app_talkdetect.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Playback a file with audio detect
 *
 * \author Mark Spencer <[email protected]>
 *
 * \ingroup applications
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/utils.h"
#include "asterisk/dsp.h"
#include "asterisk/app.h"
#include "asterisk/format.h"
#include "asterisk/format_cache.h"

/*** DOCUMENTATION
 <application name="BackgroundDetect" language="en_US">
 <synopsis>
 Background a file with talk detect.
 </synopsis>
 <syntax>
 <parameter name="filename" required="true" />
 <parameter name="sil">
 <para>If not specified, defaults to <literal>1000</literal>.</para>
 </parameter>
 <parameter name="min">
 <para>If not specified, defaults to <literal>100</literal>.</para>
 </parameter>
 <parameter name="max">
 <para>If not specified, defaults to <literal>infinity</literal>.</para>
 </parameter>
 <parameter name="analysistime">
 <para>If not specified, defaults to <literal>infinity</literal>.</para>
 </parameter>
 </syntax>
 <description>
 <para>Plays back <replaceable>filename</replaceable>, waiting for interruption from a given digit (the digit
 must start the beginning of a valid extension, or it will be ignored). During
 the playback of the file, audio is monitored in the receive direction, and if
 a period of non-silence which is greater than <replaceable>min</replaceable> ms yet less than
 <replaceable>max</replaceable> ms is followed by silence for at least <replaceable>sil</replaceable> ms,
 which occurs during the first <replaceable>analysistime</replaceable> ms, then the audio playback is
 aborted and processing jumps to the <replaceable>talk</replaceable> extension, if available.</para>
 </description>
 </application>
 ***/

static char *app = "BackgroundDetect";

static int background_detect_exec(struct ast_channel *chan, const char *data)
{
 int res = 0;
 char *tmp;
 struct ast_frame *fr;
 int notsilent = 0;
 struct timeval start = { 0, 0 };
 struct timeval detection_start = { 0, 0 };
 int sil = 1000;
 int min = 100;
 int max = -1;
 int analysistime = -1;
 int continue_analysis = 1;
 int x;
 RAII_VAR(struct ast_format *, origrformat, NULL, ao2_cleanup);
 struct ast_dsp *dsp = NULL;
 AST_DECLARE_APP_ARGS(args,
 AST_APP_ARG(filename);
 AST_APP_ARG(silence);
 AST_APP_ARG(min);
 AST_APP_ARG(max);
 AST_APP_ARG(analysistime);
 );

 if (ast_strlen_zero(data)) {
 ast_log(LOG_WARNING, "BackgroundDetect requires an argument (filename)\n");
 return -1;
 }

 tmp = ast_strdupa(data);
 AST_STANDARD_APP_ARGS(args, tmp);

 if (!ast_strlen_zero(args.silence) && (sscanf(args.silence, "%30d", &x) == 1) && (x > 0)) {
 sil = x;
 }
 if (!ast_strlen_zero(args.min) && (sscanf(args.min, "%30d", &x) == 1) && (x > 0)) {
 min = x;
 }
 if (!ast_strlen_zero(args.max) && (sscanf(args.max, "%30d", &x) == 1) && (x > 0)) {
 max = x;
 }
 if (!ast_strlen_zero(args.analysistime) && (sscanf(args.analysistime, "%30d", &x) == 1) && (x > 0)) {
 analysistime = x;
 }

 ast_debug(1, "Preparing detect of '%s', sil=%d, min=%d, max=%d, analysistime=%d\n", args.filename, sil, min, max, analysistime);
 do {
 if (ast_channel_state(chan) != AST_STATE_UP) {
 if ((res = ast_answer(chan))) {
 break;
 }
 }

 origrformat = ao2_bump(ast_channel_readformat(chan));
 if ((ast_set_read_format(chan, ast_format_slin))) {
 ast_log(LOG_WARNING, "Unable to set read format to linear!\n");
 res = -1;
 break;
 }

