CN107995452B

CN107995452B - Double-screen synchronous display method

Info

Publication number: CN107995452B
Application number: CN201711083185.7A
Authority: CN
Inventors: 万龙
Original assignee: Zhuhai Vyagoo Technology Co ltd
Current assignee: Zhuhai Vyagoo Technology Co ltd
Priority date: 2017-11-07
Filing date: 2017-11-07
Publication date: 2020-09-29
Anticipated expiration: 2037-11-07
Also published as: CN107995452A

Abstract

The invention comprises a method for double-screen synchronous display, which is characterized by comprising the following steps: initializing the extended display identification data when the equipment is started, and setting the effective pixel output of the extended display identification data to be twice of that during initialization; when the output end detects that the effective pixel output of the expanded display identification data is doubled, doubling the image data quantity required to be output and executing output; when the receiving end receives the image data corresponding to the output end, odd-even pixel separation is carried out on the image data through hardware, and the separated odd-even pixels are respectively sent through double channels; and adjusting effective pixels of the image data sent by the two channels to restore to initial settings, and sending the image data to a display device for display. The invention has the beneficial effects that: the double-screen display is completed by utilizing the characteristics of the current mainstream conversion chip, no hardware circuit is additionally designed, no software is required to perform operations such as data copying, and the performance and the reliability are superior to other schemes.

Description

Double-screen synchronous display method

Technical Field

The invention relates to a method for double-screen synchronous display, and belongs to the field of computers.

Background

With the continuous development of the AR field, many related products have the requirement of dual-screen synchronous display, many input sources of these products are HDMI, and in order to implement dual-screen display, after receiving data from the HDMI end, a special circuit needs to be designed to implement synchronous display.

The prior technical scheme is as follows: in the existing HDMI dual-screen display technical scheme, after data is received from an HDMI terminal, a special circuit is designed to realize two independent display channels, and the data to be displayed is copied and then respectively sent to the two independent display channels for display.

The existing technology has the disadvantages that the data copying work needs to be carried out locally, and the data are sent to two independent display channels respectively, and the processes are all completed by software, so that the real-time performance and the synchronism of the data are influenced to a certain extent.

Many display chips on the market support dual-channel display at present, for example, if an LVDS interface needs to support a resolution of 1080p, a single channel bandwidth is insufficient, dual channels need to be supported, one frame of data is split into odd and even pixels during dual-channel display, the odd and even pixels are output from two LVDS channels respectively, and after the display screen receives the data, the two channels of data are combined into a complete frame of image for display.

Extended Display Identification Data (Extended Display Identification Data) is a VESA standard Data format that contains parameters relating to the monitor and its capabilities, including vendor information, maximum image size, color settings, vendor presets, limits on frequency range, and strings of Display names and serial numbers.

LVDS: Low-Voltage Differential Signaling, a mode of signal transmission.

HDMI: high Definition Multimedia Interface, High Definition Multimedia Interface.

Disclosure of Invention

The technical scheme of the invention provides a double-screen synchronous display method, which displays the physical characteristics of double channels of equipment, performs repeated processing on pixel data at the output end of a high-definition multimedia interface, then outputs the pixel data to a high-definition multimedia interface switching chip, and the switching chip needs to open the double-channel characteristics when outputting, separates odd and even pixels, and directly divides the odd and even pixels into two paths of low-voltage differential signals for output, thereby solving the defects of the prior art.

The technical scheme of the invention comprises a method for double-screen synchronous display, which is characterized by comprising the following steps: initializing the extended display identification data when the equipment is started, and setting the effective pixel output of the extended display identification data to be twice of that during initialization; B. when the output end of the high-definition multimedia interface detects that the effective pixel output of the expansion display identification data is doubled, doubling the image data amount required to be output and executing output; C. when the receiving end of the high-definition multimedia interface receives the image data of the corresponding output end, odd-even pixel separation is carried out on the image data through hardware, and the separated odd-even pixels are respectively sent through double channels; D. and adjusting effective pixels of the image data sent by the two channels to restore to the initialization setting, and sending the image data to the corresponding display device.

According to the method for double-screen synchronous display, the effective output setting of the step A further comprises the following steps: and for the setting that the image output resolution is M x N and the pixel clock is T in any existing extended display identification data, the effective pixel output setting comprises the steps of modifying the resolution to be (2M) x N or M x (2N), simultaneously modifying the pixel clock to be 2T, and simultaneously sending the setting information to the high-definition multimedia interface output end.

According to the method for double-screen synchronous display, the step B further comprises the following steps: and the high-definition multimedia interface output end performs repeated processing on image data to be output after detecting the extended display identification data information, doubles the data amount and then outputs the doubled data from the high-definition multimedia interface output end, wherein the repeated processing of the output end comprises copying continuous image data and keeping the data sequence unchanged.

