Wed Aug 18 22:33:41 2010

Asterisk developer's documentation


app_nbscat.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 NBScat file -- uses nbscat8k
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: 182946 $")
00031 
00032 #include <fcntl.h>
00033 #include <sys/time.h>
00034 #include <sys/socket.h>
00035 #include <signal.h>
00036 
00037 #include "asterisk/lock.h"
00038 #include "asterisk/file.h"
00039 #include "asterisk/channel.h"
00040 #include "asterisk/frame.h"
00041 #include "asterisk/pbx.h"
00042 #include "asterisk/module.h"
00043 #include "asterisk/translate.h"
00044 #include "asterisk/app.h"
00045 
00046 #define LOCAL_NBSCAT "/usr/local/bin/nbscat8k"
00047 #define NBSCAT "/usr/bin/nbscat8k"
00048 
00049 #ifndef AF_LOCAL
00050 #define AF_LOCAL AF_UNIX
00051 #endif
00052 
00053 static char *app = "NBScat";
00054 
00055 static char *synopsis = "Play an NBS local stream";
00056 
00057 static char *descrip = 
00058 "  NBScat(): Executes nbscat to listen to the local NBS stream.\n"
00059 "User can exit by pressing any key.\n";
00060 
00061 
00062 static int NBScatplay(int fd)
00063 {
00064    int res;
00065 
00066    res = ast_safe_fork(0);
00067    if (res < 0) {
00068       ast_log(LOG_WARNING, "Fork failed\n");
00069    }
00070 
00071    if (res) {
00072       return res;
00073    }
00074 
00075    if (ast_opt_high_priority)
00076       ast_set_priority(0);
00077 
00078    dup2(fd, STDOUT_FILENO);
00079    ast_close_fds_above_n(STDERR_FILENO);
00080    /* Most commonly installed in /usr/local/bin */
00081    execl(NBSCAT, "nbscat8k", "-d", (char *)NULL);
00082    execl(LOCAL_NBSCAT, "nbscat8k", "-d", (char *)NULL);
00083    fprintf(stderr, "Execute of nbscat8k failed\n");
00084    _exit(0);
00085 }
00086 
00087 static int timed_read(int fd, void *data, int datalen)
00088 {
00089    int res;
00090    struct pollfd fds[1];
00091    fds[0].fd = fd;
00092    fds[0].events = POLLIN;
00093    res = ast_poll(fds, 1, 2000);
00094    if (res < 1) {
00095       ast_log(LOG_NOTICE, "Selected timed out/errored out with %d\n", res);
00096       return -1;
00097    }
00098    return read(fd, data, datalen);
00099    
00100 }
00101 
00102 static int NBScat_exec(struct ast_channel *chan, void *data)
00103 {
00104    int res=0;
00105    int fds[2];
00106    int ms = -1;
00107    int pid = -1;
00108    int owriteformat;
00109    struct timeval next;
00110    struct ast_frame *f;
00111    struct myframe {
00112       struct ast_frame f;
00113       char offset[AST_FRIENDLY_OFFSET];
00114       short frdata[160];
00115    } myf;
00116    
00117    if (socketpair(AF_LOCAL, SOCK_STREAM, 0, fds)) {
00118       ast_log(LOG_WARNING, "Unable to create socketpair\n");
00119       return -1;
00120    }
00121    
00122    ast_stopstream(chan);
00123 
00124    owriteformat = chan->writeformat;
00125    res = ast_set_write_format(chan, AST_FORMAT_SLINEAR);
00126    if (res < 0) {
00127       ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
00128       return -1;
00129    }
00130    
00131    res = NBScatplay(fds[1]);
00132    /* Wait 1000 ms first */
00133    next = ast_tvnow();
00134    next.tv_sec += 1;
00135    if (res >= 0) {
00136       pid = res;
00137       /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
00138          user */
00139       for (;;) {
00140          ms = ast_tvdiff_ms(next, ast_tvnow());
00141          if (ms <= 0) {
00142             res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata));
00143             if (res > 0) {
00144                myf.f.frametype = AST_FRAME_VOICE;
00145                myf.f.subclass = AST_FORMAT_SLINEAR;
00146                myf.f.datalen = res;
00147                myf.f.samples = res / 2;
00148                myf.f.mallocd = 0;
00149                myf.f.offset = AST_FRIENDLY_OFFSET;
00150                myf.f.src = __PRETTY_FUNCTION__;
00151                myf.f.delivery.tv_sec = 0;
00152                myf.f.delivery.tv_usec = 0;
00153                myf.f.data.ptr = myf.frdata;
00154                if (ast_write(chan, &myf.f) < 0) {
00155                   res = -1;
00156                   break;
00157                }
00158             } else {
00159                ast_debug(1, "No more mp3\n");
00160                res = 0;
00161                break;
00162             }
00163             next = ast_tvadd(next, ast_samp2tv(myf.f.samples, 8000));
00164          } else {
00165             ms = ast_waitfor(chan, ms);
00166             if (ms < 0) {
00167                ast_debug(1, "Hangup detected\n");
00168                res = -1;
00169                break;
00170             }
00171             if (ms) {
00172                f = ast_read(chan);
00173                if (!f) {
00174                   ast_debug(1, "Null frame == hangup() detected\n");
00175                   res = -1;
00176                   break;
00177                }
00178                if (f->frametype == AST_FRAME_DTMF) {
00179                   ast_debug(1, "User pressed a key\n");
00180                   ast_frfree(f);
00181                   res = 0;
00182                   break;
00183                }
00184                ast_frfree(f);
00185             } 
00186          }
00187       }
00188    }
00189    close(fds[0]);
00190    close(fds[1]);
00191    
00192    if (pid > -1)
00193       kill(pid, SIGKILL);
00194    if (!res && owriteformat)
00195       ast_set_write_format(chan, owriteformat);
00196 
00197    return res;
00198 }
00199 
00200 static int unload_module(void)
00201 {
00202    return ast_unregister_application(app);
00203 }
00204 
00205 static int load_module(void)
00206 {
00207    return ast_register_application(app, NBScat_exec, synopsis, descrip);
00208 }
00209 
00210 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Silly NBS Stream Application");

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