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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
#include <libfshift.h>
#include <fft/pffft/pffft.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <malloc.h>
//del
#include <stdio.h>
////////////////////////////////////////////////////////////////////////////////
struct hilbert_ctx {
PFFFT_Setup* fft_ctx;
float *pcm_in;
float *fft_bins;
float *pcm_out1;
float *pcm_out2;
const float* half_win;
};
struct fshift_ctx {
struct hilbert_ctx hilbert_ctx;
float *carrier;
size_t carrier_sz;
size_t carrier_cos_offset;
size_t carrier_cur_pos;
size_t delay_sz;
float fshift;
};
static void fill_half_win(float* w, int sz)
{
int i;
const float n = sz * 2.0 - 1;
for (i = 0; i < sz; i++)
w[i] = sinf(M_PI * (float)i / n);
}
static size_t fill_carrier(float* s, int sz, float shift)
{
// fprintf(stderr, "fill car: %d %f\n", sz, shift);
shift /= 44100;
size_t cos_offset = 0;
s[0] = sinf(2 * M_PI * shift * (float)0);
float prev = s[0];
for (int i = 1; i < sz; i++) {
s[i] = sinf(2 * M_PI * shift * (float)i);
if (!cos_offset) {
if (s[i] < prev) {
cos_offset = i - 1;
//fprintf(stderr, "cos offset: %d\n", (int)cos_offset);
} else {
prev = s[i];
}
}
//fprintf(stderr, "carrier: %d %f\n", i, s[i]);
}
return cos_offset;
}
static void do_hilbert_transform(struct hilbert_ctx* ctx, const float* const in, float* out1, float* out2, int sz)
{
int i, j;
float* cur = ctx->pcm_in + sz;
const float scale = 1.0 / (sz * 2);
// Fill second half of buffer
for (i = 0, j = sz - 1; i < sz; i++, j--) {
//fprintf(stderr, "%d in: %f , win %f\n", i, in[i], *(ctx->half_win + j));
*cur++ = in[i] * (*(ctx->half_win + j));
}
// for (i = 0; i < sz * 2; i++)
// fprintf(stderr, "in %d: %f\n", i, *(ctx->pcm_in + i));
pffft_transform_ordered(ctx->fft_ctx, ctx->pcm_in, ctx->fft_bins, NULL, PFFFT_FORWARD);
// Fill first half of buffer
cur = ctx->pcm_in;
for (i = 0; i < sz; i++)
*cur++ = in[i] * (*(ctx->half_win + i));
// Scale fft result
for (i = 0; i < sz * 2; i++)
*(ctx->fft_bins + i) *= scale;
// Zero DC
*(ctx->fft_bins) = 0.0;
*(ctx->fft_bins + 1) = 0.0;
for (i = 0; i < sz; i++)
out2[i] = *(ctx->pcm_out2 + i);
pffft_transform_ordered(ctx->fft_ctx, ctx->fft_bins, ctx->pcm_out2, NULL, PFFFT_BACKWARD);
for (i = 0; i < sz; i++) {
out2[i] += (*(ctx->pcm_out2 + i) * (*(ctx->half_win + i)));
*(ctx->pcm_out2 + i) = *(ctx->pcm_out2 + i + sz) * (*(ctx->half_win + sz - 1 - i));
}
// Multiply to -j
for (i = 2; i < sz * 2; i+=2) {
//fprintf(stderr, "fft %d: %f\n", i, *(ctx->fft_bins + i));
float t = *(ctx->fft_bins + i);
*(ctx->fft_bins + i) = *(ctx->fft_bins + i + 1);
*(ctx->fft_bins + i + 1) = -t;
}
// for (i = 0; i < sz * 2; i++)
// fprintf(stderr, "fft %d: %f\n", i, *(ctx->fft_bins + i));
for (i = 0; i < sz; i++)
out1[i] = *(ctx->pcm_out1 + i);
pffft_transform_ordered(ctx->fft_ctx, ctx->fft_bins, ctx->pcm_out1, NULL, PFFFT_BACKWARD);
// for (i = 0; i < sz * 2; i++)
// fprintf(stderr, "out %d: %f\n", i, *(ctx->pcm_out1 + i));
for (i = 0; i < sz; i++) {
out1[i] += (*(ctx->pcm_out1 + i) * (*(ctx->half_win + i)));
