Voicemain detection mod initial upload. By Eric des Courtis

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@10623 d0543943-73ff-0310-b7d9-9358b9ac24b2
2025-04-15 00:22:35 +00:00 · 2008-12-05 17:45:37 +00:00 · 2008-12-05 17:45:37 +00:00 · 3c43650cba
commit 3c43650cba
parent 26d9d0a16a
2 changed files with 728 additions and 0 deletions
--- a/src/mod/applications/mod_vmd/Makefile
+++ b/src/mod/applications/mod_vmd/Makefile
@ -0,0 +1,2 @@
+BASE=../../../..
+include $(BASE)/build/modmake.rules
--- a/src/mod/applications/mod_vmd/mod_vmd.cpp
+++ b/src/mod/applications/mod_vmd/mod_vmd.cpp
@ -0,0 +1,726 @@
+/* 
+ * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
+ * Copyright (C) 2008, Eric des Courtis <eric.des.courtis@benbria.com>
+ *
+ * Version: MPL 1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * Eric des Courtis <eric.des.courtis@benbria.com>
+ * Copyright (C) Benbria. All Rights Reserved.
+ *
+ * Contributor(s):
+ * 
+ * Eric des Courtis <eric.des.courtis@benbria.com>
+ *
+ *
+ * mod_vmd.c -- Voicemail Detection Module
+ *
+ * This module detects voicemail beeps at any frequency in O(1) time.
+ * 
+ */
+
+#include <switch.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <string.h>
+#include <math.h>
+
+/* Number of points for beep detection */
+#define POINTS 32
+
+/* Number of valid points required for beep detection */
+#define VALID 22
+
+/* Maximum number of invalid points 
+ * to declare beep has stopped */
+#define MAX_CHIRP 22
+
+/* Minimum time for a beep */
+#define MIN_TIME 8000
+
+/* Minimum amplitude of the signal */
+#define MIN_AMPL 0.10
+
+/* Minimum beep frequency */
+#define MIN_FREQ (600)
+
+/* Maximum beep frequency */
+#define MAX_FREQ (1100)
+
+/* PSI function for amplitude calculation*/
+#define PSI(x) (x[1]*x[1]-x[2]*x[0])
+
+/* Sample rate */
+#define F (8000)
+
+/* Conversion of frequency to Hz */
+#define TO_HZ(f) ((F * f) / (2.0 * M_PI))
+
+/* Number of points in discreet energy separation */
+#define P (5)
+
+/* Maximum signed value of int16_t 
+ * DEPRECATED */
+#define ADJUST (32768)
+/* Same as above times two 
+ * DEPRECATED */
+#define ADJUST_MAX (65536)
+
+/* Signed L16 to relative floating point conversion */
+#define CONVERT_PT(d, i, m) do{ d = ((((double)i + (double)m) /  \
+    (double)(2 * m)) - 0.5) * 2.0; } while(0)
+
+/* Discreet energy separation tolerance to error */
+#define TOLERANCE (0.20)
+
+/* Maximum value within tolerance */
+#define TOLERANCE_T(m) (m + (m * TOLERANCE))
+
+/* Minimum value within tolerance */
+#define TOLERANCE_B(m) (m - (m * TOLERANCE))
+
+/* Syntax of the API call */
+#define VMD_SYNTAX "<uuid> <command>"
+
+/* Number of expected parameters in api call */
+#define VMD_PARAMS 2
+
+/* FreeSWITCH CUSTOM event type */
+#define VMD_EVENT_BEEP "vmd::beep"
+
+/* Prototypes */
+SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_vmd_shutdown);
+/* SWITCH_MODULE_RUNTIME_FUNCTION(mod_vmd_runtime); */
+SWITCH_STANDARD_API(vmd_api_main);
+
+SWITCH_MODULE_LOAD_FUNCTION(mod_vmd_load);
+SWITCH_MODULE_DEFINITION(mod_vmd, mod_vmd_load, NULL, NULL);
+SWITCH_STANDARD_APP(vmd_start_function);
+
