asterisk/apps/app_mixmonitor.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005, Anthony Minessale II
 * Copyright (C) 2005 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 * Kevin P. Fleming <kpfleming@digium.com>
 *
 * Based on app_muxmon.c provided by
 * Anthony Minessale II <anthmct@yahoo.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 MixMonitor() - Record a call and mix the audio during the recording
 * \ingroup applications
 *
 * \author Mark Spencer <markster@digium.com>
 * \author Kevin P. Fleming <kpfleming@digium.com>
 *
 * \note Based on app_muxmon.c provided by
 * Anthony Minessale II <anthmct@yahoo.com>
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/paths.h"	/* use ast_config_AST_MONITOR_DIR */
#include "asterisk/file.h"
#include "asterisk/audiohook.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/cli.h"
#include "asterisk/app.h"
#include "asterisk/channel.h"
#include "asterisk/autochan.h"
#include "asterisk/manager.h"

/*** DOCUMENTATION
	<application name="MixMonitor" language="en_US">
		<synopsis>
			Record a call and mix the audio during the recording.  Use of StopMixMonitor is required
			to guarantee the audio file is available for processing during dialplan execution.
		</synopsis>
		<syntax>
			<parameter name="file" required="true" argsep=".">
				<argument name="filename" required="true">
					<para>If <replaceable>filename</replaceable> is an absolute path, uses that path, otherwise
					creates the file in the configured monitoring directory from <filename>asterisk.conf.</filename></para>
				</argument>
				<argument name="extension" required="true" />
			</parameter>
			<parameter name="options">
				<optionlist>
					<option name="a">
						<para>Append to the file instead of overwriting it.</para>
					</option>
					<option name="b">
						<para>Only save audio to the file while the channel is bridged.</para>
						<note><para>Does not include conferences or sounds played to each bridged party</para></note>
						<note><para>If you utilize this option inside a Local channel, you must make sure the Local
						channel is not optimized away. To do this, be sure to call your Local channel with the
						<literal>/n</literal> option. For example: Dial(Local/start@mycontext/n)</para></note>
					</option>
					<option name="v">
						<para>Adjust the <emphasis>heard</emphasis> volume by a factor of <replaceable>x</replaceable>
						(range <literal>-4</literal> to <literal>4</literal>)</para>
						<argument name="x" required="true" />
					</option>
					<option name="V">
						<para>Adjust the <emphasis>spoken</emphasis> volume by a factor
						of <replaceable>x</replaceable> (range <literal>-4</literal> to <literal>4</literal>)</para>
						<argument name="x" required="true" />
					</option>
					<option name="W">
						<para>Adjust both, <emphasis>heard and spoken</emphasis> volumes by a factor
						of <replaceable>x</replaceable> (range <literal>-4</literal> to <literal>4</literal>)</para>
						<argument name="x" required="true" />
					</option>
					<option name="r">
						<argument name="file" required="true" />
						<para>Use the specified file to record the <emphasis>receive</emphasis> audio feed.
						Like with the basic filename argument, if an absolute path isn't given, it will create
						the file in the configured monitoring directory.</para>