*(ctx->pcm_out1 + i) = *(ctx->pcm_out1 + i + sz) * (*(ctx->half_win + sz - 1 - i));
}
// for (i = 0; i < sz; i++)
// fprintf(stderr, "res out %d: %f\n", i, out1[i]);
}
static size_t calc_delay_sz(uint8_t sz)
{
return 1 << (sz - 1);
}
static size_t calc_carrier_size(float shift)
{
return 44100 / shift;
}
// n - number of samples to process
static int init_hilbert_ctx(struct hilbert_ctx *ctx, int n)
{
memset(ctx, 0, sizeof(struct hilbert_ctx));
int fft_sz = n * 2;
fprintf(stderr, "fft sz: %d\n", n);
ctx->fft_ctx = pffft_new_setup(fft_sz, PFFFT_REAL);
if (!ctx->fft_ctx)
goto err;
ctx->pcm_in = pffft_aligned_malloc(sizeof(float) * fft_sz);
if (!ctx->pcm_in)
goto err;
ctx->fft_bins = pffft_aligned_malloc(sizeof(float) * fft_sz);
if (!ctx->fft_bins)
goto err;
ctx->pcm_out1 = pffft_aligned_malloc(sizeof(float) * fft_sz);
if (!ctx->pcm_out1)
goto err;
ctx->pcm_out2 = pffft_aligned_malloc(sizeof(float) * fft_sz);
if (!ctx->pcm_out2)
goto err;
float *w = memalign(16, sizeof(float) * n);
if (!w)
goto err;
fill_half_win(w, n);
ctx->half_win = w;
memset(ctx->pcm_in, 0, sizeof(float) * fft_sz);
memset(ctx->pcm_out1, 0, sizeof(float) * fft_sz);
memset(ctx->pcm_out2, 0, sizeof(float) * fft_sz);
return 0;
err:
return -1;
}
static void free_hilbert_ctx(struct hilbert_ctx *ctx)
{
if (ctx->half_win)
free((void*)ctx->half_win);
if (ctx->pcm_out2)
pffft_aligned_free(ctx->pcm_out2);
if (ctx->pcm_out1)
pffft_aligned_free(ctx->pcm_out1);
if (ctx->fft_bins)
pffft_aligned_free(ctx->fft_bins);
if (ctx->pcm_in)
pffft_aligned_free(ctx->pcm_in);
if (ctx->fft_ctx)
pffft_destroy_setup(ctx->fft_ctx);
}
fshift_ctx_t fshift_create_ctx(float fshift, uint8_t sz)
{
const size_t ctx_sz = sizeof(struct fshift_ctx);
const size_t delay_sz = calc_delay_sz(sz);
const size_t carrier_sz = calc_carrier_size(fshift);
size_t cos_offset = 0;
fshift_ctx_t ctx = malloc(ctx_sz + sizeof(float) * carrier_sz);
ctx->carrier = ((void*)ctx) + ctx_sz;
ctx->carrier_sz = carrier_sz;
ctx->delay_sz = delay_sz;
memset(ctx->carrier, 0, (sizeof(float) * carrier_sz));
cos_offset = fill_carrier(ctx->carrier, carrier_sz, fshift);
ctx->carrier_cos_offset = cos_offset;
ctx->carrier_cur_pos = 0;
ctx->fshift = fshift;
init_hilbert_ctx(&ctx->hilbert_ctx, delay_sz * 2);
return ctx;
}
void fshift_free_ctx(fshift_ctx_t ctx)
{
free_hilbert_ctx(&ctx->hilbert_ctx);
free(ctx);
}
static void do_fshift(fshift_ctx_t ctx, float* out1, const float* out2)
{
size_t cur = ctx->carrier_cur_pos;
size_t block_sz = ctx->delay_sz * 2;
for (int i = 0; i < block_sz; i++, cur++) {
size_t sin_pos = cur % ctx->carrier_sz;
size_t cos_pos = (cur + ctx->carrier_cos_offset ) % ctx->carrier_sz;
float s = *(ctx->carrier + sin_pos);
float c = *(ctx->carrier + cos_pos);
//fprintf(stderr, "dsp: %d, %f %f\n", sin_pos, s, c);
out1[i] = out1[i] * s - out2[i] * c;
//out1[i] = out1[i] * s + out2[i] * c;
cur = sin_pos;
}
ctx->carrier_cur_pos = cur;
}
void fshift_run(fshift_ctx_t ctx, const float* const in, float* out1, float* out2)
{
do_hilbert_transform(&ctx->hilbert_ctx, in, out1, out2, ctx->delay_sz * 2);
do_fshift(ctx, out1, out2);
}
|
