1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_mfcc_f32.c
* Description: MFCC function for the f32 version
*
* $Date: 07 September 2021
* $Revision: V1.10.0
*
* Target Processor: Cortex-M and Cortex-A cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dsp/transform_functions.h"
#include "dsp/statistics_functions.h"
#include "dsp/basic_math_functions.h"
#include "dsp/complex_math_functions.h"
#include "dsp/fast_math_functions.h"
#include "dsp/matrix_functions.h"
/**
@ingroup groupTransforms
*/
/**
@defgroup MFCC MFCC
MFCC Transform
There are separate functions for floating-point, Q15, and Q31 data types.
*/
/**
@addtogroup MFCC
@{
*/
/**
@brief MFCC F32
@param[in] S points to the mfcc instance structure
@param[in] pSrc points to the input samples
@param[out] pDst points to the output MFCC values
@param[inout] pTmp points to a temporary buffer of complex
@return none
@par Description
The number of input samples if the FFT length used
when initializing the instance data structure.
The temporary buffer has a 2*fft length size when MFCC
is implemented with CFFT.
It has length FFT Length + 2 when implemented with RFFT
(default implementation).
The source buffer is modified by this function.
*/
void arm_mfcc_f32(
const arm_mfcc_instance_f32 * S,
float32_t *pSrc,
float32_t *pDst,
float32_t *pTmp
)
{
float32_t maxValue;
uint32_t index;
uint32_t i;
float32_t result;
const float32_t *coefs=S->filterCoefs;
arm_matrix_instance_f32 pDctMat;
/* Normalize */
arm_absmax_f32(pSrc,S->fftLen,&maxValue,&index);
arm_scale_f32(pSrc,1.0f/maxValue,pSrc,S->fftLen);
/* Multiply by window */
arm_mult_f32(pSrc,S->windowCoefs,pSrc,S->fftLen);
/* Compute spectrum magnitude
*/
#if defined(ARM_MFCC_CFFT_BASED)
/* some HW accelerator for CMSIS-DSP used in some boards
are only providing acceleration for CFFT.
With ARM_MFCC_CFFT_BASED enabled, CFFT is used and the MFCC
will be accelerated on those boards.
The default is to use RFFT
*/
/* Convert from real to complex */
for(i=0; i < S->fftLen ; i++)
{
pTmp[2*i] = pSrc[i];
pTmp[2*i+1] = 0.0f;
}
arm_cfft_f32(&(S->cfft),pTmp,0,1);
#else
/* Default RFFT based implementation */
arm_rfft_fast_f32(&(S->rfft),pSrc,pTmp,0);
/* Unpack real values */
pTmp[S->fftLen]=pTmp[1];
pTmp[S->fftLen+1]=0.0f;
pTmp[1]=0.0f;
#endif
arm_cmplx_mag_f32(pTmp,pSrc,S->fftLen);
/* Apply MEL filters */
for(i=0; i<S->nbMelFilters; i++)
{
arm_dot_prod_f32(pSrc+S->filterPos[i],
coefs,
S->filterLengths[i],
&result);
coefs += S->filterLengths[i];
pTmp[i] = result;
}
/* Compute the log */
arm_offset_f32(pTmp,1.0e-6f,pTmp,S->nbMelFilters);
arm_vlog_f32(pTmp,pTmp,S->nbMelFilters);
/* Multiply with the DCT matrix */
pDctMat.numRows=S->nbDctOutputs;
pDctMat.numCols=S->nbMelFilters;
pDctMat.pData=(float32_t*)S->dctCoefs;
arm_mat_vec_mult_f32(&pDctMat, pTmp, pDst);
}
/**
@} end of MFCC group
*/
|