					</option>
					<option name="t">
						<argument name="file" required="true" />
						<para>Use the specified file to record the <emphasis>transmit</emphasis> audio feed.
						Like with the basic filename argument, if an absolute path isn't given, it will create
						the file in the configured monitoring directory.</para>
					</option>
				</optionlist>
			</parameter>
			<parameter name="command">
				<para>Will be executed when the recording is over.</para>
				<para>Any strings matching <literal>^{X}</literal> will be unescaped to <variable>X</variable>.</para>
				<para>All variables will be evaluated at the time MixMonitor is called.</para>
			</parameter>
		</syntax>
		<description>
			<para>Records the audio on the current channel to the specified file.</para>
			<variablelist>
				<variable name="MIXMONITOR_FILENAME">
					<para>Will contain the filename used to record.</para>
				</variable>
			</variablelist>	
		</description>
		<see-also>
			<ref type="application">Monitor</ref>
			<ref type="application">StopMixMonitor</ref>
			<ref type="application">PauseMonitor</ref>
			<ref type="application">UnpauseMonitor</ref>
		</see-also>
	</application>
	<application name="StopMixMonitor" language="en_US">
		<synopsis>
			Stop recording a call through MixMonitor, and free the recording's file handle.
		</synopsis>
		<syntax />
		<description>
			<para>Stops the audio recording that was started with a call to <literal>MixMonitor()</literal>
			on the current channel.</para>
		</description>
		<see-also>
			<ref type="application">MixMonitor</ref>
		</see-also>
	</application>
	<manager name="MixMonitorMute" language="en_US">
		<synopsis>
			Mute / unMute a Mixmonitor recording.
		</synopsis>
		<syntax>
			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
			<parameter name="Channel" required="true">
				<para>Used to specify the channel to mute.</para>
			</parameter>
			<parameter name="Direction">
				<para>Which part of the recording to mute:  read, write or both (from channel, to channel or both channels).</para>
			</parameter>
			<parameter name="State">
				<para>Turn mute on or off : 1 to turn on, 0 to turn off.</para>
			</parameter>
		</syntax>
		<description>
			<para>This action may be used to mute a MixMonitor recording.</para>
		</description>
	</manager>

 ***/

#define get_volfactor(x) x ? ((x > 0) ? (1 << x) : ((1 << abs(x)) * -1)) : 0

static const char * const app = "MixMonitor";

static const char * const stop_app = "StopMixMonitor";

static const char * const mixmonitor_spy_type = "MixMonitor";

struct mixmonitor {
	struct ast_audiohook audiohook;
	char *filename;
	char *filename_read;
	char *filename_write;
	char *post_process;
	char *name;
	unsigned int flags;
	struct ast_autochan *autochan;
	struct mixmonitor_ds *mixmonitor_ds;
};

enum mixmonitor_flags {
	MUXFLAG_APPEND = (1 << 1),
	MUXFLAG_BRIDGED = (1 << 2),
	MUXFLAG_VOLUME = (1 << 3),
	MUXFLAG_READVOLUME = (1 << 4),
	MUXFLAG_WRITEVOLUME = (1 << 5),
	MUXFLAG_READ = (1 << 6),
	MUXFLAG_WRITE = (1 << 7),
	MUXFLAG_COMBINED = (1 << 8),
};

enum mixmonitor_args {
	OPT_ARG_READVOLUME = 0,
	OPT_ARG_WRITEVOLUME,
	OPT_ARG_VOLUME,
	OPT_ARG_WRITENAME,
	OPT_ARG_READNAME,
	OPT_ARG_ARRAY_SIZE,	/* Always last element of the enum */
};

AST_APP_OPTIONS(mixmonitor_opts, {
	AST_APP_OPTION('a', MUXFLAG_APPEND),
	AST_APP_OPTION('b', MUXFLAG_BRIDGED),
	AST_APP_OPTION_ARG('v', MUXFLAG_READVOLUME, OPT_ARG_READVOLUME),
	AST_APP_OPTION_ARG('V', MUXFLAG_WRITEVOLUME, OPT_ARG_WRITEVOLUME),
	AST_APP_OPTION_ARG('W', MUXFLAG_VOLUME, OPT_ARG_VOLUME),
	AST_APP_OPTION_ARG('r', MUXFLAG_READ, OPT_ARG_READNAME),
	AST_APP_OPTION_ARG('t', MUXFLAG_WRITE, OPT_ARG_WRITENAME),
});

struct mixmonitor_ds {
	unsigned int destruction_ok;
	ast_cond_t destruction_condition;
	ast_mutex_t lock;

	/* The filestream is held in the datastore so it can be stopped
	 * immediately during stop_mixmonitor or channel destruction. */
	int fs_quit;

	struct ast_filestream *fs;
	struct ast_filestream *fs_read;
	struct ast_filestream *fs_write;

	struct ast_audiohook *audiohook;
};

