app_echo.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 Echo application -- play back what you hear to evaluate latency
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \ingroup applications
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 149589 $")

#include "asterisk/file.h"
#include "asterisk/module.h"
#include "asterisk/channel.h"

static char *app = "Echo";

static char *synopsis = "Echo audio, video, or DTMF back to the calling party";

static char *descrip =
"  Echo(): This application will echo any audio, video, or DTMF frames read from\n"
"the calling channel back to itself. If the DTMF digit '#' is received, the\n"
"application will exit.\n";


static int echo_exec(struct ast_channel *chan, void *data)
{
   int res = -1;
   int format;

   format = ast_best_codec(chan->nativeformats);
   ast_set_write_format(chan, format);
   ast_set_read_format(chan, format);

   while (ast_waitfor(chan, -1) > -1) {
      struct ast_frame *f = ast_read(chan);
      if (!f) {
         break;
      }
      f->delivery.tv_sec = 0;
      f->delivery.tv_usec = 0;
      if (ast_write(chan, f)) {
         ast_frfree(f);
         goto end;
      }
      if ((f->frametype == AST_FRAME_DTMF) && (f->subclass == '#')) {
         res = 0;
         ast_frfree(f);
         goto end;
      }
      ast_frfree(f);
   }
end:
   return res;
}

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

static int load_module(void)
{
   return ast_register_application(app, echo_exec, synopsis, descrip);
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Simple Echo Application");