Recently, the "price increase tide" struck, and the main kinetic energy of the industry chain price increase is the strong demand of the LED display market. 2016 is the first year of the explosion of LED display screens. The reason why LED display screens are popular is because it presents people with wonderful pictures and unreserved display of its superb display technology. But people only see the brilliance of the display screen, but not the "heroes" behind it. The following small industry summarizes one of the "heroes" of the LED display: the basic knowledge of the LED video processor allows you to quickly understand the "heroes".
Led video processor introduction
LED video processor is also called picture processor, image converter, video controller, image processor picture converter, video format converter, independent video source, etc.
Multi-screen full-color LED splicing image processor, a single machine can support up to 16 launch cards of different resolutions at the same time, a single machine* can support 30720*1080 LED dot matrix. Multiple machines can be cascaded to achieve real-time dynamic display of unlimited amplitude LED dot matrix.
The launch card can be arbitrarily configured for LED dot matrix stacking, and the number of gray levels can be freely selected. The output matrix of a single LED launch card can be set arbitrarily.
Principle of LED video processor
During the use process, the LED video processor generally needs to complete the following processing procedures:
1. Resolution specification conversion: Generally speaking, the signal resolution provided by the image signal source (such as Blu-ray DVD, computer, high-definition playback box, etc.) has fixed specifications (refer to VESA, ITU, SMPTE and other standards), and the LED display The modular splicing display of the screen makes its resolution almost arbitrary. The video processor converts various signal resolutions into the actual physical display resolution of the LED display screen.
Second, color space conversion: LED display has a wide color gamut, and the color space of most image signals is relatively small (such as NTSC). In order for the LED display to have excellent image display effects, color space conversion must be performed.
Third, bit depth enhancement: The gray scale of the current led display has been raised to 16 bits and 17 bits, but most of the input signal source is only 8 bits. Therefore, following the footsteps of the era of high-definition display, the application of 10-bit or even 12-bit processing technology in video processors has become the general trend.
Fourth, zooming: During the conversion of resolution specifications, the image needs to be zoomed. Whether the resolution is increased or decreased, the entire image can be displayed on the screen.
V. Image processing and enhancement technology: Digital image processing technology has developed from the 1920s to the present, and a large number of patented technologies have appeared. For example, DCDi, ACC2, ACM3D and other Emmy Award-winning Faroudja laboratory's series of patented technologies. These technologies have undoubtedly greatly improved the visual effects of images.
The role of LED video processor
LED video processor is a video processor dedicated to LED. The task it needs to complete, in simple terms, is to convert the image signal from the outside (such as Blu-ray DVD, computer, high-definition playback box, etc.) into a signal that the LED display can accept. The LED video processor has the following functions:
1. Image interception: intercept any small area on the complete image and display it enlarged on the entire LED display.
Second, image enlargement: enlarge the image, * magnification is 10 times.
III. Graphic overlay: It is used to overlay another signal on the screen to complete functions such as subtitle overlay.
Fourth, fade in and out: do fade-in and fade-out switching between the two signal sources.
Fifth, seamless switching: when switching the signal source, there will be no black screen or flower screen during the replacement of the old and new pictures.
Six, multi-machine connection:
A) In the multi-machine connection state, it can realize the fade-in and fade-out switching between multiple (more than two) signal sources.
B) In the multi-machine connection state, the multi-machine template function can be used to quickly switch between multiple application scenarios. For details, see "Template Function".
VII. Synchronous follow-up: The synchronous follow-up technology ensures that the multi-screen images are complete and synchronized when the large-screen LED display of multiple machines is spliced.
Application of LED video processor in high-definition led display
1. Conversion of resolution specifications: Generally speaking, the signal resolution provided by the image signal source (such as Blu-ray DVD, computer, high-definition playback box, etc.) has fixed specifications (refer to standards such as VESA, ITU, SMPTE, etc.), and LED display The modular splicing display of the screen makes its resolution almost arbitrary. The LED video processor converts various signal resolutions to the actual physical display resolution of the LED display screen.
Second, color space conversion: LED display has a wide color gamut, and the color space of most image signals is relatively small (such as NTSC). In order for the LED display to have excellent image display effects, color space conversion must be performed.