+/* Type that holds state information about the beep */
+typedef enum vmd_state{
+    BEEP_DETECTED, BEEP_NOT_DETECTED
+} vmd_state_t;
+
+/* Type that holds data for 5 points of discreet energy separation */
+typedef struct vmd_point{
+    double freq;
+    double ampl;
+} vmd_point_t;
+
+/* Type that holds codec information */
+typedef struct vmd_codec_info{
+    int rate;
+    int channels;
+} vmd_codec_info_t;
+
+/* Type that holds session information pertinent to the vmd module */
+typedef struct vmd_session_info{
+    /* State of the session */
+    vmd_state_t state;
+    /* Snapshot of DESA samples */
+    vmd_point_t points[POINTS];
+    /* Internal FreeSWITCH session */
+    switch_core_session_t *session;
+    /* Codec information for the session */
+    vmd_codec_info_t vmd_codec;
+    /* Current position in the snapshot */
+    unsigned int pos;
+    /* Frequency aproximation of a detected beep */
+    double beep_freq;
+    /* A count of how long a distinct beep was detected by
+     * by the discreet energy separation algorithm */
+    switch_size_t timestamp;
+/*
+    int16_t *data;
+    ssize_t data_len;
+*/
+} vmd_session_info_t;
+
+static switch_bool_t process_data(vmd_session_info_t *vmd_info, 
+    switch_frame_t *frame);
+static switch_bool_t vmd_callback(switch_media_bug_t *bug, 
+    void *user_data, switch_abc_type_t type);
+static double freq_estimator(double *x);
+static double ampl_estimator(double *x);
+static void convert_pts(int16_t *i_pts, double *d_pts, int16_t max);
+static void find_beep(vmd_session_info_t *vmd_info, switch_frame_t *frame);
+static double median(double *m, int n);
+
+/*
+#define PRINT(a) do{ switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, a); }while(0)
+#define PRINT2(a, b) do{ switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, a, b); }while(0)
+*/
+
+static switch_bool_t vmd_callback(switch_media_bug_t *bug, 
+    void *user_data, switch_abc_type_t type)
+{
+    vmd_session_info_t *vmd_info;
+    switch_codec_t *read_codec;
+    switch_frame_t *frame;
+   
+    vmd_info = (vmd_session_info_t *)user_data;
+    if(vmd_info == NULL) return SWITCH_FALSE;
+
+    switch(type){
+
+    case SWITCH_ABC_TYPE_INIT:
+	read_codec = 
+	    switch_core_session_get_read_codec(vmd_info->session);
+	vmd_info->vmd_codec.rate = 
+	    read_codec->implementation->samples_per_second;
+	vmd_info->vmd_codec.channels = 
+	    read_codec->implementation->number_of_channels;
+	break;
+
+    case SWITCH_ABC_TYPE_CLOSE:
+    case SWITCH_ABC_TYPE_READ:
+    case SWITCH_ABC_TYPE_WRITE:
+	break;
+
+    case SWITCH_ABC_TYPE_READ_REPLACE:
+	frame = switch_core_media_bug_get_read_replace_frame(bug);
+	return process_data(vmd_info, frame);
+
+    case SWITCH_ABC_TYPE_WRITE_REPLACE:
+	break;
+    }
+
+    return SWITCH_TRUE;
+}
+
+static switch_bool_t process_data(vmd_session_info_t *vmd_info, 
+    switch_frame_t *frame)
+{
+    int i;
+    unsigned int j;
+    double pts[P];
+    int16_t *data;
+    int16_t max;
+    ssize_t len;
+
+    len = frame->samples * sizeof(int16_t);
+    data = (int16_t *)frame->data;
+    
+    for(max = abs(data[0]), i = 1; i < frame->samples; i++){
