a second Vsync signal to SurfaceFlinger according to the first signal period to indicate the screen refresh rate of the display screen to SurfaceFlinger. Wherein, the second Vsync signal can trigger the display screen to refresh the display image frame, and the first signal period is equal to the reciprocal of the second refresh rate.

That is to say, after the screen refresh rate of the display screen is switched from the first refresh rate to the second refresh rate, the display driver periodically sends the second Vsync signal to SurfaceFlinger according to the first signal period (that is, the reciprocal of the second refresh rate). , used for SurfaceFlinger for Vsync signal calibration. In this way, SurfaceFlinger can determine that the screen refresh rate of the display screen has switched to the second refresh rate based on the period of receiving the second Vsync signal, and SurfaceFlinger can periodically generate the first Vsync signal according to the reciprocal of the second refresh rate. As a result, the first Vsync signal and the second Vsync signal can maintain periodic synchronization.

In another possible implementation of the second aspect, the SurfaceFlinger of the electronic device receives the Before the first refresh rate switching instruction from the upper layer, the above method further includes: the display screen receives a second refresh rate switching instruction. The second refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch to the first refresh rate. In response to the second refresh rate switching instruction, the display screen switches the screen refresh rate of the display screen to a preset refresh rate, and sends a second Vsync signal to SurfaceFlinger through the display driver according to the preset cycle. Wherein, the preset period is equal to the reciprocal of the preset refresh rate, and the preset refresh rate is greater than the preset threshold. SurfaceFlinger receives the second Vsync signal from the display driver. If the period during which SurfaceFlinger receives the second Vsync signal from the display driver (i.e., the second signal period) is equal to the preset period, SurfaceFlinger sets the signal period of the first Vsync signal to the preset period and stops receiving the second Vsync signal from the display driver. .

That is to say, after the display screen receives the second refresh rate switching command, it can respond to the second refresh rate switching command by first switching the screen refresh rate of the display screen to the preset refresh rate, so that according to the preset cycle, Periodically send the second Vsync signal to SurfaceFlinger for SurfaceFlinger to perform Vsync signal calibration. After SurfaceFlinger completes the Vsync signal calibration, it can set the signal period of the first Vsync signal to the preset period and run according to the preset period. In this way, when a new refresh rate switching command is subsequently received (such as a first refresh rate command), the new refresh rate switching command can be issued in time.

In another possible implementation of the second aspect, the method further includes: in response to the second refresh rate switching instruction, the display screen switches the screen refresh rate of the display screen to the first refresh rate after a preset period of time.

That is to say, after the display screen receives the second refresh rate switching instruction, it can first switch the screen refresh rate of the display screen to the preset refresh rate in response to the second refresh rate switching instruction. In this way, the display screen can periodically send the second Vsync signal to SurfaceFlinger according to the preset cycle for SurfaceFlinger to perform Vsync signal calibration. After SurfaceFlinger completes the Vsync signal calibration, you can set the signal period of the first Vsync signal to the preset period. In response to the second refresh rate switching instruction, the display screen can switch the screen refresh rate of the display screen to the first refresh rate after a preset period of time, that is, it runs according to a cycle whose length is the reciprocal of the first refresh rate, that is, according to the length The display image frame is refreshed in a reciprocal period of the first refresh rate to reduce power consumption.

In another possible implementation of the second aspect, the preset refresh rate is a screen refresh rate supported by the display screen.

That is to say, after the display screen receives the second refresh rate switching instruction, it can respond to the second refresh rate switching instruction and refresh the screen of the display screen before switching the screen refresh rate of the display screen to the first refresh rate. rate switches to the default refresh rate. In this way, the display screen can send the second Vsync signal to SurfaceFlinger according to the preset period for SurfaceFlinger to perform Vsync signal calibration.

In another possible implementation of the second aspect, the first refresh rate is a target refresh rate when the display screen displays a static image.

When the display screen displays a static image, the screen refresh rate of the display screen can be set to the first refresh rate (low refresh rate) to reduce power consumption.

In another possible implementation of the second aspect, the preset refresh rate is 120Hz; the first refresh rate is 10Hz or 1Hz; and the second refresh rate is 60Hz, 90Hz or 120Hz.

That is to say, after the display screen receives the second refresh rate switching instruction, it can first switch the screen refresh rate of the display screen to the preset refresh rate of 120 Hz in response to the second refresh rate switching instruction. In this way, the display screen can send the second Vsync signal to SurfaceFlinger according to the 8ms cycle for SurfaceFlinger to perform Vsync signal calibration. After SurfaceFlinger completes the Vsync signal calibration, the first Vsync signal can be The cycle is set to 8ms and runs according to the 8ms cycle. In response to the second refresh rate switching instruction, the display screen can switch the screen refresh rate of the display screen to 10Hz or 1Hz after a preset period of time, that is, it runs according to a cycle of 100ms or 1000ms, that is, it refreshes the display according to a cycle of 100ms or 1000ms. image frames to reduce power consumption. Afterwards, if SurfaceFlinger receives the first refresh rate switching command, SurfaceFlinger can issue the first refresh rate switching command after the current 8ms cycle ends, so that the display screen receives the first refresh rate switching command in time and In response to the first refresh rate switching instruction, the screen refresh rate is switched to 60Hz, 90Hz or 120Hz.

In another possible implementation of the second aspect, the first refresh rate switching instruction is triggered by the electronic device after receiving a notification or user operation when displaying a static image. Among them, notifications or user operations are used to trigger the electronic device to update the interface.

That is to say, when the electronic device displays a static image, if it receives a notification or user operation, it can trigger the first refresh rate switching instruction, thereby controlling the screen refresh rate of the display screen from the first refresh rate (low refresh rate) Switch to the second refresh rate (high refresh rate).

In another possible implementation of the second aspect, the second refresh rate switching instruction is triggered when the electronic device switches from displaying dynamic images to displaying static images.

That is to say, when the electronic device switches from displaying dynamic images to displaying static images, it can trigger the second refresh rate switching instruction to control the screen refresh rate of the display screen to switch to the first refresh rate (low refresh rate) to reduce power consumption. .

In a third aspect, the present application provides an electronic device, which includes a display screen, a memory, and one or more processors. The display, memory and processor are coupled. The memory is used to store computer program code, which includes computer instructions. When the above processor executes computer instructions, the electronic device executes the method described in the first aspect or the second aspect and any possible design manner thereof.

In a fourth aspect, the present application provides a chip system, which is applied to an electronic device including a display screen. The chip system includes one or more interface circuits and one or more processors. The interface circuit and the processor are interconnected through lines. The interface circuit is used to receive signals from the memory of the electronic device and send signals to the processor, the signals including computer instructions stored in the memory. When the processor executes the computer instructions, the electronic device executes the method described in the first aspect or the second aspect and any possible design manner thereof.

In a fifth aspect, the present application provides a computer storage medium that includes computer instructions. When the computer instructions are run on an electronic device, the electronic device causes the electronic device to execute the first aspect or the second aspect and any possibility thereof. The design method described.

In a sixth aspect, the present application provides a computer program product. When the computer program product is run on a computer, it causes the computer to execute the method described in the first aspect or the second aspect and any possible design manner thereof.

It can be understood that the beneficial effects achieved by the electronic device described in the third aspect, the chip system described in the fourth aspect, the computer storage medium described in the fifth aspect, and the computer program product described in the sixth aspect are provided above. , reference may be made to the beneficial effects in the first aspect or the second aspect and any possible design method thereof, which will not be described again here.

Description of drawings

Figure 1 is a schematic diagram of the Vsync mechanism of an Android system in an embodiment of the present application;

Figure 2A is a block diagram of an electronic device software structure provided by an embodiment of the present application;

Figure 2B is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present application;

Figure 3 is a flow chart of a native refresh rate switching of the Android system in an embodiment of the present application;

Figure 4 is a refresh rate switching flow chart provided by an embodiment of the present application;

Figure 5 is a schematic diagram of refresh rate switching provided by an embodiment of the present application;

Figure 6 is another refresh rate switching flow chart provided by an embodiment of the present application;

Figure 7 is another refresh rate switching schematic diagram provided by an embodiment of the present application;

Figure 8A is another refresh rate switching flow chart provided by an embodiment of the present application;

Figure 8B is another refresh rate switching schematic diagram provided by an embodiment of the present application;

Figure 9 is a flow chart of interaction between modules in a screen refresh rate switching method provided by an embodiment of the present application;

Figure 10 is a schematic structural diagram of a chip system provided by an embodiment of the present application.

Detailed ways

In order to better understand the technical solutions in the embodiments of the present application, the display principles and related terms of the Android (Android) terminal devices involved in the embodiments of the present application are introduced below.

The display process of an application (Application, APP) in an Android terminal device can be divided into three stages: APP drawing and rendering, layer integrator (SurfaceFlinger) synthesis, and display refresh display.

(1)Screen refresh rate (Refresh Rate or Scanning Frequency)

The screen refresh rate is divided into vertical refresh rate and horizontal refresh rate. The generally mentioned screen refresh rate usually refers to the vertical refresh rate. The vertical refresh rate indicates the number of times the image displayed on the display is refreshed per second, measured in Hz (hertz). For example, a 60Hz screen means that a display can refresh and display image frames 60 times in 1 second. The higher the screen refresh rate, the more times the display can refresh and display image frames in 1 second. Correspondingly, the smoothness of the picture will be higher.

(2) Frame Rate (Frame Rate, also called frame rate)

Frame rate refers to the number of frames of images generated by the graphics card (graphics processor) per second. Frame rate = number of frames (Frames)/time (Time), the unit is frames per second (frames per second, f/s, also called fps). A high frame rate results in smoother, more realistic animations. The higher the frame rate (fps), the smoother the displayed action will be. Now the performance of graphics cards has improved significantly, and the frame rates that can be achieved are getting higher and higher. But if the frame rate exceeds the screen refresh rate, it will only waste graphics processing power, so the frame rate that exceeds the refresh rate is wasted. And because the display can't update at the same speed, frame rates that are too high can cause screen tearing. For example, if the screen refresh rate is 60Hz, if the output of the graphics card is greater than 60fps, the two will be out of sync, and the screen will tear. The Android system solves the problem of screen tearing through the vertical synchronization (Vertical synchronization, referred to as Vsync, also known as field synchronization) mechanism.

