What is the bit rate?
What is the bit rate? It is difficult to do without this term when we talk about audio and video files. It is not difficult to understand what you need to see behind this term. Even someone who is far from any modern technology.
First, you need to understand that there is a general principle for compressing and encoding files. For example, MP3 encoding assumes that the original audio file must be cut into chunks, the length of which will be 50 milliseconds. Each of these fragments is analyzed separately to break down into harmonics.
A person perceives the sound with the ear so that it throws out those harmonics that it perceives worse. That is, quieter sounds, when the loudest are heard, you do not perceive them. Therefore, due to the inertia of hearing, a person makes masked sounds. This means that you will not be able to hear any short-term signals that will pass in a fraction of a second, for example for a clap.
Information about the harmonics remaining after filtering is recorded in an MP3 file. It is significantly smaller than the original WAV. A WAV file is a complete repository of information about the original sound, which is digitized and quantized at 44 kHz. The resulting information is stored on normal audio CDs.
When playback is in progress, reverse conversion is performed. That is, the remaining harmonics are transformed back into a sound wave. Some of the information about the original signal is lost because the sound does not match the original. Since insignificant sounds were removed, the human ear does not distinguish the signal from the original. The same as it was before packing in MP3.
This means that the bit rate should be called the amount of information per unit of time. The essence of the bit rate is how much information we can spend on each second of recording. The smaller it is, the smaller the size of the files of the same length in time. This means that it will be necessary to eliminate a greater number of “extra” harmonics.
The higher the bit rate, the larger the file size and the higher its quality. For bit rates, units of measure are provided: kilobits per second (Kbps) and megabits per second (Mbps). The MP3 audio compression algorithm is mainly used with 128 kbps compression.
There are also two types: constants and variables. For example, in video compression, when using a constant bit rate, a fixed amount of data is used to encode one second of a movie. With a variable bit rate, depending on the scene in the movie, the codec sets its own bit rate value.