+	if(abs(data[i]) > max) max = abs(data[i]);
+    }
+
+/*
+    if(vmd_info->data_len != len){
+	vmd_info->data_len = len;
+	if(vmd_info->data != NULL) free(vmd_info->data);
+	vmd_info->data = (int16_t *)malloc(len);
+	if(vmd_info->data == NULL) return SWITCH_FALSE;
+    } 
+
+    (void)memcpy(vmd_info->data, data, len);
+    for(i = 2; i < frame->samples; i++){
+	vmd_info->data[i] = 
+	    0.0947997 * data[i] 
+	    - 
+	    0.0947997 * data[i - 2] 
+	    - 
+	    1.4083405 * vmd_info->data[i - 1] 
+	    + 
+	    0.8104005 * vmd_info->data[i - 2];
+    }
+*/
+
+    for(i = 0, j = vmd_info->pos; i < frame->samples; j++, j %= POINTS, i += 5){
+/*	convert_pts(vmd_info->data + i, pts); */
+	convert_pts(data + i, pts, max);
+	vmd_info->points[j].freq = TO_HZ(freq_estimator(pts));
+	vmd_info->points[j].ampl = ampl_estimator(pts);
+	vmd_info->pos = j % POINTS;
+	find_beep(vmd_info, frame);
+    }
+
+    return SWITCH_TRUE;
+}
+
+static void find_beep(vmd_session_info_t *vmd_info, switch_frame_t *frame)
+{
+    int i;
+    int c;
+    double m[POINTS];
+    double med;
+    unsigned int j = (vmd_info->pos + 1) % POINTS;
+    unsigned int k = j;
+    switch_status_t status;
+    switch_event_t *event;
+    switch_event_t *event_copy;
+
+    switch(vmd_info->state){
+    case BEEP_DETECTED:
+ 	for(c = 0, i = 0; i < POINTS; j++, j %= POINTS, i++){
+	    vmd_info->timestamp++;
+	    if(vmd_info->points[j].freq < TOLERANCE_T(vmd_info->beep_freq) &&
+		vmd_info->points[j].freq > TOLERANCE_B(vmd_info->beep_freq)){
+		    c++;
+		    vmd_info->beep_freq = (vmd_info->beep_freq * 0.95) + (vmd_info->points[j].freq * 0.05);
+	    }
+	}
+
+	if(c < (POINTS - MAX_CHIRP)){
+	    vmd_info->state = BEEP_NOT_DETECTED;
+	    if(vmd_info->timestamp < MIN_TIME) break;
+
+            status = switch_event_create_subclass(&event, 
+	        SWITCH_EVENT_CUSTOM, VMD_EVENT_BEEP);
+	    if(status != SWITCH_STATUS_SUCCESS) return;
+
+	    switch_event_add_header_string(
+		event, 
+		SWITCH_STACK_BOTTOM, 
+		"Beep-Status", 
+		"stop"
+	    );
+
+	    switch_event_add_header(
+		event,
+		SWITCH_STACK_BOTTOM,
+		"Beep-Time",
+		"%d", vmd_info->timestamp / POINTS
+	    );
+
+	    switch_event_add_header(
+		event,
+		SWITCH_STACK_BOTTOM,
+		"Unique-ID",
+		"%s", switch_core_session_get_uuid(vmd_info->session)
+	    );
+
+	    switch_event_add_header(
+		event, 
+		SWITCH_STACK_BOTTOM, 
+		"Frequency", 
+		"%6.4lf", vmd_info->beep_freq
+	    );
+           
+            switch_event_add_header_string(
+                event,
+                SWITCH_STACK_BOTTOM,
+                "call-command",
+                "vmd"
+            );
+
+            status = switch_event_dup(&event_copy, event); 
+	    if(status != SWITCH_STATUS_SUCCESS) return;
+
+            switch_core_session_queue_event(vmd_info->session, &event);
+	    switch_event_fire(&event_copy);
+
+	    vmd_info->timestamp = 0;
+	}
+
+	break;
+
+    case BEEP_NOT_DETECTED:
+
+        for(i = 0; i < POINTS; k++, k %= POINTS, i++){
+	    m[i] = vmd_info->points[k].freq;
+	    if(m[i] == NAN) m[i] = 0.0;
+	}
+
+	med = median(m, POINTS);
