#include "asterisk.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.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)*DEFAULT_SAMPLE_RATE)/1000) |
#define | TRUE (!FALSE) |
Functions | |
static int __inline__ | amdf_pitch (int min_pitch, int max_pitch, int16_t amp[], int len) |
static int16_t | fsaturate (double damp) |
static 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. | |
static void | save_history (plc_state_t *s, int16_t *buf, int len) |
Definition in file plc.c.
#define ATTENUATION_INCREMENT 0.0025 |
#define FALSE 0 |
Definition at line 45 of file plc.c.
Referenced by __sip_ack(), __sip_semi_ack(), _sip_show_peer(), _sip_show_peers(), add_sdp(), ast_tzset(), build_rpid(), check_auth(), check_pendings(), do_monitor(), does_peer_need_mwi(), expire_register(), find_call(), find_sdp(), handle_request(), handle_request_invite(), handle_request_notify(), handle_request_refer(), handle_request_subscribe(), handle_response(), handle_response_invite(), notify_extenstate_update(), parse_sip_options(), process_sdp(), process_sdp_a_audio(), process_sdp_a_image(), process_sdp_a_sendonly(), process_sdp_a_video(), process_sdp_c(), reload_config(), reqprep(), show_console(), sip_addheader(), sip_destroy_peer(), sip_hangup(), sip_no_history(), sip_prune_realtime(), sip_read(), sip_register(), sip_show_inuse(), sip_show_user(), sip_show_users(), time1(), time2(), time2sub(), transmit_register(), tzload(), tzparse(), and update_call_counter().
#define TRUE (!FALSE) |
Definition at line 48 of file plc.c.
Referenced by __sip_ack(), __sip_autodestruct(), __sip_semi_ack(), _sip_show_peer(), _sip_show_peers(), add_sdp(), aji_act_hook(), ast_tzset(), build_peer(), build_rpid(), build_user(), check_auth(), check_pendings(), cli_activate(), do_monitor(), does_peer_need_mwi(), find_sdp(), gmtload(), handle_request_invite(), handle_request_notify(), handle_request_refer(), handle_request_subscribe(), handle_response_invite(), local_attended_transfer(), parse_ok_contact(), parse_sip_options(), process_sdp(), process_sdp_a_audio(), process_sdp_a_image(), process_sdp_a_sendonly(), process_sdp_a_video(), process_sdp_c(), reg_source_db(), reqprep(), show_console(), sip_addheader(), sip_do_history(), sip_hangup(), sip_park_thread(), sip_prune_realtime(), sip_reg_timeout(), sip_register(), sip_reload(), sip_show_inuse(), sip_show_user(), sip_show_users(), time1(), time2(), transmit_register(), tzload(), and unload_module().
static int __inline__ amdf_pitch | ( | int | min_pitch, | |
int | max_pitch, | |||
int16_t | amp[], | |||
int | len | |||
) | [static] |
Definition at line 107 of file plc.c.
Referenced by plc_fillin().
00108 { 00109 int i; 00110 int j; 00111 int acc; 00112 int min_acc; 00113 int pitch; 00114 00115 pitch = min_pitch; 00116 min_acc = INT_MAX; 00117 for (i = max_pitch; i <= min_pitch; i++) { 00118 acc = 0; 00119 for (j = 0; j < len; j++) 00120 acc += abs(amp[i + j] - amp[j]); 00121 if (acc < min_acc) { 00122 min_acc = acc; 00123 pitch = i; 00124 } 00125 } 00126 return pitch; 00127 }
static int16_t fsaturate | ( | double | damp | ) | [inline, static] |
static void normalise_history | ( | plc_state_t * | s | ) | [static] |
Definition at line 93 of file plc.c.
References PLC_HISTORY_LEN, and s.
Referenced by plc_fillin().
00094 { 00095 int16_t tmp[PLC_HISTORY_LEN]; 00096 00097 if (s->buf_ptr == 0) 00098 return; 00099 memcpy(tmp, s->history, sizeof(int16_t)*s->buf_ptr); 00100 memcpy(s->history, s->history + s->buf_ptr, sizeof(int16_t) * (PLC_HISTORY_LEN - s->buf_ptr)); 00101 memcpy(s->history + PLC_HISTORY_LEN - s->buf_ptr, tmp, sizeof(int16_t) * s->buf_ptr); 00102 s->buf_ptr = 0; 00103 }
int plc_fillin | ( | plc_state_t * | s, | |
int16_t | amp[], | |||
int | len | |||
) |
Fill-in a block of missing audio samples.
Fill-in a block of missing audio samples.
s | The packet loss concealer context. | |
amp | The audio sample buffer. | |
len | The number of samples to be synthesised. |
Definition at line 174 of file plc.c.
References amdf_pitch(), ATTENUATION_INCREMENT, CORRELATION_SPAN, fsaturate(), normalise_history(), PLC_HISTORY_LEN, PLC_PITCH_MAX, PLC_PITCH_MIN, s, and save_history().
Referenced by adjust_frame_for_plc().
