A video display method, device, electronic equipment and storage medium

Abstract

The application belongs to the technical field of display, and mainly provides a video display method and device, electronic equipment and storage medium, wherein the driving current of an LED display screen is configured as a first target driving current according to the metadata of a video source, and a first pulse width modulation duty cycle for driving the video source is determined based on the metadata, a PQ inverse function, a PQ function and the gray scale processing depth of the LED display screen, so that the first target driving current and the first pulse width modulation duty cycle are designed according to the video source content and the driving capability and the gray scale processing capability of the LED display screen, the main HDR video source content is accurately reproduced, the contrast of the original HDR video source content is maintained, the highlight details are optimized, the display effect of the HDR video source is improved, the power consumption is balanced, and the risk of dead light is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of display, and relates to a video display method and device, an electronic device, and a storage medium. BACKGROUND

[0002] Due to the advantages of high color gamut, high brightness, large viewing angle, long service life and the like of an LED display screen, application scenarios of the LED display screen are constantly enriched, and the LED display screen is gradually widely applied in display application scenarios of some high dynamic range (HDR) video sources.

[0003] For an HDR video source with relatively high content brightness, the HDR video source generally has a relatively high requirement on the brightness capability of a display device. If the lamp points of an LED display screen are always driven according to maximum current, for an LED display screen driven by pulse width modulation (PWM) technology, power consumption and the risk of dead lamps are increased. Meanwhile, there is a problem that the display effect of a high gray scale of the HDR video source is poor. SUMMARY

[0004] The application provides a video display method and device, an electronic device, and a storage medium, and can solve the technical problems of high power consumption, high risk of dead lamps, and poor display effect of a high gray scale of the current LED display screen.

[0005] An embodiment of the application provides a video display method, which comprises the following steps.

[0006] obtaining the type of a video source and a preset corresponding relationship; the preset corresponding relationship is a preset corresponding relationship between driving current and display brightness of an LED display screen;

[0007] when the type of the video source is a high dynamic range image, obtaining metadata corresponding to the video source;

[0008] determining a first target driving current corresponding to the video source according to the metadata and the preset corresponding relationship;

[0009] determining a first pulse width modulation duty cycle for driving the video source based on the metadata, a PQ inverse function, a PQ function, and a gray scale processing depth of the LED display screen;

[0010] driving the LED display screen to display the video source based on the first target driving current and the first pulse width modulation duty cycle.

[0011] An embodiment of the application provides a video display device, which comprises the following steps.

[0012] The first obtaining unit is configured to obtain a type of a video source and a preset corresponding relationship, wherein the preset corresponding relationship is a preset corresponding relationship between a driving current of an LED display screen and display brightness.

[0013] The second obtaining unit is configured to obtain metadata corresponding to the video source when the type of the video source is a high dynamic range image.

[0014] The first determining unit is configured to determine a first target driving current corresponding to the video source according to the metadata and the preset corresponding relationship.

[0015] The second determining unit is configured to determine a first pulse width modulation duty cycle for driving the video source based on the metadata, a PQ inverse function, a PQ function and a gray scale processing depth of the LED display screen.

[0016] The driving unit is configured to drive the LED display screen to display the video source based on the first target driving current and the first pulse width modulation duty cycle.

[0017] The third aspect of the embodiment of the present application provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the computer program is executed by the processor to implement the steps of the video display method of the first aspect.

[0018] The fourth aspect of the embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the video display method of the first aspect.

[0019] The fifth aspect of the embodiment of the present application further provides a computer program product comprising instructions which, when executed on a computer, cause the computer to perform the steps of the video display method of the first aspect.

[0020] In the embodiment of the present application, the driving current of the LED display screen is configured as the first target driving current according to the metadata of the video source, and the first pulse width modulation duty cycle for driving the video source is determined based on the metadata, the PQ inverse function, the PQ function and the gray scale processing depth of the LED display screen, so that the first target driving current and the first pulse width modulation duty cycle are designed according to the video source content and the driving capability and the gray scale processing capability of the LED display screen, the display effect of the HDR video source is improved while the contrast of the original HDR video source content is maintained and the highlight details are optimized, the power consumption is balanced, and the risk of dead light is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1A first structural schematic diagram of a display system provided by an embodiment of the present application.

[0022] Figure 2a An EETF mapping curve diagram of an SOC end provided by an embodiment of the present application.

[0023] Figure 2b An EOTF mapping curve diagram in an LED control module provided by an embodiment of the present application.

[0024] Figure 2c A photoelectric display curve diagram after combination of an SOC+LED control module provided by an embodiment of the present application.

[0025] Figure 2d A system-level light mapping curve diagram provided by an embodiment of the present application.

[0026] Figure 3 An implementation flowchart of a video display method provided by an embodiment of the present application.

[0027] Figure 4 An implementation flowchart of step 303 of a video display method provided by an embodiment of the present application.

[0028] Figure 5 An implementation flowchart of step 304 of a video display method provided by an embodiment of the present application.

[0029] Figure 6 A tone mapping curve diagram provided by an embodiment of the present application.