The method for double-screen synchronous display, wherein the step C further comprises the following steps: the input end of the high-definition multimedia interface receives data and then completes the separation of odd and even pixels through hardware, the data are directly divided into two paths of data and are respectively output from two paths of low-voltage differential signals, and the odd pixels and the even pixels are simultaneously output from a first path or a second path.

The method for double-screen synchronous display, wherein the step D further comprises: and after the odd-even pixels are separated, the output pixel clocks of the first channel and the second channel are reduced back to the output frequency during initialization, namely the image output resolution is M x N and the pixel clock is T, and the image data are sent to the corresponding display device for display.

The invention has the beneficial effects that: the double-screen display is completed by utilizing the characteristics of the current mainstream conversion chip, no hardware circuit is additionally designed, no software is required to perform operations such as data copying, and the performance and the reliability are superior to other schemes.

Drawings

FIG. 1 shows a general flow diagram according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments. The method for double-screen synchronous display is suitable for double-screen display based on the available high-definition multimedia interface.

FIG. 1 shows a general flow diagram according to an embodiment of the invention. The method comprises the following specific steps:

initializing the EDID (extended display identification data) after the device is started, setting the horizontally valid pixel of the EDID to the previous 2 times, such as 1280x720 resolution, modifying to 2560x720 resolution, and the corresponding pixel clock also becomes the previous 2 times, such as 74.25Mhz to 148.5 Mhz;

an HDMI (high definition multimedia interface) output terminal detects EDID information and then repeatedly processes image data to be output, doubles the data amount and then outputs the data from the HDMI, for example, the previous data is "1234", after repetition, it becomes "11223344", and the data amount doubles;

after receiving the data, the HDMI input end completes the separation of odd and even pixels through hardware, and directly divides the data into two paths to be output from two paths of LVDS respectively, for example, odd pixels are output from the channel a, and even pixels are output from the channel B.

After the odd-even pixels are separated, the output pixel clock of each path is reduced to the previous frequency, such as 1280x720 resolution, and the pixel clock is still 74.25Mhz, so that the normal output of the image is ensured.

Note the configuration of the output and input terminal resolutions, if the output terminal is 1280x720, the resolution of the input terminal, i.e. the HDMI terminal, is 2560x720, which is within the bandwidth allowed by the hardware. The HDMI output end needs to support the generation of repeated pixels, and the HDMI receiving end needs to support double channels.

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment, and the present invention shall fall within the protection scope of the present invention as long as the technical effects of the present invention are achieved by the same means. The invention is capable of other modifications and variations in its technical solution and/or its implementation, within the scope of protection of the invention.

Claims

1. A method for synchronous display of double screens is characterized in that the method comprises the following steps:

A. initializing the extended display identification data when the device is started, and setting the effective pixel output of the extended display identification data to be twice as high as that when the device is initialized, further comprising: for the setting that the image output resolution is M x N and the pixel clock is T in any existing extended display identification data, the pixel effective output setting comprises the steps of modifying the resolution to be (2M) x N or M x (2N), modifying the pixel clock to be 2T, and sending the setting information to the output end of the high-definition multimedia interface;

B. when the output end of the high-definition multimedia interface detects that the effective pixel output of the expansion display identification data is doubled, doubling the image data amount required to be output and executing output;

C. when the receiving end of the high-definition multimedia interface receives the image data of the corresponding output end, the odd-even pixel separation is carried out on the image data through hardware, and the separated odd-even pixel is respectively sent through double channels, which comprises the following steps: the method comprises the following steps that after data are received by an input end of a high-definition multimedia interface, odd-even pixel separation is completed through hardware, the data are directly divided into two paths of data and are respectively output from two paths of low-voltage differential signals, wherein odd pixels and even pixels are simultaneously output from a first channel or a second channel;

D. the effective pixel of the image data that the adjustment binary channels sent restores to the initialization setting to send image data to corresponding display device, still include: and after the odd-even pixels are separated, the output pixel clocks of the first channel and the second channel are reduced back to the output frequency during initialization, namely the image output resolution is M x N and the pixel clock is T, and the image data are sent to the corresponding display device for display.

2. The method for dual-screen synchronous display according to claim 1, wherein the step B further comprises:

and the high-definition multimedia interface output end performs repeated processing on image data to be output after detecting the extended display identification data information, doubles the data amount and then outputs the doubled data from the high-definition multimedia interface output end, wherein the repeated processing of the output end comprises copying continuous image data and keeping the data sequence unchanged.