/*!
 * \internal
 * \pre mixmonitor_ds must be locked before calling this function
 */
static void mixmonitor_ds_close_fs(struct mixmonitor_ds *mixmonitor_ds)
{
	unsigned char quitting = 0;

	if (mixmonitor_ds->fs) {
		quitting = 1;
		ast_closestream(mixmonitor_ds->fs);
		mixmonitor_ds->fs = NULL;
		ast_verb(2, "MixMonitor close filestream (mixed)\n");
	}

	if (mixmonitor_ds->fs_read) {
		quitting = 1;
		ast_closestream(mixmonitor_ds->fs_read);
		mixmonitor_ds->fs_read = NULL;
		ast_verb(2, "MixMonitor close filestream (read)\n");
	}

	if (mixmonitor_ds->fs_write) {
		quitting = 1;
		ast_closestream(mixmonitor_ds->fs_write);
		mixmonitor_ds->fs_write = NULL;
		ast_verb(2, "MixMonitor close filestream (write)\n");
	}

	if (quitting) {
		mixmonitor_ds->fs_quit = 1;
	}
}

static void mixmonitor_ds_destroy(void *data)
{
	struct mixmonitor_ds *mixmonitor_ds = data;

	ast_mutex_lock(&mixmonitor_ds->lock);
	mixmonitor_ds->audiohook = NULL;
	mixmonitor_ds->destruction_ok = 1;
	ast_cond_signal(&mixmonitor_ds->destruction_condition);
	ast_mutex_unlock(&mixmonitor_ds->lock);
}

static struct ast_datastore_info mixmonitor_ds_info = {
	.type = "mixmonitor",
	.destroy = mixmonitor_ds_destroy,
};

static void destroy_monitor_audiohook(struct mixmonitor *mixmonitor)
{
	if (mixmonitor->mixmonitor_ds) {
		ast_mutex_lock(&mixmonitor->mixmonitor_ds->lock);
		mixmonitor->mixmonitor_ds->audiohook = NULL;
		ast_mutex_unlock(&mixmonitor->mixmonitor_ds->lock);
	}
	/* kill the audiohook.*/
	ast_audiohook_lock(&mixmonitor->audiohook);
	ast_audiohook_detach(&mixmonitor->audiohook);
	ast_audiohook_unlock(&mixmonitor->audiohook);
	ast_audiohook_destroy(&mixmonitor->audiohook);
}

static int startmon(struct ast_channel *chan, struct ast_audiohook *audiohook) 
{
	struct ast_channel *peer = NULL;
	int res = 0;

	if (!chan)
		return -1;

	ast_audiohook_attach(chan, audiohook);

	if (!res && ast_test_flag(chan, AST_FLAG_NBRIDGE) && (peer = ast_bridged_channel(chan)))
		ast_softhangup(peer, AST_SOFTHANGUP_UNBRIDGE);	

	return res;
}

#define SAMPLES_PER_FRAME 160

static void mixmonitor_free(struct mixmonitor *mixmonitor)
{
	if (mixmonitor) {
		if (mixmonitor->mixmonitor_ds) {
			ast_mutex_destroy(&mixmonitor->mixmonitor_ds->lock);
			ast_cond_destroy(&mixmonitor->mixmonitor_ds->destruction_condition);
			ast_free(mixmonitor->filename_write);
			ast_free(mixmonitor->filename_read);
			ast_free(mixmonitor->mixmonitor_ds);
			ast_free(mixmonitor->name);
			ast_free(mixmonitor->post_process);
		}
		ast_free(mixmonitor);
	}
}

static void mixmonitor_save_prep(struct mixmonitor *mixmonitor, char *filename, struct ast_filestream **fs, unsigned int *oflags, int *errflag)
{
	/* Initialize the file if not already done so */
	char *ext = NULL;
	char *last_slash = NULL;
	if (!ast_strlen_zero(filename)) {
		if (!*fs && !*errflag && !mixmonitor->mixmonitor_ds->fs_quit) {
			*oflags = O_CREAT | O_WRONLY;
			*oflags |= ast_test_flag(mixmonitor, MUXFLAG_APPEND) ? O_APPEND : O_TRUNC;
			
			last_slash = strrchr(filename, '/');