[0030] Figure 7 An implementation flowchart of step 502 of a video display method provided by an embodiment of the present application.

[0031] Figure 8a A luminance curve diagram obtained by an embodiment of the present application without vector intercepting step.

[0032] Figure 8b A target linear luminance curve diagram provided by an embodiment of the present application.

[0033] Figure 9 A normalized EOTF curve contrast diagram of a luminance range video source provided by an embodiment of the present application.

[0034] Figure 10 A second structural schematic diagram of an LED display system provided by an embodiment of the present application.

[0035] Figure 11 A structural block diagram of a video display device provided by an embodiment of the present application.

[0036] Figure 12 A structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0038] As shown in FIG. 1, a first structure diagram of an LED display system provided by an embodiment of the present application is shown, which includes a video source decoding module 111 and an LED control module 112. The video source decoding module 111 can be implemented by a SOC system board, and the LED control module 112 can include a sending card connected with the video source decoding module 111, and a receiving card connected with the sending card. Figure 1 For external video sources, such as HDR video sources or SDR video sources stored in a U disk, an HDMI external device or other external storage devices, etc., the SOC can analyze and extract metadata of the HDR video sources. The SOC has rich image quality processing functions, and the display mapping (EETF mapping) of the HDR can be performed in the image quality processing module. The mapped and decoded RGB data can be sent to the sending card through a low-voltage differential signal transmission interface (LVDs) or a high-definition multimedia transmission interface (HDMI). Then the gamma mapping module of the sending card is used for mapping, and the system-level electro-optical mapping (EOTF mapping) of the entire end-to-end link is completed.

[0039] In the traditional LED display system, the display data mapped by the SOC no longer contains any brightness information of the original video source, and the driving current and the EOTF mapping of the rear-end LED control module are fixed values and curves, so that the traditional LED display system has the following two shortcomings: first, the entire system uses a set of mapping curves, which cannot be adapted to HDR video sources with different dynamic ranges, resulting in poor image quality of some HDR video sources; second, the system is designed with a fixed driving current, and the lamp points of the LED display screen are always driven at the maximum current, which increases the power consumption and the risk of dead lamps.

[0040]

[0041] ​For example, when the system mapping is designed according to 1000 nit, if the maximum brightness of the HDR video source is 600 nit, the driving current of the LED display screen is large, the power consumption is high, and the risk of dead light of the LED display screen is increased. If the content brightness of the HDR video source is 2000 nit, which is higher than the display brightness of the LED display screen, the high gray scale will be overexposed, and the display effect of the high gray scale of the HDR video source is poor.

[0042] For example, as shown in FIG. 1, it is an EETF mapping curve diagram of the SOC according to the maximum brightness of the video source is 1000 nit, and the maximum display brightness of the LED display screen is 1000 nit. The abscissa represents the normalized encoding value of the input gray scale data, for example, 128 gray scales of 8 bits, the normalized encoding value is 128 / 255=0.5019; the ordinate is the normalized encoding value after mapping. Figure 2a

[0043] As shown in FIG. 2, it is an EOTF mapping curve diagram in the LED control module of 10-bit display gray scale, that is, a gamma mapping curve diagram. The abscissa is the input gray scale data, and the ordinate is the display brightness. Figure 2b As shown in FIG. 3, it is the photoelectric display curve (i.e., the system-level EOTF mapping curve) of the combination of the SOC+LED control module. The abscissa is the input gray scale data, and the ordinate is the display brightness.

[0044] Figure 2c In order to explain the problem of the system-level mapping of the traditional LED display system, the system-level EOTF mapping curve shown in FIG. 3 can be converted into a system-level optical mapping curve (OOTF mapping) for explanation. As shown in FIG. 4, the abscissa is the video source brightness, and the ordinate is the display brightness after mapping.

[0045] Referring to the curve shown in FIG. 4, for the content with the video source brightness of 0.0001-1000 nit, the brightness can be accurately reproduced on the 0-1000 nit display device. In the range of 800 nit-1000 nit, the curve is smooth, which can ensure the high-light details. However, for the content greater than 1000 nit, the high-light details will disappear, that is, the display effect of the high gray scale of the HDR video source is poor. Therefore, the HDR video sources with different content brightness are all mapped according to one curve, which will result in poor picture quality effect of some HDR video sources (for example, for the video source with the brightness range greater than the display capability of the display screen). Figure 2c Figure 2d

[0046] Referring to the curve shown in FIG. 4, for the content with the video source brightness of 0.0001-1000 nit, the brightness can be accurately reproduced on the 0-1000 nit display device. In the range of 800 nit-1000 nit, the curve is smooth, which can ensure the high-light details. However, for the content greater than 1000 nit, the high-light details will disappear, that is, the display effect of the high gray scale of the HDR video source is poor. Therefore, the HDR video sources with different content brightness are all mapped according to one curve, which will result in poor picture quality effect of some HDR video sources (for example, for the video source with the brightness range greater than the display capability of the display screen). Figure 2d

[0047] ​​​​​To solve the above problems, the embodiment of the present application provides a video display method, which can solve the technical problems of high power consumption, high risk of dead lights and poor high gray scale display effect of the current LED display screen. The video display method can be applied to the LED display system as shown in the above Figure 1

[0048] As shown in the above Figure 3 The video display method can be implemented in the following steps 301 to 305.

