Fast mode decision algorithm for spatial resolutions down-scaling transcoding to H.264

  • Bu Jia-jun 
  • Mo Lin-jian 
  • Chen Chun 
  • Yang Zhi 
Article

Abstract

A fast mode decision algorithm is proposed in this paper to accelerate the process of transcoding videos into H.264 with arbitrary rate spatial resolution down-scaling. The proposed algorithm consists of three steps. First, an early-stop technique is introduced to determine the 16×16-mode blocks, which take up about 70% of all the macroblocks; then, a bottom-up merging process is performed to determine the mode of rest non-early-stopped blocks; and then, we adopt half-pixel motion estimation to further refine the acquired predictive motion vectors. In order to obtain the predictive motion vectors for early-stop and merging processes, we propose a motion vector composition scheme, which can reuse the information in the input pre-encoded videos to handle the spatial resolution down-scaling. Experimental results showed that our algorithm is about four times faster than the Cascaded-Decoder-Encoder method and has negligible PSNR drop and little bit rate increase.

Key words

Transcoding H.264 Mode decision Motion composition 

CLC number

TN919.8 

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References

  1. Ahmad, I., Wei, X.H., Sun, Y., Zhang, Y.Q., 2005. Video transcoding: An overview of various techniques and research issues. IEEE Trans. on Multimedia, 7(5):793–804. [doi:10.1109/TMM.2005.854472]CrossRefGoogle Scholar
  2. Chang, A., Wong, P.H.W., Yeung, Y.M., Au, O.C., 2004. Fast multi-block selection for H.264 video coding. Inter. Sym. Circuits and Systems, 3:817–820.Google Scholar
  3. Kucukgoz, M., Sun, M.T., 2004. Early-stop and Motion Vector Re-using for MPEG-2 to H.264 Transcoding. Inter. Conf. SPIE-IS&T Electronic Imaging.Google Scholar
  4. Shanableh, T., Ghanbari, M., 2000. Heterogeneous video transcoding to lower spatial-temporal resolutions and different encoding formats. IEEE Trans. on Multimedia, 2(2):101–110. [doi:10.1109/6046.845014]CrossRefGoogle Scholar
  5. Takahashi, K., Satoch, K., Suzuki, T., Yagasaki, Y., 2001. Motion Vector Synthesis Algorithm for MPEG2-to-MPEG4 Transcoder. Visual Communications and Image Processing. San Jose, CA, p.872–882.Google Scholar
  6. Tu, Y.K., Yang, J.F., Shen, Y.N., Sun, M.T., 2003. Fast variable size block motion estimation using merging procedure with an adaptive threshold. Inter. Conf. Multimedia and Expo., 2:789–792.Google Scholar
  7. Xin, J., Sun, M.T., Choi, B.S., Chun, K.W., 2002. An HDTV-to-SDTV spatial transcoder. IEEE Trans. on Circuits and Systems for Video Technology, 12(11):998–1008. [doi:10.1109/TCSVT.2002.805508]CrossRefGoogle Scholar
  8. Zhou, Z., Sun, M.T., Hsu, S., 2004. Fast variable block-size motion estimation algorithms based on merge and split procedures for H.264/MPEG-4 AVC. Inter. Sym. Circuits and Systems, 3:725–728.Google Scholar

Copyright information

© Zhejiang University 2006

Authors and Affiliations

  • Bu Jia-jun 
    • 1
  • Mo Lin-jian 
    • 1
  • Chen Chun 
    • 1
  • Yang Zhi 
    • 1
  1. 1.School of Computer ScienceZhejiang UniversityHangzhouChina

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