Rate Control for Spatial/CGS Scalable Extension of H.264/AVC
Rate Control for Spatial/CGS Scalable Extension of H.264/AVC
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DOI：
10.1109/iscas.2007.378009
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发表时间：
2007-05
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通讯作者：
Yang Liu;Y. Soh;Zhengguo Li
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文献类型：
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作者：
Yang Liu;Y. Soh;Zhengguo Li
提出了一种H.264/AVC空间/粗增益-信噪比(CGS)可伸缩扩展的码率控制方案。提出了一种切换模型来预测当前层的前一帧或前一层的当前帧的平均绝对差(MAD)。这样，可以在增强层中正确地预测突然的MAD波动。此外，建立了一个总比特R-Q模型来描述纹理和非纹理信息的总比特数与量化参数(QP)之间的关系，以减少以往码率控制方案中非纹理比特估计不准确所带来的负面影响。利用H.264/AVC的峰值信噪比与QP值之间的关系，我们提出的总和比特R-Q模型可以进一步优化MB级别的QP计算。该算法可以实现对所有粗粒度可伸缩性(CGS)层和空间增强层的码率控制，并且编码器可以对每个可伸缩层实现固定码率编码。我们的方法只对序列编码一次，缓冲区得到很好的控制，以防止它溢出和下溢。
This paper presents a rate control scheme for H.264/AVC spatial/ coarse-gain-SNR (CGS) scalable extension. A switched model is proposed to predict mean absolute difference (MAD) either from the previous frame of the current layer or from the current frame of the previous layer. This way, abrupt MAD fluctuations could be predicted properly in the enhancement layer. Moreover, a sum bits R-Q model is formulated to describe the relationship between the total amount of bits for texture and non-texture information and quantization parameter (QP) so as to reduce the negative effect caused by inaccurate non-texture bits estimation of the previous rate control schemes. With the relation between PSNR and QP value of H.264/AVC, our proposed sum bits R-Q model could further optimize the QP calculation at the MB level. With our algorithm, the rate control for all the coarse-grain-scalability (CGS) and spatial enhancement layer could be realized, and the encoder could achieve fixed bitrate encoding for each scalable layer. Our method encodes the sequence only once and the buffer is well controlled to prevent it from overflowing and underflowing.