freeswitch/src/mod/applications/mod_spandsp/mod_spandsp_dsp.c

/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005-2010, Anthony Minessale II <anthm@freeswitch.org>
 *
 * 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 mod_spandsp.
 *
 * The Initial Developer of the Original Code is
 * Massimo Cetra <devel@navynet.it>
 *
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Brian West <brian@freeswitch.org>
 * Anthony Minessale II <anthm@freeswitch.org>
 * Steve Underwood <steveu@coppice.org>
 * Antonio Gallo <agx@linux.it>
 * mod_spandsp_dsp.c -- dsp applications provided by SpanDSP
 *
 */

#include "mod_spandsp.h"

typedef struct {
	switch_core_session_t *session;
    dtmf_rx_state_t *dtmf_detect;
} switch_inband_dtmf_t;

static switch_bool_t 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;
	switch_frame_t *frame = NULL;
	char digit_str[80];
	switch_channel_t *channel = switch_core_session_get_channel(pvt->session);

	switch (type) {
	case SWITCH_ABC_TYPE_INIT:
        pvt->dtmf_detect = dtmf_rx_init(NULL, NULL, NULL);
		break;
	case SWITCH_ABC_TYPE_CLOSE:
        if (pvt->dtmf_detect) {
            dtmf_rx_free(pvt->dtmf_detect);
        }
		break;
	case SWITCH_ABC_TYPE_READ_REPLACE:
		if ((frame = switch_core_media_bug_get_read_replace_frame(bug))) {
			dtmf_rx(pvt->dtmf_detect, frame->data, frame->samples);
			dtmf_rx_get(pvt->dtmf_detect, digit_str, sizeof(digit_str));
			if (digit_str[0]) {
				char *p = digit_str;
				while (p && *p) {
					switch_dtmf_t dtmf;
					dtmf.digit = *p;
					dtmf.duration = switch_core_default_dtmf_duration(0);
					switch_channel_queue_dtmf(channel, &dtmf);
					p++;
				}
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(switch_core_media_bug_get_session(bug)), SWITCH_LOG_DEBUG, "DTMF DETECTED: [%s]\n",
								  digit_str);
			}
			switch_core_media_bug_set_read_replace_frame(bug, frame);
		}
		break;
	case SWITCH_ABC_TYPE_WRITE:
	default:
		break;
	}

	return SWITCH_TRUE;
}

switch_status_t spandsp_stop_inband_dtmf_session(switch_core_session_t *session)
{
	switch_media_bug_t *bug;
	switch_channel_t *channel = switch_core_session_get_channel(session);

	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_status_t spandsp_inband_dtmf_session(switch_core_session_t *session)
{
	switch_channel_t *channel = switch_core_session_get_channel(session);
	switch_media_bug_t *bug;
	switch_status_t status;
	switch_inband_dtmf_t *pvt;
	switch_codec_implementation_t read_impl = { 0 };

	switch_core_session_get_read_impl(session, &read_impl);

	if (!(pvt = switch_core_session_alloc(session, sizeof(*pvt)))) {
		return SWITCH_STATUS_MEMERR;
	}

   	pvt->session = session;


	if (switch_channel_pre_answer(channel) != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_FALSE;
	}

	if ((status = switch_core_media_bug_add(session, "spandsp_dtmf_detect", NULL,
                                            inband_dtmf_callback, pvt, 0, SMBF_READ_REPLACE, &bug)) != SWITCH_STATUS_SUCCESS) {
		return status;
	}

	switch_channel_set_private(channel, "dtmf", bug);

	return SWITCH_STATUS_SUCCESS;
}

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