Accurate estimation of R-D characteristics for rate control in real-time video encoding

In real-time video communications, the rate control strategies must be utilized to satisfy the end-to-end delay and prevent the encoding buffer from over/underflow. In other words, to acquire the best possible video quality with a minimal quality variation in the playback video, an accurate rate-distortion (R-D) model of the video source is critical in optimizing the bit allocation for video coding. In the paper, an exponential functions based R-D model is proposed for intra-coded frames in video coding. Numerous experiments have consistently shown that the proposed model outperforms other popular R-D models in terms of both the estimation accuracy and computation complexity, making it suitable for rate control in real-time video coding