3. Bit depth improvement: The gray scale of the current LED display has been raised to 16 bits and 17 bits, but most of the input signal sources are only 8 bits. Therefore, following the footsteps of the era of high-definition display, the application of 10-bit or even 12-bit processing technology in video processors has become the general trend.
Fourth, zooming: During the conversion of resolution specifications, the image needs to be zoomed. Whether the resolution is increased or decreased, the entire image can be displayed on the screen.
V. Image processing and enhancement technology: Digital image processing technology has developed from the 1920s to the present, and a large number of patented technologies have appeared. For example, DCDi, ACC2, ACM3D and other Emmy Award-winning Faroudja laboratory's series of patented technologies. These technologies have undoubtedly greatly improved the visual effects of images.
How to avoid the LED video processor port burn out
1. Electrostatic discharge (ESD) and countermeasures
The most common cause of damage to electronic components is electrostatic discharge (ESD). Especially in the dry winter, we wear more sweaters and other clothes that are prone to static electricity. The human body may even generate tens of thousands of volts of static electricity, so that direct contact with the processor port and instantaneous discharge may cause damage to the components.
The countermeasures to avoid this problem are: when you touch the processor and other devices, touch the effectively grounded device to remove static electricity, so that when you touch the device, it is relatively safe.
2. Damage of leakage current
The leakage current of the device will also cause the port chip to be burned. First of all, we first understand the concept of leakage current. In order to reduce interference in the switching power supply, there will be a corresponding EMI filter circuit. However, the existence of the EMI circuit makes a small current to the ground after the switching power supply is connected to the market, which is the leakage current.
Countermeasures:
1. The method is still grounding. The processor and the signal source are grounded with a ground wire respectively, and a multimeter is used to test the impedance to ground or no AC voltage to ground, so that there is no problem even if it is plugged and unplugged.
2. If the grounding of the on-site power outlet ground is not guaranteed, then the operation *connects the signal line first, *then connects the power line to power on, please do not plug the signal with power on!
3. The importance of grounding
As mentioned above, grounding is the prerequisite for the ESD protection device to really play its role. It can also avoid damage to the human body caused by leakage current, which shows the importance of grounding.
Technical challenges and development trends of LED video processors
Small pitch is becoming more and more popular, but the small-pitch LED display screen can not achieve the ideal display effect without the auxiliary function of the video processor. Unlike large outdoor LED screens, small-pitch LEDs are subject to many restrictions in image display.
*. The difference in ambient brightness, indoor brightness is low, so the brightness of the LED screen must not be as high as outdoor. This requires the video processor to have more excellent image quality improvement capabilities, especially the more advanced image scaling processing algorithm, so as to ensure that the high-definition video image after the zoom processing can maintain the details of the image clarity and grayscale level. Secondly, there should be a wealth of image adjustment options and adjustment effects, especially the adjustment of image brightness, contrast and low gray processing, thereby ensuring that the screen outputs soft, clear and layered images under the indoor light environment.
Second, indoor display is limited by the area of the site, and it is required to display as high-definition video and images as possible within the limited display area. This requires the video processor to have higher resolution image output capabilities, higher resolution and more channels of video image input capabilities.
Third, the traditional applications of indoor large screens are large screen displays for monitoring, command and control occasions. These applications require large screens with high resolution, many input signals, and more channels of real-time video window images and flexible and fast Control and management.
The LED video processor is a full witness and key equipment for the birth, growth and maturity of the LED full-color display. The quality of the LED video processor directly affects the display effect of the LED display.
The video processor is a witness and iconic device for the birth, growth and maturity of the LED full-color display. LED-specific video processing equipment has gradually matured during this process. The quality of the LED video processor directly affects the LED display. The display effect of the screen. In the era of high-definition LED displays, video processors not only carry a lot of work such as image processing and analysis, encoding and decoding compression, but also embed a large number of intelligent analysis algorithms to analyze massive amounts of data. The binding use of the LED video processor and the display screen greatly facilitates the wide application of the end user and improves the depth of use of the LED display screen.