 if (!(dsp = ast_dsp_new())) {
 ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
 res = -1;
 break;
 }
 ast_stopstream(chan);
 if (ast_streamfile(chan, tmp, ast_channel_language(chan))) {
 ast_log(LOG_WARNING, "ast_streamfile failed on %s for %s\n", ast_channel_name(chan), (char *)data);
 break;
 }
 detection_start = ast_tvnow();
 while (ast_channel_stream(chan)) {
 res = ast_sched_wait(ast_channel_sched(chan));
 if ((res < 0) && !ast_channel_timingfunc(chan)) {
 res = 0;
 break;
 }
 if (res < 0) {
 res = 1000;
 }
 res = ast_waitfor(chan, res);
 if (res < 0) {
 ast_log(LOG_WARNING, "Waitfor failed on %s\n", ast_channel_name(chan));
 break;
 } else if (res > 0) {
 fr = ast_read(chan);
 if (continue_analysis && analysistime >= 0) {
 /* If we have a limit for the time to analyze voice
 * frames and the time has not expired */
 if (ast_tvdiff_ms(ast_tvnow(), detection_start) >= analysistime) {
 continue_analysis = 0;
 ast_verb(3, "BackgroundDetect: Talk analysis time complete on %s.\n", ast_channel_name(chan));
 }
 }

 if (!fr) {
 res = -1;
 break;
 } else if (fr->frametype == AST_FRAME_DTMF) {
 char t[2];
 t[0] = fr->subclass.integer;
 t[1] = '\0';
 if (ast_canmatch_extension(chan, ast_channel_context(chan), t, 1,
 S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
 /* They entered a valid extension, or might be anyhow */
 res = fr->subclass.integer;
 ast_frfree(fr);
 break;
 }
 } else if ((fr->frametype == AST_FRAME_VOICE) &&
 (ast_format_cmp(fr->subclass.format, ast_format_slin) == AST_FORMAT_CMP_EQUAL) && continue_analysis) {
 int totalsilence;
 int ms;
 res = ast_dsp_silence(dsp, fr, &totalsilence);
 if (res && (totalsilence > sil)) {
 /* We've been quiet a little while */
 if (notsilent) {
 /* We had heard some talking */
 ms = ast_tvdiff_ms(ast_tvnow(), start);
 ms -= sil;
 if (ms < 0)
 ms = 0;
 if ((ms > min) && ((max < 0) || (ms < max))) {
 char ms_str[12];
 ast_debug(1, "Found qualified token of %d ms\n", ms);

 /* Save detected talk time (in milliseconds) */
 snprintf(ms_str, sizeof(ms_str), "%d", ms);
 pbx_builtin_setvar_helper(chan, "TALK_DETECTED", ms_str);

 ast_goto_if_exists(chan, ast_channel_context(chan), "talk", 1);
 res = 0;
 ast_frfree(fr);
 break;
 } else {
 ast_debug(1, "Found unqualified token of %d ms\n", ms);
 }
 notsilent = 0;
 }
 } else {
 if (!notsilent) {
 /* Heard some audio, mark the begining of the token */
 start = ast_tvnow();
 ast_debug(1, "Start of voice token!\n");
 notsilent = 1;
 }
 }
 }
 ast_frfree(fr);
 }
 ast_sched_runq(ast_channel_sched(chan));
 }
 ast_stopstream(chan);
 } while (0);

 if (res > -1) {
 if (origrformat && ast_set_read_format(chan, origrformat)) {
 ast_log(LOG_WARNING, "Failed to restore read format for %s to %s\n",
 ast_channel_name(chan), ast_format_get_name(origrformat));
 }
 }
 if (dsp) {
 ast_dsp_free(dsp);
 }
 return res;
}

static int unload_module(void)
{
 return ast_unregister_application(app);
}

static int load_module(void)
{
 return ast_register_application_xml(app, background_detect_exec);
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Playback with Talk Detection");