freeswitch/src/mod/asr_tts/mod_openmrcp/mod_openmrcp.c

/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005/2006, Anthony Minessale II <anthmct@yahoo.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.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthmct@yahoo.com>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Traun Leyden <tleyden@branchcut.com>
 * Arsen Chaloyan <achaloyan@yahoo.com>
 *
 * Module which acts as an MRCP client to an MRCP speech recognition
 * server.  In other words it bridges freeswitch to an external speech
 * recognition system.  Documentation on how to install and configure
 * the module is here: http://wiki.freeswitch.org/wiki/Mod_openmrcp
 *
 * Uses OpenMrcp (http://wiki.freeswitch.org/wiki/OpenMRCP) as the 
 * the client library.  
 *
 * TODO
 * =======
 *
 * - There are two memory pools in use.  One in asr_session which is managed
 * by this module, and one in the switch_asr_handle_t, which is managed by freeswitch.
 * These need to be consolidated into one.  (basically throw away the one in asr_session)
 * 
 * - fs status codes (eg, SWITCH_STATUS_GENERR) and mrcp status codes (MRCP_STATUS_FAILURE)
 * are intermixed badly.  this needs cleanup
 * 
 * - openmrcp_flush_tts, openmrcp_text_param_tts, openmrcp_numeric_param_tts, 
 * openmrcp_float_param_tts need to have functionality added
 *
 * - use a regex for extracting xml from raw result received from mrcp recognition
 * server
 *
 */

#ifdef __ICC
#pragma warning (disable:188)
#endif


#include "openmrcp_client.h"
#include "mrcp_client_context.h"
#include "mrcp_recognizer.h"
#include "mrcp_synthesizer.h"
#include "mrcp_generic_header.h"

#include <switch.h>
	
SWITCH_MODULE_LOAD_FUNCTION(mod_openmrcp_load);
SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_openmrcp_shutdown);
SWITCH_MODULE_DEFINITION(mod_openmrcp, mod_openmrcp_load, 
						 mod_openmrcp_shutdown, NULL);

typedef struct {
	char                      *name;
	openmrcp_client_options_t *mrcp_options;
	mrcp_client_t             *mrcp_client;
	mrcp_client_context_t     *mrcp_context;
} openmrcp_profile_t;

typedef struct {
	openmrcp_profile_t    *profile;
	mrcp_session_t        *client_session;
	mrcp_client_channel_t *control_channel;
	mrcp_audio_channel_t  *audio_channel;
	mrcp_message_t        *mrcp_message_last_rcvd;
	apr_pool_t            *pool;
	switch_speech_flag_t   flags;
	switch_mutex_t        *flag_mutex;
	switch_thread_cond_t  *wait_object;
} openmrcp_session_t;

typedef enum {
	FLAG_HAS_MESSAGE =    (1 << 0),
	FLAG_FEED_STARTED =   (1 << 1),
	FLAG_TERMINATING =    (1 << 2)
} mrcp_flag_t;

typedef struct {
	switch_memory_pool_t *pool;
	switch_hash_t        *profile_hash;

	openmrcp_profile_t   *asr_profile;
	openmrcp_profile_t   *tts_profile;
} openmrcp_module_t;

static openmrcp_module_t openmrcp_module;


static openmrcp_session_t* openmrcp_session_create(openmrcp_profile_t *profile)
{
	openmrcp_session_t *openmrcp_session;
	apr_pool_t *session_pool;

	if(!profile) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "no profile specified\n");
		return NULL;
	}

	if(apr_pool_create(&session_pool,NULL) != APR_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "failed to create session_pool\n");
		return NULL;
	}

	openmrcp_session = apr_palloc(session_pool,sizeof(openmrcp_session_t));
	openmrcp_session->pool = session_pool;
	openmrcp_session->profile = profile;
	openmrcp_session->client_session = NULL;
	openmrcp_session->control_channel = NULL;
	openmrcp_session->audio_channel = NULL;
	openmrcp_session->mrcp_message_last_rcvd = NULL;

	switch_mutex_init(&openmrcp_session->flag_mutex, SWITCH_MUTEX_NESTED, openmrcp_session->pool);

	if (switch_thread_cond_create(&openmrcp_session->wait_object, openmrcp_session->pool)) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR,  "wait object creation failed\n");
	}

	openmrcp_session->client_session = mrcp_client_context_session_create(openmrcp_session->profile->mrcp_context,openmrcp_session);
	if (!openmrcp_session->client_session) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "session creation FAILED\n");
		apr_pool_destroy(session_pool);
		return NULL;
	}

