app_mp3.c

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/*
 * 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 Silly application to play an MP3 file -- uses mpg123
 *
 * \author Mark Spencer <[email protected]>
 *
 * \note Add feature to play local M3U playlist file
 * Vincent Li <[email protected]>
 *
 * \ingroup applications
 */

/*** MODULEINFO
   <support_level>extended</support_level>
 ***/

#include "asterisk.h"

#include <sys/time.h>
#include <sys/types.h>
#include <signal.h>

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/frame.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/app.h"
#include "asterisk/format_cache.h"

#define LOCAL_MPG_123 "/usr/local/bin/mpg123"
#define MPG_123 "/usr/bin/mpg123"

/*** DOCUMENTATION
   <application name="MP3Player" language="en_US">
      <synopsis>
         Play an MP3 file or M3U playlist file or stream.
      </synopsis>
      <syntax>
         <parameter name="Location" required="true">
            <para>Location of the file to be played.
            (argument passed to mpg123)</para>
         </parameter>
      </syntax>
      <description>
         <para>Executes mpg123 to play the given location, which typically would be a mp3 filename
         or m3u playlist filename or a URL. Please read http://en.wikipedia.org/wiki/M3U
         to see how M3U playlist file format is like, Example usage would be
         exten => 1234,1,MP3Player(/var/lib/asterisk/playlist.m3u)
         User can exit by pressing any key on the dialpad, or by hanging up.</para>
         <para>This application does not automatically answer and should be preceeded by an
         application such as Answer() or Progress().</para>
      </description>
   </application>

 ***/
static char *app = "MP3Player";

static int mp3play(const char *filename, unsigned int sampling_rate, int fd)
{
   int res;
   char sampling_rate_str[8];

   res = ast_safe_fork(0);
   if (res < 0)
      ast_log(LOG_WARNING, "Fork failed\n");
   if (res) {
      return res;
   }
   if (ast_opt_high_priority)
      ast_set_priority(0);

   dup2(fd, STDOUT_FILENO);
   ast_close_fds_above_n(STDERR_FILENO);

   snprintf(sampling_rate_str, 8, "%u", sampling_rate);

   /* Execute mpg123, but buffer if it's a net connection */
   if (!strncasecmp(filename, "http://", 7) && strstr(filename, ".m3u")) {
       char buffer_size_str[8];
       snprintf(buffer_size_str, 8, "%u", (int) 0.5*2*sampling_rate/1000); // 0.5 seconds for a live stream
      /* Most commonly installed in /usr/local/bin */
       execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
      /* But many places has it in /usr/bin */
       execl(MPG_123, "mpg123", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
      /* As a last-ditch effort, try to use PATH */
       execlp("mpg123", "mpg123", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
   }
   else if (!strncasecmp(filename, "http://", 7)) {
       char buffer_size_str[8];
       snprintf(buffer_size_str, 8, "%u", 6*2*sampling_rate/1000); // 6 seconds for a remote MP3 file
      /* Most commonly installed in /usr/local/bin */
       execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
      /* But many places has it in /usr/bin */
       execl(MPG_123, "mpg123", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
      /* As a last-ditch effort, try to use PATH */
       execlp("mpg123", "mpg123", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
   }
   else if (strstr(filename, ".m3u")) {
      /* Most commonly installed in /usr/local/bin */
       execl(LOCAL_MPG_123, "mpg123", "-q", "-z", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
      /* But many places has it in /usr/bin */
       execl(MPG_123, "mpg123", "-q", "-z", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
      /* As a last-ditch effort, try to use PATH */
       execlp("mpg123", "mpg123", "-q", "-z", "-s",  "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
   }
   else {
      /* Most commonly installed in /usr/local/bin */
       execl(MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
      /* But many places has it in /usr/bin */
       execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
      /* As a last-ditch effort, try to use PATH */
       execlp("mpg123", "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
   }
   /* Can't use ast_log since FD's are closed */
   fprintf(stderr, "Execute of mpg123 failed\n");
   _exit(0);
}