(3)Vsync mechanism

The display principle of the Android system is based on the Vsync mechanism. Under the Vsync mechanism, there are two types of Vsync signals in the Android system: one is the Vsync signal generated by hardware, which can be called the hardware Vsync signal (Vsync-HW signal, later called the second Vsync signal); the other is software simulated The Vsync signal can be called a software Vsync signal (hereinafter referred to as the first Vsync signal). The first Vsync signal may include a Vsync-APP signal and a Vsync-SF signal.

SurfaceFlinger can receive the second Vsync signal and perform Vsync signal calibration, that is, generate the first Vsync signal according to the second Vsync signal, so that the first Vsync signal and the second Vsync signal maintain period synchronization, that is, make the signal of the first Vsync signal The period varies with the signal period of the second Vsync signal. in, The signal period of the second Vsync signal is equal to the reciprocal of the screen refresh rate of the display screen. For example, when switching the screen refresh rate, SurfaceFlinger turns on Vsync signal calibration. Taking the screen refresh rate of the display screen switching from 60Hz to 120Hz as an example, the frequency of the second Vsync signal reported by the display screen switches from 60Hz to 120Hz, that is, the signal period of the second Vsync signal switches from 16ms to 8ms. At this time, SurfaceFlinger turns on Vsync signal calibration, receives the second Vsync signal, and determines that the display has completed the screen refresh rate switch based on the cycle of receiving the second Vsync signal, then switches the signal cycle of the first Vsync signal from 16ms to 8ms. , to maintain periodic synchronization of the first Vsync signal and the second Vsync signal.

SurfaceFlinger can use the DiscSync::addResyncSample function to determine whether a second Vsync signal needs to be input. If not needed, SurfaceFlinger can turn off the second Vsync signal input through the EventControlThread thread, thus turning off Vsync signal calibration. After a period of time, if SurfaceFlinger needs to receive the second Vsync signal again to calibrate the first Vsync signal, the second Vsync signal input can be enabled again through the EventControlThread thread to enable Vsync signal calibration.

The refresh process of the display screen is from left to right (horizontal refresh, Horizontal Scanning) and from top to bottom (vertical refresh, Vertical Scanning), sequentially displaying the pixels on the image. When the display screen is refreshed, that is, a vertical refresh cycle is completed, there will be a short blank period (ie, Vertical Blanking Interval, VBI, vertical retrace period). At this time, the display screen sends out the second Vsync signal. Therefore, the V in Vsync refers to the vertical in vertical refresh. The period during which the display screen sends the second Vsync signal is equal to the time it takes for the display screen to refresh and display an image frame.

For example, under the Vsync mechanism, in the display process of APP in Android terminal devices, APP drawing and rendering are triggered by the Vsync-APP signal, SurfaceFlinger synthesis is triggered by the Vsync-SF signal, and display refresh display is triggered by the second Vsync signal. After receiving a Vsync-APP signal, the APP starts drawing and rendering the next image frame by calling the Central Processing Unit (CPU) and Graphic Processing Unit (GPU). After SurfaceFlinger receives a Vsync-SF signal, it starts synthesizing the next image frame. After the display screen receives a Vsync-HW signal, it starts displaying the next image frame. This completes the synchronization of APP drawing and rendering, SurfaceFlinger synthesis, and display refresh display. Refer to Figure 1, which shows a schematic diagram of the Android Vsync mechanism. As shown in Figure 1, based on the Vsync mechanism of the Android system, the Android terminal device display process is as follows:

1) In the i-th signal period, the display screen displays the image frame Frame0 synthesized by SurfaceFlinger; the image frame Frame1 synthesized by SurfaceFlinger and drawn and rendered by APP; the APP draws and renders the image frame Frame2;

2) In the i+1 signal period, the display screen displays the image frame Frame1 synthesized by SurfaceFlinger; the image frame Frame2 synthesized by SurfaceFlinger and drawn and rendered by APP; the APP draws and renders the image frame Frame3;

3) In the i+2 signal period, the display screen displays the image frame Frame2 synthesized by SurfaceFlinger; the image frame Frame3 synthesized by SurfaceFlinger and drawn and rendered by APP; the APP draws and renders the image frame Frame4;

4) In the i+3 signal period, the display screen displays the image frame Frame3 synthesized by SurfaceFlinger; the image frame Frame4 drawn and rendered by the APP is synthesized by SurfaceFlinger; the image frame Frame5 is drawn and rendered by the APP, and so on.

The signal period refers to the signal period of the first Vsync signal and the second Vsync signal. The first Vsync signal maintains periodic synchronization with the second Vsync signal.

It can be seen that under the Vsync mechanism, the Android terminal device will pass through 2 signal cycles from drawing an image frame to the final display of the image frame on the display screen, which means there is a delay of 2 signal cycles.

Software systems of electronic devices can adopt layered architecture, event-driven architecture, microkernel architecture, microservice architecture, or cloud architecture. The embodiment of this application takes the Android system with a layered architecture as an example to illustrate the software structure of the electronic device.

FIG. 2A is a software structure block diagram of an electronic device according to an embodiment of the present application.

The layered architecture divides the software into several layers, and each layer has clear roles and division of labor. The layers communicate through software interfaces. In some embodiments, the Android system is divided into five layers, from top to bottom: application layer, application framework layer, Android runtime (Android runtime, ART) and native C/C++ library, hardware abstraction layer (Hardware Abstract Layer, HAL) and the kernel layer.

The application layer can include a series of application packages.

As shown in Figure 2A, the application package can include camera, gallery, calendar, calling, map, navigation, WLAN, Bluetooth, music, video, short message and other applications.

The application framework layer provides an application programming interface (API) and programming framework for applications in the application layer. The application framework layer includes some predefined functions.

As shown in Figure 2A, the application framework layer can include the refresh rate control module, SurfaceFlinger, window manager, content provider, view system, resource manager, notification manager, activity manager, input manager, etc.

Among them, the refresh rate control module has the ability to sense external events. For example, the refresh rate control module can detect user interface (UI) events from the application or hardware abstraction layer or kernel layer of the application layer through APIs. The UI event may be triggered by the user's click operation or sliding operation on the electronic device. Alternatively, the UI event may be automatically triggered by the electronic device. For example, when the foreground application of an electronic device automatically switches screens, the above UI event can be triggered. The foreground application is an application corresponding to the interface currently displayed on the display screen of the electronic device. For another example, the electronic device receives a message notification and needs to display a pop-up window, which triggers the above UI event. Based on the detected UI event, the screen refresh rate suitable for the current display scene can be determined, and the display screen is controlled to switch the screen refresh rate to the screen refresh rate suitable for the current display scene.

The switching process of the screen refresh rate of the display screen may include: the refresh rate control module sends a refresh rate switching instruction to SurfaceFlinger, SurfaceFlinger issues the refresh rate switching instruction to HWC (hwcomposer, hardware synthesis module), and HWC then issues the refresh rate The switching instruction is given to the display driver. After receiving the refresh rate switching instruction, the display driver notifies the display driver chip to switch to the target refresh rate. The display driver chip drives the display (such as OLED or LCD) to complete the screen refresh rate switching and refresh the screen with the new one. The image is refreshed and displayed at a certain rate, and the display driver chip periodically sends a second Vsync signal to the display driver. The display driver reports the second Vsync signal. SurfaceFlinger receives the second Vsync signal, and determines whether the signal period of the second Vsync signal is the period corresponding to the target refresh rate based on the received period of the second Vsync signal. If so, it can be determined that the screen refresh rate switching is completed. SurfaceFlinger generates the corresponding first Vsync signal according to the cycle corresponding to the target refresh rate. APP and SurfaceFlinger will perform layer drawing and layer processing only after receiving the first Vsync signal. Rendering and layer compositing operations. In this way, the frame rate of the layer drawing, layer rendering and layer composition operations of the APP and SurfaceFlinger can be switched to be consistent with the target refresh rate.

The window manager provides window management service (Window Manager Service, WMS). WMS can be used for window management, window animation management, surface management, and as a transfer station for the input system.

Content providers are used to store and retrieve data and make this data accessible to applications. This data can include videos, images, audio, calls made and received, browsing history and bookmarks, phone books, etc.

The view system includes visual controls, such as controls that display text, controls that display pictures, etc. A view system can be used to build applications. The display interface can be composed of one or more views. For example, a display interface including a text message notification icon may include a view for displaying text and a view for displaying pictures.

The resource manager provides various resources to applications, such as localized strings, icons, pictures, layout files, video files, etc.

The notification manager allows applications to display notification information in the status bar, which can be used to convey notification-type messages and can automatically disappear after a short stay without user interaction. For example, the notification manager is used to notify download completion, message reminders, etc. The notification manager can also be notifications that appear in the status bar at the top of the system in the form of charts or scroll bar text, such as notifications for applications running in the background, or notifications that appear on the screen in the form of conversation windows. For example, text information is prompted in the status bar, a beep sounds, the electronic device vibrates, the indicator light flashes, etc.

The Activity Manager can provide Activity Management Service (AMS), which can be used for the startup, switching, and scheduling of system components (such as activities, services, content providers, and broadcast receivers) as well as the management and scheduling of application processes. .

The input manager can provide input management service (Input Manager Service, IMS). IMS can be used to manage system input, such as touch screen input, key input, sensor input, etc. IMS takes out events from the input device node and distributes the events to appropriate windows through interaction with WMS.

The Android runtime includes core libraries and Android runtime. The Android runtime is responsible for converting source code into machine code. The Android runtime mainly includes the use of ahead or time (AOT) compilation technology and just in time (JIT) compilation technology.

The core library is mainly used to provide basic Java class library functions, such as basic data structures, mathematics, IO, tools, databases, networks and other libraries. The core library provides APIs for users to develop Android applications.

Native C/C++ libraries can include multiple function modules. For example: surface manager (surface manager), media framework (Media Framework), libc, OpenGL ES, SQLite, Webkit, etc.

Among them, the surface manager is used to manage the display subsystem and provides the integration of 2D and 3D layers for multiple applications. The media framework supports playback and recording of a variety of commonly used audio and video formats, as well as static image files, etc. The media library can support a variety of audio and video encoding formats, such as: MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, etc. OpenGL ES provides the drawing and manipulation of 2D graphics and 3D graphics in applications. SQLite provides a lightweight relational database for electronic device 100 applications.