	return openmrcp_session;
}

static void openmrcp_session_destroy(openmrcp_session_t *openmrcp_session)
{
	if(openmrcp_session && openmrcp_session->pool) {
		mrcp_client_context_session_destroy(openmrcp_session->profile->mrcp_context,openmrcp_session->client_session);
		apr_pool_destroy(openmrcp_session->pool);
	}
}

static mrcp_status_t openmrcp_on_session_initiate(mrcp_client_context_t *context, mrcp_session_t *session)
{
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "on_session_initiate called\n");
	return MRCP_STATUS_SUCCESS;
}

static mrcp_status_t openmrcp_on_session_terminate(mrcp_client_context_t *context, mrcp_session_t *session)
{
	openmrcp_session_t *openmrcp_session = mrcp_client_context_session_object_get(session);
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "on_session_terminate called\n");
	if(!openmrcp_session) {
		return MRCP_STATUS_FAILURE;
	}

	if (switch_test_flag(openmrcp_session, FLAG_TERMINATING)) {
		openmrcp_session_destroy(openmrcp_session);
	}
	else {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "abnormal session terminate\n");
	}
	return MRCP_STATUS_SUCCESS;
}

static mrcp_status_t openmrcp_on_channel_add(mrcp_client_context_t *context, mrcp_session_t *session, mrcp_client_channel_t *control_channel, mrcp_audio_channel_t *audio_channel)
{
	openmrcp_session_t *openmrcp_session = mrcp_client_context_session_object_get(session);
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "on_channel_add called\n");
	if(!openmrcp_session) {
		return MRCP_STATUS_FAILURE;
	}
	switch_mutex_lock(openmrcp_session->flag_mutex);
	openmrcp_session->control_channel = control_channel;
	openmrcp_session->audio_channel = audio_channel;
	switch_thread_cond_signal(openmrcp_session->wait_object);
	switch_mutex_unlock(openmrcp_session->flag_mutex);
	return MRCP_STATUS_SUCCESS;
}

static mrcp_status_t openmrcp_on_channel_remove(mrcp_client_context_t *context, mrcp_session_t *session, mrcp_client_channel_t *control_channel)
{
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "on_channel_remove called\n");
	return MRCP_STATUS_SUCCESS;
}

/** this is called by the mrcp core whenever an mrcp message is received from
    the other side. */
static mrcp_status_t openmrcp_on_channel_modify(mrcp_client_context_t *context, mrcp_session_t *session, mrcp_message_t *mrcp_message)
{
	openmrcp_session_t *openmrcp_session = mrcp_client_context_session_object_get(session);
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "on_channel_modify called\n");
	if (!openmrcp_session) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "!openmrcp_session\n");
		return MRCP_STATUS_FAILURE;
	}
	if (!mrcp_message) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "!mrcp_message\n");
		return MRCP_STATUS_FAILURE;
	}

	if (mrcp_message->start_line.message_type == MRCP_MESSAGE_TYPE_RESPONSE && mrcp_message->start_line.request_state == MRCP_REQUEST_STATE_INPROGRESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "ignoring mrcp response\n");
		return MRCP_STATUS_SUCCESS;
	}

	if (switch_test_flag(openmrcp_session, FLAG_HAS_MESSAGE)) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "already has message\n");
		return MRCP_STATUS_SUCCESS;
	}

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "setting FLAG_HAS_MESSAGE\n");
	openmrcp_session->mrcp_message_last_rcvd = mrcp_message;
	switch_set_flag_locked(openmrcp_session, FLAG_HAS_MESSAGE);
	return MRCP_STATUS_SUCCESS;
}

/** Read in the grammar and construct an MRCP Recognize message that has
    The grammar attached as the payload */
static mrcp_status_t openmrcp_recog_start(mrcp_client_context_t *context, openmrcp_session_t *asr_session, char *path)
{
	mrcp_generic_header_t *generic_header;
	apr_status_t rv;
	apr_file_t *fp;
	apr_pool_t *mp;
	apr_finfo_t finfo;
	char *buf1;
	apr_size_t bytes2read = 0;
	
	mrcp_message_t *mrcp_message = mrcp_client_context_message_get(context, asr_session->client_session, asr_session->control_channel, RECOGNIZER_RECOGNIZE);

	if(!mrcp_message) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Could not create mrcp msg\n");
		return MRCP_STATUS_FAILURE;
	}

	/* open the file with the grammar and read into char* buffer */
	mp = mrcp_message->pool;
	if ((rv = apr_file_open(&fp, path, APR_READ, APR_OS_DEFAULT, mp)) != APR_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Could not read grammar\n");
		return -1;
	}
	rv = apr_file_info_get(&finfo, APR_FINFO_NORM, fp);
	
	buf1 = apr_palloc(mp, (apr_size_t)finfo.size + 1);
	bytes2read = (apr_size_t)finfo.size;
	rv = apr_file_read(fp, buf1, &bytes2read);
	buf1[bytes2read] = '\0';

	generic_header = mrcp_generic_header_prepare(mrcp_message);
	if(!generic_header) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Could not prepare generic_header\n");
		return MRCP_STATUS_FAILURE;
	}

	generic_header->content_type = "application/srgs+xml";
	mrcp_generic_header_property_add(mrcp_message,GENERIC_HEADER_CONTENT_TYPE);
	mrcp_message->body = buf1;

