Wed Aug 18 22:33:41 2010

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: 238012 $")
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 static char *app = "MP3Player";
00048 
00049 static char *synopsis = "Play an MP3 file or stream";
00050 
00051 static char *descrip = 
00052 "  MP3Player(location): Executes mpg123 to play the given location,\n"
00053 "which typically would be a filename or a URL. User can exit by pressing\n"
00054 "any key on the dialpad, or by hanging up."; 
00055 
00056 
00057 static int mp3play(char *filename, int fd)
00058 {
00059    int res;
00060 
00061    res = ast_safe_fork(0);
00062    if (res < 0) 
00063       ast_log(LOG_WARNING, "Fork failed\n");
00064    if (res) {
00065       return res;
00066    }
00067    if (ast_opt_high_priority)
00068       ast_set_priority(0);
00069 
00070    dup2(fd, STDOUT_FILENO);
00071    ast_close_fds_above_n(STDERR_FILENO);
00072 
00073    /* Execute mpg123, but buffer if it's a net connection */
00074    if (!strncasecmp(filename, "http://", 7)) {
00075       /* Most commonly installed in /usr/local/bin */
00076        execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-b", "1024", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00077       /* But many places has it in /usr/bin */
00078        execl(MPG_123, "mpg123", "-q", "-s", "-b", "1024","-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00079       /* As a last-ditch effort, try to use PATH */
00080        execlp("mpg123", "mpg123", "-q", "-s", "-b", "1024",  "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00081    }
00082    else {
00083       /* Most commonly installed in /usr/local/bin */
00084        execl(MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00085       /* But many places has it in /usr/bin */
00086        execl(LOCAL_MPG_123, "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00087       /* As a last-ditch effort, try to use PATH */
00088        execlp("mpg123", "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
00089    }
00090    /* Can't use ast_log since FD's are closed */
00091    fprintf(stderr, "Execute of mpg123 failed\n");
00092    _exit(0);
00093 }
00094 
00095 static int timed_read(int fd, void *data, int datalen, int timeout)
00096 {
00097    int res;
00098    struct pollfd fds[1];
00099    fds[0].fd = fd;
00100    fds[0].events = POLLIN;
00101    res = ast_poll(fds, 1, timeout);
00102    if (res < 1) {
00103       ast_log(LOG_NOTICE, "Poll timed out/errored out with %d\n", res);
00104       return -1;
00105    }
00106    return read(fd, data, datalen);
00107    
00108 }
00109 
00110 static int mp3_exec(struct ast_channel *chan, void *data)
00111 {
00112    int res=0;
00113    int fds[2];
00114    int ms = -1;
00115    int pid = -1;
00116    int owriteformat;
00117    int timeout = 2000;
00118    struct timeval next;
00119    struct ast_frame *f;
00120    struct myframe {
00121       struct ast_frame f;
00122       char offset[AST_FRIENDLY_OFFSET];
00123       short frdata[160];
00124    } myf = {
00125       .f = { 0, },
00126    };
00127 
00128    if (ast_strlen_zero(data)) {
00129       ast_log(LOG_WARNING, "MP3 Playback requires an argument (filename)\n");
00130       return -1;
00131    }
00132 
00133    if (pipe(fds)) {
00134       ast_log(LOG_WARNING, "Unable to create pipe\n");
00135       return -1;
00136    }
00137    
00138    ast_stopstream(chan);
00139 
00140    owriteformat = chan->writeformat;
00141    res = ast_set_write_format(chan, AST_FORMAT_SLINEAR);
00142    if (res < 0) {
00143       ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
00144       return -1;
00145    }
00146    
00147    res = mp3play((char *)data, fds[1]);
00148    if (!strncasecmp((char *)data, "http://", 7)) {
00149       timeout = 10000;
00150    }
00151    /* Wait 1000 ms first */
00152    next = ast_tvnow();
00153    next.tv_sec += 1;
00154    if (res >= 0) {
00155       pid = res;
00156       /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
00157          user */
00158       for (;;) {
00159          ms = ast_tvdiff_ms(next, ast_tvnow());
00160          if (ms <= 0) {
00161             res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata), timeout);
00162             if (res > 0) {
00163                myf.f.frametype = AST_FRAME_VOICE;
00164                myf.f.subclass = AST_FORMAT_SLINEAR;
00165                myf.f.datalen = res;
00166                myf.f.samples = res / 2;
00167                myf.f.mallocd = 0;
00168                myf.f.offset = AST_FRIENDLY_OFFSET;
00169                myf.f.src = __PRETTY_FUNCTION__;
00170                myf.f.delivery.tv_sec = 0;
00171                myf.f.delivery.tv_usec = 0;
00172                myf.f.data.ptr = myf.frdata;
00173                if (ast_write(chan, &myf.f) < 0) {
00174                   res = -1;
00175                   break;
00176                }
00177             } else {
00178                ast_debug(1, "No more mp3\n");
00179                res = 0;
00180                break;
00181             }
00182             next = ast_tvadd(next, ast_samp2tv(myf.f.samples, 8000));
00183          } else {
00184             ms = ast_waitfor(chan, ms);
00185             if (ms < 0) {
00186                ast_debug(1, "Hangup detected\n");
00187                res = -1;
00188                break;
00189             }
00190             if (ms) {
00191                f = ast_read(chan);
00192                if (!f) {
00193                   ast_debug(1, "Null frame == hangup() detected\n");
00194                   res = -1;
00195                   break;
00196                }
00197                if (f->frametype == AST_FRAME_DTMF) {
00198                   ast_debug(1, "User pressed a key\n");
00199                   ast_frfree(f);
00200                   res = 0;
00201                   break;
00202                }
00203                ast_frfree(f);
00204             } 
00205          }
00206       }
00207    }
00208    close(fds[0]);
00209    close(fds[1]);
00210    
00211    if (pid > -1)
00212       kill(pid, SIGKILL);
00213    if (!res && owriteformat)
00214       ast_set_write_format(chan, owriteformat);
00215    
00216    return res;
00217 }
00218 
00219 static int unload_module(void)
00220 {
00221    return ast_unregister_application(app);
00222 }
00223 
00224 static int load_module(void)
00225 {
00226    return ast_register_application(app, mp3_exec, synopsis, descrip);
00227 }
00228 
00229 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Silly MP3 Application");

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