Fri Aug 17 00:17:09 2018

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 /*** MODULEINFO
00029    <support_level>extended</support_level>
00030  ***/
00031  
00032 #include "asterisk.h"
00033 
00034 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 328209 $")
00035 
00036 #include <fcntl.h>
00037 #include <sys/time.h>
00038 #include <sys/socket.h>
00039 #include <signal.h>
00040 
00041 #include "asterisk/lock.h"
00042 #include "asterisk/file.h"
00043 #include "asterisk/channel.h"
00044 #include "asterisk/frame.h"
00045 #include "asterisk/pbx.h"
00046 #include "asterisk/module.h"
00047 #include "asterisk/translate.h"
00048 #include "asterisk/app.h"
00049 
00050 /*** DOCUMENTATION
00051    <application name="NBScat" language="en_US">
00052       <synopsis>
00053          Play an NBS local stream.
00054       </synopsis>
00055       <syntax />
00056       <description>
00057          <para>Executes nbscat to listen to the local NBS stream.
00058          User can exit by pressing any key.</para>
00059       </description>
00060    </application>
00061  ***/
00062 
00063 #define LOCAL_NBSCAT "/usr/local/bin/nbscat8k"
00064 #define NBSCAT "/usr/bin/nbscat8k"
00065 
00066 #ifndef AF_LOCAL
00067 #define AF_LOCAL AF_UNIX
00068 #endif
00069 
00070 static char *app = "NBScat";
00071 
00072 static int NBScatplay(int fd)
00073 {
00074    int res;
00075 
00076    res = ast_safe_fork(0);
00077    if (res < 0) {
00078       ast_log(LOG_WARNING, "Fork failed\n");
00079    }
00080 
00081    if (res) {
00082       return res;
00083    }
00084 
00085    if (ast_opt_high_priority)
00086       ast_set_priority(0);
00087 
00088    dup2(fd, STDOUT_FILENO);
00089    ast_close_fds_above_n(STDERR_FILENO);
00090    /* Most commonly installed in /usr/local/bin */
00091    execl(NBSCAT, "nbscat8k", "-d", (char *)NULL);
00092    execl(LOCAL_NBSCAT, "nbscat8k", "-d", (char *)NULL);
00093    fprintf(stderr, "Execute of nbscat8k failed\n");
00094    _exit(0);
00095 }
00096 
00097 static int timed_read(int fd, void *data, int datalen)
00098 {
00099    int res;
00100    struct pollfd fds[1];
00101    fds[0].fd = fd;
00102    fds[0].events = POLLIN;
00103    res = ast_poll(fds, 1, 2000);
00104    if (res < 1) {
00105       ast_log(LOG_NOTICE, "Selected timed out/errored out with %d\n", res);
00106       return -1;
00107    }
00108    return read(fd, data, datalen);
00109    
00110 }
00111 
00112 static int NBScat_exec(struct ast_channel *chan, const char *data)
00113 {
00114    int res=0;
00115    int fds[2];
00116    int ms = -1;
00117    int pid = -1;
00118    int owriteformat;
00119    struct timeval next;
00120    struct ast_frame *f;
00121    struct myframe {
00122       struct ast_frame f;
00123       char offset[AST_FRIENDLY_OFFSET];
00124       short frdata[160];
00125    } myf;
00126    
00127    if (socketpair(AF_LOCAL, SOCK_STREAM, 0, fds)) {
00128       ast_log(LOG_WARNING, "Unable to create socketpair\n");
00129       return -1;
00130    }
00131    
00132    ast_stopstream(chan);
00133 
00134    owriteformat = chan->writeformat;
00135    res = ast_set_write_format(chan, AST_FORMAT_SLINEAR);
00136    if (res < 0) {
00137       ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
00138       return -1;
00139    }
00140    
00141    res = NBScatplay(fds[1]);
00142    /* Wait 1000 ms first */
00143    next = ast_tvnow();
00144    next.tv_sec += 1;
00145    if (res >= 0) {
00146       pid = res;
00147       /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
00148          user */
00149       for (;;) {
00150          ms = ast_tvdiff_ms(next, ast_tvnow());
00151          if (ms <= 0) {
00152             res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata));
00153             if (res > 0) {
00154                myf.f.frametype = AST_FRAME_VOICE;
00155                myf.f.subclass.codec = AST_FORMAT_SLINEAR;
00156                myf.f.datalen = res;
00157                myf.f.samples = res / 2;
00158                myf.f.mallocd = 0;
00159                myf.f.offset = AST_FRIENDLY_OFFSET;
00160                myf.f.src = __PRETTY_FUNCTION__;
00161                myf.f.delivery.tv_sec = 0;
00162                myf.f.delivery.tv_usec = 0;
00163                myf.f.data.ptr = myf.frdata;
00164                if (ast_write(chan, &myf.f) < 0) {
00165                   res = -1;
00166                   break;
00167                }
00168             } else {
00169                ast_debug(1, "No more mp3\n");
00170                res = 0;
00171                break;
00172             }
00173             next = ast_tvadd(next, ast_samp2tv(myf.f.samples, 8000));
00174          } else {
00175             ms = ast_waitfor(chan, ms);
00176             if (ms < 0) {
00177                ast_debug(1, "Hangup detected\n");
00178                res = -1;
00179                break;
00180             }
00181             if (ms) {
00182                f = ast_read(chan);
00183                if (!f) {
00184                   ast_debug(1, "Null frame == hangup() detected\n");
00185                   res = -1;
00186                   break;
00187                }
00188                if (f->frametype == AST_FRAME_DTMF) {
00189                   ast_debug(1, "User pressed a key\n");
00190                   ast_frfree(f);
00191                   res = 0;
00192                   break;
00193                }
00194                ast_frfree(f);
00195             } 
00196          }
00197       }
00198    }
00199    close(fds[0]);
00200    close(fds[1]);
00201    
00202    if (pid > -1)
00203       kill(pid, SIGKILL);
00204    if (!res && owriteformat)
00205       ast_set_write_format(chan, owriteformat);
00206 
00207    return res;
00208 }
00209 
00210 static int unload_module(void)
00211 {
00212    return ast_unregister_application(app);
00213 }
00214 
00215 static int load_module(void)
00216 {
00217    return ast_register_application_xml(app, NBScat_exec);
00218 }
00219 
00220 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Silly NBS Stream Application");

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