Thu Apr 28 2011 17:13:28

Asterisk developer's documentation


app_mp3.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief Silly application to play an MP3 file -- uses mpg123
00022  *
00023  * \author Mark Spencer <markster@digium.com>
00024  * 
00025  * \ingroup applications
00026  */
00027  
00028 #include "asterisk.h"
00029 
00030 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 238013 $")
00031 
00032 #include <sys/time.h>
00033 #include <signal.h>
00034 
00035 #include "asterisk/lock.h"
00036 #include "asterisk/file.h"
00037 #include "asterisk/channel.h"
00038 #include "asterisk/frame.h"
00039 #include "asterisk/pbx.h"
00040 #include "asterisk/module.h"
00041 #include "asterisk/translate.h"
00042 #include "asterisk/app.h"
00043 
00044 #define LOCAL_MPG_123 "/usr/local/bin/mpg123"
00045 #define MPG_123 "/usr/bin/mpg123"
00046 
00047 /*** DOCUMENTATION
00048    <application name="MP3Player" language="en_US">
00049       <synopsis>
00050          Play an MP3 file or stream.
00051       </synopsis>
00052       <syntax>
00053          <parameter name="Location" required="true">
00054             <para>Location of the file to be played.
00055             (argument passed to mpg123)</para>
00056          </parameter>
00057       </syntax>
00058       <description>
00059          <para>Executes mpg123 to play the given location, which typically would be a filename or a URL.
00060          User can exit by pressing any key on the dialpad, or by hanging up.</para>
00061       </description>
00062    </application>
00063 
00064  ***/
00065 static char *app = "MP3Player";
00066 
00067 static int mp3play(char *filename, int fd)
00068 {
00069    int res;
00070 
00071    res = ast_safe_fork(0);
00072    if (res < 0) 
00073       ast_log(LOG_WARNING, "Fork failed\n");
00074    if (res) {
00075       return res;
00076    }
00077    if (ast_opt_high_priority)
00078       ast_set_priority(0);
00079 
00080    dup2(fd, STDOUT_FILENO);
00081    ast_close_fds_above_n(STDERR_FILENO);
00082 
00083    /* Execute mpg123, but buffer if it's a net connection */
00084    if (!strncasecmp(filename, "http://", 7)) {
00085       /* Most commonly installed in /usr/local/bin */
00086        execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-b", "1024", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00087       /* But many places has it in /usr/bin */
00088        execl(MPG_123, "mpg123", "-q", "-s", "-b", "1024","-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00089       /* As a last-ditch effort, try to use PATH */
00090        execlp("mpg123", "mpg123", "-q", "-s", "-b", "1024",  "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00091    }
00092    else {
00093       /* Most commonly installed in /usr/local/bin */
00094        execl(MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00095       /* But many places has it in /usr/bin */
00096        execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00097       /* As a last-ditch effort, try to use PATH */
00098        execlp("mpg123", "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00099    }
00100    /* Can't use ast_log since FD's are closed */
00101    fprintf(stderr, "Execute of mpg123 failed\n");
00102    _exit(0);
00103 }
00104 
00105 static int timed_read(int fd, void *data, int datalen, int timeout)
00106 {
00107    int res;
00108    struct pollfd fds[1];
00109    fds[0].fd = fd;
00110    fds[0].events = POLLIN;
00111    res = ast_poll(fds, 1, timeout);
00112    if (res < 1) {
00113       ast_log(LOG_NOTICE, "Poll timed out/errored out with %d\n", res);
00114       return -1;
00115    }
00116    return read(fd, data, datalen);
00117    
00118 }
00119 
00120 static int mp3_exec(struct ast_channel *chan, void *data)
00121 {
00122    int res=0;
00123    int fds[2];
00124    int ms = -1;
00125    int pid = -1;
00126    int owriteformat;
00127    int timeout = 2000;
00128    struct timeval next;
00129    struct ast_frame *f;
00130    struct myframe {
00131       struct ast_frame f;
00132       char offset[AST_FRIENDLY_OFFSET];
00133       short frdata[160];
00134    } myf = {
00135       .f = { 0, },
00136    };
00137 
00138    if (ast_strlen_zero(data)) {
00139       ast_log(LOG_WARNING, "MP3 Playback requires an argument (filename)\n");
00140       return -1;
00141    }
00142 
00143    if (pipe(fds)) {
00144       ast_log(LOG_WARNING, "Unable to create pipe\n");
00145       return -1;
00146    }
00147    
00148    ast_stopstream(chan);
00149 
00150    owriteformat = chan->writeformat;
00151    res = ast_set_write_format(chan, AST_FORMAT_SLINEAR);
00152    if (res < 0) {
00153       ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
00154       return -1;
00155    }
00156    
00157    res = mp3play((char *)data, fds[1]);
00158    if (!strncasecmp((char *)data, "http://", 7)) {
00159       timeout = 10000;
00160    }
00161    /* Wait 1000 ms first */
00162    next = ast_tvnow();
00163    next.tv_sec += 1;
00164    if (res >= 0) {
00165       pid = res;
00166       /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
00167          user */
00168       for (;;) {
00169          ms = ast_tvdiff_ms(next, ast_tvnow());
00170          if (ms <= 0) {
00171             res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata), timeout);
00172             if (res > 0) {
00173                myf.f.frametype = AST_FRAME_VOICE;
00174                myf.f.subclass = AST_FORMAT_SLINEAR;
00175                myf.f.datalen = res;
00176                myf.f.samples = res / 2;
00177                myf.f.mallocd = 0;
00178                myf.f.offset = AST_FRIENDLY_OFFSET;
00179                myf.f.src = __PRETTY_FUNCTION__;
00180                myf.f.delivery.tv_sec = 0;
00181                myf.f.delivery.tv_usec = 0;
00182                myf.f.data.ptr = myf.frdata;
00183                if (ast_write(chan, &myf.f) < 0) {
00184                   res = -1;
00185                   break;
00186                }
00187             } else {
00188                ast_debug(1, "No more mp3\n");
00189                res = 0;
00190                break;
00191             }
00192             next = ast_tvadd(next, ast_samp2tv(myf.f.samples, 8000));
00193          } else {
00194             ms = ast_waitfor(chan, ms);
00195             if (ms < 0) {
00196                ast_debug(1, "Hangup detected\n");
00197                res = -1;
00198                break;
00199             }
00200             if (ms) {
00201                f = ast_read(chan);
00202                if (!f) {
00203                   ast_debug(1, "Null frame == hangup() detected\n");
00204                   res = -1;
00205                   break;
00206                }
00207                if (f->frametype == AST_FRAME_DTMF) {
00208                   ast_debug(1, "User pressed a key\n");
00209                   ast_frfree(f);
00210                   res = 0;
00211                   break;
00212                }
00213                ast_frfree(f);
00214             } 
00215          }
00216       }
00217    }
00218    close(fds[0]);
00219    close(fds[1]);
00220    
00221    if (pid > -1)
00222       kill(pid, SIGKILL);
00223    if (!res && owriteformat)
00224       ast_set_write_format(chan, owriteformat);
00225    
00226    return res;
00227 }
00228 
00229 static int unload_module(void)
00230 {
00231    return ast_unregister_application(app);
00232 }
00233 
00234 static int load_module(void)
00235 {
00236    return ast_register_application_xml(app, mp3_exec);
00237 }
00238 
00239 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Silly MP3 Application");