Patent ID: 7778827

Claim:
Apparatus providing gain quantization for use in coding a sampled sound signal represented in frames of samples, comprising: a calculator to compute an initial pitch gain g i over two subframes; a first searcher to locate, in a joint gain quantization codebook, an initial index associated to a pitch gain closest to the computed initial pitch gain g i ; a selector to select a portion of the quantization codebook containing the located initial index; an identifier to identify a selected codebook portion using at least one bit per two subframes; a second searcher to restrict the codebook search in the two subframes to the selected codebook portion; and a quantizer to express a selected index with some number of bits per subframe; where seven bits per subframe are used for Full-Rate (FR) coding to quantize pitch gain g p and innovation gain g c resulting in 28 bits per frame, where in Half-Rate (HR) voiced and generic coding the same quantization codebook as FR coding is used with only six bits per subframe and two additional bits are employed for the entire frame to indicate, in the case of a half portion, the codebook portion in the quantization every two subframes, giving a total of 26 bits per subframe, where bit allocations for expressing parameters for Generic FR, Generic HR, Voiced HR, Unvoiced HR, Unvoiced Quarter-Rate (QR) and Comfort Noise Generator-Eighth Rate (CNG-ER) are as follows: Generic Generic Voiced Unvoiced Unvoiced CNG Parameter FR HR HR HR QR ER Class Info — 1 3 2 1 — VAD bit — — — — — — LP 46 36 36 46 32 14 Parameters Pitch Delay 30 13 9 — — — Pitch 4 — 2 — — — Filtering Gains 28 26 26 24 20 6 Algebraic 144 48 48 52 — — Codebook FER 14 — — — — — protection bits Unused bits — — — — 1 — Total 266 124 124 124 54 20.