[0049] Step 301, obtaining the type of the video source and a preset corresponding relationship.

[0050] In the embodiment of the present application, the preset corresponding relationship is the corresponding relationship between the driving current of the LED display screen and the display brightness pre-stored in the LED display system.

[0051] In one embodiment, the type of the video source can include a high dynamic range image HDR and a standard dynamic range image SDR.

[0052] When playing the video source that needs to be played, the type of the video source can be obtained by identifying the video source, and the type of the video source is an identification result of an HDR video source (i.e., a high dynamic range image) or an identification result of an SDR video source (i.e., a standard dynamic range image).

[0053] In the embodiment of the present application, the dynamic range refers to the relative ratio of the highest and lowest values of the electrical signal, which is reflected on the photo as the details that can be displayed in the highlight area and the dark area. The larger the dynamic range is, the richer the level is. The HDR video source is a video file using the HDR technology. The HDR function can adjust the unbalanced state of the picture, in which the dark part is particularly black and the bright part is particularly dazzling, to the effect that the dark part does not lose details, the bright part is brighter, the overall color is richer, and the picture is closer to the real picture seen by the human eye. The standard dynamic range image, i.e., the SDR image, is generally applied to non-drawing, cutting and display that does not need to use high color gamut.

[0054] Step 302, when the type of the video source is a high dynamic range image, obtaining the metadata corresponding to the video source.

[0055] ​HDR metadata is a set of data embedded in the HDR signal that provides the signal-receiving display with parameter information about graded display, aiming to ensure the best display effect for the same image on different displays. In this embodiment, when the video source is a high dynamic range image, the metadata corresponding to the video source may include the source content's maximum brightness (max_display_mastering_luminance), minimum brightness (min_display_mastering_luminance), and the average brightness (maxfall) of the brightest frame.

[0056] In one embodiment of this application, the type of the video source in step 301 and the metadata in step 302 can be passed to the LED control module at the application layer.

[0057] Step 303: Determine the first target driving current corresponding to the video source based on the metadata and the preset correspondence.

[0058] In one embodiment of this application, such as Figure 4 As shown, step 303 above can be implemented in the manner described in steps 401 to 404 below.

[0059] Step 401: Determine the source luminance reference value Lv_reference of the video source based on the metadata;

[0060] In this embodiment, for a video source containing maxfall metadata, maxfall can be used as the source luminance reference value Lv_reference to determine the first target driving current corresponding to the video source. For a video source not containing maxfall metadata, max_display_mastering_luminance can be used as the source luminance reference value Lv_reference to determine the first target driving current corresponding to the video source.

[0061] Step 402: Determine the maximum display brightness value LV_display_max corresponding to the maximum driving current Imax of the LED display screen, and the maximum display brightness value LV_display_k corresponding to each of the k adjustable driving currents i_k, according to the preset correspondence.

[0062] Step 403: When Lv_reference>LV_display_max, Imax is determined as the first target driving current I corresponding to the video source.

[0063] Step 404, when Lv_reference < LV_display_max, the difference delta (Lv_reference-LV_display_k) between Lv_reference and LV_display_k is calculated in turn according to the arrangement order of i_k, and the i_k corresponding to the minimum delta (Lv_reference-LV_display_k) and LV_display_k > Lv_reference is taken as the first target driving current I corresponding to the video source.

[0064] Specifically, in step 404, the first target driving current corresponding to the video source can be determined according to the order of i_k from large to small, or can be determined according to the order of i_k from small to large, or any other order, which is not limited in the present application.

[0065] In practical application, the driving current of the LED display screen supports the debugging of the register value in a certain range. By adjusting different driving currents, different display maximum brightness values LV_display can be obtained. Therefore, the display maximum brightness value LV_display_max corresponding to the LED display screen under the maximum driving current Imax and the display maximum brightness value LV_display_k corresponding to the k adjustable driving currents i_k can be determined by experiment, and recorded in the above preset corresponding relationship. Then, by comparing the relationship between Lv_reference and LV_display_max, the first target driving current corresponding to the video source and the display maximum brightness value LV_display_k corresponding to the first target driving current are finally determined. The selection of the driving current (the first target driving current) suitable for the video source according to the metadata of the video source and the above preset corresponding relationship is realized, which is beneficial to reduce the power consumption of the LED display screen and reduce the risk of dead lights.

[0066] In the embodiments of the present application, in order to unify the description, the first target driving current is uniformly marked as I, and the display maximum brightness value of the LED display screen under the first target driving current I is uniformly marked as LV_display_I. Based on this, when Lv_reference > LV_display_max, I is equal to Imax, and LV_display_I is equal to LV_display_max; when Lv_reference < LV_display_max, I is equal to the i_k corresponding to the minimum delta (Lv_reference-LV_display_k) and LV_display_k > Lv_reference, and LV_display_I is equal to the LV_display_k corresponding to the i_k.

