Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | */ |
| 20 | #include <pjmedia/silencedet.h> |
| 21 | #include <pjmedia/alaw_ulaw.h> |
| 22 | #include <pjmedia/errno.h> |
| 23 | #include <pj/assert.h> |
| 24 | #include <pj/log.h> |
| 25 | #include <pj/pool.h> |
| 26 | #include <pj/string.h> |
| 27 | |
| 28 | #define THIS_FILE "silencedet.c" |
| 29 | |
| 30 | #if 1 |
| 31 | # define TRACE_(x) PJ_LOG(5,x) |
| 32 | #else |
| 33 | # define TRACE_(x) |
| 34 | #endif |
| 35 | |
| 36 | /** |
| 37 | * This enumeration specifies operation mode of silence detector |
| 38 | */ |
| 39 | typedef enum pjmedia_silence_det_mode { |
| 40 | VAD_MODE_NONE, |
| 41 | VAD_MODE_FIXED, |
| 42 | VAD_MODE_ADAPTIVE |
| 43 | } pjmedia_silence_det_mode; |
| 44 | |
| 45 | /** |
| 46 | * Default settings |
| 47 | */ |
| 48 | #define DEF_RECALC_ON_VOICED 4000 /* Time to recalculate threshold |
| 49 | in voiced condition, in ms */ |
| 50 | #define DEF_RECALC_ON_SILENCE 2000 /* Time to recalculate threshold |
| 51 | in silence condition, in ms. */ |
| 52 | #define DEF_BEFORE_SILENCE 400 /* Silence time before really changing |
| 53 | state into SILENCE, in ms. */ |
| 54 | #define DEF_THRESHOLD 1000 /* Default threshold. */ |
| 55 | |
| 56 | /** |
| 57 | * This enumeration specifies the states of the silence detector. |
| 58 | */ |
| 59 | enum pjmedia_silence_det_state { |
| 60 | STATE_SILENCE, |
| 61 | STATE_START_SILENCE, |
| 62 | STATE_VOICED |
| 63 | }; |
| 64 | |
| 65 | /** |
| 66 | * This structure holds the silence detector state. |
| 67 | */ |
| 68 | struct pjmedia_silence_det |
| 69 | { |
| 70 | char objname[PJ_MAX_OBJ_NAME]; /**< VAD name. */ |
| 71 | |
| 72 | int mode; /**< VAD mode. */ |
| 73 | unsigned ptime; /**< Frame time, in msec. */ |
| 74 | |
| 75 | unsigned threshold; /**< Current threshold level. */ |
| 76 | unsigned sum_level; /**< Total sum of recent level. */ |
| 77 | unsigned sum_cnt; /**< Number of level summed. */ |
| 78 | unsigned silence_timer; /**< Silence condition timer. */ |
| 79 | unsigned voiced_timer; /**< Voiced condition timer. */ |
| 80 | |
| 81 | enum pjmedia_silence_det_state state;/**< Silence detector state. */ |
| 82 | unsigned recalc_on_voiced; /**< Setting of time to recalc |
| 83 | threshold in voiced condition. */ |
| 84 | unsigned recalc_on_silence; /**< Setting of time to recalc |
| 85 | threshold in silence condition.*/ |
| 86 | unsigned before_silence; /**< Setting of silence time before |
| 87 | really changing state into SILENCE, |
| 88 | in ms. */ |
| 89 | }; |
| 90 | |
| 91 | |
| 92 | |
| 93 | PJ_DEF(pj_status_t) pjmedia_silence_det_create( pj_pool_t *pool, |
| 94 | unsigned clock_rate, |
| 95 | unsigned samples_per_frame, |
| 96 | pjmedia_silence_det **p_sd) |
| 97 | { |
| 98 | pjmedia_silence_det *sd; |
| 99 | |
| 100 | PJ_ASSERT_RETURN(pool && p_sd, PJ_EINVAL); |
| 101 | |
| 102 | sd = PJ_POOL_ZALLOC_T(pool, pjmedia_silence_det); |
| 103 | |
| 104 | pj_ansi_snprintf(sd->objname, PJ_MAX_OBJ_NAME, "sd%p", sd); |
| 105 | sd->objname[PJ_MAX_OBJ_NAME-1] = '\0'; |
| 106 | |
| 107 | sd->ptime = samples_per_frame * 1000 / clock_rate; |
| 108 | |
| 109 | /* Default settings */ |
| 110 | pjmedia_silence_det_set_params(sd, -1, -1, -1); |
| 111 | |