	/* send the MRCP RECOGNIZE message to MRCP server */
	return mrcp_client_context_channel_modify(context, asr_session->client_session, mrcp_message);
}


/**
 * Freeswitch calls this from switch_ivr_detect_speech() and then adds a media
 * bug to tap into the channel's audio, which will result in all data getting
 * passed to asr_feed() and calls to asr_check_results() on each recevied frame.
 * 
 * This code expects certain one-time initialization of the openmrcp client
 * engine/systeme to have already taken place.function to open the asr interface 
 */
static switch_status_t openmrcp_asr_open(switch_asr_handle_t *ah, char *codec, int rate, char *dest, switch_asr_flag_t *flags) 
{
	openmrcp_session_t *asr_session;
	mrcp_client_channel_t *asr_channel;
	
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "asr_open called, codec: %s, rate: %d\n", codec, rate);

	if (strcmp(codec,"L16")) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Sorry, only L16 codec supported\n");
		return SWITCH_STATUS_GENERR;		
	}
	if (rate != 8000) {
		// TODO: look into supporting other sample rates
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Sorry, only 8kz supported\n");
		return SWITCH_STATUS_GENERR;		
	}
	/* create session */
	asr_session = openmrcp_session_create(openmrcp_module.asr_profile);
	if (!asr_session) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "asr_session creation FAILED\n");
		return SWITCH_STATUS_GENERR;
	}

	/* create recognizer channel, also starts outgoing rtp media */
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Create Recognizer Channel\n");
	asr_channel = mrcp_client_recognizer_channel_create(asr_session->profile->mrcp_context, asr_session->client_session, NULL);
	if (!asr_channel) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to create recognizer channel\n");
		return SWITCH_STATUS_FALSE;
	}

	switch_mutex_lock(asr_session->flag_mutex);
	mrcp_client_context_channel_add(asr_session->profile->mrcp_context, asr_session->client_session, asr_channel, NULL);
	if(switch_thread_cond_timedwait(asr_session->wait_object,asr_session->flag_mutex,5000*1000) != APR_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No response from client stack\n");
	}
	switch_mutex_unlock(asr_session->flag_mutex);
	if(!asr_session->control_channel) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No recognizer channel available\n");
		return SWITCH_STATUS_FALSE;
	}

	asr_session->flags = *flags;
	ah->private_info = asr_session;
	return SWITCH_STATUS_SUCCESS;
}

/* function to load a grammar to the asr interface */
static switch_status_t openmrcp_asr_load_grammar(switch_asr_handle_t *ah, char *grammar, char *path)
{
	/** Read grammar from path and create and send and MRCP RECOGNIZE msg
	    that has the grammar attached to body.   
	
	    TODO: - how does DEFINE-GRAMMAR fit into the picture here?  (if at all) 
	*/
	
	openmrcp_session_t *asr_session = (openmrcp_session_t *) ah->private_info;
	mrcp_client_context_t *context = asr_session->profile->mrcp_context;
		
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Loading grammar\n");

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Start Recognizer\n");
	openmrcp_recog_start(context, asr_session, path);
	
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Finished loading grammar\n");
	return SWITCH_STATUS_SUCCESS;
}

/** 
 * function to feed audio to the ASR
 * asr_open and asr_feed appear to be called asynchronously -- in other 
 * words asr_open is not completed yet, but asr_feed is already called 
 * from another thread.
 */
static switch_status_t openmrcp_asr_feed(switch_asr_handle_t *ah, void *data, unsigned int len, switch_asr_flag_t *flags)
{
	openmrcp_session_t *asr_session = (openmrcp_session_t *) ah->private_info;
	media_frame_t media_frame;
	audio_sink_t *audio_sink = mrcp_client_audio_sink_get(asr_session->audio_channel);

	media_frame.type = MEDIA_FRAME_TYPE_AUDIO;
	/* sampling rate and frame size should be retrieved from audio sink */
	media_frame.codec_frame.size = 160;
	media_frame.codec_frame.buffer = data;
	while(len >= media_frame.codec_frame.size) {
		if (!audio_sink) {
			/*!
			  If there is no audio_sink established yet, discard the audio and
			  return SUCCESS.  returning anything other than success causes freeswitch
			  to abort the call and tear down the channel.  One reason there might
			  not be an audio sink is that the openmrcp client lib is still in the startup
			  process.  
			*/
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "!audio_sink\n");
			return SWITCH_STATUS_SUCCESS;  
		}
		audio_sink->method_set->write_frame(audio_sink,&media_frame);
		