			if ((ext = strrchr(filename, '.')) && (ext > last_slash)) {
				*(ext++) = '\0';
			} else {
				ext = "raw";
			}

			if (!(*fs = ast_writefile(filename, ext, NULL, *oflags, 0, 0666))) {
				ast_log(LOG_ERROR, "Cannot open %s.%s\n", filename, ext);
				*errflag = 1;
			}
		}
	}
}

static void *mixmonitor_thread(void *obj) 
{
	struct mixmonitor *mixmonitor = obj;

	struct ast_filestream **fs = NULL;
	struct ast_filestream **fs_read = NULL;
	struct ast_filestream **fs_write = NULL;

	unsigned int oflags;
	int errflag = 0;
	struct ast_format format_slin;

	ast_format_set(&format_slin, AST_FORMAT_SLINEAR, 0);
	ast_verb(2, "Begin MixMonitor Recording %s\n", mixmonitor->name);

	fs = &mixmonitor->mixmonitor_ds->fs;
	fs_read = &mixmonitor->mixmonitor_ds->fs_read;
	fs_write = &mixmonitor->mixmonitor_ds->fs_write;

	/* The audiohook must enter and exit the loop locked */
	ast_audiohook_lock(&mixmonitor->audiohook);
	while (mixmonitor->audiohook.status == AST_AUDIOHOOK_STATUS_RUNNING && !mixmonitor->mixmonitor_ds->fs_quit) {
		struct ast_frame *fr = NULL;
		struct ast_frame *fr_read = NULL;
		struct ast_frame *fr_write = NULL;

		if (!(fr = ast_audiohook_read_frame_all(&mixmonitor->audiohook, SAMPLES_PER_FRAME, &format_slin,
						&fr_read, &fr_write))) {
			ast_audiohook_trigger_wait(&mixmonitor->audiohook);

			if (mixmonitor->audiohook.status != AST_AUDIOHOOK_STATUS_RUNNING) {
				break;
			}
			continue;
		}

		/* audiohook lock is not required for the next block.
		 * Unlock it, but remember to lock it before looping or exiting */
		ast_audiohook_unlock(&mixmonitor->audiohook);

		if (!ast_test_flag(mixmonitor, MUXFLAG_BRIDGED) || (mixmonitor->autochan->chan && ast_bridged_channel(mixmonitor->autochan->chan))) {
			ast_mutex_lock(&mixmonitor->mixmonitor_ds->lock);
			mixmonitor_save_prep(mixmonitor, mixmonitor->filename, fs, &oflags, &errflag);
			mixmonitor_save_prep(mixmonitor, mixmonitor->filename_read, fs_read, &oflags, &errflag);
			mixmonitor_save_prep(mixmonitor, mixmonitor->filename_write, fs_write, &oflags, &errflag);

			/* Write out the frame(s) */
			if ((*fs_read) && (fr_read)) {
				struct ast_frame *cur;

				for (cur = fr_read; cur; cur = AST_LIST_NEXT(cur, frame_list)) {
					ast_writestream(*fs_read, cur);
				}
			}

			if ((*fs_write) && (fr_write)) {
				struct ast_frame *cur;

				for (cur = fr_write; cur; cur = AST_LIST_NEXT(cur, frame_list)) {
					ast_writestream(*fs_write, cur);
				}
			}

			if ((*fs) && (fr)) {
				struct ast_frame *cur;

				for (cur = fr; cur; cur = AST_LIST_NEXT(cur, frame_list)) {
					ast_writestream(*fs, cur);
				}
			}
			ast_mutex_unlock(&mixmonitor->mixmonitor_ds->lock);
		}
		/* All done! free it. */
		if (fr) {
			ast_frame_free(fr, 0);
		}
		if (fr_read) {
			ast_frame_free(fr_read, 0);
		}
		if (fr_write) {
			ast_frame_free(fr_write, 0);
		}

		fr = NULL;
		fr_write = NULL;
		fr_read = NULL;

		ast_audiohook_lock(&mixmonitor->audiohook);
	}
	ast_audiohook_unlock(&mixmonitor->audiohook);

	ast_autochan_destroy(mixmonitor->autochan);

