Thu Jul 9 13:40:19 2009

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 /*** MODULEINFO
00029    <depend>working_fork</depend>
00030  ***/
00031 
00032 #include "asterisk.h"
00033 
00034 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 182945 $")
00035 
00036 #include <sys/time.h>
00037 #include <signal.h>
00038 #ifdef HAVE_CAP
00039 #include <sys/capability.h>
00040 #endif /* HAVE_CAP */
00041 
00042 #include "asterisk/lock.h"
00043 #include "asterisk/file.h"
00044 #include "asterisk/channel.h"
00045 #include "asterisk/frame.h"
00046 #include "asterisk/pbx.h"
00047 #include "asterisk/module.h"
00048 #include "asterisk/translate.h"
00049 
00050 #define LOCAL_MPG_123 "/usr/local/bin/mpg123"
00051 #define MPG_123 "/usr/bin/mpg123"
00052 
00053 static char *app = "MP3Player";
00054 
00055 static char *synopsis = "Play an MP3 file or stream";
00056 
00057 static char *descrip = 
00058 "  MP3Player(location): Executes mpg123 to play the given location,\n"
00059 "which typically would be a filename or a URL. User can exit by pressing\n"
00060 "any key on the dialpad, or by hanging up."; 
00061 
00062 
00063 static int mp3play(char *filename, int fd)
00064 {
00065    int res;
00066    int x;
00067    sigset_t fullset, oldset;
00068 #ifdef HAVE_CAP
00069    cap_t cap;
00070 #endif
00071 
00072    sigfillset(&fullset);
00073    pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
00074 
00075    res = fork();
00076    if (res < 0) 
00077       ast_log(LOG_WARNING, "Fork failed\n");
00078    if (res) {
00079       pthread_sigmask(SIG_SETMASK, &oldset, NULL);
00080       return res;
00081    }
00082 #ifdef HAVE_CAP
00083    cap = cap_from_text("cap_net_admin-eip");
00084 
00085    if (cap_set_proc(cap)) {
00086       /* Careful with order! Logging cannot happen after we close FDs */
00087       ast_log(LOG_WARNING, "Unable to remove capabilities.\n");
00088    }
00089    cap_free(cap);
00090 #endif
00091    if (ast_opt_high_priority)
00092       ast_set_priority(0);
00093    signal(SIGPIPE, SIG_DFL);
00094    pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
00095 
00096    dup2(fd, STDOUT_FILENO);
00097    for (x=STDERR_FILENO + 1;x<256;x++) {
00098       close(x);
00099    }
00100    /* Execute mpg123, but buffer if it's a net connection */
00101    if (!strncasecmp(filename, "http://", 7)) {
00102       /* Most commonly installed in /usr/local/bin */
00103        execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-b", "1024", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00104       /* But many places has it in /usr/bin */
00105        execl(MPG_123, "mpg123", "-q", "-s", "-b", "1024","-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00106       /* As a last-ditch effort, try to use PATH */
00107        execlp("mpg123", "mpg123", "-q", "-s", "-b", "1024",  "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00108    }
00109    else {
00110       /* Most commonly installed in /usr/local/bin */
00111        execl(MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00112       /* But many places has it in /usr/bin */
00113        execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00114       /* As a last-ditch effort, try to use PATH */
00115        execlp("mpg123", "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00116    }
00117    ast_log(LOG_WARNING, "Execute of mpg123 failed\n");
00118    _exit(0);
00119 }
00120 
00121 static int timed_read(int fd, void *data, int datalen, int timeout)
00122 {
00123    int res;
00124    struct pollfd fds[1];
00125    fds[0].fd = fd;
00126    fds[0].events = POLLIN;
00127    res = ast_poll(fds, 1, timeout);
00128    if (res < 1) {
00129       ast_log(LOG_NOTICE, "Poll timed out/errored out with %d\n", res);
00130       return -1;
00131    }
00132    return read(fd, data, datalen);
00133    
00134 }
00135 
00136 static int mp3_exec(struct ast_channel *chan, void *data)
