Added protection against false tone detection.

	modified:   ss5.cpp
	modified:   ss5.h

diff --git a/ss5.cpp b/ss5.cpp
index 164ef0c..5f4d706 100644 (file)
--- a/ss5.cpp
+++ b/ss5.cpp
@@ -346,6 +346,7 @@ Pss5::Pss5(int type, struct mISDNport *mISDNport, char *portname, struct port_se
        p_m_s_digit_i = 0;
        p_m_s_pulsecount = 0;
        p_m_s_last_digit = ' ';
+       p_m_s_last_digit_used = ' ';
        p_m_s_signal_loss = 0;
        p_m_s_decoder_count = 0;
        //p_m_s_decoder_buffer;
@@ -428,7 +429,7 @@ void Pss5::inband_receive(unsigned char *buffer, int len)
                PDEBUG(DEBUG_SS5, "%s: detecting signal '%c' start (state=%s signal=%s)\n", p_name, digit, ss5_state_name[p_m_s_state], ss5_signal_name[p_m_s_signal]);
 #endif
 
-       /* ignore short loss of signal */
+       /* ignore short loss of signal, or change within one decode window */
        if (p_m_s_signal_loss) {
                if (digit == ' ') {
                        /* still lost */
@@ -460,11 +461,19 @@ void Pss5::inband_receive(unsigned char *buffer, int len)
                        p_m_s_last_digit = digit;
                        /* starting to loose signal */
                        p_m_s_signal_loss = SS5_DECODER_NPOINTS;
+               } else if (digit != p_m_s_last_digit) {
+                       /* digit changes, but we keep old digit until it is detected twice */
+#ifdef DEBUG_DETECT
+                       PDEBUG(DEBUG_SS5, "%s: signal '%c' changes to '%c'\n", p_name, p_m_s_last_digit, digit);
+#endif
+                       p_m_s_last_digit = digit;
+                       digit = p_m_s_last_digit_used;
                } else {
                        /* storing last signal, in case it is lost */
                        p_m_s_last_digit = digit;
                }
        }
+       p_m_s_last_digit_used = digit;
 
        /* update mute */
        if ((p_m_mISDNport->ss5 & SS5_FEATURE_SUPPRESS)) {
@@ -1597,6 +1606,8 @@ void Pss5::do_release(int cause, int location)
 {
        struct lcr_msg *message;
 
+       p_m_s_timer = 0.0;
+
        /* sending release to endpoint */
        while(p_epointlist) {
                message = message_create(p_serial, p_epointlist->epoint_id, PORT_TO_EPOINT, MESSAGE_RELEASE);
@@ -1926,6 +1937,8 @@ if (0      || p_type==PORT_TYPE_SS5_OUT) { /* outgoing exchange */
        start_signal(SS5_STATE_CLEAR_BACK);
 
        new_state(PORT_STATE_OUT_DISCONNECT);
+//     p_m_s_timer_fn = &Pss5::register_timeout;
+//     p_m_s_timer = now + 30.0;
 }
 
 /* MESSAGE_RELEASE */
@@ -1934,6 +1947,10 @@ void Pss5::message_release(unsigned int epoint_id, int message_id, union paramet
        do_release(param->disconnectinfo.cause, param->disconnectinfo.location);
 }
 
+void Pss5::register_timeout(void)
+{
+       do_release(CAUSE_NORMAL, LOCATION_BEYOND);
+}
 
 /*
  * endpoint sends messages to the port

diff --git a/ss5.h b/ss5.h
index 238501f..b1cc215 100644 (file)
--- a/ss5.h
+++ b/ss5.h
@@ -34,7 +34,8 @@ class Pss5 : public PmISDN
        char p_m_s_dial[64]; /* current dialing register */
        int p_m_s_digit_i; /* current digit of register counter */
        int p_m_s_pulsecount; /* counts pule dialing half cycles */
-       char p_m_s_last_digit; /* stores last digit to fill short signal losses */
+       char p_m_s_last_digit; /* stores last digit that was detected, to fill short signal losses */
+       char p_m_s_last_digit_used; /* stores last digit that was used, to ignore short changes of signal due to noise */
        int p_m_s_signal_loss; /* sample counter for loss of signal check */
        int p_m_s_decoder_count; /* samples currently decoded */
        unsigned char p_m_s_decoder_buffer[SS5_DECODER_NPOINTS]; /* buffer for storing one goertzel window */
@@ -76,6 +77,8 @@ class Pss5 : public PmISDN
        void message_disconnect(unsigned int epoint_id, int message_id, union parameter *param);
        void message_release(unsigned int epoint_id, int message_id, union parameter *param);
 
+       void register_timeout(void);
+
 };
 
 #define new_ss5_state(a) _new_ss5_state(a, __FUNCTION__, __LINE__)