app_milliwatt.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 Digital Milliwatt Test
 *
 * \author Mark Spencer <markster@digium.com>
 * 
 * \ingroup applications
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 209842 $")

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/indications.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 char *app = "Milliwatt";

static 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);
   int i, *indexp = (int *) data;
   struct ast_frame wf = {
      .frametype = AST_FRAME_VOICE,
      .subclass = AST_FORMAT_ULAW,
      .offset = AST_FRIENDLY_OFFSET,
      .src = __FUNCTION__,
   };
   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;
   }

   if (ast_write(chan,&wf) < 0) {
      ast_log(LOG_WARNING,"Failed to write frame to '%s': %s\n",chan->name,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 (chan->_state != 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",chan->name);
      return -1;
   }

   while (!ast_safe_sleep(chan, 10000))
      ;

   ast_deactivate_generator(chan);

   return -1;
}

static int milliwatt_exec(struct ast_channel *chan, void *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");