What is Constrained Variable Bitrate (CVBR)?

Constrained Variable Bitrate, or CVBR, is a way to encode your video using adaptive bitrate. Essentially, more bitrate will be allocated when the video frame is more complex, and less bitrate will be used when the video frame is simple. Please remember that the higher the bitrate used, the bigger the file size. Therefore, using CVBR may reduce file size.

 

Under PowerDirector, the user still has to select an average bitrate. When in DVD profile, CBVR will be applied, using that average bitrate as a general rule of thumb. Sometimes less bitrate will be used, sometimes more, but always around the average selected.