diff options
| -rwxr-xr-x | plc.c | 325 |
1 files changed, 159 insertions, 166 deletions
@@ -54,205 +54,198 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #endif /* We do a straight line fade to zero volume in 50ms when we are filling in for missing data. */ -#define ATTENUATION_INCREMENT 0.0025 /* Attenuation per sample */ +#define ATTENUATION_INCREMENT 0.0025 /* Attenuation per sample */ -#define ms_to_samples(t) (((t)*SAMPLE_RATE)/1000) +#define ms_to_samples(t) (((t)*SAMPLE_RATE)/1000) static inline int16_t fsaturate(double damp) { - if (damp > 32767.0) - return INT16_MAX; - if (damp < -32768.0) - return INT16_MIN; - return (int16_t) rint(damp); + if (damp > 32767.0) + return INT16_MAX; + if (damp < -32768.0) + return INT16_MIN; + return (int16_t) rint(damp); } static void save_history(plc_state_t *s, int16_t *buf, int len) { - if (len >= PLC_HISTORY_LEN) - { - /* Just keep the last part of the new data, starting at the beginning of the buffer */ - memcpy(s->history, buf + len - PLC_HISTORY_LEN, sizeof(int16_t)*PLC_HISTORY_LEN); - s->buf_ptr = 0; - return; - } - if (s->buf_ptr + len > PLC_HISTORY_LEN) - { - /* Wraps around - must break into two sections */ - memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr)); - len -= (PLC_HISTORY_LEN - s->buf_ptr); - memcpy(s->history, buf + (PLC_HISTORY_LEN - s->buf_ptr), sizeof(int16_t)*len); - s->buf_ptr = len; - return; - } - /* Can use just one section */ - memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*len); - s->buf_ptr += len; + if (len >= PLC_HISTORY_LEN) { + /* Just keep the last part of the new data, starting at the beginning of the buffer */ + memcpy(s->history, buf + len - PLC_HISTORY_LEN, sizeof(int16_t)*PLC_HISTORY_LEN); + s->buf_ptr = 0; + return; + } + if (s->buf_ptr + len > PLC_HISTORY_LEN) { + /* Wraps around - must break into two sections */ + memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr)); + len -= (PLC_HISTORY_LEN - s->buf_ptr); + memcpy(s->history, buf + (PLC_HISTORY_LEN - s->buf_ptr), sizeof(int16_t)*len); + s->buf_ptr = len; + return; + } + /* Can use just one section */ + memcpy(s->history + s->buf_ptr, buf, sizeof(int16_t)*len); + s->buf_ptr += len; } + /*- End of function --------------------------------------------------------*/ static void normalise_history(plc_state_t *s) { - int16_t tmp[PLC_HISTORY_LEN]; - - if (s->buf_ptr == 0) - return; - memcpy(tmp, s->history, sizeof(int16_t)*s->buf_ptr); - memcpy(s->history, s->history + s->buf_ptr, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr)); - memcpy(s->history + PLC_HISTORY_LEN - s->buf_ptr, tmp, sizeof(int16_t)*s->buf_ptr); - s->buf_ptr = 0; + int16_t tmp[PLC_HISTORY_LEN]; + + if (s->buf_ptr == 0) + return; + memcpy(tmp, s->history, sizeof(int16_t)*s->buf_ptr); + memcpy(s->history, s->history + s->buf_ptr, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr)); + memcpy(s->history + PLC_HISTORY_LEN - s->buf_ptr, tmp, sizeof(int16_t)*s->buf_ptr); + s->buf_ptr = 0; } + /*- End of function --------------------------------------------------------*/ static int __inline__ amdf_pitch(int min_pitch, int max_pitch, int16_t amp[], int len) { - int i; - int j; - int acc; - int min_acc; - int pitch; - - pitch = min_pitch; - min_acc = INT_MAX; - for (i = max_pitch; i <= min_pitch; i++) - { - acc = 0; - for (j = 0; j < len; j++) - acc += abs(amp[i + j] - amp[j]); - if (acc < min_acc) - { - min_acc = acc; - pitch = i; - } - } - return pitch; + int i; + int j; + int acc; + int min_acc; + int pitch; + + pitch = min_pitch; + min_acc = INT_MAX; + for (i = max_pitch; i <= min_pitch; i++) { + acc = 0; + for (j = 0; j < len; j++) + acc += abs(amp[i + j] - amp[j]); + if (acc < min_acc) { + min_acc = acc; + pitch = i; + } + } + return pitch; } + /*- End of function --------------------------------------------------------*/ int plc_rx(plc_state_t *s, int16_t amp[], int len) { - int i; - int pitch_overlap; - float old_step; - float new_step; - float old_weight; - float new_weight; - float gain; - - if (s->missing_samples) - { - /* Although we have a real signal, we need to smooth it to fit well - with the synthetic signal we used for the previous block */ - - /* The start of the real data is overlapped with the next 1/4 cycle - of the synthetic data. */ - pitch_overlap = s->pitch >> 2; - if (pitch_overlap > len) - pitch_overlap = len; - gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; - if (gain < 0.0) - gain = 0.0; - new_step = 1.0/pitch_overlap; - old_step = new_step*gain; - new_weight = new_step; - old_weight = (1.0 - new_step)*gain; - for (i = 0; i < pitch_overlap; i++) - { - amp[i] = fsaturate(old_weight*s->pitchbuf[s->pitch_offset] + new_weight*amp[i]); - if (++s->pitch_offset >= s->pitch) - s->pitch_offset = 0; - new_weight += new_step; - old_weight -= old_step; - if (old_weight < 0.0) - old_weight = 0.0; - } - s->missing_samples = 0; - } - save_history(s, amp, len); - return len; + int i; + int pitch_overlap; + float old_step; + float new_step; + float old_weight; + float new_weight; + float gain; + + if (s->missing_samples) { + /* Although we have a real signal, we need to smooth it to fit well + with the synthetic signal we used for the previous block */ + + /* The start of the real data is overlapped with the next 1/4 cycle + of the synthetic data. */ + pitch_overlap = s->pitch >> 2; + if (pitch_overlap > len) + pitch_overlap = len; + gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; + if (gain < 0.0) + gain = 0.0; + new_step = 1.0/pitch_overlap; + old_step = new_step*gain; + new_weight = new_step; + old_weight = (1.0 - new_step)*gain; + for (i = 0; i < pitch_overlap; i++) { + amp[i] = fsaturate(old_weight*s->pitchbuf[s->pitch_offset] + new_weight*amp[i]); + if (++s->pitch_offset >= s->pitch) + s->pitch_offset = 0; + new_weight += new_step; + old_weight -= old_step; + if (old_weight < 0.0) + old_weight = 0.0; + } + s->missing_samples = 0; + } + save_history(s, amp, len); + return len; } + /*- End of function --------------------------------------------------------*/ int plc_fillin(plc_state_t *s, int16_t amp[], int len) { - int i; - int pitch_overlap; - float old_step; - float new_step; - float old_weight; - float new_weight; - float gain; - int16_t *orig_amp; - int orig_len; - - orig_amp = amp; - orig_len = len; - if (s->missing_samples == 0) - { - /* As the gap in real speech starts we need to assess the last known pitch, - and prepare the synthetic data we will use for fill-in */ - normalise_history(s); - s->pitch = amdf_pitch(PLC_PITCH_MIN, PLC_PITCH_MAX, s->history + PLC_HISTORY_LEN - CORRELATION_SPAN - PLC_PITCH_MIN, CORRELATION_SPAN); - /* We overlap a 1/4 wavelength */ - pitch_overlap = s->pitch >> 2; - /* Cook up a single cycle of pitch, using a single of the real signal with 1/4 - cycle OLA'ed to make the ends join up nicely */ - /* The first 3/4 of the cycle is a simple copy */ - for (i = 0; i < s->pitch - pitch_overlap; i++) - s->pitchbuf[i] = s->history[PLC_HISTORY_LEN - s->pitch + i]; - /* The last 1/4 of the cycle is overlapped with the end of the previous cycle */ - new_step = 1.0/pitch_overlap; - new_weight = new_step; - for ( ; i < s->pitch; i++) - { - 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; - new_weight += new_step; - } - /* We should now be ready to fill in the gap with