[0067] Step 304: Determine the first pulse width modulation duty cycle for driving the video source based on metadata, the inverse PQ function, the PQ function, and the grayscale processing depth of the LED display screen.

[0068] In this embodiment of the application, for an LED display screen driven by PWM, the brightness of the display screen is proportional to the product of the driving current and the PWM duty cycle. Therefore, after the first target driving current is determined, it is also necessary to determine the duty cycle corresponding to each gray level of the video source, that is, the first pulse width modulation duty cycle, and then drive the display screen to display the video source based on the first target driving current and the first pulse width modulation duty cycle.

[0069] Step 305: Drive the display screen to display the video source based on the first target driving current and the first pulse width modulation duty cycle.

[0070] In this embodiment, the driving current of the LED display is configured as the first target driving current based on the metadata of the video source. A first pulse width modulation duty cycle for driving the video source is determined based on the metadata, the inverse PQ function, the PQ function, and the grayscale processing depth of the LED display. This achieves the design of the first target driving current and the first pulse width modulation duty cycle according to the video source content, the driving capability of the LED display, and its grayscale processing capability. While ensuring accurate reproduction of the main HDR video source content and maintaining the contrast of the original HDR video source content, it optimizes high-brightness details, improves the display effect of the HDR video source, and balances power consumption, reducing the risk of dead LEDs.

[0071] Specifically, in one embodiment of this application, such as Figure 5 As shown, in step 304 above, in the process of determining the first pulse width modulation duty cycle for driving the video source based on metadata, the inverse PQ function, the PQ function and the grayscale processing depth of the LED display screen, the following steps 501 to 503 can be used to achieve this.

[0072] Step 501: Based on the maximum display brightness value corresponding to the first target driving current, the preset minimum display brightness value, and metadata, determine the tone mapping curve corresponding to the video source based on the inverse PQ function.

[0073] The above Figure 4 In the steps shown, the value of the first target driving current I has been determined, and the maximum display brightness value corresponding to the first target driving current I is LV_display_I; the LED display screen is a self-emissive display device with a dark state brightness of 0 nit. For subsequent calculations, in this embodiment of the application, a preset minimum display brightness value LV_display_min>0 is taken. For example, LV_display_min can be set to 0.005.

[0074] Step 401 above has determined the source luminance reference value Lv_reference of the video source, and the metadata obtained in step 302 above includes the minimum luminance of the source content min_display_mastering_luminance; the formula for the inverse PQ function applied in the numerical conversion process of this application is defined as follows:

[0075] Where L = C / 100000 represents the linearly normalized color value; m1 = 0.1593; m2 = 78.8437; c1 = c3 - c2; c2 = 18.8516; c3 = 18.6875.

[0076] C represents any one of the luminance values ​​among LV_display_I, LV_display_min, Lv_reference, and min_display_mastering_luminance.

[0077] Let L W =Lv_reference / 10000; L B =min_display_mastering_luminance / 10000;

[0078] L min =LV_display_min / 10000; L max =LV_display_I / 10000.

[0079] Next, based on the above inverse PQ function, the following calculations are performed:

[0080] minLum=(PQEOTF -1 [L min ]-PQEOTF -1 [L B ]) / (PQEOTF -1 [L W ]-

[0081] PQEOTF -1 [L B ]);

[0082] maxLum=(PQEOTF -1 [L max ]-PQEOTF -1 [L B ]) / (PQEOTF -1 [L W ]-

[0083] PQEOTF-1 [L B ]);

[0084] where PQEOTF -1 is the inverse function of PQ, as the formula

[0085] Then, let E1 = (E' - PQEOTF -1 [L B ]) / (PQEOTF -1 [L W ] - PQEOTF -1 [L B ]); where E' corresponds to the normalized vector value of full gray scale, for example, for a 10-bit display system, the vector of E' is composed of floating-point data within [0, 1], and the number of elements is 2^10-1, that is, 1024. The element values are i / 1023, respectively, where i represents an integer value from 0 to 1023 with a step size of 1.

[0086] Next, introduce high gray scale and low gray scale mapping control points KS and b, which are expressed as follows: KS = a*maxLum + c; b = minLum; a and c are adjustable parameters. In an embodiment, a = 1.5; b is -0.5;

[0087] Next, based on the following steps S1 to S5, the tone mapping curve is calculated according to KS and the spline interpolation method:

[0088] Step S1: construct a variable T = (E1 - KS) / (1 - KS);

[0089] Step S2: calculate the cubic spline interpolation curve

[0090] P_E1 = (2*T^3 - 3*T^2 + 1)*KS + (T^3 - 2*T^2 + T)*(1 - KS) + (-2

[0091] *T^3 + 3*T^2)*maxLum

[0092] Step S3: let

[0093] Step S4: let E3 = E2 + b*(1 - E2) 4 for 1≤E2≤1;

[0094] Step S5: calculate:

[0095] E4 = E3*(PQEOTF -1 [L W ] - PQEOTF -1 [L B]+PQEOTF -1 [ L B ]; E4 is the color

[0096] The basic form of the tone mapping curve.