| 112 | /* Restart in adaptive, silent mode */ |
| 113 | pjmedia_silence_det_set_adaptive( sd, -1 ); |
| 114 | |
| 115 | *p_sd = sd; |
| 116 | return PJ_SUCCESS; |
| 117 | } |
| 118 | |
| 119 | |
| 120 | PJ_DEF(pj_status_t) pjmedia_silence_det_set_name( pjmedia_silence_det *sd, |
| 121 | const char *name) |
| 122 | { |
| 123 | PJ_ASSERT_RETURN(sd && name, PJ_EINVAL); |
| 124 | |
| 125 | pj_ansi_snprintf(sd->objname, PJ_MAX_OBJ_NAME, name, sd); |
| 126 | sd->objname[PJ_MAX_OBJ_NAME-1] = '\0'; |
| 127 | return PJ_SUCCESS; |
| 128 | } |
| 129 | |
| 130 | PJ_DEF(pj_status_t) pjmedia_silence_det_set_adaptive(pjmedia_silence_det *sd, |
| 131 | int threshold) |
| 132 | { |
| 133 | PJ_ASSERT_RETURN(sd, PJ_EINVAL); |
| 134 | |
| 135 | if (threshold < 0) |
| 136 | threshold = DEF_THRESHOLD; |
| 137 | |
| 138 | sd->mode = VAD_MODE_ADAPTIVE; |
| 139 | sd->threshold = threshold; |
| 140 | |
| 141 | return PJ_SUCCESS; |
| 142 | } |
| 143 | |
| 144 | PJ_DEF(pj_status_t) pjmedia_silence_det_set_fixed( pjmedia_silence_det *sd, |
| 145 | int threshold ) |
| 146 | { |
| 147 | PJ_ASSERT_RETURN(sd, PJ_EINVAL); |
| 148 | |
| 149 | if (threshold < 0) |
| 150 | threshold = DEF_THRESHOLD; |
| 151 | |
| 152 | sd->mode = VAD_MODE_FIXED; |
| 153 | sd->threshold = threshold; |
| 154 | |
| 155 | return PJ_SUCCESS; |
| 156 | } |
| 157 | |
| 158 | PJ_DEF(pj_status_t) pjmedia_silence_det_set_params( pjmedia_silence_det *sd, |
| 159 | int before_silence, |
| 160 | int recalc_time1, |
| 161 | int recalc_time2) |
| 162 | { |
| 163 | PJ_ASSERT_RETURN(sd, PJ_EINVAL); |
| 164 | |
| 165 | if (recalc_time1 < 0) |
| 166 | recalc_time1 = DEF_RECALC_ON_VOICED; |
| 167 | if (recalc_time2 < 0) |
| 168 | recalc_time2 = DEF_RECALC_ON_SILENCE; |
| 169 | if (before_silence < 0) |
| 170 | before_silence = DEF_BEFORE_SILENCE; |
| 171 | |
| 172 | sd->recalc_on_voiced = recalc_time1; |
| 173 | sd->recalc_on_silence = recalc_time2; |
| 174 | sd->before_silence = before_silence; |
| 175 | |
| 176 | return PJ_SUCCESS; |
| 177 | } |
| 178 | |
| 179 | |
| 180 | PJ_DEF(pj_status_t) pjmedia_silence_det_disable( pjmedia_silence_det *sd ) |
| 181 | { |
| 182 | PJ_ASSERT_RETURN(sd, PJ_EINVAL); |
| 183 | |
| 184 | sd->mode = VAD_MODE_NONE; |
| 185 | |
| 186 | return PJ_SUCCESS; |
| 187 | } |
| 188 | |
| 189 | |
| 190 | PJ_DEF(pj_int32_t) pjmedia_calc_avg_signal( const pj_int16_t samples[], |
| 191 | pj_size_t count) |
| 192 | { |
| 193 | pj_uint32_t sum = 0; |
| 194 | |
| 195 | const pj_int16_t * pcm = samples; |
| 196 | const pj_int16_t * end = samples + count; |
| 197 | |
| 198 | if (count==0) |
| 199 | return 0; |
| 200 | |
| 201 | while (pcm != end) { |
| 202 | if (*pcm < 0) |
| 203 | sum -= *pcm++; |
| 204 | else |
| 205 | sum += *pcm++; |
| 206 | } |
| 207 | |
| 208 | return (pj_int32_t)(sum / count); |
| 209 | } |
| 210 | |
| 211 | PJ_DEF(pj_bool_t) pjmedia_silence_det_apply( pjmedia_silence_det *sd, |
| 212 | pj_uint32_t level) |
| 213 | { |
| 214 | int avg_recent_level; |
| 215 | |
| 216 | if (sd->mode == VAD_MODE_NONE) |
| 217 | return PJ_FALSE; |
| 218 | |
| 219 | if (sd->mode == VAD_MODE_FIXED) |
| 220 | return (level < sd->threshold); |
| 221 | |
| 222 | /* Calculating recent level */ |
| 223 | sd->sum_level += level; |
