app_talkdetect.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * 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 <markster@digium.com>
 *
 * \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");