00175 { 00176 int i; 00177 int pitch_overlap; 00178 float old_step; 00179 float new_step; 00180 float old_weight; 00181 float new_weight; 00182 float gain; 00183 int16_t *orig_amp; 00184 int orig_len; 00185 00186 orig_amp = amp; 00187 orig_len = len; 00188 if (s->missing_samples == 0) { 00189 /* As the gap in real speech starts we need to assess the last known pitch, 00190 and prepare the synthetic data we will use for fill-in */ 00191 normalise_history(s); 00192 s->pitch = amdf_pitch(PLC_PITCH_MIN, PLC_PITCH_MAX, s->history + PLC_HISTORY_LEN - CORRELATION_SPAN - PLC_PITCH_MIN, CORRELATION_SPAN); 00193 /* We overlap a 1/4 wavelength */ 00194 pitch_overlap = s->pitch >> 2; 00195 /* Cook up a single cycle of pitch, using a single of the real signal with 1/4 00196 cycle OLA'ed to make the ends join up nicely */ 00197 /* The first 3/4 of the cycle is a simple copy */ 00198 for (i = 0; i < s->pitch - pitch_overlap; i++) 00199 s->pitchbuf[i] = s->history[PLC_HISTORY_LEN - s->pitch + i]; 00200 /* The last 1/4 of the cycle is overlapped with the end of the previous cycle */ 00201 new_step = 1.0/pitch_overlap; 00202 new_weight = new_step; 00203 for ( ; i < s->pitch; i++) { 00204 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; 00205 new_weight += new_step; 00206 } 00207 /* We should now be ready to fill in the gap with repeated, decaying cycles 00208 of what is in pitchbuf */ 00209 00210 /* We need to OLA the first 1/4 wavelength of the synthetic data, to smooth 00211 it into the previous real data. To avoid the need to introduce a delay 00212 in the stream, reverse the last 1/4 wavelength, and OLA with that. */ 00213 gain = 1.0; 00214 new_step = 1.0 / pitch_overlap; 00215 old_step = new_step; 00216 new_weight = new_step; 00217 old_weight = 1.0 - new_step; 00218 for (i = 0; i < pitch_overlap; i++) { 00219 amp[i] = fsaturate(old_weight * s->history[PLC_HISTORY_LEN - 1 - i] + new_weight * s->pitchbuf[i]); 00220 new_weight += new_step; 00221 old_weight -= old_step; 00222 if (old_weight < 0.0) 00223 old_weight = 0.0; 00224 } 00225 s->pitch_offset = i; 00226 } else { 00227 gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; 00228 i = 0; 00229 } 00230 for ( ; gain > 0.0 && i < len; i++) { 00231 amp[i] = s->pitchbuf[s->pitch_offset] * gain; 00232 gain -= ATTENUATION_INCREMENT; 00233 if (++s->pitch_offset >= s->pitch) 00234 s->pitch_offset = 0; 00235 } 00236 for ( ; i < len; i++) 00237 amp[i] = 0; 00238 s->missing_samples += orig_len; 00239 save_history(s, amp, len); 00240 return len; 00241 }
plc_state_t* plc_init | ( | plc_state_t * | s | ) |
Process a block of received V.29 modem audio samples.
Process a block of received V.29 modem audio samples.
s | The packet loss concealer context. |
Definition at line 245 of file plc.c.
References s.
00246 { 00247 memset(s, 0, sizeof(*s)); 00248 return s; 00249 }
int plc_rx | ( | plc_state_t * | s, | |
int16_t | amp[], | |||
int | len | |||
) |
Process a block of received audio samples.
Process a block of received audio samples.
s | The packet loss concealer context. | |
amp | The audio sample buffer. | |
len | The number of samples in the buffer. |
Definition at line 131 of file plc.c.
References ATTENUATION_INCREMENT, fsaturate(), s, and save_history().
Referenced by adjust_frame_for_plc().
00132 { 00133 int i; 00134 int pitch_overlap; 00135 float old_step; 00136 float new_step; 00137 float old_weight; 00138 float new_weight; 00139 float gain; 00140 00141 if (s->missing_samples) { 00142 /* Although we have a real signal, we need to smooth it to fit well 00143 with the synthetic signal we used for the previous block */ 00144 00145 /* The start of the real data is overlapped with the next 1/4 cycle 00146 of the synthetic data. */ 00147 pitch_overlap = s->pitch >> 2; 00148 if (pitch_overlap > len) 00149 pitch_overlap = len; 00150 gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; 00151 if (gain < 0.0) 00152 gain = 0.0; 00153 new_step = 1.0/pitch_overlap; 00154 old_step = new_step*gain; 00155 new_weight = new_step; 00156 old_weight = (1.0 - new_step)*gain; 00157 for (i = 0; i < pitch_overlap; i++) { 00158 amp[i] = fsaturate(old_weight * s->pitchbuf[s->pitch_offset] + new_weight * amp[i]); 00159 if (++s->pitch_offset >= s->pitch) 00160 s->pitch_offset = 0; 00161 new_weight += new_step; 00162 old_weight -= old_step; 00163 if (old_weight < 0.0) 00164 old_weight = 0.0; 00165 } 00166 s->missing_samples = 0; 00167 } 00168 save_history(s, amp, len); 00169 return len; 00170 }
static void save_history | ( | plc_state_t * | s, | |
int16_t * | buf, | |||
int | len | |||
) | [static] |
Definition at line 70 of file plc.c.
References PLC_HISTORY_LEN, and s.
Referenced by plc_fillin(), and plc_rx().
00071 { 00072 if (len >= PLC_HISTORY_LEN) { 00073 /* Just keep the last part of the new data, starting at the beginning of the buffer */ 00074 memcpy(s->history, buf + len - PLC_HISTORY_LEN, sizeof(int16_t) * PLC_HISTORY_LEN); 00075 s->buf_ptr = 0; 00076 return; 00077 } 00078 if (s->buf_ptr + len > PLC_HISTORY_LEN) { 00079 /* Wraps around - must break into two sections */ 00080 memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t) * (PLC_HISTORY_LEN - s->buf_ptr)); 00081 len -= (PLC_HISTORY_LEN - s->buf_ptr); 00082 memcpy(s->history, buf + (PLC_HISTORY_LEN - s->buf_ptr), sizeof(int16_t)*len); 00083 s->buf_ptr = len; 00084 return; 00085 } 00086 /* Can use just one section */ 00087 memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*len); 00088 s->buf_ptr += len; 00089 }