		len -= (unsigned int)media_frame.codec_frame.size;
		media_frame.codec_frame.buffer = (char*)media_frame.codec_frame.buffer + media_frame.codec_frame.size;
	}
	if(len > 0) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "None frame alligned data len [%d]\n",len);
	}
	return SWITCH_STATUS_SUCCESS;
}


static switch_status_t openmrcp_asr_pause(switch_asr_handle_t *ah)
{

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "openmrcp_asr_pause called\n");

	return SWITCH_STATUS_SUCCESS;

}

static switch_status_t openmrcp_asr_resume(switch_asr_handle_t *ah)
{

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "openmrcp_asr_resume called\n");

	return SWITCH_STATUS_SUCCESS;
}


/*! function to unload a grammar to the asr interface */
static switch_status_t openmrcp_asr_unload_grammar(switch_asr_handle_t *ah, char *grammar)
{

	return SWITCH_STATUS_SUCCESS;
}

/**
 * Freeswitch calls this whenever the channel is hungup or the
 * speech detection is stopped via a call to switch_ivr_stop_detect_speech()
 */
static switch_status_t openmrcp_asr_close(switch_asr_handle_t *ah, switch_asr_flag_t *flags)
{
	openmrcp_session_t *asr_session = (openmrcp_session_t *) ah->private_info;
	mrcp_client_context_t *context = asr_session->profile->mrcp_context;

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "openmrcp_asr_close()\n");

	// TODO!! should we do a switch_pool_clear(switch_memory_pool_t *p) on the pool held
	// by asr_session?

	// terminate client session
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Going to TERMINATE SESSION\n");
	switch_set_flag_locked(asr_session, FLAG_TERMINATING);  
	mrcp_client_context_session_terminate(context, asr_session->client_session);
	
	switch_set_flag(ah, SWITCH_ASR_FLAG_CLOSED);

	return SWITCH_STATUS_SUCCESS;
}


/**
 * Freeswitch calls this method from the speech_thread() thread body method
 * in switch_ivr_async.c every time a new frame is received by the media bug
 * attached to the audio channel.  If this method returns SWITCH_STATUS_SUCCESS,
 * then Freeswitch will call openmrcp_asr_get_results() to get the result value.
 */
static switch_status_t openmrcp_asr_check_results(switch_asr_handle_t *ah, switch_asr_flag_t *flags)
{
	openmrcp_session_t *asr_session = (openmrcp_session_t *) ah->private_info;
	
	switch_status_t rv = (switch_test_flag(asr_session, FLAG_HAS_MESSAGE)) ? SWITCH_STATUS_SUCCESS : SWITCH_STATUS_FALSE;

	return rv;
}

/*! This will be called after asr_check_results returns SUCCESS */
static switch_status_t openmrcp_asr_get_results(switch_asr_handle_t *ah, char **xmlstr, switch_asr_flag_t *flags)
{
	openmrcp_session_t *asr_session = (openmrcp_session_t *) ah->private_info;
	switch_status_t ret = SWITCH_STATUS_SUCCESS;
	mrcp_message_t *message;
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "openmrcp_asr_get_results called\n");

	message = asr_session->mrcp_message_last_rcvd;
	asr_session->mrcp_message_last_rcvd = NULL;
	// since we are returning our result here, future calls to check_results
	// should return False
	switch_clear_flag_locked(asr_session, FLAG_HAS_MESSAGE);

	if (message->start_line.message_type == MRCP_MESSAGE_TYPE_RESPONSE) {
		if (message->start_line.status_code != MRCP_STATUS_CODE_SUCCESS && 
			message->start_line.status_code != MRCP_STATUS_CODE_SUCCESS_WITH_IGNORE) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "error code received [%d]\n", message->start_line.status_code);
			ret = SWITCH_STATUS_FALSE;
		}
	} 
	else if (message->start_line.message_type == MRCP_MESSAGE_TYPE_EVENT) {
		if (message->start_line.method_id == RECOGNIZER_RECOGNITION_COMPLETE) {
			/*! 
			   we have to extract the XML but stripping off the <?xml version="1.0"?>
			   header.  the body looks like:
			
			   Completion-Cause:001 no-match
			   Content-Type: application/nlsml+xml
			   Content-Length: 260
			 