+	if(med == NAN){
+	    for(i = 0; i < POINTS; i++){
+		if(m[i] != NAN){
+		    med = m[i];
+		    break;
+		}
+	    }
+	}
+
+	for(c = 0, i = 0; i < POINTS; j++, j %= POINTS, i++){
+	    if(vmd_info->points[j].freq < TOLERANCE_T(med) &&
+		vmd_info->points[j].freq > TOLERANCE_B(med)){
+		if(vmd_info->points[j].ampl > MIN_AMPL &&
+		    vmd_info->points[j].freq > MIN_FREQ &&
+		    vmd_info->points[j].freq < MAX_FREQ){
+		    c++;
+		}
+	    }
+	}
+
+	
+	if(c >= VALID){
+	    vmd_info->state = BEEP_DETECTED;
+	    vmd_info->beep_freq = med;
+	    vmd_info->timestamp = 0;
+	}
+
+	break;
+    }
+}
+
+/* Find the median of an array of doubles */
+static double median(double *m, int n)
+{
+    int i;
+    int less;
+    int greater;
+    int equal;
+    double min;
+    double max;
+    double guess;
+    double maxltguess;
+    double mingtguess;
+
+    min = max = m[0] ;
+
+    for (i = 1; i < n; i++) {
+	if(m[i] < min) min = m[i];
+	if(m[i] > max) max = m[i];
+    }
+
+    while(1){
+	guess = ( min + max ) / 2;
+        less = 0;
+	greater = 0;
+	equal = 0;
+        maxltguess = min;
+	mingtguess = max;
+    
+	for(i = 0; i < n; i++) {
+	    if(m[i] < guess){
+		less++;
+		if(m[i] > maxltguess) maxltguess = m[i];
+	    }else if (m[i] > guess) {
+		greater++;
+		if(m[i] < mingtguess) mingtguess = m[i];
+	    }else equal++;
+	}
+
+	if (less <= ( n + 1 ) / 2 && greater <= ( n + 1 ) / 2) break;
+        else if (less > greater) max = maxltguess;
+	else min = mingtguess;
+    }
+
+    if(less >= ( n + 1 ) / 2) return maxltguess;
+    else if(less + equal >= ( n + 1 ) / 2) return guess;
+
+    return mingtguess;
+}
+
+/* Convert many points for Signed L16 to relative floating point */
+static void convert_pts(int16_t *i_pts, double *d_pts, int16_t max)
+{
+    int i;
+    for(i = 0; i < P; i++) CONVERT_PT(d_pts[i], i_pts[i], max);
+}
+
+/* Amplitude estimator for DESA-2 */
+double ampl_estimator(double *x)
+{
+    double freq_sq;
+
+    freq_sq = freq_estimator(x);
+    freq_sq *= freq_sq;
+
+    return sqrt( PSI(x) / sin(freq_sq) ); 
+}
+
+/* The DESA-2 algorithm */
+double freq_estimator(double *x)
+{
+    return 0.5 * acos(
+	(((x[2] * x[2]) - (x[0] * x[4]))
+	-
+	( (x[1] * x[1]) - (x[0] * x[2]))
+	-
+	( (x[3] * x[3]) - (x[2] * x[4])))
+	/
+	(2.0 * ((x[2] * x[2]) - (x[1] * x[3])))
+ 
+    );
+}
+
+
+SWITCH_MODULE_LOAD_FUNCTION(mod_vmd_load)
+{
+    switch_application_interface_t *app_interface;
+    switch_api_interface_t *api_interface;
+    /* connect my internal structure to the blank pointer passed to me */
+    *module_interface = 
+	switch_loadable_module_create_module_interface(pool, modname);
+    
+    switch_log_printf(
+	SWITCH_CHANNEL_LOG, 
+	SWITCH_LOG_NOTICE, 
+	"Voicemail detection enabled\n"
+    );
+
+    SWITCH_ADD_APP(app_interface, "vmd", "Detect beeps", "Detect voicemail beeps", 
+	vmd_start_function, "[start] [stop]", SAF_NONE);
+    
+    SWITCH_ADD_API(api_interface, "vmd", "Detected voicemail beeps", 
+	vmd_api_main, VMD_SYNTAX);
+
+    /* indicate that the module should continue to be loaded */
+    return SWITCH_STATUS_SUCCESS;
+}
+
+/* Same as api function see it for comments */
