In this work, a simplified rate control algorithm is proposed for non-conversational H.264 video applications. When a GOP (group of pictures) structure is imposed on an encoded video, a bit rate control and a bit allocation among frames are two important components of a rate control algorithm. We employ a GOP rate model and the monotonicity property to address the bit rate control and the frame-layer bit allocation problem, respectively. Since the proposed algorithm employs only a GOP rate model, the rate control mechanism can be greatly simplified while it achieves better video quality as compared with that in the H.264 JM8.6 reference encoder.