PSNR-based Initial QP Determination for Low Bit Rate Video Coding

  • Park, Sang-Hyun (Department of Multimedia Engineering, Sunchon National University)
  • Received : 2012.06.15
  • Accepted : 2012.07.27
  • Published : 2012.09.30


In H.264/AVC, the first frame of a group of pictures (GOP) is encoded in intra mode which generates a large number of bits. The number of bits for the I-frame affects the qualities of the following frames of a GOP since they are encoded using the bits remaining among the bits allocated to the GOP. In addition, the first frame is used for the inter mode encoding of the following frames. Thus, the initial quantization parameter (QP) affects the following frames as well as the first frame. In this paper, an adaptive peak signal to noise ratio (PSNR)-based initial QP determination algorithm is presented. In the proposed algorithm, a novel linear model is established based on the observation of the relation between the initial QPs and PSNRs of frames. Using the linear model and PSNR results of the encoded GOPs, the proposed algorithm accurately estimates the optimal initial QP which maximizes the PSNR of the current GOP. It is shown by experimental results that the proposed algorithm predicts the optimal initial QP accurately and thus achieves better PSNR performance than that of the existing algorithm.


  1. T. Wiegand, G. J. Sullivan, G. Bjontegaard, and A. Luthra, "Overview of the H.264/AVC video coding standard," IEEE Transactions on Circuits and Systems for Video Technology, vol. 13, no. 7, pp. 560-576, 2003.
  2. S. C. Lim, H. R. Na, and Y. L. Lee, "Rate control based on linear regression for H.264/MPEG-4 AVC," Image Communication, vol. 22, no. 1, pp. 39-58, 2007.
  3. Z. Li, F. Pan, and K. Pang, " Adaptive basic unit layer rate control for JVT," Proceedings of Joint Video Team (JVT) of ISO/IEC MPEG and ITU-T VCEG, JVT-G012, Pattaya, Thailand, 2003.
  4. H. Wang and S. Kwong, "Rate-distortion optimization of rate control for H.264 with adaptive initial quantization parameter determination," IEEE Transactions on Circuits and Systems for Video Technology, vol. 18, no. 1, pp. 140-144, 2008.
  5. X. Jing and L. P. Chau, and W. C. Siu, "Frame complexity-based rate-quantization model for H.264/AVC intraframe rate control," IEEE Signal Processing Letters, vol. 15, pp. 373-376, 2008.
  6. B. Yan and M. Wang, "Adaptive distortion-based intra-rate estimation for H.264/AVC rate control," IEEE Signal Processing Letters, vol. 16, no. 3, pp. 145-148, 2009.
  7. K. P. Lim, G. Sullivan, and T. Wiegand, "Text description of joint model reference encoding methods and decoding concealment methods," Proceeding of Joint Video Team (JVT) of ISO/IEC MPEG and TUT-T VCEG, JVT-W057, San Jose, CA, 2007.