+SWITCH_STANDARD_APP(vmd_start_function)
+{
+    switch_media_bug_t *bug;
+    switch_status_t status;
+    switch_channel_t *channel;
+    vmd_session_info_t *vmd_info;
+    int i;
+
+    if(session == NULL) return;    
+
+    channel = switch_core_session_get_channel(session);
+
+    /* Is this channel already set? */
+    bug = (switch_media_bug_t *) switch_channel_get_private(channel, "_vmd_");
+    /* If yes */
+    if(bug != NULL){
+	/* If we have a stop remove audio bug */
+	if(strcasecmp(data, "stop") == 0){
+	    switch_channel_set_private(channel, "_vmd_", NULL);
+	    switch_core_media_bug_remove(session, &bug);
+	    return;
+	}
+
+	/* We have already started */
+	switch_log_printf(
+	    SWITCH_CHANNEL_LOG, 
+	    SWITCH_LOG_WARNING, 
+	    "Cannot run 2 at once on the same channel!\n"
+	);
+
+	return;
+    }
+    
+    vmd_info = (vmd_session_info_t *)switch_core_session_alloc(
+	session, 
+	sizeof(vmd_session_info_t)
+    );
+
+    vmd_info->state = BEEP_NOT_DETECTED;
+    vmd_info->session = session;
+    vmd_info->pos = 0;
+/*
+    vmd_info->data = NULL;
+    vmd_info->data_len = 0;
+*/
+    for(i = 0; i < POINTS; i++){
+	vmd_info->points[i].freq = 0.0;
+	vmd_info->points[i].ampl = 0.0;
+    }
+
+    status = switch_core_media_bug_add(
+	session, 
+	vmd_callback, 
+	vmd_info,
+	0, 
+	SMBF_READ_REPLACE, 
+	&bug
+    );
+
+    if(status != SWITCH_STATUS_SUCCESS){
+	switch_log_printf(
+	    SWITCH_CHANNEL_LOG,
+	    SWITCH_LOG_ERROR,
+	    "Failure hooking to stream\n"
+	);
+
+	return;
+    }
+    
+
+    switch_channel_set_private(channel, "_vmd_", bug);
+
+}
+
+/* Called when the system shuts down */
+SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_vmd_shutdown)
+{
+    switch_log_printf(
+	SWITCH_CHANNEL_LOG, 
+	SWITCH_LOG_NOTICE, 
+	"Voicemail detection disabled\n"
+    );
+
+    return SWITCH_STATUS_SUCCESS;
+}
+
+SWITCH_STANDARD_API(vmd_api_main)
+{
+    switch_core_session_t *vmd_session;
+    switch_media_bug_t *bug;
+    vmd_session_info_t *vmd_info;
+    switch_channel_t *channel;
+    switch_event_t *event;
+    switch_status_t status;
+    int argc;
+    char *argv[VMD_PARAMS];
+    char *ccmd;
+    char *uuid;
+    char *command;
+    int i;
+    
+    /* No command? Display usage */
+    if(cmd == NULL){
+	stream->write_function(stream, "-USAGE: %s\n", VMD_SYNTAX);
+	return SWITCH_STATUS_SUCCESS;
+    }
+
+    /* Duplicated contents of original string */
+    ccmd = strdup(cmd);
+    /* Separate the arguments */
+    argc = switch_separate_string(ccmd, ' ', argv, VMD_PARAMS);
+
+    /* If we don't have the expected number of parameters 
+     * display usage */
+    if(argc != VMD_PARAMS){
+	stream->write_function(stream, "-USAGE: %s\n", VMD_SYNTAX);
+	switch_safe_free(ccmd);
+	return SWITCH_STATUS_SUCCESS;
+    }
+
+    uuid = argv[0];
+    command = argv[1];
+     
+    /* using uuid locate a reference to the FreeSWITCH session */
+    vmd_session = switch_core_session_locate(uuid);
+
+    /* If the session was not found exit */
+    if(vmd_session == NULL){
+	switch_safe_free(ccmd);
+	stream->write_function(stream, "-USAGE: %s\n", VMD_SYNTAX);	
