| US 7,464,030 B1 | ||
| Vector search method | ||
| Yuji Maeda, Tokyo (Japan); and Shuichi Maeda, Kanagawa (Japan) | ||
| Assigned to Sony Corporation, Tokyo (Japan) | ||
| Filed on Mar. 26, 1998, as Appl. No. 9/48,076. | ||
| Claims priority of application No. P09-078615 (JP), filed on Mar. 28, 1997. | ||
| Int. Cl. G10L 19/00 (2006.01) | ||
| U.S. Cl. 704—222 [704/230] | 5 Claims |
| 1. A vector search method for obtaining an optimal sound source vector in vector quantization, in which a difference error
between a prediction vector and an input vector is calculated in such a way that combinations of factors respectively multiplied
by a plurality of basic vectors are changed according to the Gray code, the method comprising the steps of:
obtaining an intermediate value Gu by calculation of a synthetic vector created according to a sign word u of the Gray code;
expressing said value Gu by an intermediate value Gi, obtained by calculation of a synthetic vector created according to an
adjacent sign word i different from said sign word u only in a predetermined bit position v, and a change ΔGu calculated by
utilizing the Gray code characteristic;
using said ΔGu to express a change ΔGu′ between an intermediate value Gi′ according to another sign word i′ in said Gray code
and an intermediate value Gu′ according to an adjacent sign word u′ different from said sign word i′ only in a predetermined
bit position v; and
using said intermediate value Gi and said change ΔGu′ to obtain said optimal sound source vector.
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