What is Variable Bitrate? [2024 Updated]

You may have heard about Adaptive Bitrate, but do you know Variable Bitrate? It's fine if you don't. This post will share the basics.

What is Variable Bitrate?

Variable bitrate (VBR) is a term used in sound or video encoding. It is opposed to constant bitrate (CBR). The main difference is that VBR files vary the amount of output data per time segment. Also, VBR allows a higher bitrate to be allocated to the more complex segments of media files while less space is allocated to less complex segments. The files we know that can be encoded in VBR are MP3, WMA, and AAC audio files.

Variable Bitrate vs. Adaptive Bitrate

You may have known about Adaptive Bitrate before. This part mainly focuses on the differences between Variable Bitrate and Adaptive Bitrate. Let's dive in.

Adaptive Bitrate (ABR) enables the encoder to automatically set a fixed bit rate based on the stream's input resolution. In this case, ABR makes better use of the available bandwidth than a user-specified fixed bit rate.

However, Variable Bitrate (VBR) enables the encoder to automatically vary the bitrate based on the stream's content and input resolution. The bitrate can vary from less than 150 Mbps to a maximum of 750 Mbps.

In a word, a Variable Bitrate uses less bandwidth to produce the same image quality as an Adaptive Bitrate.

Conclusion

Now, you have known what the Variable Bitrate is and what's the difference between Variable Bitrate and Adaptive Bitrate. Share this post with more people if you find it helpful!