diff options
Diffstat (limited to 'drivers/dahdi/ecdis.h')
| -rw-r--r-- | drivers/dahdi/ecdis.h | 66 |
1 files changed, 32 insertions, 34 deletions
diff --git a/drivers/dahdi/ecdis.h b/drivers/dahdi/ecdis.h index 205b2e3..e8083fe 100644 --- a/drivers/dahdi/ecdis.h +++ b/drivers/dahdi/ecdis.h @@ -53,10 +53,10 @@ static inline void echo_can_disable_detector_init (echo_can_disable_detector_sta /*- End of function --------------------------------------------------------*/ static inline int echo_can_disable_detector_update (echo_can_disable_detector_state_t *det, - int16_t amp) + int16_t amp) { - int16_t notched; - + int16_t notched; + notched = biquad2 (&det->notch, amp); /* Estimate the overall energy in the channel, and the energy in the notch (i.e. overall channel energy - tone energy => noise). @@ -66,40 +66,38 @@ static inline int echo_can_disable_detector_update (echo_can_disable_detector_st blip every time the phase reverses */ det->channel_level += ((abs(amp) - det->channel_level) >> 5); det->notch_level += ((abs(notched) - det->notch_level) >> 4); - if (det->channel_level > 280) - { - /* There is adequate energy in the channel. Is it mostly at 2100Hz? */ - if (det->notch_level*6 < det->channel_level) - { - /* The notch says yes, so we have the tone. */ - if (!det->tone_present) - { - /* Do we get a kick every 450+-25ms? */ - if (det->tone_cycle_duration >= 425*8 - && - det->tone_cycle_duration <= 475*8) - { - det->good_cycles++; - if (det->good_cycles > 2) - det->hit = TRUE; - } - det->tone_cycle_duration = 0; + if (det->channel_level >= 70) { + /* There is adequate energy in the channel. Is it mostly at 2100Hz? */ + if (det->notch_level*6 < det->channel_level) { + det->tone_cycle_duration++; + /* The notch says yes, so we have the tone. */ + if (!det->tone_present) { + /* Do we get a kick every 450+-25ms? */ + if ((det->tone_cycle_duration >= (425 * 8)) && + (det->tone_cycle_duration <= (475 * 8))) { + /* It's ANS/PR (CED with polarity reversals), so wait + for at least three cycles before returning a hit. */ + det->good_cycles++; + if (det->good_cycles > 2) + det->hit = TRUE; + } + det->tone_cycle_duration = 0; + det->tone_present = TRUE; + } else if (det->tone_cycle_duration >= 600 * 8) { + /* It's ANS (CED without polarity reversals) + so return a hit. */ + det->hit = TRUE; + } + } else { + det->tone_present = FALSE; } - det->tone_present = TRUE; - } - else - { + } else { det->tone_present = FALSE; - } - det->tone_cycle_duration++; - } - else - { - det->tone_present = FALSE; - det->tone_cycle_duration = 0; - det->good_cycles = 0; + det->tone_cycle_duration = 0; + det->good_cycles = 0; } - return det->hit; + + return det->hit; } /*- End of function --------------------------------------------------------*/ /*- End of file ------------------------------------------------------------*/ |