Frame bit allocation for the H.264/AVC video coder via Cauchy-density-based rate and distortion models
Frame bit allocation for the H.264/AVC video coder via Cauchy-density-based rate and distortion models
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DOI：
10.1109/tcsvt.2005.852400
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发表时间：
2005-08
影响因子：
8.4
通讯作者：
Nejat Kamaci;Y. Altunbasak;R. Mersereau
中科院分区：
文献类型：
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作者：
Nejat Kamaci;Y. Altunbasak;R. Mersereau
基于柯西密度比传统的拉普拉斯密度更准确地估计交流系数的分布，建立了精度更高的速率模型和失真模型。在H.264的帧比特分配应用中，量化离散余弦变换系数的熵和失真模型是合理的。对精心选择的锚定视频序列的广泛分析表明，与JM 8.4码率控制算法相比，平均峰值信噪比(PSNR)提高了0.24-d B，与Li等人最近提出的基于TM5的比特分配算法相比，平均PSNR提高了0.33-d B。分析还表明，与JM 8.4码率控制算法和基于TM5的比特分配算法相比，编码图像之间的PSNR变化分别减少了20%和60%。
Based on the observation that a Cauchy density is more accurate in estimating the distribution of the ac coefficients than the traditional Laplacian density, rate and distortion models with improved accuracy are developed. The entropy and distortion models for quantized discrete cosine transform coefficients are justified in a frame bit-allocation application for H.264. Extensive analysis with carefully selected anchor video sequences demonstrates a 0.24-dB average peak signal-to-noise ratio (PSNR) improvement over the JM 8.4 rate control algorithm, and a 0.33-dB average PSNR improvement over the TM5-based bit-allocation algorithm that has recently been proposed for H.264 by Li et al. The analysis also demonstrates 20% and 60% reductions in PSNR variation among the encoded pictures when compared to the JM 8.4 rate control algorithm and the TM5-based bit-allocation algorithm, respectively.