	/* Datastore cleanup.  close the filestream and wait for ds destruction */
	ast_mutex_lock(&mixmonitor->mixmonitor_ds->lock);
	mixmonitor_ds_close_fs(mixmonitor->mixmonitor_ds);
	if (!mixmonitor->mixmonitor_ds->destruction_ok) {
		ast_cond_wait(&mixmonitor->mixmonitor_ds->destruction_condition, &mixmonitor->mixmonitor_ds->lock);
	}
	ast_mutex_unlock(&mixmonitor->mixmonitor_ds->lock);

	/* kill the audiohook */
	destroy_monitor_audiohook(mixmonitor);

	if (mixmonitor->post_process) {
		ast_verb(2, "Executing [%s]\n", mixmonitor->post_process);
		ast_safe_system(mixmonitor->post_process);
	}

	ast_verb(2, "End MixMonitor Recording %s\n", mixmonitor->name);
	mixmonitor_free(mixmonitor);
	return NULL;
}

static int setup_mixmonitor_ds(struct mixmonitor *mixmonitor, struct ast_channel *chan)
{
	struct ast_datastore *datastore = NULL;
	struct mixmonitor_ds *mixmonitor_ds;

	if (!(mixmonitor_ds = ast_calloc(1, sizeof(*mixmonitor_ds)))) {
		return -1;
	}

	ast_mutex_init(&mixmonitor_ds->lock);
	ast_cond_init(&mixmonitor_ds->destruction_condition, NULL);

	if (!(datastore = ast_datastore_alloc(&mixmonitor_ds_info, NULL))) {
		ast_mutex_destroy(&mixmonitor_ds->lock);
		ast_cond_destroy(&mixmonitor_ds->destruction_condition);
		ast_free(mixmonitor_ds);
		return -1;
	}

	mixmonitor_ds->audiohook = &mixmonitor->audiohook;
	datastore->data = mixmonitor_ds;

	ast_channel_lock(chan);
	ast_channel_datastore_add(chan, datastore);
	ast_channel_unlock(chan);

	mixmonitor->mixmonitor_ds = mixmonitor_ds;
	return 0;
}

static void launch_monitor_thread(struct ast_channel *chan, const char *filename,
				  unsigned int flags, int readvol, int writevol,
				  const char *post_process, const char *filename_write,
				  const char *filename_read) 
{
	pthread_t thread;
	struct mixmonitor *mixmonitor;
	char postprocess2[1024] = "";

	postprocess2[0] = 0;
	/* If a post process system command is given attach it to the structure */
	if (!ast_strlen_zero(post_process)) {
		char *p1, *p2;

		p1 = ast_strdupa(post_process);
		for (p2 = p1; *p2; p2++) {
			if (*p2 == '^' && *(p2+1) == '{') {
				*p2 = '$';
			}
		}
		pbx_substitute_variables_helper(chan, p1, postprocess2, sizeof(postprocess2) - 1);
	}

	/* Pre-allocate mixmonitor structure and spy */
	if (!(mixmonitor = ast_calloc(1, sizeof(*mixmonitor)))) {
		return;
	}

	/* Setup the actual spy before creating our thread */
	if (ast_audiohook_init(&mixmonitor->audiohook, AST_AUDIOHOOK_TYPE_SPY, mixmonitor_spy_type, 0)) {
		mixmonitor_free(mixmonitor);
		return;
	}