[0097] As Figure 6 shown, the ordinate represents E4, and the abscissa represents the input gray scale value. If it is a 10-bit mapping process, the abscissa represents an integer value from 0 to 1023.

[0098] In step 502, the target luminance curve corresponding to the video source is determined based on the tone mapping curve and the PQ function.

[0099] In an embodiment of the present application, as Figure 7 shown, the determination of the target luminance curve in step 502 can be realized based on steps 701 to 704 as follows.

[0100] In step 701, the minimum abscissa value corresponding to the maximum ordinate of the tone mapping curve is determined.

[0101] For example, as Figure 6 shown, the tone mapping curve starts at point A (860, 0.74) and the ordinate reaches the maximum value. The abscissa of the coordinate point on the tone mapping curve greater than 860 corresponds to the ordinate equal to the ordinate of point A, i.e., 0.74. The abscissa of the coordinate point on the tone mapping curve less than 860 corresponds to the ordinate less than the ordinate of point A, i.e., 0.74. Therefore, the abscissa of point A, i.e., 860, is the minimum abscissa value corresponding to the maximum ordinate of the tone mapping curve.

[0102] In step 702, the gray scale vector corresponding to the video source is intercepted based on the minimum abscissa value to obtain an intercepted vector.

[0103] In step 703, the intercepted vector is interpolated to obtain a target gray scale vector with a length equal to the total number of system gray scale gradients.

[0104] In step 704, the luminance value of each gray scale value in the target gray scale vector is mapped based on the PQ function to obtain a target linear luminance curve corresponding to the video source.

[0105] In actual applications, the minimum abscissa value is generally less than the maximum value in the gray scale vector corresponding to the video source. Therefore, the gray scale vector corresponding to the video source needs to be intercepted, and then interpolated and mapped to the luminance value, so that the detail display of the video source is more delicate, and the display effect of the video source is improved.

[0106] Continuing the above example, when the tone mapping curve corresponding to the video source is as Figure 6The shown tone mapping curve is, since the minimum abscissa value corresponding to the maximum ordinate of the tone mapping curve is 860, it indicates that the LED display screen uses 0-860 gray stages to display 0-1000 nit display brightness, if no vector intercepting is performed, then as shown in Figure 8a the LED display screen in 860-1000 gray stages will be wasted, and after the vector intercepting is performed, then as shown in Figure 8b the LED display screen in 0-1023 gray stages can be used to express 0-1000 nit brightness range, thus, the presentation of the video source will be more delicate.

[0107] In the embodiment of the application, when the video source is a video source encoded by using 10bit data, and the maximum display brightness of the video source is 1000 nit, and the minimum abscissa value corresponding to the maximum ordinate of the tone mapping curve is 860, since 860 is less than 1023, thus, the gray scale vector corresponding to the video source can be intercepted to obtain an intercepted vector with gray scale values in [0, 860], then, after the interpolation calculation of the intercepted vector is performed to obtain a target gray scale vector with a length equal to the total number of system gray scale gradients 1024, the brightness value mapping of each gray scale value in the target gray scale vector is performed based on the PQ function to obtain the brightness mapping curve as shown in Figure 8b , so that the detail display of the video source is more delicate.

[0108] In the process of the brightness value mapping of each gray scale value in the target gray scale vector based on the PQ function in the above step 704, the PQ function can be used, where m1=0.1593; m2=78.8437; c1=c3-c2; c2=18.8516; c3=18.6875; the dependent variable N corresponds to each gray scale value in the target gray scale vector, the each gray scale value in the target gray scale vector is substituted into N to obtain the corresponding P value, which is the target brightness value in the target brightness curve corresponding to the video source, recorded as LV_target’.

[0109] It should be noted that the above steps 701-704 are only used to illustrate the determination method of the target brightness curve, in other embodiments of the application, other ways can also be used to determine the target brightness curve, which is not limited in the application.

[0110] For example, in an embodiment of the present application, in the process of intercepting the gray scale vector corresponding to the video source to obtain the intercepted vector, in addition to intercepting the minimum abscissa value corresponding to the maximum ordinate of the tone mapping curve based on the tone mapping curve, the abscissa value corresponding to the preset coordinate value of the ordinate of the tone mapping curve can also be intercepted, or the abscissa value corresponding to the ordinate of the tone mapping curve tending to be stable can also be intercepted. Wherein, the ordinate of the tone mapping curve tending to be stable refers to the case that the change rate of the slope of the tone mapping curve is less than the preset change rate threshold.

[0111] Step 503, converting each target luminance value corresponding to the video source in the target luminance curve into a first pulse width modulation duty cycle based on the gray scale processing depth of the LED display screen.

[0112] In the embodiment of the present application, the target luminance curve in step 503 can be realized based on the following steps 901 to 902.

[0113] Step 901, obtaining the luminance value after luminance mapping of each gray scale value in the target gray scale vector as each target luminance value corresponding to the video source in the target luminance curve;

[0114] Step 902, converting each target luminance value corresponding to the video source in the target luminance curve into a first pulse width modulation duty cycle E5'(i) based on the formula E5'(i)=floor((LV_target'(i) / max(LV_target'))*power(2,bit)).

