For years, users have known variable bitrate (VBR) as one thing only: bandwidth varies, compression stays the same.
This is not an accident but an essential characteristic of VBR. By allowing the bit rate to vary, the compression level can stay the same regardless of the changes in scene complexity (think hallway when a school is closed vs hallway during recess vs hallway at night).
But now, in a confusing move, some manufacturers have changed their definition of VBR, giving users no option to adjust image quality. We take a look at these issues in this note.