Initial QP Determination Algorithm for Low Bit Rate Video Coding

저전송률 비디오 압축에서 초기 QP 결정 알고리즘

  • 박상현 (순천대학교 멀티미디어공학과)
  • Published : 2009.10.31

Abstract

The first frame is encoded in intra mode which generates a larger number of bits. In addition, the first frame is used for the inter mode encoding of the following frames. Thus the intial QP (Quantization Parameter) for the first frame affects the first frame as well as the following frames. Traditionally, the initial QP is determined among four constant values only depending on the bpp. In the case of low bit rate video coding, the initial QP value is fixed to 35 regardless of the output bandwidth. Although this initialization scheme is simple, yet it is not accurate enough. An accurate intial QP prediction scheme should not only depends on bpp but also on the complexity of the video sequence and the output bandwidth. In the proposed scheme, we use a linear model because there is a linear inverse proportional relationship between the output bandwidth and the optimal intial QP. Model parameters of the model are determined depending on the spatial complexity of the first frame. It is shown by experimental results that the new algorithm can predict the optimal initial QP more accurately and generate the PSNR performance better than that of the existing JM algorithm.

References

  1. Z. Chen and K.N. Ngan, "Recent advances in rate control for video coding," Signal Process.: Image Commun., vol 22, pp. 19-38, Jan. 2007 https://doi.org/10.1016/j.image.2006.11.002
  2. 윤홍준, 서영호, 최현준, 김동욱, ".H264/A 고속 인트라 예측 방법," 한국해양정보통신학회논문지, vol. 10, no. 7 pp. 1172-1179, 2006년 7월
  3. T. Wiegand, H. Schwarz, A. Joch, F. Kossentini, and G. J. Sullivan, "Rate-constrained coder control and comparison of video coding standards," IEEE Trans. Circuits Syst. Video Technol., vol. 7, pp. 688-703, Jul. 2003
  4. T. Wiegand, G. J. Sullivan, G. Bjontegaard, and A. Luthra, "Overview of the H.264/AVC video coding standard," IEEE Trans. Circuits Syst. Video Technol., vol. 7, no. 7, pp. 1-19, Jul. 2003
  5. H. Wang and S. Kwong, "Rate-Distortion Optimization of Rate Control for H.264 With Adaptive Initial Quantization Parameter Determination," IEEE Trans. Circuits Syst. Video Technol., vol. 18, no. 1, pp. 140-144, Jan. 2008 https://doi.org/10.1109/TCSVT.2007.913757
  6. C. Lee, Y. Jung, S. Lee, Y. Oh, and J. Kim, "Real-Time Frame-Layer H.264 Rate Control for Scene-Transition Video at Low Bit Rate," IEEE Trans. Consumer Elect., vol. 53, no. 3, pp. 1084-1092, Aug. 2007 https://doi.org/10.1109/TCE.2007.4341589
  7. 박상현, "적응적 베이직 유닛 레벨 H.264 비트율 제어," 한국해양정보통신학회논문지, vol. 13, no. 2, pp. 355-361, 2009년 2월
  8. Z. Li, F. Pan, and K. P. Lim, Adaptive Basic Unit Layer Rate Control for JVT Doc. JVT-G012-rl, Thailand, Mar. 2003