From 17bf41e15808c53fdb31cab1eda244ca7ed7e42b Mon Sep 17 00:00:00 2001
From: Michael Jerris <mike@jerris.com>
Date: Sat, 3 Feb 2007 04:09:43 +0000
Subject: [PATCH] Initial structure for generic inband dtmf detection.  NOTE:
 This code does not currently remove the inband dtmf tones from the stream (as
 that is not supported using read media bugs) and it is also COMPLETELY
 untested and unused anywhere.  This code is there for somone who wants to
 implement this feature in mod_sofia to test.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@4111 d0543943-73ff-0310-b7d9-9358b9ac24b2
---
 src/include/switch_ivr.h |  3 ++
 src/switch_ivr.c         | 91 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)

diff --git a/src/include/switch_ivr.h b/src/include/switch_ivr.h
index b91c15b0ea..752029fc51 100644
--- a/src/include/switch_ivr.h
+++ b/src/include/switch_ivr.h
@@ -174,6 +174,9 @@ SWITCH_DECLARE(switch_status_t) switch_ivr_record_session(switch_core_session_t
 */
 SWITCH_DECLARE(switch_status_t) switch_ivr_stop_record_session(switch_core_session_t *session, char *file);
 
+SWITCH_DECLARE(switch_status_t) switch_ivr_inband_dtmf_session(switch_core_session_t *session);
+SWITCH_DECLARE(switch_status_t) switch_ivr_stop_inband_dtmf_session(switch_core_session_t *session);
+
 /*!
   \brief play a file from the disk to the session
   \param session the session to play the file too
diff --git a/src/switch_ivr.c b/src/switch_ivr.c
index 8307e12d06..a6fc980c6c 100644
--- a/src/switch_ivr.c
+++ b/src/switch_ivr.c
@@ -27,6 +27,7 @@
  * Paul D. Tinsley <pdt at jackhammer.org>
  * Neal Horman <neal at wanlink dot com>
  * Matt Klein <mklein@nmedia.net>
+ * Michael Jerris <mike@jerris.com>
  *
  * switch_ivr.c -- IVR Library
  *
@@ -675,6 +676,96 @@ SWITCH_DECLARE(switch_status_t) switch_ivr_record_session(switch_core_session_t
 	return SWITCH_STATUS_SUCCESS;
 }
 
+typedef struct {
+	switch_core_session_t *session;
+	teletone_dtmf_detect_state_t dtmf_detect;
+} switch_inband_dtmf_t;
+
+static void inband_dtmf_callback(switch_media_bug_t *bug, void *user_data, switch_abc_type_t type)
+{
+	switch_inband_dtmf_t *pvt = (switch_inband_dtmf_t *) user_data;
+	uint8_t data[SWITCH_RECCOMMENDED_BUFFER_SIZE];
+	switch_frame_t frame = {0};
+	char digit_str[80];
+	switch_channel_t *channel = switch_core_session_get_channel(pvt->session);
+
+	assert(channel != NULL);
+	frame.data = data;
+	frame.buflen = SWITCH_RECCOMMENDED_BUFFER_SIZE;
+
+	switch(type) {
+		case SWITCH_ABC_TYPE_INIT:
+			break;
+		case SWITCH_ABC_TYPE_CLOSE:
+			break;
+		case SWITCH_ABC_TYPE_READ:
+			if (switch_core_media_bug_read(bug, &frame) == SWITCH_STATUS_SUCCESS) {
+				teletone_dtmf_detect(&pvt->dtmf_detect, frame.data, frame.samples);
+				teletone_dtmf_get(&pvt->dtmf_detect, digit_str, sizeof(digit_str));
+				if(digit_str[0]) {
+					switch_channel_queue_dtmf(channel, digit_str);
+					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "DTMF DETECTED: [%s]\n", digit_str);
+				}
+			}
+			break;
+		case SWITCH_ABC_TYPE_WRITE:
+		default:
+			break;
+	}
+}
+
+SWITCH_DECLARE(switch_status_t) switch_ivr_stop_inband_dtmf_session(switch_core_session_t *session) 
+{
+	switch_media_bug_t *bug;
+	switch_channel_t *channel = switch_core_session_get_channel(session);
+
+	assert(channel != NULL);
+	if ((bug = switch_channel_get_private(channel, "dtmf"))) {
+		switch_channel_set_private(channel, "dtmf", NULL);
+		switch_core_media_bug_remove(session, &bug);
+		return SWITCH_STATUS_SUCCESS;
+	}
+
+	return SWITCH_STATUS_FALSE;
+
+}
+
+SWITCH_DECLARE(switch_status_t) switch_ivr_inband_dtmf_session(switch_core_session_t *session)
+{
+	switch_channel_t *channel;
+	switch_codec_t *read_codec;
+	switch_media_bug_t *bug;
+	switch_status_t status;
+	switch_inband_dtmf_t *pvt;
+
+	channel = switch_core_session_get_channel(session);
+	assert(channel != NULL);
+
+	read_codec = switch_core_session_get_read_codec(session);
+	assert(read_codec != NULL);
+
+	if (!(pvt = switch_core_session_alloc(session, sizeof(*pvt)))) {
+		return SWITCH_STATUS_MEMERR;
+	}
+
+	teletone_dtmf_detect_init(&pvt->dtmf_detect, read_codec->implementation->samples_per_second);
+
+	pvt->session = session;
+
+	switch_channel_answer(channel);	
+
+	if ((status = switch_core_media_bug_add(session,
+		inband_dtmf_callback,
+		pvt,
+		SMBF_READ_STREAM,
+		&bug)) != SWITCH_STATUS_SUCCESS) {
+			return status;
+	}
+
+	switch_channel_set_private(channel, "dtmf", bug);
+
+	return SWITCH_STATUS_SUCCESS;
+}
 
 struct speech_thread_handle {
 	switch_core_session_t *session;