Popular science: basic concepts of audio and video encoders

Video encoder refers to a network transmission device that compresses digital video and processes audio and video data. In the process of network transmission, what is more important is whether there is a difference in the clarity of the video picture and the broadband during the processing of the video. Let's learn more about the basic concepts of the video encoder:
**Frame rate:** The so-called frame rate is how many images there are in one second, and the video is composed of one image. Therefore, there is a concept of frame rate in the acquisition and playback encoding. That is, the frequency (rate) of the video on the display. The higher the acquisition frame rate, the better the restoration.
Bit rate : Bit rate is the concept of video transmission. It refers to the bit rate transmitted per second and how much data is sent in one second. In real-time applications, adaptive bandwidth has always been the goal of the encoder rate control algorithm. In terms of the device, it is the concept of compression rate, such as the amount of binary data after a frame of video (an image) is encoded and compressed. In channel coding, a source data block with a size of K symbols is mapped into a codeword with a size of N symbols through coding, and then K/N becomes the code rate.
**Resolution: **Resolution is the video clarity, ultra-clear, high-definition and the like. The most common ones are:
720P (Ultra
HD) source requires a code stream of 4M 1080P (Full HD) source requires a code stream of 8M
4K (Ultra HD) source requires a code stream of 10M
**lossy/lossless Coding: **In the digital compression technology, lossless and lossless coding applications are everywhere, and the information in the transmission process is not damaged. The coding method will completely restore the original information, which is lossless coding. Lossy coding is more common in image, video, audio, and other multimedia information compression. Because the original information of multimedia information is too large, invisible information will be lost during the encoding process, and the lost data cannot be recovered, and the compression is relatively large.
H.264/H.265 encoding : H.264 encoding is a low-latency high-definition video image processing algorithm, standard H.264 video compression algorithm;
H.264 can realize standard definition digital image transmission at a speed lower than 2Mbps, while H.265 HighProfile can realize 1080p full HD video transmission at a transmission bandwidth lower than 1.5Mbps.
H.264 encoding and H.265 encoding are both Video encoding format. Compared with H.264, H.265 can transmit higher quality network video under limited bandwidth, which means that only half of the bandwidth of the original H.264 encoding can transmit the same quality video.