1mlib_SignalLPC2Cepstral_S16m(e3dMiLaILBi)b Library Fumnlcitbi_oSnisgnalLPC2Cepstral_S16(3MLIB)
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6 mlib_SignalLPC2Cepstral_S16 - convert linear prediction coefficients to
7 cepstral coefficients
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10 cc [ flag... ] file... -lmlib [ library... ]
11 #include <mlib.h>
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13 mlib_status mlib_SignalLPC2Cepstral_S16(mlib_s16 *cepst,
14 mlib_s32 cscale, const mlib_s16 *lpc, mlib_s32 lscale,
15 mlib_s16 gain, mlib_s32 gscale, mlib_s32 length,
16 mlib_s32 order);
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20 The mlib_SignalLPC2Cepstral_S16() function converts linear prediction
21 coefficients to cepstral coefficients. The user supplied scaling fac‐
22 tor, cscale, will be used and the output will be saturated if neces‐
23 sary.
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26 The cepstral coefficients are the coefficients of the Fourier transform
27 representation of the log magnitude spectrum.
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30 The LPC cepstral coefficients can be derived recursively from the LPC
31 coefficients as following.
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33 c(0) = log(G)
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35 m-1 k
36 c(m) = a(m) + SUM --- * c(k) * a(m-k), 1 ≤ m ≤ M
37 k=1 m
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39 m-1 k
40 c(m) = SUM --- * c(k) * a(m-k), m > M
41 k=1 m
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45 See Fundamentals of Speech Recognition by Lawrence Rabiner and Biing-
46 Hwang Juang, Prentice Hall, 1993.
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49 The function takes the following arguments:
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51 cepst The cepstral coefficients.
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54 cscale The scaling factor of the cepstral coefficients, where
55 actual_data = output_data * 2**(-scaling_factor).
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58 lpc The linear prediction coefficients.
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61 lscale The scaling factor of the linear prediction coefficients,
62 where actual_data = input_data * 2**(-scaling_factor).
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65 gain The gain of the LPC model.
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68 gscale The scaling factor of the gain of the LPC model, where
69 actual_data = input_data * 2**(-scaling_factor).
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72 length The length of the cepstral coefficients.
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75 order The order of the linear prediction filter.
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79 The function returns MLIB_SUCCESS if successful. Otherwise it returns
80 MLIB_FAILURE.
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83 See attributes(5) for descriptions of the following attributes:
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88 ┌─────────────────────────────┬─────────────────────────────┐
89 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
90 ├─────────────────────────────┼─────────────────────────────┤
91 │Interface Stability │Committed │
92 ├─────────────────────────────┼─────────────────────────────┤
93 │MT-Level │MT-Safe │
94 └─────────────────────────────┴─────────────────────────────┘
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97 mlib_SignalLPC2Cepstral_S16(3MLIB), mlib_SignalLPC2Cep‐
98 stral_S16_Adp(3MLIB), mlib_SignalLPC2Cepstral_F32(3MLIB), attributes(5)
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102SunOS 5.11 2 Mar 2007mlib_SignalLPC2Cepstral_S16(3MLIB)