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Diffstat (limited to 'trunk/apps/app_waitforsilence.c')
| -rw-r--r-- | trunk/apps/app_waitforsilence.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/trunk/apps/app_waitforsilence.c b/trunk/apps/app_waitforsilence.c new file mode 100644 index 000000000..e45f24344 --- /dev/null +++ b/trunk/apps/app_waitforsilence.c @@ -0,0 +1,189 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 1999 - 2005, Digium, Inc. + * + * WaitForSilence Application by David C. Troy <dave@popvox.com> + * Version 1.11 2006-06-29 + * + * 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 Wait for Silence + * - Waits for up to 'x' milliseconds of silence, 'y' times \n + * - WaitForSilence(500,2) will wait for 1/2 second of silence, twice \n + * - WaitForSilence(1000,1) will wait for 1 second of silence, once \n + * - WaitForSilence(300,3,10) will wait for 300ms of silence, 3 times, and return after 10sec \n + * + * \author David C. Troy <dave@popvox.com> + * + * \ingroup applications + */ + +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include "asterisk/file.h" +#include "asterisk/channel.h" +#include "asterisk/pbx.h" +#include "asterisk/dsp.h" +#include "asterisk/module.h" + +static char *app = "WaitForSilence"; +static char *synopsis = "Waits for a specified amount of silence"; +static char *descrip = +" WaitForSilence(silencerequired[,iterations][,timeout]):\n" +"Wait for Silence: Waits for up to 'silencerequired' \n" +"milliseconds of silence, 'iterations' times or once if omitted.\n" +"An optional timeout specified the number of seconds to return\n" +"after, even if we do not receive the specified amount of silence.\n" +"Use 'timeout' with caution, as it may defeat the purpose of this\n" +"application, which is to wait indefinitely until silence is detected\n" +"on the line. This is particularly useful for reverse-911-type\n" +"call broadcast applications where you need to wait for an answering\n" +"machine to complete its spiel before playing a message.\n" +"The timeout parameter is specified only to avoid an infinite loop in\n" +"cases where silence is never achieved. Typically you will want to\n" +"include two or more calls to WaitForSilence when dealing with an answering\n" +"machine; first waiting for the spiel to finish, then waiting for the beep, etc.\n\n" + "Examples:\n" +" - WaitForSilence(500,2) will wait for 1/2 second of silence, twice\n" +" - WaitForSilence(1000) will wait for 1 second of silence, once\n" +" - WaitForSilence(300,3,10) will wait for 300ms silence, 3 times,\n" +" and returns after 10 sec, even if silence is not detected\n\n" +"Sets the channel variable WAITSTATUS with to one of these values:\n" +"SILENCE - if exited with silence detected\n" +"TIMEOUT - if exited without silence detected after timeout\n"; + +static int do_waiting(struct ast_channel *chan, int silencereqd, time_t waitstart, int timeout) { + struct ast_frame *f; + int dspsilence = 0; + static int silencethreshold = 128; + int rfmt = 0; + int res = 0; + struct ast_dsp *sildet; /* silence detector dsp */ + time_t now; + + rfmt = chan->readformat; /* Set to linear mode */ + res = ast_set_read_format(chan, AST_FORMAT_SLINEAR); + if (res < 0) { + ast_log(LOG_WARNING, "Unable to set channel to linear mode, giving up\n"); + return -1; + } + + sildet = ast_dsp_new(); /* Create the silence detector */ + if (!sildet) { + ast_log(LOG_WARNING, "Unable to create silence detector :(\n"); + return -1; + } + ast_dsp_set_threshold(sildet, silencethreshold); + + /* Await silence... */ + f = NULL; + for(;;) { + /* Start with no silence received */ + dspsilence = 0; + + res = ast_waitfor(chan, silencereqd); + + /* Must have gotten a hangup; let's exit */ + if (res <= 0) { + f = NULL; + break; + } + + /* We waited and got no frame; sounds like digital silence or a muted digital channel */ + if (!res) { + dspsilence = silencereqd; + } else { + /* Looks like we did get a frame, so let's check it out */ + f = ast_read(chan); + if (!f) + break; + if (f && f->frametype == AST_FRAME_VOICE) { + ast_dsp_silence(sildet, f, &dspsilence); + ast_frfree(f); + } + } + + ast_verb(3, "Got %dms silence< %dms required\n", dspsilence, silencereqd); + + if (dspsilence >= silencereqd) { + ast_verb(3, "Exiting with %dms silence >= %dms required\n", dspsilence, silencereqd); + /* Ended happily with silence */ + res = 1; + pbx_builtin_setvar_helper(chan, "WAITSTATUS", "SILENCE"); + ast_debug(1, "WAITSTATUS was set to SILENCE\n"); + break; + } + + if ( timeout && (difftime(time(&now),waitstart) >= timeout) ) { + pbx_builtin_setvar_helper(chan, "WAITSTATUS", "TIMEOUT"); + ast_debug(1, "WAITSTATUS was set to TIMEOUT\n"); + res = 0; + break; + } + } + + + if (rfmt && ast_set_read_format(chan, rfmt)) { + ast_log(LOG_WARNING, "Unable to restore format %s to channel '%s'\n", ast_getformatname(rfmt), chan->name); + } + ast_dsp_free(sildet); + return res; +} + +static int waitforsilence_exec(struct ast_channel *chan, void *data) +{ + int res = 1; + int silencereqd = 1000; + int timeout = 0; + int iterations = 1, i; + time_t waitstart; + + res = ast_answer(chan); /* Answer the channel */ + + if (!data || ( (sscanf(data, "%d,%d,%d", &silencereqd, &iterations, &timeout) != 3) && + (sscanf(data, "%d|%d", &silencereqd, &iterations) != 2) && + (sscanf(data, "%d", &silencereqd) != 1) ) ) { + ast_log(LOG_WARNING, "Using default value of 1000ms, 1 iteration, no timeout\n"); + } + + ast_verb(3, "Waiting %d time(s) for %d ms silence with %d timeout\n", iterations, silencereqd, timeout); + + time(&waitstart); + res = 1; + for (i=0; (i<iterations) && (res == 1); i++) { + res = do_waiting(chan, silencereqd, waitstart, timeout); + } + if (res > 0) + res = 0; + return res; +} + + +static int unload_module(void) +{ + return ast_unregister_application(app); +} + +static int load_module(void) +{ + return ast_register_application(app, waitforsilence_exec, synopsis, descrip); +} + +AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Wait For Silence"); + |