+	return SWITCH_STATUS_FALSE;
+    }
+
+    /* Get current channel of the session to tag the session
+     * This indicates that our module is present */
+    channel = switch_core_session_get_channel(vmd_session);
+
+    /* Is this channel already set? */
+    bug = (switch_media_bug_t *) switch_channel_get_private(channel, "_vmd_");
+    /* If yes */
+    if(bug != NULL){
+        /* If we have a stop remove audio bug */
+        if(strcasecmp(command, "stop") == 0){
+            switch_channel_set_private(channel, "_vmd_", NULL);
+            switch_core_media_bug_remove(vmd_session, &bug);
+            switch_safe_free(ccmd);
+            stream->write_function(stream, "+OK\n");
+            return SWITCH_STATUS_SUCCESS;
+        }
+
+	/* We have already started */
+	switch_log_printf(
+	    SWITCH_CHANNEL_LOG, 
+	    SWITCH_LOG_WARNING, 
+	    "Cannot run 2 at once on the same channel!\n"
+	);
+	
+	switch_safe_free(ccmd);
+	return SWITCH_STATUS_FALSE;
+    }
+
+    /* If we don't see the expected start exit */
+    if(strcasecmp(command, "start") != 0){
+	switch_safe_free(ccmd);	
+	stream->write_function(stream, "-USAGE: %s\n", VMD_SYNTAX);
+	return SWITCH_STATUS_FALSE;
+    }
+
+    /* Allocate memory attached to this FreeSWITCH session for
+     * use in the callback routine and to store state information */
+    vmd_info = (vmd_session_info_t *)switch_core_session_alloc(
+	vmd_session, 
+	sizeof(vmd_session_info_t)
+    );
+
+    /* Set initial values and states */
+    vmd_info->state = BEEP_NOT_DETECTED;
+    vmd_info->session = vmd_session;
+    vmd_info->pos = 0;
+/*
+    vmd_info->data = NULL;
+    vmd_info->data_len = 0;
+*/
+
+    for(i = 0; i < POINTS; i++){
+	vmd_info->points[i].freq = 0.0;
+	vmd_info->points[i].ampl = 0.0;
+    }
+
+    /* Add a media bug that allows me to intercept the 
+     * reading leg of the audio stream */
+    status = switch_core_media_bug_add(
+	vmd_session, 
+	vmd_callback, 
+	vmd_info,
+	0, 
+	SMBF_READ_REPLACE, 
+	&bug
+    );
+
+    /* If adding a media bug fails exit */
+    if(status != SWITCH_STATUS_SUCCESS){
+	switch_log_printf(
+	    SWITCH_CHANNEL_LOG, 
+	    SWITCH_LOG_ERROR, 
+	    "Failure hooking to stream\n"
+	);
+    
+	switch_safe_free(ccmd);
+	return SWITCH_STATUS_FALSE;
+    }
+
+    /* Set the vmd tag to detect an existing vmd media bug */
+    switch_channel_set_private(channel, "_vmd_", bug);
+    
+    /* Everything went according to plan! Notify the user */
+    stream->write_function(stream, "+OK\n"); 
+ 
+    switch_safe_free(ccmd);
+    return SWITCH_STATUS_SUCCESS;
+}
+
+/*
+  If it exists, this is called in it's own thread 
+  when the module-load completes. If it returns anything
+  but SWITCH_STATUS_TERM it will be called again automatically
+*/
+
+/*
+SWITCH_MODULE_RUNTIME_FUNCTION(mod_vmd_runtime)
+{
+	while(looping){
+		
+		switch_yield(1000);
+	}
+
+	return SWITCH_STATUS_TERM;
+}
+*/
+
+/* For Emacs:
+ * Local Variables:
+ * mode:c
+ * indent-tabs-mode:t
+ * tab-width:4
+ * c-basic-offset:4
+ * End:
+ * For VIM:
+ * vim:set softtabstop=4 shiftwidth=4 tabstop=4 expandtab:
+ */
+