	/* Copy over flags and channel name */
	mixmonitor->flags = flags;
	if (!(mixmonitor->autochan = ast_autochan_setup(chan))) {
		mixmonitor_free(mixmonitor);
		return;
	}

	if (setup_mixmonitor_ds(mixmonitor, chan)) {
		ast_autochan_destroy(mixmonitor->autochan);
		mixmonitor_free(mixmonitor);
		return;
	}

	mixmonitor->name = ast_strdup(chan->name);

	if (!ast_strlen_zero(postprocess2)) {
		mixmonitor->post_process = ast_strdup(postprocess2);
	}

	if (!ast_strlen_zero(filename)) {
		mixmonitor->filename = ast_strdup(filename);
	}

	if (!ast_strlen_zero(filename_write)) {
		mixmonitor->filename_write = ast_strdup(filename_write);
	}

	if (!ast_strlen_zero(filename_read)) {
		mixmonitor->filename_read = ast_strdup(filename_read);
	}

	ast_set_flag(&mixmonitor->audiohook, AST_AUDIOHOOK_TRIGGER_SYNC);

	if (readvol)
		mixmonitor->audiohook.options.read_volume = readvol;
	if (writevol)
		mixmonitor->audiohook.options.write_volume = writevol;

	if (startmon(chan, &mixmonitor->audiohook)) {
		ast_log(LOG_WARNING, "Unable to add '%s' spy to channel '%s'\n",
			mixmonitor_spy_type, chan->name);
		ast_audiohook_destroy(&mixmonitor->audiohook);
		mixmonitor_free(mixmonitor);
		return;
	}

	ast_pthread_create_detached_background(&thread, NULL, mixmonitor_thread, mixmonitor);
}

/* a note on filename_parse: creates directory structure and assigns absolute path from relative paths for filenames */
/* requires immediate copying of string from return to retain data since otherwise it will immediately lose scope */
static char *filename_parse(char *filename, char *buffer, size_t len)
{
	char *slash;
	if (ast_strlen_zero(filename)) {
		ast_log(LOG_WARNING, "No file name was provided for a file save option.\n");
	} else if (filename[0] != '/') {
		char *build;
		build = alloca(strlen(ast_config_AST_MONITOR_DIR) + strlen(filename) + 3);
		sprintf(build, "%s/%s", ast_config_AST_MONITOR_DIR, filename);
		filename = build;
	}

	ast_copy_string(buffer, filename, len);

	if ((slash = strrchr(filename, '/'))) {
		*slash = '\0';
	}
	ast_mkdir(filename, 0777);

	return buffer;
}

static int mixmonitor_exec(struct ast_channel *chan, const char *data)
{
	int x, readvol = 0, writevol = 0;
	char *filename_read = NULL;
	char *filename_write = NULL;
	char filename_buffer[1024] = "";

	struct ast_flags flags = { 0 };
	char *parse;
	AST_DECLARE_APP_ARGS(args,
		AST_APP_ARG(filename);
		AST_APP_ARG(options);
		AST_APP_ARG(post_process);
	);
	
	if (ast_strlen_zero(data)) {
		ast_log(LOG_WARNING, "MixMonitor requires an argument (filename or ,t(filename) and/or r(filename)\n");
		return -1;
	}

	parse = ast_strdupa(data);

	AST_STANDARD_APP_ARGS(args, parse);

	if (args.options) {
		char *opts[OPT_ARG_ARRAY_SIZE] = { NULL, };

		ast_app_parse_options(mixmonitor_opts, &flags, opts, args.options);

		if (ast_test_flag(&flags, MUXFLAG_READVOLUME)) {
			if (ast_strlen_zero(opts[OPT_ARG_READVOLUME])) {
				ast_log(LOG_WARNING, "No volume level was provided for the heard volume ('v') option.\n");
			} else if ((sscanf(opts[OPT_ARG_READVOLUME], "%2d", &x) != 1) || (x < -4) || (x > 4)) {
				ast_log(LOG_NOTICE, "Heard volume must be a number between -4 and 4, not '%s'\n", opts[OPT_ARG_READVOLUME]);
			} else {
				readvol = get_volfactor(x);
			}
		}
		
		if (ast_test_flag(&flags, MUXFLAG_WRITEVOLUME)) {
			if (ast_strlen_zero(opts[OPT_ARG_WRITEVOLUME])) {
				ast_log(LOG_WARNING, "No volume level was provided for the spoken volume ('V') option.\n");
			} else if ((sscanf(opts[OPT_ARG_WRITEVOLUME], "%2d", &x) != 1) || (x < -4) || (x > 4)) {
				ast_log(LOG_NOTICE, "Spoken volume must be a number between -4 and 4, not '%s'\n", opts[OPT_ARG_WRITEVOLUME]);
			} else {
				writevol = get_volfactor(x);
			}
		}
		
