1mlib_SignalLPC2Cepstral_S16m_eAddipa(L3iMbLILBi)brarmyliFbu_nScitginoanlsLPC2Cepstral_S16_Adp(3MLIB)
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6 mlib_SignalLPC2Cepstral_S16_Adp - convert linear prediction coeffi‐
7 cients to 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_Adp(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_Adp() function converts linear predic‐
21 tion coefficients to cepstral coefficients. The scaling factor of the
22 output data, cscale, will be calculated based on the actual data.
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25 The cepstral coefficients are the coefficients of the Fourier transform
26 representation of the log magnitude spectrum.
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29 The LPC cepstral coefficients can be derived recursively from the LPC
30 coefficients as following.
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32 c(0) = log(G)
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34 m-1 k
35 c(m) = a(m) + SUM --- * c(k) * a(m-k), 1 ≤ m ≤ M
36 k=1 m
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38 m-1 k
39 c(m) = SUM --- * c(k) * a(m-k), m > M
40 k=1 m
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44 See Fundamentals of Speech Recognition by Lawrence Rabiner and Biing-
45 Hwang Juang, Prentice Hall, 1993.
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48 The function takes the following arguments:
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50 cepst The cepstral coefficients.
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53 cscale The scaling factor of the cepstral coefficients, where
54 actual_data = output_data * 2**(-scaling_factor).
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57 lpc The linear prediction coefficients.
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60 lscale The scaling factor of the linear prediction coefficients,
61 where actual_data = input_data * 2**(-scaling_factor).
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64 gain The gain of the LPC model.
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67 gscale The scaling factor of the gain of the LPC model, where
68 actual_data = input_data * 2**(-scaling_factor).
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71 length The length of the cepstral coefficients.
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74 order The order of the linear prediction filter.
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78 The function returns MLIB_SUCCESS if successful. Otherwise it returns
79 MLIB_FAILURE.
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82 See attributes(5) for descriptions of the following attributes:
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87 ┌─────────────────────────────┬─────────────────────────────┐
88 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
89 ├─────────────────────────────┼─────────────────────────────┤
90 │Interface Stability │Committed │
91 ├─────────────────────────────┼─────────────────────────────┤
92 │MT-Level │MT-Safe │
93 └─────────────────────────────┴─────────────────────────────┘
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96 mlib_SignalLPC2Cepstral_S16(3MLIB), mlib_SignalLPC2Cep‐
97 stral_S16_Adp(3MLIB), mlib_SignalLPC2Cepstral_F32(3MLIB), attributes(5)
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101SunOS 5.11 2 Mar 2m0l0i7b_SignalLPC2Cepstral_S16_Adp(3MLIB)