repeated, decaying cycles - of what is in pitchbuf */ - - /* We need to OLA the first 1/4 wavelength of the synthetic data, to smooth - it into the previous real data. To avoid the need to introduce a delay - in the stream, reverse the last 1/4 wavelength, and OLA with that. */ - gain = 1.0; - new_step = 1.0/pitch_overlap; - old_step = new_step; - new_weight = new_step; - old_weight = 1.0 - new_step; - for (i = 0; i < pitch_overlap; i++) - { - amp[i] = fsaturate(old_weight*s->history[PLC_HISTORY_LEN - 1 - i] + new_weight*s->pitchbuf[i]); - new_weight += new_step; - old_weight -= old_step; - if (old_weight < 0.0) - old_weight = 0.0; - } - s->pitch_offset = i; - } - else - { - gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; - i = 0; - } - for ( ; gain > 0.0 && i < len; i++) - { - amp[i] = s->pitchbuf[s->pitch_offset]*gain; - gain -= ATTENUATION_INCREMENT; - if (++s->pitch_offset >= s->pitch) - s->pitch_offset = 0; - } - for ( ; i < len; i++) - amp[i] = 0; - s->missing_samples += orig_len; - save_history(s, amp, len); - return len; + int i; + int pitch_overlap; + float old_step; + float new_step; + float old_weight; + float new_weight; + float gain; + int16_t *orig_amp; + int orig_len; + + orig_amp = amp; + orig_len = len; + if (s->missing_samples == 0) { + /* As the gap in real speech starts we need to assess the last known pitch, + and prepare the synthetic data we will use for fill-in */ + normalise_history(s); + s->pitch = amdf_pitch(PLC_PITCH_MIN, PLC_PITCH_MAX, s->history + PLC_HISTORY_LEN - CORRELATION_SPAN - PLC_PITCH_MIN, CORRELATION_SPAN); + /* We overlap a 1/4 wavelength */ + pitch_overlap = s->pitch >> 2; + /* Cook up a single cycle of pitch, using a single of the real signal with 1/4 + cycle OLA'ed to make the ends join up nicely */ + /* The first 3/4 of the cycle is a simple copy */ + for (i = 0; i < s->pitch - pitch_overlap; i++) + s->pitchbuf[i] = s->history[PLC_HISTORY_LEN - s->pitch + i]; + /* The last 1/4 of the cycle is overlapped with the end of the previous cycle */ + new_step = 1.0/pitch_overlap; + new_weight = new_step; + for ( ; i < s->pitch; i++) { + 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; + new_weight += new_step; + } + /* We should now be ready to fill in the gap with repeated, decaying cycles + of what is in pitchbuf */ + + /* We need to OLA the first 1/4 wavelength of the synthetic data, to smooth + it into the previous real data. To avoid the need to introduce a delay + in the stream, reverse the last 1/4 wavelength, and OLA with that. */ + gain = 1.0; + new_step = 1.0/pitch_overlap; + old_step = new_step; + new_weight = new_step; + old_weight = 1.0 - new_step; + for (i = 0; i < pitch_overlap; i++) { + amp[i] = fsaturate(old_weight*s->history[PLC_HISTORY_LEN - 1 - i] + new_weight*s->pitchbuf[i]); + new_weight += new_step; + old_weight -= old_step; + if (old_weight < 0.0) + old_weight = 0.0; + } + s->pitch_offset = i; + } else { + gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; + i = 0; + } + for ( ; gain > 0.0 && i < len; i++) { + amp[i] = s->pitchbuf[s->pitch_offset]*gain; + gain -= ATTENUATION_INCREMENT; + if (++s->pitch_offset >= s->pitch) + s->pitch_offset = 0; + } + for ( ; i < len; i++) + amp[i] = 0; + s->missing_samples += orig_len; + save_history(s, amp, len); + return len; } + /*- End of function --------------------------------------------------------*/ plc_state_t *plc_init(plc_state_t *s) { - memset(s, 0, sizeof(*s)); - return s; + memset(s, 0, sizeof(*s)); + return s; } /*- End of function --------------------------------------------------------*/ /*- End of file ------------------------------------------------------------*/ |