The hardware abstraction layer runs in user space, encapsulates the kernel layer driver, and provides a calling interface to the upper layer. The hardware abstraction layer can include HWC. HWC has the function or ability to use hardware to complete the combination and display of image data. The specific image display can be completed by multiple classes such as SurfaceFlinger, HWC, display screen, etc.

HWC is a module of the hardware abstraction layer that synthesizes and displays windows/layers in the Android system. Provide hardware support for SurfaceFlinger service.

Among them, SurfaceFlinger provides all soft layer information to HWC and asks HWC how to process it. Furthermore, HWC can decide whether to use HWC's underlying hardware (for example, hardware synthesizer) or GPU synthesis based on hardware performance; for example, HWC will mark the synthesis method for each layer, whether it is synthesized through GPU or HWC. On the one hand, SurfaceFlinger processes soft layers that require GPU synthesis and submits the results to the display through HWC; on the other hand, soft layers that require hardware compositor synthesis are processed by HWC itself.

SurfaceFlinger can use 3D graphics processing libraries (such as OpenGL ES) to synthesize layers, which requires and consumes GPU resources. Most GPUs are not optimized for layer compositing, and while SurfaceFlinger composites layers through the GPU, applications cannot use the GPU for their own rendering. HWC performs layer synthesis through a hardware synthesizer, which can reduce the synthesis pressure on the GPU.

The kernel layer is the layer between hardware and software. The kernel layer contains at least display driver, camera driver, audio driver, and sensor driver. Specific to this application solution, the hardware involved may include display driver chips (such as display driver integrated circuit, DDIC) and display screens (such as OLED or LCD). The display driver is used to drive the DDIC to complete display processing and implementation.

Taking the user starting application A as an example, after the user starts application A, the display screen will display the interface of application A. Specifically, Application A sends the display parameters of the interface to be displayed to SurfaceFlinger. SurfaceFlinger is responsible for controlling the integration of the surface. As an example, the interface here may be the interface presented by the status bar, the system bar, the application itself (the interface to be displayed by application A), wallpaper, background, etc. Therefore, SurfaceFlinger can not only obtain the display parameters of the interface to be displayed by application A, but also obtain the display parameters of other interfaces. SurfaceFlinger sends the display parameters of each interface (such as memory address, color, etc.) to HWC through interfaces (such as set Layer Buffer, set Layer Color, etc.) for interface fusion. Usually, in image synthesis (for example, when an electronic device displays an image, it needs to synthesize the status bar, system bar, application itself and wallpaper background), HWC is obtained through the underlying hardware of HWC (such as hardware synthesizer) according to the display parameters of each interface. The combined image. It should be noted that SurfaceFlinger will not end the task of synthesizing images until HWC obtains the synthesized image through the underlying hardware. HWC sends the underlying hardware-synthesized image to the kernel-layer display driver. The display driver of the kernel layer sends the synthesized image to the display driver chip of the hardware layer. The display driver chip of the hardware layer performs secondary processing on the synthesized image and sends the secondary processed image to the display screen for display. In practical applications, secondary processing may not be performed. If no secondary processing is performed, the display driver at the hardware layer directly sends the synthesized image to the display screen for display. According to the above method, the display screen can complete a refresh display process. The electronic device can execute the above refresh display process in a certain period according to the screen refresh rate of the display screen. For example, the screen refresh rate of the display screen is 60Hz, and the corresponding signal period is 16ms, which is equivalent to executing the above refresh display process every 16ms.

For example, the electronic device in the embodiment of the present application may be a mobile phone, a tablet computer, a desktop, a laptop, a handheld computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, and a cellular phone. Telephones, personal digital assistants (PDAs), augmented reality (AR)/virtual reality (VR) devices, and other devices including touch screens. The embodiments of this application do not make special arrangements for the specific form of the electronic devices. limit.

The implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Please refer to FIG. 2B , which is a schematic structural diagram of an electronic device 200 provided by an embodiment of the present application. As shown in Figure 2B As shown, the electronic device 200 may include a processor 210, an external memory interface 220, an internal memory 221, a universal serial bus (USB) interface 230, a charging management module 240, a power management module 241, a battery 242, and an antenna 1 , antenna 2, mobile communication module 250, wireless communication module 260, audio module 270, sensor module 280, button 290, motor 291, indicator 292, camera 293, display screen 294, and subscriber identification module (SIM) Card interface 295, etc.

Among them, the sensor module 280 may include a touch sensor. It can be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the electronic device 200 . In other embodiments, the electronic device 200 may include more or fewer components than illustrated, or some components may be combined, or some components may be separated, or may be arranged differently. The components illustrated may be implemented in hardware, software, or a combination of software and hardware.

Processor 210 may include one or more processing units. Among them, different processing units can be independent devices or integrated in one or more processors.

The controller may be the nerve center and command center of the electronic device 200 . The controller can generate operation control signals based on the instruction operation code and timing signals to complete the control of fetching and executing instructions.

The processor 210 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in processor 210 is cache memory. This memory may hold instructions or data that have been recently used or recycled by processor 210 . If the processor 210 needs to use the instructions or data again, it can be called directly from the memory. Repeated access is avoided and the waiting time of the processor 210 is reduced, thus improving the efficiency of the system.

In some embodiments, processor 210 may include one or more interfaces. Interfaces may include integrated circuit (inter-integrated circuit, I2C) interface, integrated circuit built-in audio (inter-integrated circuit sound, I2S) interface, pulse code modulation (pulse code modulation, PCM) interface, universal asynchronous receiver and transmitter (universal asynchronous receiver/transmitter (UART) interface, mobile industry processor interface (MIPI), general-purpose input/output (GPIO) interface, subscriber identity module (SIM) interface, and /or universal serial bus (USB) interface, etc.

It can be understood that the interface connection relationships between the modules illustrated in this embodiment are only schematic illustrations and do not constitute a structural limitation of the electronic device 200 . In other embodiments, the electronic device 200 may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

The charge management module 240 is used to receive charging input from the charger. While charging the battery 242, the charging management module 240 can also provide power to the electronic device through the power management module 241.

The power management module 241 is used to connect the battery 242, the charging management module 240 and the processor 210. The power management module 241 receives input from the battery 242 and/or the charging management module 240 and supplies power to the processor 210, internal memory 221, external memory, display screen 294, camera 293, wireless communication module 260, etc. In some other embodiments, the power management module 241 may also be provided in the processor 210 . In other embodiments, the power management module 241 and the charging management module 240 may also be provided in the same device.

The wireless communication function of the electronic device 200 can be implemented through the antenna 1, the antenna 2, the mobile communication module 250, the wireless communication module 260, the modem processor and the baseband processor.

Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in electronic device 200 may be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example: Antenna 1 can be reused as a diversity antenna for a wireless LAN.

The mobile communication module 250 can provide wireless communication solutions including 2G/3G/4G/5G applied to the electronic device 200 . The mobile communication module 250 may include at least one filter, switch, power amplifier, low noise amplifier (LNA), etc. The mobile communication module 250 can receive electromagnetic waves from the antenna 1, perform filtering, amplification and other processing on the received electromagnetic waves, and transmit them to the modem processor for demodulation. The mobile communication module 250 can also amplify the signal modulated by the modem processor and convert it into electromagnetic waves through the antenna 1 for radiation.

A modem processor may include a modulator and a demodulator. Among them, the modulator is used to modulate the low-frequency baseband signal to be sent into a medium-high frequency signal. The demodulator is used to demodulate the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing. After the low-frequency baseband signal is processed by the baseband processor, it is passed to the application processor. The application processor outputs sound signals through the audio device, or displays images or videos through the display screen 294.

The wireless communication module 260 can provide applications on the electronic device 200 including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) network), Bluetooth (bluetooth, BT), and global navigation satellites. System (global navigation satellite system, GNSS), frequency modulation (frequency modulation, FM), near field communication technology (near field communication, NFC), infrared technology (infrared, IR) and other wireless communication solutions. The wireless communication module 260 may be one or more devices integrating at least one communication processing module. The wireless communication module 260 receives electromagnetic waves via the antenna 2 , frequency modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 210 . The wireless communication module 260 can also receive the signal to be sent from the processor 210, frequency modulate it, amplify it, and convert it into electromagnetic waves through the antenna 2 for radiation.

In some embodiments, the antenna 1 of the electronic device 200 is coupled to the mobile communication module 250, and the antenna 2 is coupled to the wireless communication module 260, so that the electronic device 200 can communicate with the network and other devices through wireless communication technology.

The electronic device 200 implements display functions through a GPU, a display screen 294, an application processor, and the like. The GPU is an image processing microprocessor and is connected to the display screen 294 and the application processor. GPUs are used to perform mathematical and geometric calculations for graphics rendering. Processor 210 may include one or more GPUs that execute program instructions to generate or alter display information.

The display screen 294 is used to display images, videos, etc. The display screen 294 includes a display panel. The display panel can use a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active matrix organic light emitting diode or an active matrix organic light emitting diode (active-matrix organic light emitting diode). emitting diode (AMOLED), flexible light-emitting diode (FLED), Miniled, MicroLed, Micro-OLED, quantum dot light emitting diode (QLED), etc.

Among them, the display screen 294 in the embodiment of the present application may be a touch screen. That is, the display screen 294 integrates a touch sensor. The touch sensor may also be referred to as a "touch panel." That is to say, the display screen 294 may include a display panel and a touch panel. The touch sensor and the display screen 294 form a touch screen, which is also called a "touch screen". Touch sensors are used to detect touches on or near them. After the touch operation detected by the touch sensor, it can be passed to the upper layer by the kernel layer driver (such as TP driver) to determine the touch event type. Visual output related to the touch operation may be provided through display screen 294. In other embodiments, the touch sensor may also be provided The surface of the electronic device 200 is in a different position from the display screen 294 .

The electronic device 200 can implement the shooting function through an ISP, a camera 293, a video codec, a GPU, a display screen 294, and an application processor. The ISP is used to process the data fed back by the camera 293. Camera 293 is used to capture still images or video. Digital signal processors are used to process digital signals. In addition to digital image signals, they can also process other digital signals. Video codecs are used to compress or decompress digital video. Electronic device 200 may support one or more video codecs. In this way, the electronic device 200 can play or record videos in multiple encoding formats, such as: moving picture experts group (MPEG) 1, MPEG2, MPEG3, MPEG4, etc.

