Bit rate is the number of digits transmitted per unit time during data transmission. Generally, the unit is kbps, that is, kilobytes per second.
A more general understanding is the sampling rate. The larger the sampling rate per unit time, the higher the accuracy. The closer the processed file is to the original file, that is, the richer the image details. But the file volume is proportional to the sampling rate, that is, the higher the bit rate, the larger the video file volume. So almost all encoding formats focus on how to use the lowest Bit Rate to achieve the least distortion. Early CBR (fixed bit rate) and current VBR (Variable Bit Rate) are derived from this core ), all articles made in this respect. (Fixed bit rate refers to the fixed bit rate used for video preparation. Variable Bit Rate refers to the variable bit rate used for video production, that is, when the action is not intense, it is made with a low bit rate, and when the action is intense, it is made with a high bit rate, this not only keeps the quality of the video file, but also reduces the size of the video file .) However, it is not absolute. In terms of audio, the higher the bit rate, the smaller the compression ratio, and the smaller the sound loss, the closer the sound quality to the source. Bit Rate Calculation formula: file volume = time x bit rate/8
The unit of time is second, and the bit rate is divided by 8. For example, the D5 disk has a capacity of 4.3 GB. Considering the different audio formats, the disk occupies a certain amount of space. The value is 600 mb, and the video file should not exceed 3.7 GB, the video length is 100 minutes (6000 seconds). The calculation result is: the bit rate is 4900 kb.
Bit Rate principles
1. the bit rate is proportional to the quality (nonsense), but the file volume is also proportional to the bit rate. This should be kept in mind.
2. the bit rate exceeds a certain value, which has little impact on the image quality.
3. The capacity of the DVD is limited. Either the standard 4.3 GB, ultra-engraved, or D9, there are limits. This is also nonsense, but some people can't remember or ignore this.
Video Bit Rate
The information in the computer is represented by binary 0 and 1. Each 0 or 1 is called a single bit, which is expressed by lowercase B, that is, bit. uppercase B indicates byte, that is, byte. one byte = eight bits, that is, 1B = 8B; the upper-case k indicates the meaning of a thousand, that is, a thousand bits (Kb) or a thousand bits (KB ). Indicates the size unit of the file. Generally, bytes (Kb) are used to indicate the file size.
Kbps: First, you need to know that PS refers to/s, that is, every second. Kbps indicates the network speed, that is, the number of kilobytes of information transmitted per second (k indicates the kilobytes and kb indicates the number of kilobytes ), in order to intuitively display the fast transmission speed of the network, companies generally use KB (kilobytes) to indicate the number of kilobytes transmitted per second if it is kbps. 1 kbps = 8 kbps. The Internet access speed of ADSL is 512 kbps. If it is converted into bytes, It is 512/8 = 64 Kbps (that is, 64 kilobytes per second ).
Wav: lossless is a sound file format developed by Microsoft. It complies with the piffresource Interchange File Format File Specification and is used to save Audio Information Resources on Windows platforms, supported by the Windows platform and its applications. "*. The WAV format supports multiple compression algorithms, such as msadpcm and CCITT a law. It supports multiple audio bits, sampling frequencies, and channels. the wav files in the standard format are the same as those in the CD format and are also the 44.1k sampling frequencies, the speed is 88 KB/second, and the 16-bit quantize bits are displayed. The quality of Wav-format audio files is almost the same as that of CD files. It is also a popular audio file format on PCs, almost all audio editing software are in WAV format. However, the disadvantage is that it is too big ".
WMV is a technical standard for transmitting multimedia in real time on the Internet independently of the encoding method. Microsoft wants to use it to replace technical standards such as QuickTime and file extensions such as WAV and Avi. The main advantages of WMV are: scalable media types, local or network playback, scalable media types, streaming priority, multi-language support, and scalability.