		if (ast_test_flag(&flags, MUXFLAG_VOLUME)) {
			if (ast_strlen_zero(opts[OPT_ARG_VOLUME])) {
				ast_log(LOG_WARNING, "No volume level was provided for the combined volume ('W') option.\n");
			} else if ((sscanf(opts[OPT_ARG_VOLUME], "%2d", &x) != 1) || (x < -4) || (x > 4)) {
				ast_log(LOG_NOTICE, "Combined volume must be a number between -4 and 4, not '%s'\n", opts[OPT_ARG_VOLUME]);
			} else {
				readvol = writevol = get_volfactor(x);
			}
		}

		if (ast_test_flag(&flags, MUXFLAG_WRITE)) {
			filename_write = ast_strdupa(filename_parse(opts[OPT_ARG_WRITENAME], filename_buffer, sizeof(filename_buffer)));
		}

		if (ast_test_flag(&flags, MUXFLAG_READ)) {
			filename_read = ast_strdupa(filename_parse(opts[OPT_ARG_READNAME], filename_buffer, sizeof(filename_buffer)));
		}
	}

	/* If there are no file writing arguments/options for the mix monitor, send a warning message and return -1 */

	if (!ast_test_flag(&flags, MUXFLAG_WRITE) && !ast_test_flag(&flags, MUXFLAG_READ) && ast_strlen_zero(args.filename)) {
		ast_log(LOG_WARNING, "MixMonitor requires an argument (filename)\n");
		return -1;
	}

	/* If filename exists, try to create directories for it */
	if (!(ast_strlen_zero(args.filename))) {
		args.filename = ast_strdupa(filename_parse(args.filename, filename_buffer, sizeof(filename_buffer)));
	}

	pbx_builtin_setvar_helper(chan, "MIXMONITOR_FILENAME", args.filename);
	launch_monitor_thread(chan, args.filename, flags.flags, readvol, writevol, args.post_process, filename_write, filename_read);

	return 0;
}

static int stop_mixmonitor_exec(struct ast_channel *chan, const char *data)
{
	struct ast_datastore *datastore = NULL;

	ast_channel_lock(chan);
	ast_audiohook_detach_source(chan, mixmonitor_spy_type);
	if ((datastore = ast_channel_datastore_find(chan, &mixmonitor_ds_info, NULL))) {
		struct mixmonitor_ds *mixmonitor_ds = datastore->data;

		ast_mutex_lock(&mixmonitor_ds->lock);

		/* closing the filestream here guarantees the file is avaliable to the dialplan
	 	 * after calling StopMixMonitor */
		mixmonitor_ds_close_fs(mixmonitor_ds);

		/* The mixmonitor thread may be waiting on the audiohook trigger.
		 * In order to exit from the mixmonitor loop before waiting on channel
		 * destruction, poke the audiohook trigger. */
		if (mixmonitor_ds->audiohook) {
			ast_audiohook_lock(mixmonitor_ds->audiohook);
			ast_cond_signal(&mixmonitor_ds->audiohook->trigger);
			ast_audiohook_unlock(mixmonitor_ds->audiohook);
			mixmonitor_ds->audiohook = NULL;
		}

		ast_mutex_unlock(&mixmonitor_ds->lock);

		/* Remove the datastore so the monitor thread can exit */
		if (!ast_channel_datastore_remove(chan, datastore)) {
			ast_datastore_free(datastore);
		}
	}
	ast_channel_unlock(chan);

	return 0;
}

static char *handle_cli_mixmonitor(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	struct ast_channel *chan;

	switch (cmd) {
	case CLI_INIT:
		e->command = "mixmonitor {start|stop}";
		e->usage =
			"Usage: mixmonitor <start|stop> <chan_name> [args]\n"
			"       The optional arguments are passed to the MixMonitor\n"
			"       application when the 'start' command is used.\n";
		return NULL;
	case CLI_GENERATE:
		return ast_complete_channels(a->line, a->word, a->pos, a->n, 2);
	}