[0115] Wherein, floor represents rounding, power represents the power function with base 2 and exponent bit, and bit is a parameter determined based on the gray scale processing depth of the LED display screen, and the value range can be 12-16; LV_target'(i) is the i-th target luminance value to be calculated for duty cycle, and max(LV_target') is the maximum target luminance value in each target luminance value corresponding to the video source.

[0116] In the embodiments of the present application, the driving current (first target driving current) of the LED display screen is adjusted according to the configuration of the metadata of the video source, and the tone mapping curve corresponding to the video source is determined based on the PQ inverse function according to the maximum display luminance value of the LED display screen, the preset minimum display luminance value and the metadata, then the target linear luminance curve corresponding to the video source is determined based on the tone mapping curve and the PQ function; finally, each target luminance value corresponding to the video source in the target linear luminance curve is converted into a first pulse width modulation duty cycle based on the gray scale processing depth of the LED display screen, and the video source is displayed based on the first target driving current and the first pulse width modulation duty cycle; the driving current and the electro-optical mapping curve are designed according to the video source content and the driving capability and the gray scale number of the LED display screen, the main HDR content is accurately reproduced, the contrast of the original HDR content is maintained, the highlight details are optimized, the power consumption is balanced, and the risk of dead light is reduced while the HDR display effect is optimized.

[0117] For example, when the HDR video source is only 600 nit, which is obviously lower than the display capability 1000 nit of the display device, a low driving current can be used for LED display to accurately reproduce the luminance while saving power consumption. When the peak luminance of the HDR source reaches 2000 nit, which is obviously higher than the luminance limit of the display capability 1000 nit of the display device, the maximum driving current of the LED within the power consumption design consideration range is used, and tone mapping is performed to better ensure the representation of highlight details.

[0118] As shown in FIG. 1, Figure 9 Figure 9 Curve 1 is a normalized EOTF curve when the maximum luminance of the input video source content is 1000 nit and the maximum display luminance of the LED display screen is 1000 nit, and the current is assumed to be I2_1. Curve 2 is a normalized EOTF curve when the maximum luminance of the input video source content is 800 nit and the maximum display luminance of the LED display screen is 800 nit, and the current is assumed to be I2_2, then I2_2<I2_1, that is, under the 800 nit input video source, the driving current can be reduced to save power consumption.

[0119] Figure 9 Curve 3 is the EOTF mapping curve corresponding to the input source content with a maximum luminance of 2000 nit and the LED display screen with a maximum luminance of 1000 nit, and the driving current is still I2_1 at this moment. Compared with the curves in Figure 2c and Figure 2d Curve 3 has no obvious oversaturation area, so the highlight detail display will be better.

[0120] ​In one embodiment of this application, when the video source is a standard dynamic range image, the second target driving current corresponding to the video source can be determined according to the maximum display brightness in the video source and the preset correspondence. Then, the grayscale data of the video source is mapped according to the preset gamma function to obtain the second pulse width modulation duty cycle corresponding to each grayscale data of the video source. Then, the display screen is driven to display the video source based on the second target driving current and the second pulse width modulation duty cycle.

[0121] When the video source is a standard dynamic range image, the process of determining the second target driving current corresponding to the video source based on the maximum display brightness in the video source and the preset correspondence can refer to the aforementioned... Figure 4 The steps shown will not be repeated here.

[0122] In the process described above, mapping the grayscale data of the video source according to a preset gamma function to obtain the second pulse width modulation duty cycle corresponding to each grayscale data of the video source can be based on the formula...

[0123] The function `E = floor(E_max * power(G / Gmax, gamma))` maps the grayscale data of the video source to obtain the second pulse width modulation (PWM) duty cycle corresponding to each grayscale data point. Here, `E` represents the second PWM duty cycle, `E_max` represents the maximum PWM duty cycle (related to the grayscale levels of the LED display driver system), `G` represents the grayscale data of the video source, and `Gmax` represents the maximum value of the grayscale data. For example, in a 10-bit encoded video source, `Gmax` is 1023, where `G` is an integer value within the range [0, 1023]. `floor` indicates rounding. `Gamma` represents a preset exponent value, i.e., an exponent value designed according to the display effect, such as 2.2, 2.4, 2.6, 2.8, etc.

[0124] There are many HDR technology specifications, with HDR10 being the most widely used. HDR10 video sources typically contain metadata for the display to reference during mapping. Therefore, this application can adjust the LED drive current based on the metadata configuration, and further balance the display effect of the HDR video source with the choice of drive current through software algorithms and hardware control.

