Add WaitForSilence application (bug #2467)

git-svn-id: http://svn.digium.com/svn/asterisk/trunk@4329 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 168 insertions, 0 deletions

diff --git a/apps/app_waitforsilence.c b/apps/app_waitforsilence.c
new file mode 100755
index 000000000..b29286a36
--- /dev/null
+++ b/apps/app_waitforsilence.c
@@ -0,0 +1,168 @@
+/*
+ * Asterisk -- A telephony toolkit for Linux.
+ * 
+ * Copyright (C) 1999-2004, Digium, Inc.
+ *
+ * Mark Spencer <markster@digium.com>
+ *
+ * Wait for Silence
+ *   - Waits for up to 'x' milliseconds of silence, 'y' times
+ *   - WaitForSilence(500,2) will wait for 1/2 second of silence, twice
+ *   - WaitForSilence(1000,1) will wait for 1 second of silence, once
+ *
+ * WaitForSilence Application by David C. Troy <dave@popvox.com>
+ * Version 1.00 2004-01-29
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#include <asterisk/file.h>
+#include <asterisk/logger.h>
+#include <asterisk/channel.h>
+#include <asterisk/pbx.h>
+#include <asterisk/dsp.h>
+#include <asterisk/module.h>
+#include <asterisk/options.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+
+static char *tdesc = "Wait For Silence";
+static char *app = "WaitForSilence";
+static char *synopsis = "Waits for a specified amount of silence";
+static char *descrip = 
+"  WaitForSilence(x[|y]) Wait for Silence: Waits for up to 'x' \n"
+"milliseconds of silence, 'y' times or 1 if omitted\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";
+
+STANDARD_LOCAL_USER;
+
+LOCAL_USER_DECL;
+
+static int do_waiting(struct ast_channel *chan, int duration) {
+
+	struct ast_frame *f;
+	int totalsilence = 0;
+	int dspsilence = 0;
+	int gotsilence = 0; 
+	static int silencethreshold = 64;
+	int rfmt = 0;
+	int res = 0;
+	struct ast_dsp *sildet;	 /* silence detector dsp */
+
+	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 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(;;) {
+		res = ast_waitfor(chan, 2000);
+		if (!res) {
+			ast_log(LOG_WARNING, "One waitfor failed, trying another\n");
+			/* Try one more time in case of masq */
+			res = ast_waitfor(chan, 2000);
+			if (!res) {
+				ast_log(LOG_WARNING, "No audio available on %s??\n", chan->name);
+				res = -1;
+			}
+		}
+
+		if (res < 0) {
+			f = NULL;
+			break;
+		}
+		f = ast_read(chan);
+		if (!f)
+			break;
+		if (f->frametype == AST_FRAME_VOICE) {
+			dspsilence = 0;
+			ast_dsp_silence(sildet, f, &dspsilence);
+			if (dspsilence)
+				totalsilence = dspsilence;
+			else
+				totalsilence = 0;
+			/* ast_verbose(VERBOSE_PREFIX_3 "dspsilence: %d, totalsilence: %d\n", dspsilence, totalsilence); */
+
+			if (totalsilence >= duration) {
+				ast_verbose(VERBOSE_PREFIX_3 "exiting with %d silence > %d required\n", totalsilence, duration);
+				/* Ended happily with silence */
+				ast_frfree(f);
+				gotsilence = 1;
+				break;
+			}
+		}
+		ast_frfree(f);
+	}
+	ast_dsp_free(sildet);
+	return gotsilence;
+}
+
+static int waitforsilence_exec(struct ast_channel *chan, void *data)
+{
+	int res=1;
+	struct localuser *u;
+	int duration = 1000;
+	int iterations = 1, i;
+
+	res = ast_answer(chan); /* Answer the channel */
+
+	if (!data || ((sscanf(data, "%d|%d", &duration, &iterations) != 2) &&
+		(sscanf(data, "%d", &duration != 1)))) {
+		ast_log(LOG_WARNING, "Using default value of 1000ms, 1 iteration\n");
+	}
+
+	ast_verbose(VERBOSE_PREFIX_3 "Waiting %d time(s) for %d ms silence\n", iterations, duration);
+	LOCAL_USER_ADD(u);
+	res = 1;
+	for ( i=0; (i<iterations) && (res == 1); i++) {
+		res = do_waiting(chan, duration);
+	}
+	LOCAL_USER_REMOVE(u);
+	if (res > 0)
+		res = 0;
+	return res;
+}
+
+int unload_module(void)
+{
+	STANDARD_HANGUP_LOCALUSERS;
+	return ast_unregister_application(app);
+}
+
+int load_module(void)
+{
+	return ast_register_application(app, waitforsilence_exec, synopsis, descrip);
+}
+
+char *description(void)
+{
+	return tdesc;
+}
+
+int usecount(void)
+{
+	int res;
+	STANDARD_USECOUNT(res);
+	return res;
+}
+
+char *key()
+{
+	return ASTERISK_GPL_KEY;
+}
+