app_milliwatt.c

Go to the documentation of this file.

/*
 * 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 Digital Milliwatt Test
 *
 * \author Mark Spencer <[email protected]>
 *
 * \ingroup applications
 */

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

#include "asterisk.h"

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/indications.h"
#include "asterisk/format_cache.h"

/*** DOCUMENTATION
 <application name="Milliwatt" language="en_US">
 <synopsis>
 Generate a Constant 1004Hz tone at 0dbm (mu-law).
 </synopsis>
 <syntax>
 <parameter name="options">
 <optionlist>
 <option name="o">
 <para>Generate the tone at 1000Hz like previous version.</para>
 </option>
 </optionlist>
 </parameter>
 </syntax>
 <description>
 <para>Previous versions of this application generated the tone at 1000Hz. If for
 some reason you would prefer that behavior, supply the <literal>o</literal> option to get the
 old behavior.</para>
 </description>
 </application>
 ***/

static const char app[] = "Milliwatt";

static const char digital_milliwatt[] = {0x1e,0x0b,0x0b,0x1e,0x9e,0x8b,0x8b,0x9e} ;

static void *milliwatt_alloc(struct ast_channel *chan, void *params)
{
 return ast_calloc(1, sizeof(int));
}

static void milliwatt_release(struct ast_channel *chan, void *data)
{
 ast_free(data);
 return;
}

static int milliwatt_generate(struct ast_channel *chan, void *data, int len, int samples)
{
 unsigned char buf[AST_FRIENDLY_OFFSET + 640];
 const int maxsamples = ARRAY_LEN(buf) - (AST_FRIENDLY_OFFSET / sizeof(buf[0]));
 int i, *indexp = (int *) data, res;
 struct ast_frame wf = {
 .frametype = AST_FRAME_VOICE,
 .offset = AST_FRIENDLY_OFFSET,
 .src = __FUNCTION__,
 };

 wf.subclass.format = ast_format_ulaw;
 wf.data.ptr = buf + AST_FRIENDLY_OFFSET;

 /* Instead of len, use samples, because channel.c generator_force
 * generate(chan, tmp, 0, 160) ignores len. In any case, len is
 * a multiple of samples, given by number of samples times bytes per
 * sample. In the case of ulaw, len = samples. for signed linear
 * len = 2 * samples */
 if (samples > maxsamples) {
 ast_log(LOG_WARNING, "Only doing %d samples (%d requested)\n", maxsamples, samples);
 samples = maxsamples;
 }

 len = samples * sizeof (buf[0]);
 wf.datalen = len;
 wf.samples = samples;

 /* create a buffer containing the digital milliwatt pattern */
 for (i = 0; i < len; i++) {
 buf[AST_FRIENDLY_OFFSET + i] = digital_milliwatt[(*indexp)++];
 *indexp &= 7;
 }

 res = ast_write(chan, &wf);
 ast_frfree(&wf);

 if (res < 0) {
 ast_log(LOG_WARNING,"Failed to write frame to '%s': %s\n",ast_channel_name(chan),strerror(errno));
 return -1;
 }

 return 0;
}

static struct ast_generator milliwattgen = {
 .alloc = milliwatt_alloc,
 .release = milliwatt_release,
 .generate = milliwatt_generate,
};

static int old_milliwatt_exec(struct ast_channel *chan)
{
 ast_set_write_format(chan, ast_format_ulaw);
 ast_set_read_format(chan, ast_format_ulaw);

 if (ast_channel_state(chan) != AST_STATE_UP) {
 ast_answer(chan);
 }

 if (ast_activate_generator(chan,&milliwattgen,"milliwatt") < 0) {
 ast_log(LOG_WARNING,"Failed to activate generator on '%s'\n",ast_channel_name(chan));
 return -1;
 }

 while (!ast_safe_sleep(chan, 10000))
 ;

 ast_deactivate_generator(chan);

 return -1;
}

static int milliwatt_exec(struct ast_channel *chan, const char *data)
{
 const char *options = data;
 int res = -1;

 if (!ast_strlen_zero(options) && strchr(options, 'o')) {
 return old_milliwatt_exec(chan);
 }

 res = ast_playtones_start(chan, 23255, "1004/1000", 0);

 while (!res) {
 res = ast_safe_sleep(chan, 10000);
 }

 return res;
}

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

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

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Digital Milliwatt (mu-law) Test Application");