改进的用于增强层码流的差错鲁棒编码

Improved error robust coding for the enhancement bitstream

在MPEG-4标准的视频流化框架中,精细的可伸缩性视频编码FGS是关键的编码技术。FGS编码框架所生成的分层码流具有可伸缩性和出错恢复能力,这使得FGS码流适合在易发生差错的信道中传输。由于增强层之间的关联关系,任何一个发生在增强层的传输差错都会导致大量接收到的增强层码字因不能解码而被丢弃。为此提出了在进行增强层的位平面编码时,使用再同步变长编码RVLC来代替变长编码,从而将错误的影响尽可能地限制在一个块中,以提高编码的鲁棒性。

The fine granularity scalability(FGS) video coding is an important technique in the MPEG-4 streaming profile. The property that FGS video coding provides a layered bitstream with scalability and error recovery makes FGS bitstream suitable for transmission over the error-prone channels. On the other hand, each transmission error in the FGS enhancement bitstream will cause a lot of received enhancement bits to be undecodable because of the dependency among enhancement layers. In this paper, the resynchronizing variable length code(RVLC) technology is used when bit plane coding further limits the effects of transmission errors within only one block, so the FGS enhancement bitstream is more robust to transmission errors.