An encode control strategy is provided for variable bit rate encoding of a sequence of video frames in a single pass. The control strategy includes determining whether a video frame has a complexity level statistically outside a defined range from a complexity level of at least one preceding frame of the sequence of video frames, and if so, determining a new average bit rate target for the video frame. The new average bit rate for the video frame is determined employing at least one of spatial complexity and temporal complexity of the video frame. The new average bit rate target for the video frame is used to set frame level bit rate control parameter(s), and the video frame is encoded using the set frame level bit rate control parameter(s).