| 摘要 |
<p>In audio communication carried out by encoding/decoding processes different from one another, a code obtained by encoding audio in accordance with a process is converted into a code decodable in accordance with other process, in high audio quality and with a small amount of calculation. In an apparatus for converting a first code string to a second code string, an audio-decoding circuit (1500) obtains a first linear prediction coefficient and excitation-signal information, based on a first code string, and generates a first audio signal by driving a filter having the first linear prediction coefficient with an excitation signal obtained from the excitation-signal information, and a fixed-codebook code generation circuit (1800) uses fixed-codebook information included in the excitation-signal information, as a part of the fixed-codebook information in the second code string, and obtains the fixed-codebook information in the second code string by minimizing a distance between a second audio signal generated, based on information obtained from the second code string, and the first audio signal. <IMAGE></p> |
