#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#include "asterisk.h"
#include "asterisk/plc.h"
Go to the source code of this file.
Defines | |
#define | ATTENUATION_INCREMENT 0.0025 |
#define | FALSE 0 |
#define | INT16_MAX (32767) |
#define | INT16_MIN (-32767-1) |
#define | ms_to_samples(t) (((t)*SAMPLE_RATE)/1000) |
#define | TRUE (!FALSE) |
Functions | |
int __inline__ | amdf_pitch (int min_pitch, int max_pitch, int16_t amp[], int len) |
int16_t | fsaturate (double damp) |
void | normalise_history (plc_state_t *s) |
int | plc_fillin (plc_state_t *s, int16_t amp[], int len) |
Fill-in a block of missing audio samples. | |
plc_state_t * | plc_init (plc_state_t *s) |
Process a block of received V.29 modem audio samples. | |
int | plc_rx (plc_state_t *s, int16_t amp[], int len) |
Process a block of received audio samples. | |
void | save_history (plc_state_t *s, int16_t *buf, int len) |
Definition in file plc.c.
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Definition at line 44 of file plc.c. Referenced by P(), and show_console(). |
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Definition at line 47 of file plc.c. Referenced by gmtload(), show_console(), and tzload(). |
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Definition at line 106 of file plc.c. Referenced by plc_fillin(). 00107 { 00108 int i; 00109 int j; 00110 int acc; 00111 int min_acc; 00112 int pitch; 00113 00114 pitch = min_pitch; 00115 min_acc = INT_MAX; 00116 for (i = max_pitch; i <= min_pitch; i++) { 00117 acc = 0; 00118 for (j = 0; j < len; j++) 00119 acc += abs(amp[i + j] - amp[j]); 00120 if (acc < min_acc) { 00121 min_acc = acc; 00122 pitch = i; 00123 } 00124 } 00125 return pitch; 00126 }
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Definition at line 60 of file plc.c. Referenced by plc_fillin(), and plc_rx(). 00061 { 00062 if (damp > 32767.0) 00063 return INT16_MAX; 00064 if (damp < -32768.0) 00065 return INT16_MIN; 00066 return (int16_t) rint(damp); 00067 }
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Definition at line 92 of file plc.c. References plc_state_t::buf_ptr, plc_state_t::history, PLC_HISTORY_LEN, and s. Referenced by plc_fillin(). 00093 { 00094 int16_t tmp[PLC_HISTORY_LEN]; 00095 00096 if (s->buf_ptr == 0) 00097 return; 00098 memcpy(tmp, s->history, sizeof(int16_t)*s->buf_ptr); 00099 memcpy(s->history, s->history + s->buf_ptr, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr)); 00100 memcpy(s->history + PLC_HISTORY_LEN - s->buf_ptr, tmp, sizeof(int16_t)*s->buf_ptr); 00101 s->buf_ptr = 0; 00102 }
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Fill-in a block of missing audio samples. Fill-in a block of missing audio samples.
Definition at line 173 of file plc.c. References amdf_pitch(), CORRELATION_SPAN, fsaturate(), plc_state_t::history, plc_state_t::missing_samples, normalise_history(), plc_state_t::pitch, plc_state_t::pitch_offset, plc_state_t::pitchbuf, PLC_HISTORY_LEN, PLC_PITCH_MAX, PLC_PITCH_MIN, s, and save_history(). Referenced by adpcmtolin_framein(), alawtolin_framein(), g726tolin_framein(), gsmtolin_framein(), lpc10tolin_framein(), and ulawtolin_framein(). 00174 { 00175 int i; 00176 int pitch_overlap; 00177 float old_step; 00178 float new_step; 00179 float old_weight; 00180 float new_weight; 00181 float gain; 00182 int16_t *orig_amp; 00183 int orig_len; 00184 00185 orig_amp = amp; 00186 orig_len = len; 00187 if (s->missing_samples == 0) { 00188 /* As the gap in real speech starts we need to assess the last known pitch, 00189 and prepare the synthetic data we will use for fill-in */ 00190 normalise_history(s); 00191 s->pitch = amdf_pitch(PLC_PITCH_MIN, PLC_PITCH_MAX, s->history + PLC_HISTORY_LEN - CORRELATION_SPAN - PLC_PITCH_MIN, CORRELATION_SPAN); 00192 /* We overlap a 1/4 wavelength */ 00193 pitch_overlap = s->pitch >> 2; 00194 /* Cook up a single cycle of pitch, using a single of the real signal with 1/4 00195 cycle OLA'ed to make the ends join up nicely */ 00196 /* The first 3/4 of the cycle is a simple copy */ 00197 for (i = 0; i < s->pitch - pitch_overlap; i++) 00198 s->pitchbuf[i] = s->history[PLC_HISTORY_LEN - s->pitch + i]; 00199 /* The last 1/4 of the cycle is overlapped with the end of the previous cycle */ 00200 new_step = 1.0/pitch_overlap; 00201 new_weight = new_step; 00202 for ( ; i < s->pitch; i++) { 00203 s->pitchbuf[i] = s->history[PLC_HISTORY_LEN - s->pitch + i]*(1.0 - new_weight) + s->history[PLC_HISTORY_LEN - 2*s->pitch + i]*new_weight; 00204 new_weight += new_step; 00205 } 00206 /* We should now be ready to fill in the gap with repeated, decaying cycles 00207 of what is in pitchbuf */ 00208 00209 /* We need to OLA the first 1/4 wavelength of the synthetic data, to smooth 00210 it into the previous real data. To avoid the need to introduce a delay 00211 in the stream, reverse the last 1/4 wavelength, and OLA with that. */ 00212 gain = 1.0; 00213 new_step = 1.0/pitch_overlap; 00214 old_step = new_step; 00215 new_weight = new_step; 00216 old_weight = 1.0 - new_step; 00217 for (i = 0; i < pitch_overlap; i++) { 00218 amp[i] = fsaturate(old_weight*s->history[PLC_HISTORY_LEN - 1 - i] + new_weight*s->pitchbuf[i]); 00219 new_weight += new_step; 00220 old_weight -= old_step; 00221 if (old_weight < 0.0) 00222 old_weight = 0.0; 00223 } 00224 s->pitch_offset = i; 00225 } else { 00226 gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; 00227 i = 0; 00228 } 00229 for ( ; gain > 0.0 && i < len; i++) { 00230 amp[i] = s->pitchbuf[s->pitch_offset]*gain; 00231 gain -= ATTENUATION_INCREMENT; 00232 if (++s->pitch_offset >= s->pitch) 00233 s->pitch_offset = 0; 00234 } 00235 for ( ; i < len; i++) 00236 amp[i] = 0; 00237 s->missing_samples += orig_len; 00238 save_history(s, amp, len); 00239 return len; 00240 }
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Process a block of received V.29 modem audio samples. Process a block of received V.29 modem audio samples.
Definition at line 244 of file plc.c. References s. Referenced by adpcmtolin_new(), alawtolin_new(), g726tolin_new(), gsm_new(), lpc10_dec_new(), and ulawtolin_new(). 00245 { 00246 memset(s, 0, sizeof(*s)); 00247 return s; 00248 }
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Process a block of received audio samples. Process a block of received audio samples.
Definition at line 130 of file plc.c. References fsaturate(), plc_state_t::missing_samples, plc_state_t::pitch, plc_state_t::pitch_offset, plc_state_t::pitchbuf, s, and save_history(). Referenced by adpcmtolin_framein(), alawtolin_framein(), g726tolin_framein(), gsmtolin_framein(), lpc10tolin_framein(), and ulawtolin_framein(). 00131 { 00132 int i; 00133 int pitch_overlap; 00134 float old_step; 00135 float new_step; 00136 float old_weight; 00137 float new_weight; 00138 float gain; 00139 00140 if (s->missing_samples) { 00141 /* Although we have a real signal, we need to smooth it to fit well 00142 with the synthetic signal we used for the previous block */ 00143 00144 /* The start of the real data is overlapped with the next 1/4 cycle 00145 of the synthetic data. */ 00146 pitch_overlap = s->pitch >> 2; 00147 if (pitch_overlap > len) 00148 pitch_overlap = len; 00149 gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; 00150 if (gain < 0.0) 00151 gain = 0.0; 00152 new_step = 1.0/pitch_overlap; 00153 old_step = new_step*gain; 00154 new_weight = new_step; 00155 old_weight = (1.0 - new_step)*gain; 00156 for (i = 0; i < pitch_overlap; i++) { 00157 amp[i] = fsaturate(old_weight*s->pitchbuf[s->pitch_offset] + new_weight*amp[i]); 00158 if (++s->pitch_offset >= s->pitch) 00159 s->pitch_offset = 0; 00160 new_weight += new_step; 00161 old_weight -= old_step; 00162 if (old_weight < 0.0) 00163 old_weight = 0.0; 00164 } 00165 s->missing_samples = 0; 00166 } 00167 save_history(s, amp, len); 00168 return len; 00169 }
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Definition at line 69 of file plc.c. References plc_state_t::buf_ptr, plc_state_t::history, PLC_HISTORY_LEN, and s. Referenced by plc_fillin(), and plc_rx(). 00070 { 00071 if (len >= PLC_HISTORY_LEN) { 00072 /* Just keep the last part of the new data, starting at the beginning of the buffer */ 00073 memcpy(s->history, buf + len - PLC_HISTORY_LEN, sizeof(int16_t)*PLC_HISTORY_LEN); 00074 s->buf_ptr = 0; 00075 return; 00076 } 00077 if (s->buf_ptr + len > PLC_HISTORY_LEN) { 00078 /* Wraps around - must break into two sections */ 00079 memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr)); 00080 len -= (PLC_HISTORY_LEN - s->buf_ptr); 00081 memcpy(s->history, buf + (PLC_HISTORY_LEN - s->buf_ptr), sizeof(int16_t)*len); 00082 s->buf_ptr = len; 00083 return; 00084 } 00085 /* Can use just one section */ 00086 memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*len); 00087 s->buf_ptr += len; 00088 }
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