This article can learn:
- A bit is the smallest unit of data a computer can use to represent data. Byte indicates the byte. 1byte=8 bits. 1 byte = 8 bits.
- The relation between video bit rate and bandwidth, bandwidth = bit rate * (1 + 12%).
bandwidth
What is bandwidth?
Network bandwidth refers to the amount of data transmitted per unit of time (usually 1 second). It is usually represented by bit/s, BPS (bit per second). Bit stands for bit or bit and is the smallest unit of information technology storage. Store one binary digit, i.e., 0 or 1. Ps is divided by s, per second.
What does 2M bandwidth mean?
When someone tells us that the bandwidth is 2Mbit/s (2Mbps), we can imagine that the transmission rate of the network is 2Mbit/s. This means that in one second, the amount of data that can be sent is 2Mbit.
Bit rate
What is the bit rate?
Bit rate refers to the data flow rate used by a video file in a unit of time (usually 1 second), also known as bit rate, sampling rate, and bit rate. It is usually expressed as bit/s, (i.e. Bit per second).
What does it do to know the bit rate?
Bit rate is strongly correlated with video quality. First of all, let’s understand the position of video coding in the process of video capture to push stream.
Often, the video files collected from the video source data are very large, so we need to go through the coding process. The core of the whole coding process is the volume of the compressed video, and the impact of the packaging process on the volume of the video is very small and can be almost ignored. So let’s calculate the compression ratio required for a 720P video capture at 25 frames per second at a fixed bit rate of 2000 KBPS.
It can be calculated that the compression rate is 1-2000/2700 x 25 ≈ 0.9703 ≈ 97.03%. H264 has a compression rate of 99%. Compression ratio = 1 – Compressed video size/original video size x 100%.
Therefore, with the same resolution, the higher the bit rate of the video, the smaller the compression rate and the higher the picture quality. The larger the code flow, the larger the sampling rate per unit time, the higher the accuracy of the data flow, the closer the processed file is to the original file, the better the image quality, the clearer the picture quality.
Calculate bandwidth based on bit rate
The bit rate of the video is the bandwidth required to upload the video. Can our 2M bandwidth support 2M bit rate video? Of course not, bandwidth has a certain loss. The 2M bandwidth has 12% loss and only 2 x 1024 x (1-12%) = 1802.24 KBPS can be used. The 2M bit rate is 2 x 1024 = 2048 KBPS.
The unit of conversion here: 1024 KB = 1Mb
That requires at least 2 x (1+12%) Mbps = 2.24 Mbps to support a 2Mbps bit rate. That is, at least 2.24M upstream bandwidth is required.
Computer Housekeeper verification
Upstream speed of the pusher software: 2317/8 KB/s = 289.625 KB/s (here big K and small K are the same meaning, both represent thousands). Here 8 bits = 1 byte. 1byte is 1B. The computer butler’s uplink speed: 326.5 KB/s than 289.625 KB/s is larger, we can suspect that, first, the computer butler may detect inaccurate. Second, computer housekeeper will wear and tear. We calculate it based on the loss of 12% of the bandwidth. 289.625 x 1.12 = 324.38 KB/s Equals 326.5 KB/s. Because it is not clear how the computer butler detects Internet speed, the algorithm is not correct, just a play.