			  <?xml version="1.0"?>
			  <result xmlns="http://www.ietf.org/xml/ns/mrcpv2" xmlns:ex="http://www.example.com/example" score="100" grammar="session:request1@form-level.store">
				<interpretation>             <input mode="speech">open a</input>
				</interpretation>
			  </result>
			*/

			if(message->body) {
				char *marker = "?>";  // FIXME -- lame and brittle way of doing this.  use regex or better.
				char *position = strstr(message->body, marker);
				if (!position) {
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Bad result received from mrcp server: %s", message->body);
					ret = SWITCH_STATUS_FALSE;
				}
				else {
					position += strlen(marker);
					*xmlstr = strdup(position);
				}
			}
			else {
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No result received from mrcp server\n");
				ret = SWITCH_STATUS_FALSE;
			}

			ret = SWITCH_STATUS_SUCCESS;	
		} 
		else if (message->start_line.method_id == RECOGNIZER_START_OF_INPUT) {
			ret = SWITCH_STATUS_BREAK;
		}
	}
	return ret;
}


static mrcp_status_t synth_speak(mrcp_client_context_t *context, openmrcp_session_t *tts_session, char *text)
{
	mrcp_generic_header_t *generic_header;
	mrcp_message_t *mrcp_message;

	char *text2speak;
	const char xml_head[] = 
		"<?xml version=\"1.0\"?>\r\n"
		"<speak>\r\n"
		"<paragraph>\r\n"
		"    <sentence>";

	const char xml_tail[] = "</sentence>\r\n"
		"</paragraph>\r\n"
		"</speak>\r\n";

	size_t len = sizeof(xml_head) + sizeof(text) + sizeof(xml_tail);
	text2speak = (char *) switch_core_alloc(tts_session->pool, len);
	strcat(text2speak, xml_head);
	strcat(text2speak, text);
	strcat(text2speak, xml_tail);

	mrcp_message = mrcp_client_context_message_get(context,tts_session->client_session,tts_session->control_channel,SYNTHESIZER_SPEAK);
	if(!mrcp_message) {
		return MRCP_STATUS_FAILURE;
	}

	generic_header = mrcp_generic_header_prepare(mrcp_message);
	if(!generic_header) {
		return MRCP_STATUS_FAILURE;
	}

	generic_header->content_type = "application/synthesis+ssml";
	mrcp_generic_header_property_add(mrcp_message,GENERIC_HEADER_CONTENT_TYPE);
	mrcp_message->body = text2speak;

	return mrcp_client_context_channel_modify(context,tts_session->client_session,mrcp_message);
}

static mrcp_status_t synth_stop(mrcp_client_context_t *context, openmrcp_session_t *tts_session)
{
	mrcp_message_t *mrcp_message = mrcp_client_context_message_get(context,tts_session->client_session,tts_session->control_channel,SYNTHESIZER_STOP);
	if(!mrcp_message) {
		return MRCP_STATUS_FAILURE;
	}

	return mrcp_client_context_channel_modify(context,tts_session->client_session,mrcp_message);
}


static switch_status_t openmrcp_tts_open(switch_speech_handle_t *sh, char *voice_name, int rate, switch_speech_flag_t *flags) 
{
	openmrcp_session_t *tts_session;
	mrcp_client_channel_t *tts_channel;

	/* create session */
	tts_session = openmrcp_session_create(openmrcp_module.tts_profile);
	if (!tts_session) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "tts_session creation FAILED\n");
		return SWITCH_STATUS_GENERR;
	}

	/* create synthesizer channel */
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Create Synthesizer Channel\n");
	tts_channel = mrcp_client_synthesizer_channel_create(tts_session->profile->mrcp_context, tts_session->client_session, NULL);
	if (!tts_channel) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to create synthesizer channel\n");
		return SWITCH_STATUS_FALSE;
	}
	switch_mutex_lock(tts_session->flag_mutex);
	mrcp_client_context_channel_add(tts_session->profile->mrcp_context, tts_session->client_session, tts_channel, NULL);
	if(switch_thread_cond_timedwait(tts_session->wait_object,tts_session->flag_mutex,5000*1000) != APR_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No response from client stack\n");
	}
	switch_mutex_unlock(tts_session->flag_mutex);
	if(!tts_session->control_channel) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No synthesizer channel available\n");
		return SWITCH_STATUS_FALSE;
	}

	tts_session->flags = *flags;
	sh->private_info = tts_session;
	return SWITCH_STATUS_SUCCESS;
}

static switch_status_t openmrcp_tts_close(switch_speech_handle_t *sh, switch_speech_flag_t *flags)
{
	openmrcp_session_t *tts_session = (openmrcp_session_t *) sh->private_info;
	mrcp_client_context_t *context = tts_session->profile->mrcp_context;