The external memory interface 220 can be used to connect an external memory card, such as a MicroSD card, to expand the storage capacity of the electronic device 200 . The external memory card communicates with the processor 210 through the external memory interface 220 to implement the data storage function. Such as saving music, videos, etc. files in external memory card. Internal memory 221 may be used to store computer executable program code, which includes instructions. The processor 210 executes instructions stored in the internal memory 221 to execute various functional applications and data processing of the electronic device 200 . For example, in this embodiment of the present application, the processor 210 can execute instructions stored in the internal memory 221, and the internal memory 221 can include a program storage area and a data storage area. Among them, the stored program area can store an operating system, at least one application program required for a function (such as a sound playback function, an image playback function, etc.). The storage data area may store data created during use of the electronic device 200 (such as audio data, phone book, etc.). In addition, the internal memory 221 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.

The electronic device 200 can implement audio functions through the audio module 270, the speaker 270A, the receiver 270B, the microphone 170C, the headphone interface 270D, and the application processor. Such as music playback, recording, etc.

The audio module 270 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. Audio module 270 may also be used to encode and decode audio signals.

The buttons 290 include a power button, a volume button, etc. Key 290 may be a mechanical key. It can also be a touch button. The electronic device 200 may receive key input and generate key signal input related to user settings and function control of the electronic device 200 . The motor 291 can generate vibration prompts. The motor 291 can be used for vibration prompts for incoming calls and can also be used for touch vibration feedback. The indicator 292 may be an indicator light, which may be used to indicate charging status, power changes, or may be used to indicate messages, missed calls, notifications, etc. The SIM card interface 295 is used to connect a SIM card. The SIM card can be connected to or separated from the electronic device 200 by inserting it into the SIM card interface 295 or pulling it out from the SIM card interface 295 . The electronic device 200 may support 1 or N SIM card interfaces, where N is a positive integer greater than 1. SIM card interface 295 can support Nano SIM card, Micro SIM card, SIM card, etc.

The methods in the following embodiments can all be implemented in the electronic device 200 with the above hardware structure.

In one scenario, if the user does not operate the electronic device, the electronic device does not receive notifications, etc., no pop-up window appears, and the display screen of the electronic device displays a static image, at this time, the screen refresh rate of the display screen is changed from high to high. Switching the refresh rate to a low refresh rate can save power and CPU resources. Among them, low refresh rate means that the screen refresh rate of the display screen is less than or equal to the preset threshold, such as the screen refresh rate is 10Hz or 1Hz. High refresh rate means that the screen refresh rate of the display is greater than the preset threshold, such as the screen refresh rate of 60Hz, 90Hz or 120Hz. However, when the screen refresh rate of the display is low, if the user performs a click operation or sliding operation, or the terminal receives a message notification, If the display screen needs to display pop-up windows, or the electronic device display screen needs to display animations, etc., the display screen needs to exit the low refresh rate and switch back to the high refresh rate.

Referring to Figure 3, Figure 3 shows a screen refresh rate switching flow chart under the native mechanism of the Android system in a scenario where the display screen needs to exit a low refresh rate and switch back to a high refresh rate. As shown in Figure 3, the screen refresh rate switching process under the native mechanism of the Android system includes the following steps:

S301, SurfaceFlinger in the i-th signal period (the signal period is the signal period T1 corresponding to the first refresh rate f1, T1 is equal to the reciprocal of the first refresh rate, that is, T1=1/f1, for example, in the case of f1=10Hz, Receive the first refresh rate switching command within T1=100ms). The first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. Wherein, the first refresh rate is less than or equal to the preset threshold, and the second refresh rate is greater than the preset threshold.

It should be understood that if the electronic device receives a user operation (such as a click or sliding operation) or receives a notification that an interface update is required during the i-th signal period, the frame rate control module of the electronic device will respond to the above situation after sensing the above situation. SurfaceFlinger issues a first refresh rate switching command to instruct the display screen refresh rate to switch from the first refresh rate to the second refresh rate.

S302. SurfaceFlinger receives the first refresh rate switching instruction. In response to the end of the i-th signal period, that is, the beginning of the i+1th signal period, a first Vsync signal will be generated to trigger SurfaceFlinger to perform new layer synthesis, and Send the first refresh rate switching command to the display driver; and start Vsync signal calibration.

S303. The display driver receives the first refresh rate switching command and sends the first refresh rate switching command to the display screen.

S304. The display screen receives the first refresh rate switching instruction, and refreshes and displays an image frame in the i+1th signal period.

S305. The display screen refreshes and displays one image frame. According to the first refresh rate switching instruction, the screen refresh rate of the display screen is switched from the first refresh rate to the second refresh rate, and the image frame is refreshed and displayed according to the second refresh rate. And the display screen periodically sends the second Vsync signal to the display driver according to the second refresh rate.

Through the above steps, the signal period of the second Vsync signal can be switched from T1 to the signal period T2 corresponding to the second refresh rate f2, and a second Vsync signal is reported to the display driver every other T2. Among them, T2 is equal to the reciprocal of the second refresh rate, that is, T2=1/f2.

S306. The display driver periodically receives the second Vsync signal from the display screen, and reports the received second Vsync signal to SurfaceFlinger.

S307. SurfaceFlinger periodically receives the second Vsync signal. If the period of receiving the second Vsync signal (period, that is, the interval between receiving two adjacent second Vsync signals) is T2, SurfaceFlinger confirms that the screen refresh rate switching is completed and turns off Vsync signal calibration. If the period of the second Vsync signal received by SurfaceFlinger is not equal to T2, step S307 is continued.

In this way, after SurfaceFlinger determines that the screen refresh rate switching is completed, it can respond to the end of the current signal period (i+2 signal period) and periodically generate the first Vsync signal according to the calibrated signal period of the Vsync signal, that is, T2. . That is to say, the signal period of the first Vsync signal is adjusted to T2.

It should be understood that in the above step S306, after SurfaceFlinger confirms that the screen refresh rate switching is completed, it adjusts the signal period of the first Vsync signal to T2, which needs to take effect at the end of the i+2th signal period, that is, That is to say, SurfaceFlinger can periodically generate the first Vsync signal (including the Vsync-APP signal and the Vsync-SF signal) at the second refresh rate and with T2 as the period at the end of the i+2 signal period.

For example, the first refresh rate is 10Hz, and the corresponding T1 is 100ms. The second refresh rate is 60Hz, and the corresponding T2 is 16ms. The default refresh rate is 120Hz, and the corresponding preset period is 8ms.

According to the screen refresh rate switching process under the native mechanism of the Android system mentioned above, when it is necessary to switch the screen refresh rate of the display from a low refresh rate (first refresh rate) to a high refresh rate (second refresh rate), SurfaceFlinger receives After the first refresh rate switching instruction, SurfaceFlinger still needs to complete the layer synthesis of the current image frame according to the current signal period (i-th signal period). At the end of the i-th signal period, that is, the i+1-th signal period begins. A first Vsync signal will be generated to trigger new layer synthesis. Only then will the first refresh rate switching command be issued and Vsync signal calibration started. Moreover, after the display screen receives the first refresh rate switching command, it still needs to perform an image frame refresh display according to the current signal cycle (i+1th signal cycle) before changing the screen refresh rate of the display screen from the first refresh rate to the first refresh rate switching command. The refresh rate is switched to the second refresh rate, that is, the signal period of the second Vsync signal is switched from T1 to T2 (for example, 16 ms), and a second Vsync signal is reported to the display driver every T2. SurfaceFlinger receives the second Vsync signal, and determines whether the signal period of the second Vsync signal is T2 based on the interval between receiving the two second Vsync signals. If so, it can be confirmed that the screen refresh rate switching is completed. However, SurfaceFlinger needs to end at the current signal period (i+2 signal period) before it can generate the first Vsync signal at the second refresh rate and T2 as the signal period. In this way, according to the screen refresh rate switching process under the native mechanism of the Android system, the entire screen refresh rate switching process (from SurfaceFlinger receiving the first refresh rate switching instruction to SurfaceFlinger generating the first Vsync signal at the second refresh rate) requires at least two The signal period (the signal period is T1, and the two signal periods are the 2-frame processing time at a low refresh rate) can be completed.

For example, the first situation: SurfaceFlinger receives the first refresh rate switching instruction when the i-th signal period is about to end, that is, the t1 moment shown in Figure 3 is close to the end of the i-th signal period, x1≈0. SurfaceFlinger issues the first refresh rate switching command at the beginning of the i+1th signal cycle. The display screen receives the first refresh rate switching command during the i+1th signal cycle. According to the current signal cycle (ith signal cycle) +1 signal period) after executing an image frame refresh display, the screen refresh rate of the display screen is switched from the first refresh rate to the second refresh rate, and a second Vsync signal is reported to the display driver every T2. SurfaceFlinger receives the second Vsync signal, and determines whether the signal period of the second Vsync signal is T2 based on the interval between receiving the two second Vsync signals. If so, it can be confirmed that the screen refresh rate switch is completed. At this time, it is already in the second Vsync signal. Within i+2 signal periods. Therefore, SurfaceFlinger needs to end at the current signal period (i+2 signal period) (at the t2 moment as shown in Figure 3) to generate the first Vsync signal at the second refresh rate and with T2 as the signal period. The first situation is the situation where the entire screen refresh rate switching process takes the shortest time. It takes nearly One signal period (the signal period is T1, such as T1 = 100ms, one signal period is 100ms), and the first refresh rate switching instruction is received from SurfaceFlinger to SurfaceFlinger generating the first Vsync signal at the second refresh rate (from t1 time to time t2) it takes two signal periods (the signal period is T1, for example, T1=100ms, the two signal periods are 200ms).

For another example, the second case: SurfaceFlinger receives the first refresh rate switching command at the beginning of the i-th signal cycle, that is, the t1 moment shown in Figure 3 is close to the beginning of the i-th signal cycle, x1≈100. but SurfaceFlinger needs to wait until the end of the current signal cycle and issue the first refresh rate switching command at the beginning of the i+1th signal cycle. The display screen receives the first refresh rate switching command within the i+1th signal cycle. It is still necessary to perform an image frame refresh display according to the current signal period (i+1th signal period), and then switch the screen refresh rate of the display screen from the first refresh rate to the second refresh rate, and every T2 Report a second Vsync signal to the display driver. When SurfaceFlinger receives the second Vsync signal and determines that the period of the second Vsync signal is T2, it can confirm that the screen refresh rate switching is completed, which is already within the i+2th signal period. Therefore, SurfaceFlinger needs to end at the current signal period (i+2 signal period) (at the t2 moment as shown in Figure 3) to generate the first Vsync signal at the second refresh rate and with T2 as the signal period. The second case is the one that takes the longest time for the entire screen refresh rate switching process. It takes time from SurfaceFlinger receiving the first refresh rate switching instruction to the time the screen refresh rate of the display screen switches from the first refresh rate to the second refresh rate. Nearly two signal periods (the signal period is T1, such as T1 = 100ms, the two signal periods are 200ms), and from when SurfaceFlinger receives the first refresh rate switching command to when SurfaceFlinger generates the first Vsync signal at the second refresh rate It takes three signal periods (from time t1 to time t2) (the signal period is T1, for example, T1=100ms, and the three signal periods are 300ms).

