A video encoder is a device that encodes acquired information and data into a machine-recognizable code. In the surveillance system, the video decoder has a very important position, so you know the video encoder principle? It is estimated that many people are not clear, so today we will talk about the principle of video encoder.
Before we talk about the principle of video encoder, let's take a look at the structure of the video encoder.
The video encoder consists of functional module boards, each of which is plugged into a backplane, interconnected by a backplane to form a system, and connected to other devices through the interface board on the back of the chassis. The interface/display panel has a string of digital video signals, a parallel input port, and communicates with the multiplexer and the digital compression system monitoring computer through a connection to the multiplexer interface.
Module board function
Interface/display rights (Interface board) receive serial, parallel input digital video signals and LCD display.
The format board (Format board) converts the digital luminance and chrominance signals Y, Cb, and Cr outputted by the A/D converter into video signals of the MP@ML format.
The pixel plate (Pixel board) performs frame prediction (Frame Prediction) and field prediction (Field Prediction). The field prediction is to make independent predictions by using the data of the previously solved field; the frame prediction is to predict the current frame by using the data of the previously solved frame.
The DCTQ board performs DCT discrete cosine transform and quantization with image data. The image block of 8 pixels × 8 lines is subjected to DCT transform to generate DCT coefficients of the image block. Quantization is the process of reducing the number of bits per DCT coefficient.
The Level/Classification Board and the Vector Board (Horizon & Vector Board) perform Motion Estimation and Motion Compensation. Motion estimation is to estimate the displacement of a moving object, that is, to estimate the direction and number of pixels of the moving object from the previous frame (field) to the current frame (field), that is, to find the motion vector. Motion compensation calculates the prediction error based on the motion vector.
The management/variable length coding board (Regul board) performs variable length coding VLG on the quantized DCT coefficients. The variable length coding utilizes the statistical characteristics of the quantized DCT coefficients, assigning short code words to frequently occurring values, and transmitting infrequently occurring values ​​with longer code words, so that the total number of bits is reduced, and an effective drop is achieved. Bit rate. At the same time, it is connected to the multiplexer to read many important information from the multiplexer. For example, some important parameters in the PES stream, such as stream id, copyright, original copy, and PES priority, are provided by the multiplexer at boot time, and the program reference clock PCR is received from the multiplexer 90000 times per second. To form a common system clock to ensure that the system is properly synchronized. In addition, the output of the encoder is managed, and when receiving a signal that the multiplexer input buffer overflows, the control encoder stops outputting until the multiplexer can receive data to prevent data loss and loss of image.
After knowing the structure of the video encoder, let's understand the principle of the video encoder.
Video encoder principle
The digital brightness and chrominance signals Y, Cb, and Cr input from the interface board are converted into MP@ML format video signals by the format board, and the original image and the prediction error calculated by motion estimation and motion compensation are calculated by the DCTQ board. The differential image data generated by the value is DCT transformed and quantized, and then VLC encoded by the management/VLC board to generate an output PES stream.
The above is the introduction of the video encoder principle, want to continue to understand the video encoder related information, please continue to browse the hot security investment network.
Recommended reading: video encoder function
Screen Pipe
Screen pipe is a new type of corrugated plastic pipe with corrugated appearance formed by high density polypropylene (PPR) with other additives. The permeable corrugated pipe is formed by drilling holes in the grooves and processing polyester spun-bonded nonwoven geotextiles around the pipe.Widely usedin highway, railway subgrade, subway, soft foundation treatment engineering, waste landfill site, tunnel, greenbelt, sports field and slope protection caused by high water content, as well as agricultural and horticultural underground irrigation and drainage system.
application
1.Vertical and horizontal drainage and water transmission of expressway;
2. Vertical and horizontal drainage on the back of various retaining walls and side trenches of the expressway;
3. Drainage of tunnels and underground tunnels;
4. Municipal engineering, water purification plants, sewage plants, garbage dumps, etc.
5. Drainage of leisure green Spaces such as golf courses, sports fields and parks;
6. Soil and water conservation of slope development;
7. Underground drainage of land works;
8. Ultra-soft foundation treatment project.
advantage
1. High safety of drainage, and the orifice is not easily blocked, which ensures unimpeded water transmission system.
2. Compared with the soft spring drain pipe, the plastic is not easy to rust.
3. Organic combination of strength and flexibility
4. Compared with other drainage pipes of the same caliber, the price is lower.
Packaging Details
Plastic caps on both ends, Steel bundle, Woven bag or acc. to customers' request.
Delivery Time
15 days after receiving deposit
If you have any questions, please contact with us directly and welcome you can visit our Factory.
Screen Pipe
Pipe Screens,Oil Screen Pipe,Slotted Screen Pipe,Fock Oil Composite Sand Screen
HEBEI CHENGYUAN PIPE INDUSTRY GROUP CO.,LTD , https://www.hbcytube.com