| 224 | ++sd->sum_cnt; |
| 225 | avg_recent_level = (sd->sum_level / sd->sum_cnt); |
| 226 | |
| 227 | if (level > sd->threshold || |
| 228 | level >= PJMEDIA_SILENCE_DET_MAX_THRESHOLD) |
| 229 | { |
| 230 | sd->silence_timer = 0; |
| 231 | sd->voiced_timer += sd->ptime; |
| 232 | |
| 233 | switch(sd->state) { |
| 234 | case STATE_VOICED: |
| 235 | if (sd->voiced_timer > sd->recalc_on_voiced) { |
| 236 | /* Voiced for long time (>recalc_on_voiced), current |
| 237 | * threshold seems to be too low. |
| 238 | */ |
| 239 | sd->threshold = (avg_recent_level + sd->threshold) >> 1; |
| 240 | TRACE_((THIS_FILE,"Re-adjust threshold (in talk burst)" |
| 241 | "to %d", sd->threshold)); |
| 242 | |
| 243 | sd->voiced_timer = 0; |
| 244 | |
| 245 | /* Reset sig_level */ |
| 246 | sd->sum_level = avg_recent_level; |
| 247 | sd->sum_cnt = 1; |
| 248 | } |
| 249 | break; |
| 250 | |
| 251 | case STATE_SILENCE: |
| 252 | TRACE_((THIS_FILE,"Starting talk burst (level=%d threshold=%d)", |
| 253 | level, sd->threshold)); |
| 254 | |
| 255 | case STATE_START_SILENCE: |
| 256 | sd->state = STATE_VOICED; |
| 257 | |
| 258 | /* Reset sig_level */ |
| 259 | sd->sum_level = level; |
| 260 | sd->sum_cnt = 1; |
| 261 | |
| 262 | break; |
| 263 | |
| 264 | default: |
| 265 | pj_assert(0); |
| 266 | break; |
| 267 | } |
| 268 | } else { |
| 269 | sd->voiced_timer = 0; |
| 270 | sd->silence_timer += sd->ptime; |
| 271 | |
| 272 | switch(sd->state) { |
| 273 | case STATE_SILENCE: |
| 274 | if (sd->silence_timer >= sd->recalc_on_silence) { |
| 275 | sd->threshold = avg_recent_level << 1; |
| 276 | TRACE_((THIS_FILE,"Re-adjust threshold (in silence)" |
| 277 | "to %d", sd->threshold)); |
| 278 | |
| 279 | sd->silence_timer = 0; |
| 280 | |
| 281 | /* Reset sig_level */ |
| 282 | sd->sum_level = avg_recent_level; |
| 283 | sd->sum_cnt = 1; |
| 284 | } |
| 285 | break; |
| 286 | |
| 287 | case STATE_VOICED: |
| 288 | sd->state = STATE_START_SILENCE; |
| 289 | |
| 290 | /* Reset sig_level */ |
| 291 | sd->sum_level = level; |
| 292 | sd->sum_cnt = 1; |
| 293 | |
| 294 | case STATE_START_SILENCE: |
| 295 | if (sd->silence_timer >= sd->before_silence) { |
| 296 | sd->state = STATE_SILENCE; |
| 297 | sd->threshold = avg_recent_level << 1; |
| 298 | TRACE_((THIS_FILE,"Starting silence (level=%d " |
| 299 | "threshold=%d)", level, sd->threshold)); |
| 300 | |
| 301 | /* Reset sig_level */ |
| 302 | sd->sum_level = avg_recent_level; |
| 303 | sd->sum_cnt = 1; |
| 304 | } |
| 305 | break; |
| 306 | |
| 307 | default: |
| 308 | pj_assert(0); |
| 309 | break; |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | return (sd->state == STATE_SILENCE); |
| 314 | } |
| 315 | |
| 316 | |
| 317 | PJ_DEF(pj_bool_t) pjmedia_silence_det_detect( pjmedia_silence_det *sd, |
| 318 | const pj_int16_t samples[], |
| 319 | pj_size_t count, |
| 320 | pj_int32_t *p_level) |
| 321 | { |
| 322 | pj_uint32_t level; |
| 323 | |
| 324 | /* Calculate average signal level. */ |
| 325 | level = pjmedia_calc_avg_signal(samples, count); |
| 326 | |
| 327 | /* Report to caller, if required. */ |
| 328 | if (p_level) |
| 329 | *p_level = level; |
| 330 | |
| 331 | return pjmedia_silence_det_apply(sd, level); |
| 332 | } |
| 333 | |