And if the first refresh rate is 1Hz, the corresponding T1 is 1000ms. According to the screen refresh rate switching process under the native mechanism of the Android system, the entire screen refresh rate switching process requires at least 2000ms, or 2s).

Therefore, when switching the screen refresh rate of the display from a high refresh rate to a low refresh rate, since the signal period corresponding to the high refresh rate is shorter, the screen refresh rate switching process takes less time and will not cause lag problems. However, in terms of the processing mechanism for switching the screen refresh rate of the display from a low refresh rate back to a high refresh rate, according to the native mechanism of the Android system, it takes at least two cycles at a low refresh rate to complete the entire screen refresh rate. switching process. For example, if the initial screen refresh rate of the display is 10Hz, it will take at least 200ms to complete the entire screen refresh rate switching process. For another example, if the initial screen refresh rate of the display is 1Hz, it will take at least 2 seconds to complete the entire screen refresh rate switching process. The screen refresh rate switching process takes a long time and the switching performance is poor. Under such a mechanism, lag may occur when the screen refresh rate of the display screen is switched, seriously affecting the chirality of the electronic device.

Among them, the hand-following performance of electronic equipment can be reflected in the length of user operation response delay. User operation response delay can be understood as the delay time from "the user performs a click or slide operation on the electronic device" to "the electronic device displays the image corresponding to the click or slide operation and is perceived by the human eye."

Specifically, the longer the user operation response delay, the worse the follow-up performance; the shorter the user operation response delay, the better the follow-up performance. Among them, the better the tracking performance of the electronic device, the better the user experience of controlling the electronic device through clicking or sliding operations, and the smoother it feels.

Based on this, embodiments of the present application provide a screen refresh rate switching method, which can be applied to electronic devices, where the electronic devices include a display screen. The method includes: the SurfaceFlinger of the electronic device receives a first refresh rate switching instruction from an upper layer (such as a frame rate control module of the electronic device). The first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. Wherein, the first refresh rate is less than or equal to the preset threshold, and the second refresh rate is greater than the preset threshold. SurfaceFlinger sends a first refresh rate switching instruction to the display driver of the electronic device in response to the end of the signal period of the current first Vsync signal. Among them, the first Vsync signal is used to trigger SurfaceFlinger for layer synthesis. The signal period of the first Vsync signal is set to a preset period when the screen refresh rate of the display screen is the first refresh rate. The preset period is less than the first The reciprocal of the refresh rate. In response to the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate.

It should be understood that the above-mentioned first refresh rate is less than or equal to the preset threshold, which is a low refresh rate. The above second refresh rate is greater than the preset threshold, which is a high refresh rate.

Illustratively, the technical solutions provided by the above embodiments of this application can be applied to the following scenarios:

In the first application scenario, the display screen of the electronic device displays a static image, the screen refresh rate of the display screen is low, and the user performs a click operation at this time. In response to the user's click operation, the electronic device needs to update the display screen of the display screen, and the screen refresh rate of the display screen switches from the first refresh rate to the second refresh rate.

In the second application scenario, the display screen of the electronic device displays a static image, the screen refresh rate of the display screen is low, and the user performs a sliding operation at this time. In response to the user's sliding operation, the electronic device needs to update the display screen of the display screen, and the screen refresh rate of the display screen switches from the first refresh rate to the second refresh rate.

In the third application scenario, the display screen of the electronic device displays a static image, and the screen refresh rate of the display screen is a low refresh rate. At this time, the electronic device receives a message notification and the display screen needs to display a pop-up window. That is, it is necessary to update the display screen of the display screen and switch the screen refresh rate of the display screen from the first refresh rate to the second refresh rate.

In the fourth application scenario, the display screen of the electronic device displays a static image, and the screen refresh rate of the display screen is a low refresh rate, and at this time the display screen needs to display animation. That is, it is necessary to update the display screen of the display screen and switch the screen refresh rate of the display screen from the first refresh rate to the second refresh rate.

In the above application scenarios and similar scenarios, using the screen refresh rate switching method provided by the above embodiments of the present application, when the display screen of the electronic device displays a static image and the screen refresh rate of the display screen is low, the first Vsync The signal period of the signal is set to the preset period, and SurfaceFlinger runs according to the preset period. In this way, when it is necessary to switch the screen refresh rate of the display screen from a low refresh rate back to a high refresh rate, SurfaceFlinger can issue the first refresh rate switching command in time, and the display screen can also receive the first refresh rate switching command in time and respond in time. The first refresh rate switching command should be used to switch the screen refresh rate, so that the display can quickly exit the low refresh rate and switch back to the high refresh rate, reducing the screen refresh rate switching time of the display to ensure that the new image frame is pressed Displaying with a high refresh rate can ensure the sliding effect of the display and the smooth display of animation effects, ensuring that users will not feel stuck and ensuring the user experience. Through the methods of the embodiments of the present application, the speed with which the electronic device responds to user operations and switches from a low refresh rate back to a high refresh rate can be improved, and the switching performance can be optimized. This can shorten the user operation response delay of the electronic device, improve the tracking performance of the electronic device, and enhance the user experience.

Before the display screen of an electronic device switches from a low refresh rate back to a high refresh rate, it goes through a stage where the screen refresh rate switches to a low refresh rate. The technical solution provided by the embodiment of the present application can make some preparations in advance when the screen refresh rate of the display screen switches to a low refresh rate stage (such as controlling SurfaceFlinger to set its signal period to a preset value at a low refresh rate). cycle), to facilitate the electronic device to switch from a low refresh rate to a high refresh rate, the method (such as S601-S603) in the embodiment of the present application can be executed to solve the corresponding technical problem.

Specifically, referring to FIG. 4 , embodiments of the present application provide a screen refresh rate switching method for the scenario where the screen refresh rate is switched to a low refresh rate. The method can be applied to electronic devices including display screens. The method includes steps S401-S405.

S401. The display screen receives the second refresh rate switching instruction. The second refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch to the first refresh rate. Wherein, the first refresh rate is less than or equal to the preset threshold.

For example, in some scenarios, the display screen refresh rate of the electronic device can be switched from a high refresh rate to a low refresh rate. refresh rate. For example, the refresh rate of the electronic device can be switched from another refresh rate (such as a third refresh rate) higher than the first refresh rate to the first refresh rate. For example, after the electronic device switches from displaying dynamic images to displaying static images, the screen refresh rate of the display screen can be switched from a high refresh rate to a low refresh rate to reduce power consumption.

For example, if the electronic device does not receive the user's operation within a certain period of time, the electronic device can automatically display the above static image. At this time, the upper layer can send a second refresh rate switching instruction to the display screen of the electronic device to instruct the screen refresh rate of the display screen to switch from the third refresh rate to the first refresh rate. At this time, the display screen can receive the above-mentioned second refresh rate switching instruction.

For another example, after the electronic device finishes playing the dynamic image (such as a video), it can automatically display the static image. At this time, the upper layer can send a second refresh rate switching instruction to the display screen of the electronic device to instruct the screen refresh rate of the display screen to switch from the third refresh rate to the first refresh rate. The display screen can receive the above-mentioned second refresh rate switching instruction.

Of course, the scenario in which the screen refresh rate of the display screen switches from a high refresh rate to a low refresh rate includes but is not limited to the situation shown in the above example, and other situations will not be described in detail here in the embodiment of the present application.

S402. The display screen responds to the second refresh rate switching instruction, switches the screen refresh rate of the display screen to the preset refresh rate, and sends the second Vsync signal to SurfaceFlinger through the display driver according to the preset cycle. Wherein, the preset period is equal to the reciprocal of the preset refresh rate, and the preset refresh rate is greater than the preset threshold. The second Vsync signal is used to trigger the display screen to refresh the display image frame.

S403. SurfaceFlinger receives the second Vsync signal from the display driver.

S404: SurfaceFlinger determines whether the period of receiving the second Vsync signal from the display driver (ie, the second signal period) is equal to the preset period.

If the period of receiving the second Vsync signal from the display driver (ie, the second signal period) is equal to the preset period, step S404 is performed. If the period of receiving the second Vsync signal from the display driver (ie, the second signal period) is not equal to the preset period, step 403 is continued.

S405. SurfaceFlinger sets the signal period of the first Vsync signal to the preset period, and stops receiving the second Vsync signal from the display driver. Among them, the first Vsync signal is used to trigger SurfaceFlinger for layer synthesis.

That is to say, after the display screen receives the second refresh rate switching instruction, in response to the second refresh rate switching instruction, before switching the screen refresh rate of the display screen to a low refresh rate, the display screen first changes the screen refresh rate of the display screen to a low refresh rate. Switch to default refresh rate. In this way, the display screen can send the second Vsync signal to SurfaceFlinger according to the preset period (that is, every preset period, a second Vsync signal is reported to SurfaceFlinger through the display driver). The second Vsync signal can be used by SurfaceFlinger to perform Vsync signal calibration to achieve cycle synchronization between the first Vsync signal and the second Vsync signal. After SurfaceFlinger completes the Vsync signal calibration, it can run according to the preset period, that is, the signal period of the first Vsync signal is the preset period. In this way, when a new refresh rate switching instruction (such as a first refresh rate switching instruction) is subsequently received, the refresh rate switching instruction can be issued in a timely manner.

In some embodiments, the display screen responds to the second refresh rate switching instruction and switches the screen refresh rate of the display screen to the first refresh rate after a preset period of time.