00137 {
00138    int res=0;
00139    int fds[2];
00140    int ms = -1;
00141    int pid = -1;
00142    int owriteformat;
00143    int timeout = 2000;
00144    struct timeval next;
00145    struct ast_frame *f;
00146    struct myframe {
00147       struct ast_frame f;
00148       char offset[AST_FRIENDLY_OFFSET];
00149       short frdata[160];
00150    } myf;
00151    
00152    if (ast_strlen_zero(data)) {
00153       ast_log(LOG_WARNING, "MP3 Playback requires an argument (filename)\n");
00154       return -1;
00155    }
00156 
00157    if (pipe(fds)) {
00158       ast_log(LOG_WARNING, "Unable to create pipe\n");
00159       return -1;
00160    }
00161    
00162    ast_stopstream(chan);
00163 
00164    owriteformat = chan->writeformat;
00165    res = ast_set_write_format(chan, AST_FORMAT_SLINEAR);
00166    if (res < 0) {
00167       ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
00168       return -1;
00169    }
00170    
00171    res = mp3play((char *)data, fds[1]);
00172    if (!strncasecmp((char *)data, "http://", 7)) {
00173       timeout = 10000;
00174    }
00175    /* Wait 1000 ms first */
00176    next = ast_tvnow();
00177    next.tv_sec += 1;
00178    if (res >= 0) {
00179       pid = res;
00180       /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
00181          user */
00182       for (;;) {
00183          ms = ast_tvdiff_ms(next, ast_tvnow());
00184          if (ms <= 0) {
00185             res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata), timeout);
00186             if (res > 0) {
00187                myf.f.frametype = AST_FRAME_VOICE;
00188                myf.f.subclass = AST_FORMAT_SLINEAR;
00189                myf.f.datalen = res;
00190                myf.f.samples = res / 2;
00191                myf.f.mallocd = 0;
00192                myf.f.offset = AST_FRIENDLY_OFFSET;
00193                myf.f.src = __PRETTY_FUNCTION__;
00194                myf.f.delivery.tv_sec = 0;
00195                myf.f.delivery.tv_usec = 0;
00196                myf.f.data = myf.frdata;
00197                if (ast_write(chan, &myf.f) < 0) {
00198                   res = -1;
00199                   break;
00200                }
00201             } else {
00202                ast_debug(1, "No more mp3\n");
00203                res = 0;
00204                break;
00205             }
00206             next = ast_tvadd(next, ast_samp2tv(myf.f.samples, 8000));
00207          } else {
00208             ms = ast_waitfor(chan, ms);
00209             if (ms < 0) {
00210                ast_debug(1, "Hangup detected\n");
00211                res = -1;
00212                break;
00213             }
00214             if (ms) {
00215                f = ast_read(chan);
00216                if (!f) {
00217                   ast_debug(1, "Null frame == hangup() detected\n");
00218                   res = -1;
00219                   break;
00220                }
00221                if (f->frametype == AST_FRAME_DTMF) {
00222                   ast_debug(1, "User pressed a key\n");
00223                   ast_frfree(f);
00224                   res = 0;
00225                   break;
00226                }
00227                ast_frfree(f);
00228             } 
00229          }
00230       }
00231    }
00232    close(fds[0]);
00233    close(fds[1]);
00234    
00235    if (pid > -1)
00236       kill(pid, SIGKILL);
00237    if (!res && owriteformat)
00238       ast_set_write_format(chan, owriteformat);
00239    
00240    return res;
00241 }
00242 
00243 static int unload_module(void)
00244 {
00245    return ast_unregister_application(app);
00246 }
00247 
00248 static int load_module(void)
00249 {
00250    return ast_register_application(app, mp3_exec, synopsis, descrip);
00251 }
00252 
00253 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Silly MP3 Application");

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