	/* terminate tts session */
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "terminate tts_session\n");
	switch_set_flag_locked(tts_session, FLAG_TERMINATING);
	mrcp_client_context_session_terminate(context,tts_session->client_session);
	return SWITCH_STATUS_SUCCESS;	
}

static switch_status_t openmrcp_feed_tts(switch_speech_handle_t *sh, char *text, switch_speech_flag_t *flags)
{
	openmrcp_session_t *tts_session = (openmrcp_session_t *) sh->private_info;
	mrcp_client_context_t *context = tts_session->profile->mrcp_context;

	if(!tts_session->control_channel) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "no synthesizer channel too feed tts\n");
		return SWITCH_STATUS_FALSE;
	}
	
	synth_speak(context, tts_session, text); 
	
	switch_clear_flag(tts_session,FLAG_FEED_STARTED);
	return SWITCH_STATUS_SUCCESS;	
}

/**
 * Freeswitch calls this when its ready to read datalen bytes of data.
 * 
 * TODO: check the blocking flag passed in flags and act accordingly  
 *       (see mod_cepstral.c)
 */
static switch_status_t openmrcp_read_tts(switch_speech_handle_t *sh, void *data, size_t *datalen, uint32_t *rate, switch_speech_flag_t *flags)
{
	openmrcp_session_t *tts_session = (openmrcp_session_t *) sh->private_info;
	size_t return_len=0;
	media_frame_t media_frame;
	audio_source_t *audio_source;

	if (switch_test_flag(tts_session, FLAG_HAS_MESSAGE)) {
		mrcp_message_t *message = tts_session->mrcp_message_last_rcvd;
		tts_session->mrcp_message_last_rcvd = NULL;
		switch_clear_flag_locked(tts_session, FLAG_HAS_MESSAGE);

		if (message->start_line.message_type == MRCP_MESSAGE_TYPE_RESPONSE) {
			if (message->start_line.status_code != MRCP_STATUS_CODE_SUCCESS && 
				message->start_line.status_code != MRCP_STATUS_CODE_SUCCESS_WITH_IGNORE) {
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "error code received [%d]\n", message->start_line.status_code);
				return SWITCH_STATUS_BREAK;
			}
		} 
		else if (message->start_line.message_type == MRCP_MESSAGE_TYPE_EVENT) {
			if (message->start_line.method_id == SYNTHESIZER_SPEAK_COMPLETE) {
				/* tell fs we are done */
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "FLAG_SPEAK_COMPLETE\n");
				return SWITCH_STATUS_BREAK;
			}
		}
	}

	audio_source = mrcp_client_audio_source_get(tts_session->audio_channel);
	if(!audio_source) {
		return SWITCH_STATUS_BREAK;
	}

	if (!switch_test_flag(tts_session, FLAG_FEED_STARTED)) {
		switch_set_flag(tts_session, FLAG_FEED_STARTED);  // shouldn't this use set_flag_locked? -tl
		if(audio_source->method_set->open) {
			audio_source->method_set->open(audio_source);
		}
	}

	/* sampling rate and frame size should be retrieved from audio source */
	*rate = 8000;
	media_frame.codec_frame.size = 160;
	while(return_len < *datalen) {
		media_frame.codec_frame.buffer = (char*)data + return_len;
		audio_source->method_set->read_frame(audio_source,&media_frame);
		if(media_frame.type != MEDIA_FRAME_TYPE_AUDIO) {
			memset(media_frame.codec_frame.buffer,0,media_frame.codec_frame.size);
		}
		return_len += media_frame.codec_frame.size;
	}
	*datalen = return_len;
	return SWITCH_STATUS_SUCCESS;	
}


static void openmrcp_flush_tts(switch_speech_handle_t *sh)
{
	openmrcp_session_t *tts_session = (openmrcp_session_t *) sh->private_info;
	mrcp_client_context_t *context = tts_session->profile->mrcp_context;

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "flush_tts called\n");
	synth_stop(context,tts_session); // TODO
}

static void openmrcp_text_param_tts(switch_speech_handle_t *sh, char *param, char *val)
{

}

static void openmrcp_numeric_param_tts(switch_speech_handle_t *sh, char *param, int val)
{

}

static void openmrcp_float_param_tts(switch_speech_handle_t *sh, char *param, double val)
{