[0125] like Figure 10As shown, a second structural schematic diagram of an LED display system provided by the embodiment of the present application is shown, which can include a video source decoding module 11, an operation module 12, a first storage unit 13, a second storage unit 14, and an LED display screen 15. The video source decoding module 11 is a chip with the capability of extracting metadata in video source frame information and realizing YUV to RGB data conversion processing, for example, an HDMI decoding chip, a SOC chip, or a DSP chip, etc. The output of the video source decoding module 11 after decoding the video source is divided into two parts, image data stream and calculation stream. The calculation stream is obtained in two parts, one is the current driving signal output to the LED display screen, which is used to control the driving current of the LED display screen, and the other is the EOTF mapped pulse width modulation duty cycle stored in the second storage unit for image data stream display, which is used to drive the LED display screen to realize brightness display under different gray scales together with the driving current. The corresponding relationship between the driving current and the display brightness of the LED display screen is pre-stored in the first storage unit. The operation module is used to execute the method steps related in the foregoing various embodiments, and the operation module can be realized by FPGA, i.e. the processor type in the traditional sending card, or ASIC or GPU and other hardware forms.

[0126] It should be noted that the video source decoding module 11 can also include part of the modules in the operation module, for example, the video source brightness and screen brightness calculation processing module and the EETF calculation conversion unit, which are not limited by the present application. The video source decoding module 11 in the embodiment and the video source decoding module 111 in the Figure 1

[0127] It should be noted that for the foregoing method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action order described, and in some embodiments of the present application, certain steps can be performed in other orders as needed.

[0128] As Figure 11 ​As shown in the illustration, this application also provides a video display device 110, which may include a first acquisition unit 101, a second acquisition unit 102, a first determination unit 103, a second determination unit 104, and a driving unit 105. The first acquisition unit is used to acquire the type of the video source and a preset correspondence; the preset correspondence is a pre-stored correspondence between the LED display drive current and the display brightness. The second acquisition unit is used to acquire metadata corresponding to the video source when the type of the video source is a high dynamic range image. The first determination unit is used to determine a first target drive current corresponding to the video source based on the metadata and the preset correspondence. The second determination unit is used to determine a first pulse width modulation duty cycle for driving the video source based on the metadata, the inverse PQ function, the PQ function, and the grayscale processing depth of the LED display. The driving unit is used to drive the LED display to display the video source based on the first target drive current and the first pulse width modulation duty cycle.

[0129] It should be noted that, for the sake of convenience and brevity, the specific working process of the video display device 110 described above can be referred to the corresponding process of the video display method described above, and will not be repeated here. Each unit module of the video display device 110 can execute the corresponding steps in the above method embodiment, so each unit module will not be described in detail here. For details, please refer to the description of the corresponding steps above.

[0130] like Figure 12 As shown, this application also provides an electronic device. The electronic device may include: a processor 90, a memory 91, and a computer program 92 stored in the memory 91 and executable on the processor 90. When the processor 90 executes the computer program 92, it implements the steps in the various video display method embodiments described above, for example, Figure 3 Steps 301 to 305 are shown.

[0131] The aforementioned computer program can be divided into one or more units, which are stored in the aforementioned memory 91 and executed by the aforementioned processor 90 to complete this application. The aforementioned one or more units can be a series of computer program instruction segments capable of performing a specific function, which describe the process by which the computer program executes the aforementioned video display method in an electronic device. For example, the aforementioned computer program can be divided into... Figure 11 The first acquisition unit, the second acquisition unit, the first determination unit, the second determination unit, and the driving unit are shown.

[0132] This application also provides a computer-readable storage medium storing a computer program that, when executed by a central processing module, implements the steps of the video display method described in any of the above embodiments.

[0133] The embodiment of the present application further provides a computer program product containing instructions, which, when executed on a computer, cause the computer to perform the steps of the video display method according to any of the above-described embodiments.

[0134] In the above-described embodiments, the description of each embodiment focuses on different aspects, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0135] Those skilled in the art can understand that the steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software mode depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0136] In the embodiments provided in the present application, it should be understood that the disclosed terminal and method can be implemented in other ways. For example, the terminal embodiments described above are only schematic. For example, the division of components is only a logical function division, and there can be another division in actual implementation. For example, multiple components can be combined or integrated into another system, or a feature can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed components can be indirect coupling or communication connection through an interface, system or unit, and can be electrical, mechanical or other forms.

[0137] If implemented in the form of software functional units and sold or used as independent products, these functional units can be stored in a computer readable storage medium. Based on such an understanding, all or part of the flow of the method embodiments described above can also be implemented by computer programs instructing relevant hardware, and the computer programs can be stored in a computer readable storage medium. When the computer programs are executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0138] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A video display method characterized by, The video display method comprises: acquiring a type of a video source and a preset corresponding relationship; the preset corresponding relationship is a preset corresponding relationship between LED display screen driving current and display brightness; when the type of the video source is a high dynamic range image, acquiring metadata corresponding to the video source; determining a first target driving current corresponding to the video source according to the metadata and the preset corresponding relationship; determining a first pulse width modulation duty cycle for driving the video source based on the metadata, a PQ inverse function, a PQ function and a gray scale processing depth of the LED display screen; driving the LED display screen to display the video source based on the first target driving current and the first pulse width modulation duty cycle.