It should be understood that the display screen responds to the second refresh rate switching instruction. After a preset period of time, SurfaceFlinger has completed the Vsync signal calibration. At this time, the screen refresh rate of the display screen can be switched to the first refresh rate, that is, the screen refresh rate can be reduced. How often to refresh display image frames to save power and CPU resources. And SurfaceFlinger at this time Vsync signal calibration has been turned off, and SurfaceFlinger continues to run according to the preset cycle. It should be noted that although SurfaceFlinger runs according to the preset cycle, if it is to display a static image and the display screen needs to display static content, then the Surface content in the display area is not updated, and SurfaceFlinger does not need to perform a synthesis operation. The APP does not need to perform layer drawing and layer rendering operations. Therefore, SurfaceFlinger runs according to the preset cycle and does not increase the energy consumption of layer composition operations.

In some embodiments, the preset threshold may be 30 Hz. The preset threshold can be determined based on the screen refresh rate switching performance requirements of the electronic device for the display screen.

In some embodiments, the preset refresh rate is a screen refresh rate supported by the display screen.

In some embodiments, the preset refresh rate may be 120 Hz, and the reciprocal of the preset refresh rate, that is, the preset period is 8 ms. The first refresh rate may be 10Hz or 1Hz, and the reciprocal T1 of the first refresh rate is 100ms or 1s. The second refresh rate may be 60Hz, 90Hz or 120Hz, and the reciprocal T2 of the second refresh rate is 16ms, 11ms or 8ms.

It should be understood that the second refresh rate switching instruction in the above step S401 is issued to the display screen by SurfaceFlinger. For example, when the electronic device (such as the frame rate control module of the electronic device) determines that the display content has not been updated, it can sequentially send the second refresh rate switching instructions to the display screen (such as the display driver of the display screen) through SurfaceFlinger, HWC, and the display driver. chip).

In some embodiments, SurfaceFlinger can receive the second refresh rate switching instruction from the upper layer, and in response to the second refresh rate switching instruction, start receiving the second Vsync signal from the lower layer, and issue the second refresh rate switching instruction. to the display.

In other words, SurfaceFlinger can start receiving the second Vsync signal from the lower layer after receiving the second refresh rate switching command, that is, when SurfaceFlinger determines that the screen refresh rate needs to be switched, Vsync signal calibration is turned on. In this way, SurfaceFlinger can receive the second Vsync signal according to the period (that is, the signal period of the second Vsync signal). Determine whether the screen refresh rate switching is completed, and then complete the Vsync signal calibration, that is, adjust the period during which SurfaceFlinger generates the first Vsync signal (that is, the signal period of the first Vsync signal. The first Vsync signal may include the Vsync-APP signal and the Vsync- SF signal), making the signal period of the first Vsync signal equal to the signal period of the second Vsync signal. After SurfaceFlinger completes the Vsync signal calibration, you can turn off the hardware Vsync calibration, that is, stop receiving the second Vsync signal from the display driver. At this time, SurfaceFlinger can periodically generate the first Vsync signal according to the signal cycle after Vsync signal calibration is completed to control the drawing and rendering cycle of the APP and the drawing cycle of SurfaceFlinger. In this way, SurfaceFlinger can confirm that the screen refresh rate of the display has been switched to the preset refresh rate, and SurfaceFlinger runs according to the preset cycle to synchronize with the screen refresh rate of the display. If a new refresh rate switching command is received later (such as the first refresh rate switching command), SurfaceFlinger can quickly respond to the new refresh rate switching command and issue the new refresh rate switching command after the current preset cycle. This allows the display to quickly switch from a low refresh rate back to a high refresh rate.

For example, in an application scenario, after the electronic device switches from displaying dynamic images to displaying static images, the screen refresh rate of the display screen needs to be switched from 60 Hz to 10 Hz. Referring to Figure 5, as shown in Figure 5, the screen refresh rate switching process can adopt the screen refresh rate switching method provided in the above embodiment (such as steps S401-S405), and the corresponding signal transmission process between various parts of the electronic device can include S501-S507.

S501. SurfaceFlinger receives the second refresh rate switching instruction from the upper layer (such as the frame rate control module) in the i-th signal period. The second refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to change from 60Hz to 60Hz. Switch to 10Hz.

The signal period refers to the signal period of the first Vsync signal. In this embodiment, the signal period is 16ms.

S502. SurfaceFlinger responds to the end of the i-th signal period (that is, the start of the i+1-th signal period), sends the second refresh rate switching instruction to the display driver, and turns on Vsync signal calibration.

For example, in response to the end of the i-th signal period, SurfaceFlinger issues the second refresh rate switching instruction to the display driver through the HWC.

S503. After receiving the second refresh rate switching command, the display driver issues the second refresh rate switching command to the display screen (such as the display driver chip of the display screen).

S504. The display screen receives the second refresh rate switching instruction.

S505. According to the second refresh rate switching instruction, the display screen first switches the screen refresh rate of the display screen to 120Hz, refreshes and displays the image frames according to the 8ms cycle, and the display screen periodically sends the second Vsync according to the 8ms cycle. The signal is sent to the display driver (that is, a second Vsync signal is reported to the display driver every 8ms).

S506. The display driver periodically receives the second Vsync signal from the display screen, and reports the received second Vsync signal to SurfaceFlinger.

S507. SurfaceFlinger periodically receives the second Vsync signal, and determines whether the signal period of the second Vsync signal is 8ms based on the period of receiving the second Vsync signal (that is, the interval between receiving two adjacent second Vsync signals). , if so, it can be determined that the screen refresh rate switching is completed and Vsync signal calibration is turned off. If the period of the second Vsync signal is not equal to 8ms, continue to step 507.

It should be understood that after SurfaceFlinger determines that the screen refresh rate switching is completed, in response to the end of the current signal period (16ms), it can periodically generate the first Vsync signal according to the calibrated signal period of the Vsync signal, that is, the 8ms signal period. That is to say, the signal period of the first Vsync signal is adjusted to 8ms.

It should be understood that the display screen responds to the second refresh rate switching instruction and switches the screen refresh rate of the display screen to 10 Hz after a preset period of time.

In some application scenarios, after the screen refresh rate of the display screen is switched to a low refresh rate, the screen refresh rate of the display screen needs to be switched back to a high refresh rate when user operations (such as clicks or sliding operations) or notifications are received. Referring to Figure 6, an embodiment of the present application provides a screen refresh rate switching method for the above application scenarios. The method can be applied to electronic devices including display screens. The method includes steps S601-S603.

S601. The SurfaceFlinger of the electronic device receives the first refresh rate switching instruction from the upper layer. The first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. Wherein, the first refresh rate is less than or equal to the preset threshold, and the second refresh rate is greater than the preset threshold.

S602. SurfaceFlinger sends a first refresh rate switching instruction to the display driver in response to the end of the signal period of the current first Vsync signal. Among them, the first Vsync signal is used to trigger SurfaceFlinger for layer synthesis. The signal period of the first Vsync signal is set to a preset period when the screen refresh rate of the display screen is the first refresh rate. The preset period is less than the reciprocal of the first refresh rate.

S603. In response to the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate.

It should be understood that if the electronic device receives a user operation (such as a click or sliding operation) or receives a notification within the signal period of the j-th first Vsync signal and needs to perform an interface update, the electronic device (such as the frame rate control module of the electronic device) ) can send the first refresh rate switching instruction to SurfaceFlinger after sensing the above situation. SurfaceFlinger can sequentially send the first refresh rate switching instructions to the display screen (such as the display driver chip of the display screen) through HWC and display driver to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. . The second refresh rate is greater than the first refresh rate.

In the above technical solution, when the screen refresh rate of the display screen of the electronic device is the first refresh rate (low refresh rate), the signal period of the first Vsync signal is set to the preset period. In this way, when it is necessary to switch the screen refresh rate of the display screen from the first refresh rate (low refresh rate) to the second refresh rate (high refresh rate), SurfaceFlinger can use the current signal period (preset period) of the first Vsync signal. At the end, the first refresh rate switching command is issued. Since the preset period is less than the reciprocal of the first refresh rate, compared to the native mechanism of the Android system, SurfaceFlinger needs to wait until the end of a cycle whose length is the reciprocal of the first refresh rate before it can issue the third refresh rate switching command. Once the refresh rate switching command is issued, the timeliness of SurfaceFlinger's issuance of the first refresh rate switching command is improved, so that the display screen can also receive the first refresh rate switching command in time and respond to the first refresh rate switching command in a timely manner to adjust the screen refresh rate. switching, thus reducing the switching time of the screen refresh rate of the display screen, avoiding lagging, improving the chirality of the electronic device, and improving the user experience.

In some embodiments, after the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate in response to the first refresh rate switching instruction, the method further includes: the display driver switches according to the first signal period. , sending a second Vsync signal to SurfaceFlinger to indicate the screen refresh rate of the display to SurfaceFlinger. The second Vsync signal is used to trigger the display screen to refresh the display image frame, and the first signal period is equal to the reciprocal of the second refresh rate.

For example, in an application scenario, after the screen refresh rate of the display screen is switched to 10 Hz, and a user operation (such as a click or sliding operation) is received, the screen refresh rate of the display screen needs to be switched back from 10 Hz to 60 Hz. Referring to Figure 7, as shown in Figure 7, the screen refresh rate switching process can adopt the screen refresh rate switching method provided in the above embodiment (such as steps S601-S603), and the corresponding signal transmission process between various parts of the electronic device can include :

S701. SurfaceFlinger receives the first refresh rate switching instruction from the upper layer (such as the frame rate control module of the electronic device) in the j-th signal period, that is, at time t3 as shown in Figure 7.

The signal period refers to the signal period of the first Vsync signal. In this embodiment, the signal period is 8ms.

S702. SurfaceFlinger responds to the end of the j-th signal period (the start of the j+1-th signal period) and issues the first refresh rate switching instruction to the display driver (for example, sends the second refresh rate switching instruction to the display through HWC). driver), and turn on Vsync signal calibration.

S703. After receiving the first refresh rate switching command, the display driver issues the first refresh rate switching command to the display screen (such as the display driver chip of the display screen).

S704. The display screen receives the first refresh rate switching instruction.

S705. The display screen drives the display screen to complete the screen refresh rate switching according to the first refresh rate switching instruction, that is, the screen refresh rate of the display screen is switched from the first refresh rate to the second refresh rate, and the image frame is updated according to the second refresh rate. The display is refreshed, and the display screen periodically sends a second Vsync signal to the display driver according to the second refresh rate (a second Vsync signal is reported to the display driver every other first signal period).

