Rate control for MPEG transcoders
Rate control for MPEG transcoders
复制标题
MPEG 转码器的速率控制
DOI：
10.1109/76.905987
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
Robert O. Eifrig
中科院分区：
文献类型：
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作者：
Limin Wang;A. Luthra;Robert O. Eifrig
在MPEG中，输入图像可以被编码成三种不同的类型：I、P和B。这三幅图像由于其时间处理的不同性质而需要相当不同的比特数。因此，智能位分配策略应该根据图片的类型以及图片组织来分配图片的位数。这意味着对于给定的比特预算需要图像类型的先验知识。这个要求对于编码器来说不是问题，因为编码器可以决定每个输入图片的类型。事实上，编码器可以提前计划图片的类型。然而，代码转换器在实际处理图片之前没有关于图片类型的这种先验知识。这在代码转换器的比特分配中产生了困难。本文提出了一种新的速率控制方案的MPEG转码器，不需要事先知道的图片类型。我们的研究表明，所提出的速率控制与不事先知道的图片类型确定的图片目标率是非常接近的。
In MPEG, the input pictures can be coded in three different types: I, P, and B. The three pictures require quite different numbers of bits because of different natures of their temporal processing. Hence, an intelligent bit-allocation strategy should assign a picture the number of bits according to the picture's type, as well as the picture organization. This implies a requirement of a prior knowledge of the picture types for a given bit budget. This requirement is not a problem for the encoder, as the encoder can decide the type for each input picture. In fact, the encoder can plan ahead the types of the pictures. A transcoder however has no such a prior knowledge about a picture's type before actually processing the picture. This creates a difficulty in bit allocation for the transcoder. This paper presents a novel rate control scheme for MPEG transcoder that requires no a prior knowledge of the picture types. Our study indicates that the picture target rates determined by the proposed rate control with and without a prior knowledge of the picture types are very close.