static int timed_read(int fd, void *data, int datalen, int timeout, int pid)
{
   int res;
   int i;
   struct pollfd fds[1];
   fds[0].fd = fd;
   fds[0].events = POLLIN;
   for (i = 0; i < timeout; i++) {
      res = ast_poll(fds, 1, 1000);
      if (res > 0) {
         break;
      } else if (res == 0) {
         /* is mpg123 still running? */
         kill(pid, 0);
         if (errno == ESRCH) {
            return -1;
         }
      } else {
         ast_log(LOG_NOTICE, "error polling mpg123: %s\n", strerror(errno));
         return -1;
      }
   }

   if (i == timeout) {
      ast_log(LOG_NOTICE, "Poll timed out.\n");
      return -1;
   }

   return read(fd, data, datalen);

}

static int mp3_exec(struct ast_channel *chan, const char *data)
{
   int res=0;
   int fds[2];
   int ms = -1;
   int pid = -1;
   RAII_VAR(struct ast_format *, owriteformat, NULL, ao2_cleanup);
   int timeout = 2;
   struct timeval next;
   struct ast_frame *f;
   struct myframe {
      struct ast_frame f;
      char offset[AST_FRIENDLY_OFFSET];
      short frdata[160];
   } myf = {
      .f = { 0, },
   };
   struct ast_format * native_format;
   unsigned int sampling_rate;
   struct ast_format * write_format;

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "MP3 Playback requires an argument (filename)\n");
      return -1;
   }

   if (pipe(fds)) {
      ast_log(LOG_WARNING, "Unable to create pipe\n");
      return -1;
   }

   ast_stopstream(chan);

   native_format = ast_format_cap_get_format(ast_channel_nativeformats(chan), 0);
   sampling_rate = ast_format_get_sample_rate(native_format);
   write_format = ast_format_cache_get_slin_by_rate(sampling_rate);

   owriteformat = ao2_bump(ast_channel_writeformat(chan));
   res = ast_set_write_format(chan, write_format);
   if (res < 0) {
      ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
      return -1;
   }

   myf.f.frametype = AST_FRAME_VOICE;
   myf.f.subclass.format = write_format;
   myf.f.mallocd = 0;
   myf.f.offset = AST_FRIENDLY_OFFSET;
   myf.f.src = __PRETTY_FUNCTION__;
   myf.f.delivery.tv_sec = 0;
   myf.f.delivery.tv_usec = 0;
   myf.f.data.ptr = myf.frdata;

   res = mp3play(data, sampling_rate, fds[1]);
   if (!strncasecmp(data, "http://", 7)) {
      timeout = 10;
   }
   /* Wait 1000 ms first */
   next = ast_tvnow();
   next.tv_sec += 1;
   if (res >= 0) {
      pid = res;
      /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
         user */
      for (;;) {
         ms = ast_tvdiff_ms(next, ast_tvnow());
         if (ms <= 0) {
            res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata), timeout, pid);
            if (res > 0) {
               myf.f.datalen = res;
               myf.f.samples = res / 2;
               if (ast_write(chan, &myf.f) < 0) {
                  res = -1;
                  break;
               }
            } else {
               ast_debug(1, "No more mp3\n");
               res = 0;
               break;
            }
            next = ast_tvadd(next, ast_samp2tv(myf.f.samples, sampling_rate));
         } else {
            ms = ast_waitfor(chan, ms);
            if (ms < 0) {
               ast_debug(1, "Hangup detected\n");
               res = -1;
               break;
            }
            if (ms) {
               f = ast_read(chan);
               if (!f) {
                  ast_debug(1, "Null frame == hangup() detected\n");
                  res = -1;
                  break;
               }
               if (f->frametype == AST_FRAME_DTMF) {
                  ast_debug(1, "User pressed a key\n");
                  ast_frfree(f);
                  res = 0;
                  break;
               }
               ast_frfree(f);
            }
         }
      }
   }
   close(fds[0]);
   close(fds[1]);

   if (pid > -1)
      kill(pid, SIGKILL);
   if (!res && owriteformat)
      ast_set_write_format(chan, owriteformat);

   ast_frfree(&myf.f);

   return res;
}

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

static int load_module(void)
{
   return ast_register_application_xml(app, mp3_exec);
}

AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "Silly MP3 Application");