Glossary

VBR is a technique of encoding voice and video which allows the output bitstream to vary in the amount of bits per a given amount of time. This allows higher bitrates to be allocated to segments in the bitstream that are more complex than others.

VBR is usually used for encoding of files or stored media, where there is no real need to maintain a constant bit rate.

VBR is not suitable for video conferencing, where maintaining bitrates within specific ranges is important for maintaining quality of service and ensuring limited packet loss. In video conferencing CBR is used instead.

VBR vs CBR

VBR's main target is to maintain constant quality, while CBR's main target is to maintain constant bitrate.