S706. The display driver periodically receives the second Vsync signal from the display screen, and reports the received second Vsync signal to SurfaceFlinger.

S707. SurfaceFlinger periodically receives the second Vsync signal, and determines whether the signal period of the second Vsync signal is 16ms based on the period of receiving the second Vsync signal (that is, the interval between receiving two adjacent second Vsync signals). , if so, it can be determined that the screen refresh rate switching is completed and Vsync signal calibration is turned off. If the period of the second Vsync signal is not equal to 16ms, continue to step 707.

It should be understood that after SurfaceFlinger determines that the screen refresh rate switching is completed, it can respond to the end of the current signal period (8ms), that is, the t4 moment as shown in Figure 7, and periodically follow the calibrated signal period of the Vsync signal, which is 16ms. Generate the first Vsync signal. That is to say, the signal period of the first Vsync signal is adjusted to 16ms.

Based on the technical solutions provided by the above embodiments, when the display screen of the electronic device displays a static image and the screen refresh rate of the display screen is the first refresh rate (low refresh rate), the corresponding display screen refreshes the display image frame at the first refresh rate. The reciprocal of the refresh rate T1, and SurfaceFlinger sets the preset refresh rate mode and runs according to the preset refresh rate (such as 120Hz), that is, the signal period of the first Vsync signal is the preset period. The preset period is smaller than the reciprocal T1 of the first refresh rate. In this way, when it is necessary to switch the screen refresh rate of the display screen from the first refresh rate to the second refresh rate (high refresh rate), SurfaceFlinger can download the screen at the end of the current signal cycle after receiving the first refresh rate switching command. Send the first refresh rate switching command and start Vsync signal calibration. Moreover, after the display screen receives the first refresh rate switching command, it can immediately switch the screen refresh rate of the display screen from the first refresh rate to the second refresh rate, thereby changing the period of the second Vsync signal from the first refresh rate to the second refresh rate. The reciprocal T1 is switched to the reciprocal T2 of the second refresh rate, and every other reciprocal T2 of the second refresh rate reports a second Vsync signal to the display driver. SurfaceFlinger receives the second Vsync signal, and determines whether the signal period of the second Vsync signal is based on the interval between receiving the two second Vsync signals. If so, it can be confirmed that the screen refresh rate switching is completed. SurfaceFlinger can generate the first Vsync signal at the frequency of the second refresh rate and the reciprocal T2 of the second refresh rate as the cycle after confirming that the screen refresh rate switching is completed and the current signal cycle is over. Compared with Android's native Vsync mechanism, the switching performance is greatly optimized and the chirality is improved.

For example, the first refresh rate is 10 Hz, and the reciprocal T1 of the first refresh rate is 100 ms. The second refresh rate is 60Hz, and the reciprocal T2 of the second refresh rate is 16ms. The default refresh rate is 120Hz, and the reciprocal of the default refresh rate, that is, the default period is 8ms.

For example, the first situation: SurfaceFlinger receives the first refresh rate switching instruction when the j-th signal period is about to end, that is, the t3 moment shown in Figure 7 is close to the end of the j-th signal period, x2≈0. SurfaceFlinger issues the first refresh rate switching command at the beginning of the j+1th signal cycle, and the display screen receives the first refresh rate switching command during the j+1th signal cycle, changing the screen refresh rate of the display screen from The first refresh rate is switched to the second refresh rate, and a second Vsync signal is reported to the display driver every other reciprocal T2 of the second refresh rate. SurfaceFlinger receives the second Vsync signal, and based on the interval between receiving the two second Vsync signals, determines whether the signal period of the second Vsync signal is the reciprocal T2 of the second refresh rate. If so, it can be confirmed that the screen refresh rate switching is completed. At this time, it is already within the j+3 signal period. Therefore, SurfaceFlinger needs to end in the current signal period (j+3 signal period) before it can refresh with the second is the frequency, and the first Vsync signal is generated with the reciprocal T2 of the second refresh rate as the period. The first situation is the situation where the entire screen refresh rate switching process takes the shortest time. From the time SurfaceFlinger receives the first refresh rate switching instruction to the display screen's screen refresh rate switching from the first refresh rate to the second refresh rate, it only takes It takes less than one signal period (the signal period is the preset period, that is, 8ms), and from when SurfaceFlinger receives the first refresh rate switching instruction to when SurfaceFlinger generates the first Vsync signal at the new refresh rate (from t3 to t4 ) only needs to go through three signal periods (the signal period is the preset period, that is, 8ms), a total of 24ms.

For another example, the second case: SurfaceFlinger receives the first refresh rate switching command at the beginning of the j-th signal period, that is, the t3 moment shown in Figure 7 is close to the beginning of the j-th signal period, x2≈8. However, SurfaceFlinger needs to wait until the end of the current signal cycle and issue the first refresh rate switching command at the beginning of the j+1th signal cycle. The display screen receives the first refresh rate switching command within the j+1th signal cycle. , switching the screen refresh rate of the display screen from the first refresh rate to the second refresh rate, and reporting a second Vsync signal to the display driver every other reciprocal T2 of the second refresh rate. When SurfaceFlinger receives the second Vsync signal and determines that the period of the second Vsync signal is T2, the reciprocal of the second refresh rate, it can confirm that the screen refresh rate switching is completed, which is already within the j+3 signal period. Therefore, SurfaceFlinger needs to end at the current signal period (j+3 signal period) in order to generate the first Vsync signal at the second refresh rate frequency and the reciprocal T2 of the second refresh rate as the period. The second case is the one where the entire screen refresh rate switching process takes the longest time, but it only takes a few seconds from SurfaceFlinger to receive the first refresh rate switching instruction to when the screen refresh rate of the display screen switches from the first refresh rate to the second refresh rate. It takes less than two signal periods (the signal period is the preset period, that is, 8ms, and the two signal periods are 16ms), and from the time when SurfaceFlinger receives the first refresh rate switching command to when SurfaceFlinger generates the second refresh rate at the new refresh rate. A Vsync signal (from time t3 to time t4) only needs to experience four signal periods (the signal period is the preset period), a total of 32ms.

To sum up, when the preset refresh rate is set to 120Hz, the technical solution provided by the embodiment of the present application is compared with the screen refresh rate switching process under the native mechanism of the Android system. The effect of optimizing the switching time is as shown in Table 1. .

Table 1

In some embodiments, the first refresh rate is a target refresh rate when the display screen displays a static image.

In some embodiments, the first refresh rate switching instruction is triggered after the electronic device receives a notification or user operation when displaying a static image. Among them, notifications or user operations are used to trigger the electronic device to update the interface.

In some embodiments, the second refresh rate switching instruction is triggered when the electronic device switches from displaying dynamic images to displaying static images.

Referring to Figure 8A, as shown in Figure 8A, in some embodiments, the screen refresh rate switching method provided by the embodiment of the present application may also include steps S401-S405 before the above step S601.

That is to say, the screen refresh rate switching method provided by the embodiment of the present application can be used to switch the screen refresh rate of the display screen from a certain refresh rate (such as the third refresh rate) to a low refresh rate, and then switch from the low refresh rate to a low refresh rate. to high refresh rates.

For example, when the screen refresh rate of the display screen is the third refresh rate, in response to the electronic device switching from displaying dynamic images to displaying static images, the screen refresh rate of the display screen is switched from the third refresh rate to the first refresh rate. rate, and set the signal period of the first Vsync signal to the preset period. Wherein, the third refresh rate is greater than the first refresh rate, and the first refresh rate is less than or equal to the preset threshold, and the preset period is less than the reciprocal of the first refresh rate. For the specific implementation process, please refer to the above-mentioned steps S401-S405, which will not be described again here. It should be understood that, accordingly, the second refresh rate switching instruction in step S401 is used to instruct the screen refresh rate of the display screen to switch from the third refresh rate to the first refresh rate. The above-mentioned third refresh rate may be equal to the second refresh rate. Afterwards, in response to the electronic device switching from displaying static images to displaying dynamic images, the SurfaceFlinger of the electronic device may receive a first refresh rate switching instruction. The first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate. The second refresh rate is greater than the preset threshold. In response to the current signal period of the first Vsync signal ending, SurfaceFlinger sends a first refresh rate switching instruction to the display driver of the electronic device. Among them, the first Vsync signal is used to trigger SurfaceFlinger for layer synthesis. In response to the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate. For the specific implementation process, please refer to the above-mentioned steps S601-S603, which will not be described again here.

Exemplarily, see FIG. 8B , which shows the signal transmission process corresponding to steps S401-S405 and steps S601-S603 in the screen refresh rate switching method provided by the above embodiment. The left side of Figure 8B shows the signal transmission process corresponding to switching the screen refresh rate of the display screen from a high refresh rate (such as 60Hz, the corresponding signal period is 16ms) to a low refresh rate (such as 10Hz, the corresponding signal period is 100ms). The specific steps are S801-S807. For the specific execution process of steps S801-S807, please refer to the above-mentioned steps S501-S507, which will not be described again here. The right side of Figure 8B shows the signal transmission process corresponding to switching the screen refresh rate of the display screen from a low refresh rate (such as 10Hz, the corresponding signal period is 100ms) to a high refresh rate (such as 60Hz, the corresponding signal period is 16ms), specifically The steps are S811-S817. For the specific execution process of steps S811-S817, please refer to the above-mentioned steps S701-S707, which will not be described again here.

It should be understood that in the above step S402, the display screen receives the second refresh rate switching instruction, and in response to the second refresh rate switching instruction, switches the screen refresh rate of the display screen to the preset refresh rate, and sends the third refresh rate to SurfaceFlinger according to the preset cycle. two Vsync signals so that SurfaceFlinger can complete the Vsync signal calibration. In step S405, the period of the first Vsync signal is set to the preset period. After the display screen responds to the second refresh rate switching instruction for a preset period of time, the screen refresh rate of the display screen switches to the first refresh rate (such as 10Hz), that is, after a certain delay as shown in Figure 8B, it switches to 100ms. . In this way, the display can display static images at a low refresh rate. status image, saving power and CPU resources.

It should be understood that in scenarios where the screen refresh rate of the display needs to be switched from one high refresh rate to another, such as switching from 90Hz to 60Hz, or from 60Hz to 90Hz, the Android system can still be used Screen refresh rate switching method under native mechanism.

