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comparison spandsp-0.0.6pre17/src/time_scale.c @ 4:26cd8f1ef0b1

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import spandsp-0.0.6pre17
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 15:50:58 +0200
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3:c6c5a16ce2f2 4:26cd8f1ef0b1
1 /*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * time_scale.c - Time scaling for linear speech data
5 *
6 * Written by Steve Underwood <steveu@coppice.org>
7 *
8 * Copyright (C) 2004 Steve Underwood
9 *
10 * All rights reserved.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Lesser General Public License version 2.1,
14 * as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 *
25 * $Id: time_scale.c,v 1.30 2009/02/10 13:06:47 steveu Exp $
26 */
27
28 /*! \file */
29
30 #if defined(HAVE_CONFIG_H)
31 #include "config.h"
32 #endif
33
34 #include <stdlib.h>
35 #include <stdio.h>
36 #include <inttypes.h>
37 #include <string.h>
38 #include <fcntl.h>
39 #include <time.h>
40 #include <limits.h>
41 #if defined(HAVE_TGMATH_H)
42 #include <tgmath.h>
43 #endif
44 #if defined(HAVE_MATH_H)
45 #include <math.h>
46 #endif
47 #include "floating_fudge.h"
48
49 #include "spandsp/telephony.h"
50 #include "spandsp/fast_convert.h"
51 #include "spandsp/time_scale.h"
52 #include "spandsp/saturated.h"
53
54 #include "spandsp/private/time_scale.h"
55
56 /*
57 Time scaling for speech, based on the Pointer Interval Controlled
58 OverLap and Add (PICOLA) method, developed by Morita Naotaka.
59 */
60
61 static __inline__ int amdf_pitch(int min_pitch, int max_pitch, int16_t amp[], int len)
62 {
63 int i;
64 int j;
65 int acc;
66 int min_acc;
67 int pitch;
68
69 pitch = min_pitch;
70 min_acc = INT_MAX;
71 for (i = max_pitch; i <= min_pitch; i++)
72 {
73 acc = 0;
74 for (j = 0; j < len; j++)
75 acc += abs(amp[i + j] - amp[j]);
76 if (acc < min_acc)
77 {
78 min_acc = acc;
79 pitch = i;
80 }
81 }
82 return pitch;
83 }
84 /*- End of function --------------------------------------------------------*/
85
86 static __inline__ void overlap_add(int16_t amp1[], int16_t amp2[], int len)
87 {
88 int i;
89 float weight;
90 float step;
91
92 step = 1.0f/len;
93 weight = 0.0f;
94 for (i = 0; i < len; i++)
95 {
96 /* TODO: saturate */
97 amp2[i] = (int16_t) ((float) amp1[i]*(1.0f - weight) + (float) amp2[i]*weight);
98 weight += step;
99 }
100 }
101 /*- End of function --------------------------------------------------------*/
102
103 SPAN_DECLARE(int) time_scale_rate(time_scale_state_t *s, float playout_rate)
104 {
105 if (playout_rate <= 0.0f)
106 return -1;
107 /*endif*/
108 if (playout_rate >= 0.99f && playout_rate <= 1.01f)
109 {
110 /* Treat rate close to normal speed as exactly normal speed, and
111 avoid divide by zero, and other numerical problems. */
112 playout_rate = 1.0f;
113 }
114 else if (playout_rate < 1.0f)
115 {
116 s->rcomp = playout_rate/(1.0f - playout_rate);
117 }
118 else
119 {
120 s->rcomp = 1.0f/(playout_rate - 1.0f);
121 }
122 /*endif*/
123 s->playout_rate = playout_rate;
124 return 0;
125 }
126 /*- End of function --------------------------------------------------------*/
127
128 SPAN_DECLARE(time_scale_state_t *) time_scale_init(time_scale_state_t *s, int sample_rate, float playout_rate)
129 {
130 int alloced;
131
132 if (sample_rate > TIME_SCALE_MAX_SAMPLE_RATE)
133 return NULL;
134 alloced = FALSE;
135 if (s == NULL)
136 {
137 if ((s = (time_scale_state_t *) malloc(sizeof (*s))) == NULL)
138 return NULL;
139 /*endif*/
140 alloced = TRUE;
141 }
142 /*endif*/
143 s->sample_rate = sample_rate;
144 s->min_pitch = sample_rate/TIME_SCALE_MIN_PITCH;
145 s->max_pitch = sample_rate/TIME_SCALE_MAX_PITCH;
146 s->buf_len = 2*sample_rate/TIME_SCALE_MIN_PITCH;
147 if (time_scale_rate(s, playout_rate))
148 {
149 if (alloced)
150 free(s);
151 return NULL;
152 }
153 /*endif*/
154 s->rate_nudge = 0.0f;
155 s->fill = 0;
156 s->lcp = 0;
157 return s;
158 }
