Weight Based Fast Mode Decision for H.264/AVC Video Coding Standard
H.264/AVC video coding standard outperforms former standards in terms of coding efficiency but at the expense of higher computation complexity. Of all the encoding elements in H.264/AVC, inter prediction is computationally most intensive and thus adds to the computational burden for the encoder. In this paper, we propose a fast inter prediction algorithm for JVT video coding standard H.264/AVC. All images have certain characteristics that are inherent to them. Natural videos have many homogeneous regions. In video sequences, there are stationary regions between frames and regions with moderate to complex motion. From an in-depth analysis of the full search algorithm in which properties of each macroblock (MB) are studied in details, a method is proposed where each MB is given a weight depending upon its characteristics. The motion content and the homogeneity parameters of each MB is determined prior to the ME process. The MBs correlation with neighboring MBs in respect of predicted motion vectors (MV) and encoding modes are studied. Weights are assigned for these parameters and the final mode is selected based upon these weights. We propose a Weight Based Fast Mode Decision (WBFMD) process where we define four weights for each MB based on its motion content, homogeneity, value of the predicted MV and the encoding modes of the neighboring MBs. Smaller weights are assigned when these parameters have low values indicating a simple MB whereas larger weights are assigned when these parameters have high value indicating a more complex MB. The average video encoding time reduction in the proposed method is 70% compared to the JVT benchmark JM12.4 while maintaining similar PSNR and bit rate. Experimental results for various test sequences at different resolutions are presented to show the effectiveness of the proposed method.
KeywordsH.264/AVC Inter prediction Motion estimation Weighted prediction
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- 1.Joint Video Team of ITU-T and ISO/IEC JTC 1, Draft ITU-T Recommendation and Final Draft International Standard of Joint Video Specification (ITU-T Rec. H.264—ISO/IEC 14496-10 AVC), document JVT-G050r1 (2003 )Google Scholar
- 3.Richardson, I.E.G.: H.264 and MPEG-4 Video Compression: Video Coding for Next-generation Multimedia. John Wiley and Sons (2003)Google Scholar
- 6.Kim, G.Y., Moon, Y.H., Kim, J.H.: An Early Detection of All-Zero DCT Block in H.264. ICIP 13, 453–456 (2004)Google Scholar
- 8.Liu, Z., Shen, L., Zhang, Z.: An Efficient Intermode Decision Algorithm Based on Motion Homogeneity for H.264/AVC. IEEE Trans. on Circuits and System for Video Technology. 19, 28–132 (2009)Google Scholar
- 9.Park, I., Capson, D.W.: Improved Inter Mode Decision Based on Residue in H.264/AVC. In: International Conference on Multimedia and Expo., pp. 709–712 (2008)Google Scholar
- 12.Ganguly, A., Mahanta, A.: Fast Mode Decision Algorithm for H.264/AVC Intra Prediction. IEEE Region 10 Conference,TENCON, Singapore (2009)Google Scholar
- 15.Bjontegaard, G.: Calculation of average PSNR difference between RD-curves. ITU-T VCEG, Doc. VCEG-M33. 1–2 (2001)Google Scholar
- 16.Sullivan, G., Bjontegaard, G.: Recommended Simulation Common Conditions for H.26L Coding Efficiency Experiments on Low-Resolution Progressive-Scan Source Material. ITU-T VCEG, Doc. VCEG-N81, 1–3 (2001)Google Scholar