}


static switch_status_t do_config()
{
	char *cf = "mod_openmrcp.conf";
	const char *asr_profile_name = NULL;
	const char *tts_profile_name = NULL;
	switch_xml_t cfg, xml, settings, profiles, xprofile, param;
	openmrcp_profile_t *mrcp_profile;
	openmrcp_client_options_t *mrcp_options;

	if (!(xml = switch_xml_open_cfg(cf, &cfg, NULL))) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "open of %s failed\n", cf);
		return SWITCH_STATUS_TERM;
	}

	mrcp_logger.priority = MRCP_PRIO_EMERGENCY;
	if ((settings = switch_xml_child(cfg, "settings"))) {
		for (param = switch_xml_child(settings, "param"); param; param = param->next) {
			const char *var = switch_xml_attr_soft(param, "name");
			const char *val = switch_xml_attr_soft(param, "value");

			if (!strcasecmp(var, "asr_default_profile")) {
				asr_profile_name = val;
			} else if (!strcasecmp(var, "tts_default_profile")) {
				tts_profile_name = val;
			} else if (!strcasecmp(var, "log_level")) {
				mrcp_logger.priority = atoi(val);
			}
		}
	}
	else {
		goto error;
	}
	if ((profiles = switch_xml_child(cfg, "profiles"))) {
		for (xprofile = switch_xml_child(profiles, "profile"); xprofile; xprofile = xprofile->next) {
			const char *profile_name = switch_xml_attr_soft(xprofile, "name");
			mrcp_profile = switch_core_alloc(openmrcp_module.pool,sizeof(openmrcp_profile_t));
			mrcp_profile->mrcp_client = NULL;
			mrcp_profile->mrcp_context = NULL;
			mrcp_profile->name = "noname";
			if(profile_name) {
				mrcp_profile->name = switch_core_strdup(openmrcp_module.pool,profile_name);
			}

			mrcp_options = openmrcp_client_options_create(openmrcp_module.pool);
			for (param = switch_xml_child(xprofile, "param"); param; param = param->next) {
				const char *var = switch_xml_attr_soft(param, "name");
				const char *val = switch_xml_attr_soft(param, "value");

				if (!strcasecmp(var, "proto_version")) {
					mrcp_options->proto_version =(mrcp_version_t) atoi(val);
				}
				else if (!strcasecmp(var, "client_ip")) {
					mrcp_options->client_ip = switch_core_strdup(openmrcp_module.pool,val);
				} else if (!strcasecmp(var, "server_ip")) {
					mrcp_options->server_ip = switch_core_strdup(openmrcp_module.pool,val);
				} else if (!strcasecmp(var, "client_port")) {
					mrcp_options->client_port = (apr_port_t) atoi(val);
				} else if (!strcasecmp(var, "server_port")) {
					mrcp_options->server_port = (apr_port_t) atoi(val);
				} else if (!strcasecmp(var, "rtp_port_min")) {
					mrcp_options->rtp_port_min = (apr_port_t) atoi(val);
				} else if (!strcasecmp(var, "rtp_port_max")) {
					mrcp_options->rtp_port_max = (apr_port_t) atoi(val);
				}
			}
			mrcp_profile->mrcp_options = mrcp_options;

			/* add profile */
			if (!switch_core_hash_find(openmrcp_module.profile_hash, mrcp_profile->name)) {
				switch_core_hash_insert(openmrcp_module.profile_hash, mrcp_profile->name, mrcp_profile);

				/* try to set default asr profile */
				if (!openmrcp_module.asr_profile) {
					if (asr_profile_name) {
						if (!strcasecmp(mrcp_profile->name,asr_profile_name)) {
							openmrcp_module.asr_profile = mrcp_profile;
						}
					}
					else {
						openmrcp_module.asr_profile = mrcp_profile;
					}
				}
				/* try to set default tts profile */
				if (!openmrcp_module.tts_profile) {
					if (tts_profile_name) {
						if (!strcasecmp(mrcp_profile->name,tts_profile_name)) {
							openmrcp_module.tts_profile = mrcp_profile;
						}
					}
					else {
						openmrcp_module.tts_profile = mrcp_profile;
					}
				}
			}
		}
	}
	else {
		goto error;
	}

	switch_xml_free(xml);
	return SWITCH_STATUS_SUCCESS;

 error:
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to load module configuration\n");
	switch_xml_free(xml);
	return SWITCH_STATUS_TERM;

}

static switch_status_t openmrcp_profile_run(openmrcp_profile_t *profile)
{
	mrcp_client_event_handler_t *mrcp_event_handler;
	mrcp_client_t *mrcp_client;
	mrcp_client_context_t *mrcp_context;
	
	/*!
	Perform one-time initialization of mrcp client library
	*/
	mrcp_event_handler = switch_core_alloc(openmrcp_module.pool,sizeof(mrcp_client_event_handler_t));
	mrcp_event_handler->on_session_initiate = openmrcp_on_session_initiate;
	mrcp_event_handler->on_session_terminate = openmrcp_on_session_terminate;
	mrcp_event_handler->on_channel_add = openmrcp_on_channel_add;
	mrcp_event_handler->on_channel_remove = openmrcp_on_channel_remove;
	mrcp_event_handler->on_channel_modify = openmrcp_on_channel_modify;