159 /*- End of function --------------------------------------------------------*/
160
161 SPAN_DECLARE(int) time_scale_release(time_scale_state_t *s)
162 {
163 return 0;
164 }
165 /*- End of function --------------------------------------------------------*/
166
167 SPAN_DECLARE(int) time_scale_free(time_scale_state_t *s)
168 {
169 free(s);
170 return 0;
171 }
172 /*- End of function --------------------------------------------------------*/
173
174 SPAN_DECLARE(int) time_scale(time_scale_state_t *s, int16_t out[], int16_t in[], int len)
175 {
176 double lcpf;
177 int pitch;
178 int out_len;
179 int in_len;
180 int k;
181
182 out_len = 0;
183 in_len = 0;
184
185 /* Top up the buffer */
186 if (s->fill + len < s->buf_len)
187 {
188 /* Cannot continue without more samples */
189 memcpy(s->buf + s->fill, in, sizeof(int16_t)*len);
190 s->fill += len;
191 return out_len;
192 }
193 k = s->buf_len - s->fill;
194 memcpy(s->buf + s->fill, in, sizeof(int16_t)*k);
195 in_len += k;
196 s->fill = s->buf_len;
197 while (s->fill == s->buf_len)
198 {
199 while (s->lcp >= s->buf_len)
200 {
201 memcpy(out + out_len, s->buf, sizeof(int16_t)*s->buf_len);
202 out_len += s->buf_len;
203 if (len - in_len < s->buf_len)
204 {
205 /* Cannot continue without more samples */
206 memcpy(s->buf, in + in_len, sizeof(int16_t)*(len - in_len));
207 s->fill = len - in_len;
208 s->lcp -= s->buf_len;
209 return out_len;
210 }
211 memcpy(s->buf, in + in_len, sizeof(int16_t)*s->buf_len);
212 in_len += s->buf_len;
213 s->lcp -= s->buf_len;
214 }
215 if (s->lcp > 0)
216 {
217 memcpy(out + out_len, s->buf, sizeof(int16_t)*s->lcp);
218 out_len += s->lcp;
219 memcpy(s->buf, s->buf + s->lcp, sizeof(int16_t)*(s->buf_len - s->lcp));
220 if (len - in_len < s->lcp)
221 {
222 /* Cannot continue without more samples */
223 memcpy(s->buf + (s->buf_len - s->lcp), in + in_len, sizeof(int16_t)*(len - in_len));
224 s->fill = s->buf_len - s->lcp + len - in_len;
225 s->lcp = 0;
226 return out_len;
227 }
228 memcpy(s->buf + (s->buf_len - s->lcp), in + in_len, sizeof(int16_t)*s->lcp);
229 in_len += s->lcp;
230 s->lcp = 0;
231 }
232 if (s->playout_rate == 1.0f)
233 {
234 s->lcp = 0x7FFFFFFF;
235 }
236 else
237 {
238 pitch = amdf_pitch(s->min_pitch, s->max_pitch, s->buf, s->min_pitch);
239 lcpf = (double) pitch*s->rcomp;
240 /* Nudge around to compensate for fractional samples */
241 s->lcp = (int) lcpf;
242 /* Note that s->lcp and lcpf are not the same, as lcpf has a fractional part, and s->lcp doesn't */
243 s->rate_nudge += s->lcp - lcpf;
244 if (s->rate_nudge >= 0.5f)
245 {
246 s->lcp--;
247 s->rate_nudge -= 1.0f;
248 }
249 else if (s->rate_nudge <= -0.5f)
250 {
251 s->lcp++;
252 s->rate_nudge += 1.0f;
253 }
254 if (s->playout_rate < 1.0f)
255 {
256 /* Speed up - drop a chunk of data */
257 overlap_add(s->buf, s->buf + pitch, pitch);
258 memcpy(&s->buf[pitch], &s->buf[2*pitch], sizeof(int16_t)*(s->buf_len - 2*pitch));
259 if (len - in_len < pitch)
260 {
261 /* Cannot continue without more samples */
262 memcpy(s->buf + s->buf_len - pitch, in + in_len, sizeof(int16_t)*(len - in_len));
263 s->fill += (len - in_len - pitch);
264 return out_len;
265 }
266 memcpy(s->buf + s->buf_len - pitch, in + in_len, sizeof(int16_t)*pitch);
267 in_len += pitch;
268 }
269 else
270 {
271 /* Slow down - insert a chunk of data */
272 memcpy(out + out_len, s->buf, sizeof(int16_t)*pitch);
273 out_len += pitch;
274 overlap_add(s->buf + pitch, s->buf, pitch);
275 }
276 }
277 }
278 return out_len;
279 }
280 /*- End of function --------------------------------------------------------*/
281
282 SPAN_DECLARE(int) time_scale_max_output_len(time_scale_state_t *s, int input_len)
283 {
284 return (int) (input_len*s->playout_rate + s->min_pitch + 1);
285 }
286 /*- End of function --------------------------------------------------------*/
287 /*- End of file ------------------------------------------------------------*/

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