In some embodiments, the display driver can set a real refresh rate (first refresh rate, such as 10Hz or 1Hz) mode (or gear) and a simulated refresh rate mode. The simulated refresh rate mode corresponds to a simulated refresh rate and a real refresh rate. The simulated refresh rate (ie, the preset refresh rate) is a high refresh rate (such as 120Hz), and the real refresh rate is a low refresh rate (10Hz or 1Hz). ). The display driver can report the refresh rate mode it supports to SurfaceFlinger and/or the frame rate control module through HWC. SurfaceFlinger and/or the frame rate control module can determine whether each refresh rate is a real refresh rate or a simulated refresh rate based on the identification (id) attribute of each refresh rate in the refresh rate mode. For example, the frame rate control module can query the display driver through Display.getSupportedModes() to obtain the refresh rate modes it supports. The display driver can respond to the query request and report the refresh rate modes it supports to the frame rate control module through HWC.

As shown in Figure 9, Figure 9 is a flow chart of interaction between modules in a screen refresh rate switching method provided by an embodiment of the present application.

For example, the signal transmission process is shown by the solid arrow in Figure 9 . The display driver sets the simulated refresh rate mode (simulated 120Hz mode), which corresponds to a simulated 120Hz refresh rate and a real 10Hz or 1Hz refresh rate. The display driver can report information that it supports simulated 120Hz mode to SurfaceFlinger through HWC.

For example, the signal transmission process is shown by the dotted arrow in Figure 9, which corresponds to the above-mentioned steps S501-S505. After the frame rate control module of the electronic device detects that the electronic device switches from displaying dynamic images to displaying static images, it controls the screen refresh rate of the display screen to switch to 10 Hz (or 1 Hz). The process is: the frame rate control module sends an instruction to the SurfaceFlinger to switch the screen refresh rate of the display screen to the simulated 120Hz mode (such as the second refresh rate switching instruction). After receiving the second refresh rate switching command sent by the frame rate control module, SurfaceFlinger can send the second refresh rate switching command to the display driver through HWC. It should be understood that after the display driver receives the second refresh rate switching instruction, according to the id attribute of the refresh rate in the instruction, it can be known that the simulated 120Hz mode in the second refresh rate switching instruction corresponds to a simulated 120Hz refresh rate and a real 10Hz or 1Hz refresh rate. In this way, after the display driver receives the second refresh rate switching command, it first switches the screen refresh rate of the display to 120Hz so that SurfaceFlinger can complete the Vsync signal calibration, that is, adjust the signal period of the first Vsync signal to 8ms (i.e. 1/120ms) . The display driver switches the screen refresh rate of the display to 10Hz or 1Hz after a preset period of time to save power and CPU resources.

For example, the signal transmission process is shown by the dash-dotted arrow in Figure 9 , which corresponds to the above-mentioned steps S701-S705. When the frame rate control module of the electronic device detects that the current display scene is a user clicking or sliding, or a pop-up notification appears, the frame rate control module sends an instruction to SurfaceFlinger to switch the screen refresh rate of the display to 60Hz, 90Hz or 120Hz ( Such as the first refresh rate switching instruction). When SurfaceFlinger sends the first refresh rate switching instruction from the frame rate control module, SurfaceFlinger can send the first refresh rate switching instruction to the display driver through HWC. After receiving the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen to 60Hz, 90Hz or 120Hz.

Some embodiments of the present application provide an electronic device. The electronic device may include: a display screen, a memory and one or more processors. The display, memory and processor are coupled. The memory is used to store computer program code, which includes computer instructions. When the processor executes computer instructions, the electronic device may perform various functions or steps performed by the electronic device in the above method embodiments. The structure of the electronic device may refer to the structure of the electronic device 200 shown in FIG. 2B.

An embodiment of the present application also provides a chip system. As shown in FIG. 10 , the chip system includes at least one processor 1001 and at least one interface circuit 1002 . The processor 1001 and the interface circuit 1002 may be interconnected by wires. For example, interface circuit 1002 may be used to receive signals from other devices, such as memory of an electronic device. As another example, the interface circuit 1002 may be used to send signals to other devices, such as the processor 1001 or a touch screen of an electronic device. For example, the interface circuit 1002 can read instructions stored in the memory and send the instructions to the processor 1001. When the instructions are executed by the processor 1001, the electronic device can be caused to perform various steps in the above embodiments. Of course, the chip system may also include other discrete devices, which are not specifically limited in the embodiments of this application.

Embodiments of the present application also provide a computer storage medium. The computer storage medium includes computer instructions. When the computer instructions are run on the above-mentioned electronic device, the electronic device causes the electronic device to perform each function performed by the electronic device in the above method embodiment or step.

An embodiment of the present application also provides a computer program product. When the computer program product is run on a computer, it causes the computer to perform various functions or steps performed by the electronic device in the above method embodiment.

Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above functional modules is used as an example. In practical applications, the above functions can be allocated according to needs. Different functional modules are completed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be The combination can either be integrated into another device, or some features can be omitted, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated. The components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place, or they may be distributed to multiple different places. . Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application are essentially or contribute to the existing technology, or all or part of the technical solution can be embodied in the form of a software product, and the software product is stored in a storage medium , including several instructions to cause a device (which can be a microcontroller, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage media include: U disk, mobile hard disk, read only memory (read only memory) Various media that can store program code, such as memory (ROM), random access memory (random access memory (RAM)), magnetic disks or optical disks.

The above contents are only specific implementation modes of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be covered by the protection scope of the present application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A screen refresh rate switching method, characterized in that it is applied to electronic equipment, the electronic equipment includes a display screen, and the method includes:

In the case where the screen refresh rate of the display screen is a third refresh rate, in response to the electronic device switching from displaying dynamic images to displaying static images, the screen refresh rate of the display screen is switched by the third refresh rate. to the first refresh rate, and set the signal period of the first Vsync signal to the preset period, wherein the third refresh rate is greater than the first refresh rate, and the first refresh rate is less than or equal to the preset threshold, The preset period is less than the reciprocal of the first refresh rate;

In response to the electronic device switching from displaying static images to displaying dynamic images, the SurfaceFlinger of the electronic device receives a first refresh rate switching instruction, wherein the first refresh rate switching instruction is used to indicate the screen of the display screen. The refresh rate is switched from a first refresh rate to a second refresh rate, where the second refresh rate is greater than the preset threshold;

In response to the end of the signal period of the current first Vsync signal, the SurfaceFlinger sends the first refresh rate switching instruction to the display driver of the electronic device, wherein the first Vsync signal is used to trigger the SurfaceFlinger to perform image processing. layer synthesis;

The display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate in response to the first refresh rate switching instruction.
A screen refresh rate switching method, characterized in that it is applied to electronic equipment, the electronic equipment includes a display screen, and the method includes:

The SurfaceFlinger of the electronic device receives a first refresh rate switching instruction from the upper layer; wherein the first refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch from the first refresh rate to the second refresh rate, The first refresh rate is less than or equal to a preset threshold, and the second refresh rate is greater than the preset threshold;

In response to the end of the signal period of the current first vertical synchronization Vsync signal, the SurfaceFlinger sends the first refresh rate switching instruction to the display driver of the electronic device; wherein the first Vsync signal is used to trigger the SurfaceFlinger Perform layer synthesis; the signal period of the first Vsync signal is set to a preset period when the screen refresh rate of the display screen is the first refresh rate, and the preset period is smaller than the first refresh rate. The reciprocal of the refresh rate;

The display driver switches the screen refresh rate of the display screen from the first refresh rate to the second refresh rate in response to the first refresh rate switching instruction.
The method according to claim 2, characterized in that, in response to the first refresh rate switching instruction, the display driver switches the screen refresh rate of the display screen from the first refresh rate to the third refresh rate. After the second refresh rate, the method also includes:

The display driver sends a second Vsync signal to the SurfaceFlinger according to the first signal period to indicate the screen refresh rate of the display screen to the SurfaceFlinger; wherein the second Vsync signal is used to trigger the display screen The display image frame is refreshed, and the first signal period is equal to the reciprocal of the second refresh rate.
The method according to claim 2 or 3, characterized in that, before the SurfaceFlinger of the electronic device receives the first refresh rate switching instruction from the upper layer, the method further includes:

The display screen receives a second refresh rate switching instruction; wherein the second refresh rate switching instruction is used to instruct the screen refresh rate of the display screen to switch to the first refresh rate;

In response to the second refresh rate switching instruction, the display screen switches the screen refresh rate of the display screen to a preset refresh rate, and sends the display driver to the SurfaceFlinger according to the preset cycle. A second Vsync signal; wherein the preset period is equal to the reciprocal of the preset refresh rate, and the preset refresh rate is greater than the preset threshold;

The SurfaceFlinger receives the second Vsync signal from the display driver;

If the second signal period is equal to the preset period, the SurfaceFlinger sets the signal period of the first Vsync signal to the preset period, and stops receiving the second Vsync signal from the display driver;

Wherein, the second signal period is a period in which the SurfaceFlinger receives the second Vsync signal from the display driver.
The method of claim 4, further comprising:

The display screen responds to the second refresh rate switching instruction and switches the screen refresh rate of the display screen to the first refresh rate after a preset period of time.
The method according to any one of claims 2 to 5, characterized in that the preset refresh rate is a screen refresh rate supported by the display screen.
The method of claim 6, wherein the first refresh rate is a target refresh rate when the display screen displays a static image.
The method according to any one of claims 4 to 6, characterized in that the preset refresh rate is 120Hz; the first refresh rate is 10Hz or 1Hz; the second refresh rate is 60Hz, 90Hz or Either of 120Hz.
The method according to any one of claims 2 to 7, characterized in that the first refresh rate switching instruction is triggered after the electronic device receives a notification or user operation when displaying a static image; Wherein, the notification or user operation is used to trigger the electronic device to update the interface.
The method according to claim 4 or 5, characterized in that the second refresh rate switching instruction is triggered when the electronic device switches from displaying dynamic images to displaying static images.
An electronic device, characterized in that the electronic device includes a display screen, a memory and one or more processors; the display screen, the memory and the processor are coupled; computer program code is stored in the memory , the computer program code includes computer instructions, which when executed by the processor, cause the electronic device to perform the method of claim 1, or, any one of claims 2-10. method described.
A computer-readable storage medium, characterized by comprising computer instructions, which when the computer instructions are run on an electronic device, cause the electronic device to perform the method of claim 1, or claims 2-10 any one of the methods.