2. The video display method of claim 1, wherein, The determining of the first target driving current corresponding to the video source according to the metadata and the preset corresponding relationship comprises: determining a source brightness reference value Lv_reference of the video source according to the metadata; determining a display maximum brightness value LV_display_max corresponding to the LED display screen under a maximum driving current Imax and a display maximum brightness value LV_display_k corresponding to each of k adjustable driving currents i_k according to the preset corresponding relationship; when Lv_reference> LV_display_max, determining Imax as the first target driving current I corresponding to the video source; when Lv_reference< LV_display_max, calculating a difference value delta (Lv_reference-LV_display_k) between Lv_reference and LV_display_k according to the arrangement order of i_k, and taking i_k corresponding to the minimum delta (Lv_reference-LV_display_k) and LV_display_k> Lv_reference as the first target driving current I corresponding to the video source.

3. The video display method of claim 1, wherein, The video display method further comprises determining a display maximum brightness value corresponding to the first target driving current according to the preset corresponding relationship; and the determining of the first pulse width modulation duty cycle for driving the video source based on the metadata, the PQ inverse function, the PQ function and the gray scale processing depth of the LED display screen comprises: determining a tone mapping curve corresponding to the video source based on the PQ inverse function according to the display maximum brightness value corresponding to the first target driving current, a preset display minimum brightness value and the metadata; determining a target brightness curve corresponding to the video source based on the tone mapping curve and the PQ function; converting each target brightness value corresponding to the video source in the target brightness curve into the first pulse width modulation duty cycle based on the gray scale processing depth of the LED display screen.

4. The video display method of claim 3, wherein, The horizontal coordinate of the tone mapping curve is a gray scale value, and the vertical coordinate is a tone mapping value; and the determining of the target linear brightness curve corresponding to the video source based on the tone mapping curve and the PQ function comprises: determining a minimum abscissa value corresponding to a maximum ordinate of the tone mapping curve based on the tone mapping curve; intercepting a gray scale vector corresponding to the video source based on the minimum abscissa value to obtain an intercepted vector; performing interpolation calculation on the intercepted vector to obtain a target gray scale vector with a length equal to a total number of system gray scale gradients; mapping each gray scale value in the target gray scale vector to a luminance value based on the PQ function to obtain a target linear luminance curve corresponding to the video source.

5. The video display method of claim 4, wherein, The method for converting each target luminance value in the target luminance curve corresponding to the video source into the first pulse width modulation duty cycle based on the gray scale processing depth of the LED display screen comprises: taking the luminance value obtained after luminance mapping of each gray scale value in the target gray scale vector as each target luminance value in the target luminance curve corresponding to the video source; converting each target luminance value in the target luminance curve corresponding to the video source into the first pulse width modulation duty cycle E5'(i) based on the formula E5'(i)=floor((LV_target'(i) / max(LV_target'))*power(2,bit)); wherein floor represents rounding, power represents a power function with a base of 2 and an exponent of bit, bit is a parameter determined based on the gray scale processing depth of the LED display screen; LV_target'(i) is each target luminance value corresponding to the video source, and max(LV_target') is the maximum target luminance value in each target luminance value corresponding to the video source.

6. The video display method according to any one of claims 1 to 5, wherein The video display method further comprises: when the type of the video source is a standard dynamic range image, determining a second target driving current corresponding to the video source according to the maximum display luminance in the video source and the preset corresponding relationship; mapping the gray scale data of the video source according to a preset gamma function to obtain a second pulse width modulation duty cycle corresponding to each gray scale data of the video source; driving the display screen to display the video source based on the second target driving current and the second pulse width modulation duty cycle.

7. The video display method of claim 6, wherein, The method for mapping the gray scale data of the video source according to a preset gamma function to obtain a second pulse width modulation duty cycle corresponding to each gray scale data of the video source comprises: mapping the gray scale data of the video source according to the formula E=floor(E_max*power(G / Gmax,gamma)) to obtain a second pulse width modulation duty cycle corresponding to each gray scale data of the video source; wherein E represents a second pulse width modulation duty cycle, E_max represents a maximum pulse width modulation duty cycle, G represents the gray scale data of the video source, Gmax represents the maximum value of the gray scale data, floor represents rounding calculation, and Gamma represents a preset exponential value.

8. A video display device, characterized by comprising: The video display device comprises: a first acquisition unit configured to acquire the type of a video source and a preset corresponding relationship; the preset corresponding relationship is a corresponding relationship between a driving current and a display luminance of an LED display screen that is stored in advance; A second obtaining unit, configured to obtain metadata corresponding to the video source when the type of the video source is a high dynamic range image; A first determining unit, configured to determine a first target driving current corresponding to the video source according to the metadata and the preset correspondence relationship; A second determining unit, configured to determine a first pulse width modulation duty cycle for driving the video source based on the metadata, a PQ inverse function, a PQ function, and a gray scale processing depth of the LED display screen; A driving unit, configured to drive the LED display screen to display the video source based on the first target driving current and the first pulse width modulation duty cycle.

9. An electronic device, comprising: A computer program product, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and when the computer program is executed by the processor, the steps of the video display method according to any one of claims 1-7 are implemented.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and when the computer program is executed by the processor, the video display method according to any one of claims 1-7 is implemented.

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