Under the premise of ensuring good speech quality and resistance to steganalysis, how to embed as much information as possible into low-bit-rate speech is a challenge. The existing research mainly focuses on least significant bits in the compressed speech streams or line spectral frequencies in the encoding processes of the G.723.1 and G.729a codecs. In this paper, we are concentrating on steganography in Internet Low Bitrate Codec speech streams. Specifically, we present a novel steganographic method on the basis of the gain quantization (GQS), which is included in the vector quantization of dynamic codebooks. The secret information is embedded by modifying the search range of the gain codebook to quantize the gain value. The experimental results show that the proposed GQS method achieves a higher hiding capacity, less signal distortion, and better resistance to steganalysis.

中文翻译：

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一种基于增益量化的 iLBC 语音流隐写方法

在保证良好的语音质量和抗隐写分析的前提下，如何将尽可能多的信息嵌入到低码率语音中是一个挑战。现有的研究主要集中在G.723.1和G.729a编解码器的编码过程中压缩语音流中的最低有效位或线谱频率。在本文中，我们专注于互联网低比特率编解码器语音流中的隐写术。具体来说，我们提出了一种基于增益量化（GQS）的新型隐写方法，该方法包含在动态码本的矢量量化中。通过修改增益码本的搜索范围以量化增益值来嵌入秘密信息。实验结果表明，所提出的 GQS 方法实现了更高的隐藏能力，更少的信号失真，