1 /*
2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11
12 /*
13 * This file contains the function WebRtcSpl_ComplexFFT().
14 * The description header can be found in signal_processing_library.h
15 *
16 */
17
18 #include "signal_processing_library.h"
19
20 #define CFFTSFT 14
21 #define CFFTRND 1
22 #define CFFTRND2 16384
23
24 #if (defined ARM9E_GCC) || (defined ARM_WINM) || (defined ANDROID_AECOPT)
25 extern "C" int FFT_4OFQ14(void *src, void *dest, int NC, int shift);
26
27 // For detailed description of the fft functions, check the readme files in fft_ARM9E folder.
WebRtcSpl_ComplexFFT2(WebRtc_Word16 frfi[],WebRtc_Word16 frfiOut[],int stages,int mode)28 int WebRtcSpl_ComplexFFT2(WebRtc_Word16 frfi[], WebRtc_Word16 frfiOut[], int stages, int mode)
29 {
30 return FFT_4OFQ14(frfi, frfiOut, 1 << stages, 0);
31 }
32 #endif
33
WebRtcSpl_ComplexFFT(WebRtc_Word16 frfi[],int stages,int mode)34 int WebRtcSpl_ComplexFFT(WebRtc_Word16 frfi[], int stages, int mode)
35 {
36 int i, j, l, k, istep, n, m;
37 WebRtc_Word16 wr, wi;
38 WebRtc_Word32 tr32, ti32, qr32, qi32;
39
40 /* The 1024-value is a constant given from the size of WebRtcSpl_kSinTable1024[],
41 * and should not be changed depending on the input parameter 'stages'
42 */
43 n = 1 << stages;
44 if (n > 1024)
45 return -1;
46
47 l = 1;
48 k = 10 - 1; /* Constant for given WebRtcSpl_kSinTable1024[]. Do not change
49 depending on the input parameter 'stages' */
50
51 if (mode == 0)
52 {
53 // mode==0: Low-complexity and Low-accuracy mode
54 while (l < n)
55 {
56 istep = l << 1;
57
58 for (m = 0; m < l; ++m)
59 {
60 j = m << k;
61
62 /* The 256-value is a constant given as 1/4 of the size of
63 * WebRtcSpl_kSinTable1024[], and should not be changed depending on the input
64 * parameter 'stages'. It will result in 0 <= j < N_SINE_WAVE/2
65 */
66 wr = WebRtcSpl_kSinTable1024[j + 256];
67 wi = -WebRtcSpl_kSinTable1024[j];
68
69 for (i = m; i < n; i += istep)
70 {
71 j = i + l;
72
73 tr32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j])
74 - WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j + 1])), 15);
75
76 ti32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j + 1])
77 + WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j])), 15);
78
79 qr32 = (WebRtc_Word32)frfi[2 * i];
80 qi32 = (WebRtc_Word32)frfi[2 * i + 1];
81 frfi[2 * j] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qr32 - tr32, 1);
82 frfi[2 * j + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qi32 - ti32, 1);
83 frfi[2 * i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qr32 + tr32, 1);
84 frfi[2 * i + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qi32 + ti32, 1);
85 }
86 }
87
88 --k;
89 l = istep;
90
91 }
92
93 } else
94 {
95 // mode==1: High-complexity and High-accuracy mode
96 while (l < n)
97 {
98 istep = l << 1;
99
100 for (m = 0; m < l; ++m)
101 {
102 j = m << k;
103
104 /* The 256-value is a constant given as 1/4 of the size of
105 * WebRtcSpl_kSinTable1024[], and should not be changed depending on the input
106 * parameter 'stages'. It will result in 0 <= j < N_SINE_WAVE/2
107 */
108 wr = WebRtcSpl_kSinTable1024[j + 256];
109 wi = -WebRtcSpl_kSinTable1024[j];
110
111 for (i = m; i < n; i += istep)
112 {
113 j = i + l;
114
115 tr32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j])
116 - WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j + 1]) + CFFTRND),
117 15 - CFFTSFT);
118
119 ti32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j + 1])
120 + WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j]) + CFFTRND), 15 - CFFTSFT);
121
122 qr32 = ((WebRtc_Word32)frfi[2 * i]) << CFFTSFT;
123 qi32 = ((WebRtc_Word32)frfi[2 * i + 1]) << CFFTSFT;
124 frfi[2 * j] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
125 (qr32 - tr32 + CFFTRND2), 1 + CFFTSFT);
126 frfi[2 * j + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
127 (qi32 - ti32 + CFFTRND2), 1 + CFFTSFT);
128 frfi[2 * i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
129 (qr32 + tr32 + CFFTRND2), 1 + CFFTSFT);
130 frfi[2 * i + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
131 (qi32 + ti32 + CFFTRND2), 1 + CFFTSFT);
132 }
133 }
134
135 --k;
136 l = istep;
137 }
138 }
139 return 0;
140 }
141