	if (a->argc < 3)
		return CLI_SHOWUSAGE;

	if (!(chan = ast_channel_get_by_name_prefix(a->argv[2], strlen(a->argv[2])))) {
		ast_cli(a->fd, "No channel matching '%s' found.\n", a->argv[2]);
		/* Technically this is a failure, but we don't want 2 errors printing out */
		return CLI_SUCCESS;
	}

	ast_channel_lock(chan);

	if (!strcasecmp(a->argv[1], "start")) {
		mixmonitor_exec(chan, a->argv[3]);
		ast_channel_unlock(chan);
	} else {
		ast_channel_unlock(chan);
		ast_audiohook_detach_source(chan, mixmonitor_spy_type);
	}

	chan = ast_channel_unref(chan);

	return CLI_SUCCESS;
}

/*! \brief  Mute / unmute  a MixMonitor channel */
static int manager_mute_mixmonitor(struct mansession *s, const struct message *m)
{
	struct ast_channel *c = NULL;

	const char *name = astman_get_header(m, "Channel");
	const char *id = astman_get_header(m, "ActionID");
	const char *state = astman_get_header(m, "State");
	const char *direction = astman_get_header(m,"Direction");

	int clearmute = 1;

	enum ast_audiohook_flags flag;

	if (ast_strlen_zero(direction)) {
		astman_send_error(s, m, "No direction specified. Must be read, write or both");
		return AMI_SUCCESS;
	}

	if (!strcasecmp(direction, "read")) {
		flag = AST_AUDIOHOOK_MUTE_READ;
	} else  if (!strcasecmp(direction, "write")) {
		flag = AST_AUDIOHOOK_MUTE_WRITE;
	} else  if (!strcasecmp(direction, "both")) {
		flag = AST_AUDIOHOOK_MUTE_READ | AST_AUDIOHOOK_MUTE_WRITE;
	} else {
		astman_send_error(s, m, "Invalid direction specified. Must be read, write or both");
		return AMI_SUCCESS;
	}

	if (ast_strlen_zero(name)) {
		astman_send_error(s, m, "No channel specified");
		return AMI_SUCCESS;
	}

	if (ast_strlen_zero(state)) {
		astman_send_error(s, m, "No state specified");
		return AMI_SUCCESS;
	}

	clearmute = ast_false(state);
	c = ast_channel_get_by_name(name);

	if (!c) {
		astman_send_error(s, m, "No such channel");
		return AMI_SUCCESS;
	}

	if (ast_audiohook_set_mute(c, mixmonitor_spy_type, flag, clearmute)) {
		c = ast_channel_unref(c);
		astman_send_error(s, m, "Cannot set mute flag");
		return AMI_SUCCESS;
	}

	astman_append(s, "Response: Success\r\n");

	if (!ast_strlen_zero(id)) {
		astman_append(s, "ActionID: %s\r\n", id);
	}

	astman_append(s, "\r\n");

	c = ast_channel_unref(c);

	return AMI_SUCCESS;
}

static struct ast_cli_entry cli_mixmonitor[] = {
	AST_CLI_DEFINE(handle_cli_mixmonitor, "Execute a MixMonitor command")
};

static int unload_module(void)
{
	int res;

	ast_cli_unregister_multiple(cli_mixmonitor, ARRAY_LEN(cli_mixmonitor));
	res = ast_unregister_application(stop_app);
	res |= ast_unregister_application(app);
	res |= ast_manager_unregister("MixMonitorMute");
	
	return res;
}

static int load_module(void)
{
	int res;

	ast_cli_register_multiple(cli_mixmonitor, ARRAY_LEN(cli_mixmonitor));
	res = ast_register_application_xml(app, mixmonitor_exec);
	res |= ast_register_application_xml(stop_app, stop_mixmonitor_exec);
	res |= ast_manager_register_xml("MixMonitorMute", 0, manager_mute_mixmonitor);

	return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Mixed Audio Monitoring Application");