	// create client context, which must be passed to client engine 
	mrcp_context = mrcp_client_context_create(&openmrcp_module,mrcp_event_handler);
	if(!mrcp_context) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "mrcp_client_context creation failed\n");
		return SWITCH_STATUS_GENERR;
	}
	profile->mrcp_context = mrcp_context;

	// this basically starts a thread that pulls events from the event queue
	// and handles them 
	mrcp_client = openmrcp_client_start(profile->mrcp_options,mrcp_context);
	if(!mrcp_client) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "openmrcp_client_start FAILED\n");
		mrcp_client_context_destroy(mrcp_context);
		return SWITCH_STATUS_GENERR;
	}
	profile->mrcp_client = mrcp_client;
	return SWITCH_STATUS_SUCCESS;
}


static switch_status_t openmrcp_init()
{
	/* one-time mrcp global initialization */
	mrcp_global_init();

	openmrcp_module.pool = mrcp_global_pool_get();
	openmrcp_module.asr_profile = NULL;
	openmrcp_module.tts_profile = NULL;

	switch_core_hash_init(&openmrcp_module.profile_hash,openmrcp_module.pool);

	/* read config */
	if (do_config() != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_FALSE;
	}

	/* run default asr/tts profiles */
	if(openmrcp_module.asr_profile) {
		openmrcp_profile_run(openmrcp_module.asr_profile);
	}
	if(openmrcp_module.tts_profile && openmrcp_module.tts_profile != openmrcp_module.asr_profile) {
		openmrcp_profile_run(openmrcp_module.tts_profile);
	}

	return SWITCH_STATUS_SUCCESS;
}

static switch_status_t openmrcp_destroy()
{
	/* destroy asr/tts profiles */
	if(openmrcp_module.asr_profile) {
		/* shutdown client engine */
		openmrcp_client_shutdown(openmrcp_module.asr_profile->mrcp_client);
		/* destroy client context */
		mrcp_client_context_destroy(openmrcp_module.asr_profile->mrcp_context);
		if(openmrcp_module.tts_profile == openmrcp_module.asr_profile) {
			openmrcp_module.tts_profile = NULL;
		}
		openmrcp_module.asr_profile = NULL;
	}
	if(openmrcp_module.tts_profile) {
		/* shutdown client engine */
		openmrcp_client_shutdown(openmrcp_module.tts_profile->mrcp_client);
		/* destroy client context */
		mrcp_client_context_destroy(openmrcp_module.tts_profile->mrcp_context);
		openmrcp_module.tts_profile = NULL;
	}

	switch_core_hash_destroy(&openmrcp_module.profile_hash);
	openmrcp_module.profile_hash = NULL;

	/* one-time mrcp global destroy */
	mrcp_global_destroy();
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_MODULE_LOAD_FUNCTION(mod_openmrcp_load)
{
	switch_speech_interface_t *speech_interface;
	switch_asr_interface_t *asr_interface;

	/* connect my internal structure to the blank pointer passed to me */
	*module_interface = switch_loadable_module_create_module_interface(pool, modname);
	speech_interface = switch_loadable_module_create_interface(*module_interface, SWITCH_SPEECH_INTERFACE);
	speech_interface->interface_name = "openmrcp";
	speech_interface->speech_open = openmrcp_tts_open;
	speech_interface->speech_close = openmrcp_tts_close;
	speech_interface->speech_feed_tts = openmrcp_feed_tts;
	speech_interface->speech_read_tts = openmrcp_read_tts;
	speech_interface->speech_flush_tts = openmrcp_flush_tts;
	speech_interface->speech_text_param_tts = openmrcp_text_param_tts;
	speech_interface->speech_numeric_param_tts = openmrcp_numeric_param_tts;
	speech_interface->speech_float_param_tts = openmrcp_float_param_tts;
	asr_interface = switch_loadable_module_create_interface(*module_interface, SWITCH_ASR_INTERFACE);
	asr_interface->interface_name = "openmrcp";
	asr_interface->asr_open = openmrcp_asr_open;
	asr_interface->asr_load_grammar = openmrcp_asr_load_grammar;
	asr_interface->asr_unload_grammar = openmrcp_asr_unload_grammar;
	asr_interface->asr_close = openmrcp_asr_close;
	asr_interface->asr_feed = openmrcp_asr_feed;
	asr_interface->asr_resume = openmrcp_asr_resume;
	asr_interface->asr_pause = openmrcp_asr_pause;
	asr_interface->asr_check_results = openmrcp_asr_check_results;
	asr_interface->asr_get_results = openmrcp_asr_get_results;

	/* initialize openmrcp */
	if (openmrcp_init() != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_FALSE;		
	}

	/* indicate that the module should continue to be loaded */
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_openmrcp_shutdown)
{
	/* destroy openmrcp */
	openmrcp_destroy();
	return SWITCH_STATUS_SUCCESS;
}