Bit rate is the number of bits of information per second which can be transmitted over internet and local networks. When you see something like ‘320kbps’ – you look at bit rate. This particular value shows that there is 320 thousands bits per second can be transmitted via the internet. Obviously as higher the rate as higher quality you get and also as larger your file gets.
Are there different kinds of bit rate?
Yeap, there are some.  Actually there are three different kinds of bit rates and they are the following CBR (Constant Bit Rate), VBR (Variable Bit Rate), and ABR (Average Bit Rate). Let’s take a good look at them and try to understand what it has to do with mp3 music
CBR or Constant Bit Rate – this is a type of encoding in which the initial audio stream is divided into blocks or frames and then encoded with the same parameters (the same bit rate) applied equally to each sector, block and frame.
VBR or Variable Bit Rate – this is a type of encoding in which the initial stream is also divided into separate frames and gets encoded after that. But this type of encoding implies applying various parameters (bit rates) to each frame. The value is identified automatically by the software.
ABR or Average Bit Rate – this is a type of encoding which is rather similar to Constant Bit Rate encoding type however it has a significant difference. ABR doesn’t apply the same bit rate for all the frames but it tries to determine and apply the best, the most suitable value of bit rate for every single frame. It may sound like VBR but Variable Bit Rate tries to choose the lowest bitrate for separate parts in order to create a file which will have a good quality enough. The majority of frames in ABR method are close to the value which was input by a user and each frame may have bitrate which equals any value in the range 8-320 kbps.
These are the main kinds of bitrate. So the main point is that every kind of encoding has some advantages and disadvantages comparing to other and mostly it has to do with quality of mp3 music files in the end of process. A Higher bitrate value allows you to hear some additional instruments and sounds used during the record. However when in order to distinguish 500kbps from 1000kbps you need to have some professional Hi-Fi systems otherwise you won’t notice any differences and in this case the only parameter that will be important is free space.

2 Responses to “What is bit rate?”
  1. Terry Jones says:

    Nice to read some knowledgeable text. Best for you, Terry.

  2. Steve says:

    I know only that it is an important factor determining the quality of an mp3 file.

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