app_mp3.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*! \file
 *
 * \brief Silly application to play an MP3 file -- uses mpg123
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \note Add feature to play local M3U playlist file
 * Vincent Li <mchun.li@gmail.com>
 *
 * \ingroup applications
 */
 
/*** MODULEINFO
    <support_level>extended</support_level>
 ***/
 
#include "asterisk.h"
 
#include <sys/time.h>
#include <sys/types.h>
#include <signal.h>
 
#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/frame.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/app.h"
#include "asterisk/format_cache.h"
 
#define LOCAL_MPG_123 "/usr/local/bin/mpg123"
#define MPG_123 "/usr/bin/mpg123"
 
/*** DOCUMENTATION
    <application name="MP3Player" language="en_US">
        <synopsis>
            Play an MP3 file or M3U playlist file or stream.
        </synopsis>
        <syntax>
            <parameter name="Location" required="true">
                <para>Location of the file to be played.
                (argument passed to mpg123)</para>
            </parameter>
        </syntax>
        <description>
            <para>Executes mpg123 to play the given location, which typically would be a mp3 filename
            or m3u playlist filename or a URL. Please read https://en.wikipedia.org/wiki/M3U
            to see what the M3U playlist file format is like.</para>
            <para>Note that mpg123 does not support HTTPS, so use HTTP for web streams.</para>
            <para>User can exit by pressing any key on the dialpad, or by hanging up.</para>
            <example title="Play an MP3 playlist">
            exten => 1234,1,MP3Player(/var/lib/asterisk/playlist.m3u)
            </example>
            <para>This application does not automatically answer and should be preceeded by an
            application such as Answer() or Progress().</para>
        </description>
    </application>
 
 ***/
static char *app = "MP3Player";
 
static int mp3play(const char *filename, unsigned int sampling_rate, int fd)
{
    int res;
    char sampling_rate_str[8];
 
    res = ast_safe_fork(0);
    if (res < 0)
        ast_log(LOG_WARNING, "Fork failed\n");
    if (res) {
        return res;
    }
    if (ast_opt_high_priority)
        ast_set_priority(0);
 
    dup2(fd, STDOUT_FILENO);
    ast_close_fds_above_n(STDERR_FILENO);
 
    snprintf(sampling_rate_str, 8, "%u", sampling_rate);
 
    /* Execute mpg123, but buffer if it's a net connection */
    if (!strncasecmp(filename, "http://", 7) && strstr(filename, ".m3u")) {
        char buffer_size_str[8];
        snprintf(buffer_size_str, 8, "%u", (int) 0.5*2*sampling_rate/1000); /* 0.5 seconds for a live stream */
        /* Most commonly installed in /usr/local/bin */
        execl(LOCAL_MPG_123, "mpg123", "-e", "s16", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
        /* But many places has it in /usr/bin */
        execl(MPG_123, "mpg123", "-e", "s16", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
        /* As a last-ditch effort, try to use PATH */
        execlp("mpg123", "mpg123", "-e", "s16", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
    }
    else if (!strncasecmp(filename, "http://", 7)) {
        char buffer_size_str[8];
        snprintf(buffer_size_str, 8, "%u", 6*2*sampling_rate/1000); /* 6 seconds for a remote MP3 file */
        /* Most commonly installed in /usr/local/bin */
        execl(LOCAL_MPG_123, "mpg123", "-e", "s16", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
        /* But many places has it in /usr/bin */
        execl(MPG_123, "mpg123", "-e", "s16", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
        /* As a last-ditch effort, try to use PATH */
        execlp("mpg123", "mpg123", "-e", "s16", "-q", "-s", "-b", buffer_size_str, "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
    }
    else if (strstr(filename, ".m3u")) {
        /* Most commonly installed in /usr/local/bin */
        execl(LOCAL_MPG_123, "mpg123", "-e", "s16", "-q", "-z", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
        /* But many places has it in /usr/bin */
        execl(MPG_123, "mpg123", "-e", "s16", "-q", "-z", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
        /* As a last-ditch effort, try to use PATH */
        execlp("mpg123", "mpg123", "-e", "s16", "-q", "-z", "-s",  "-f", "8192", "--mono", "-r", sampling_rate_str, "-@", filename, (char *)NULL);
    }
    else {
        /* Most commonly installed in /usr/local/bin */
        execl(MPG_123, "mpg123", "-e", "s16", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
        /* But many places has it in /usr/bin */
        execl(LOCAL_MPG_123, "mpg123", "-e", "s16", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
        /* As a last-ditch effort, try to use PATH */
        execlp("mpg123", "mpg123", "-e", "s16", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
    }
    /* Can't use ast_log since FD's are closed */
    fprintf(stderr, "Execute of mpg123 failed\n");
    _exit(0);
}
 
static int timed_read(int fd, void *data, int datalen, int timeout, int pid)
{
    int res;
    int i;
    struct pollfd fds[1];
    fds[0].fd = fd;
    fds[0].events = POLLIN;
    for (i = 0; i < timeout; i++) {
        res = ast_poll(fds, 1, 1000);
        if (res > 0) {
            break;
        } else if (res == 0) {
            /* is mpg123 still running? */
            kill(pid, 0);
            if (errno == ESRCH) {
                return -1;
            }
        } else {
            ast_log(LOG_NOTICE, "error polling mpg123: %s\n", strerror(errno));
            return -1;
        }
    }
 
    if (i == timeout) {
        ast_log(LOG_NOTICE, "Poll timed out.\n");
        return -1;
    }
 
    return read(fd, data, datalen);
 
}
 
static int mp3_exec(struct ast_channel *chan, const char *data)
{
    int res=0;
    int fds[2];
    int ms = -1;
    int pid = -1;
    RAII_VAR(struct ast_format *, owriteformat, NULL, ao2_cleanup);
    int timeout = 2;
    int startedmp3 = 0;
    struct timeval next;
    struct ast_frame *f;
    struct myframe {
        struct ast_frame f;
        char offset[AST_FRIENDLY_OFFSET];
        short frdata[160];
    } myf = {
        .f = { 0, },
    };
    struct ast_format * native_format;
    unsigned int sampling_rate;
    struct ast_format * write_format;
 
    if (ast_strlen_zero(data)) {
        ast_log(LOG_WARNING, "MP3 Playback requires an argument (filename)\n");
        return -1;
    }
 
    if (pipe(fds)) {
        ast_log(LOG_WARNING, "Unable to create pipe\n");
        return -1;
    }
 
    ast_stopstream(chan);
 
    native_format = ast_format_cap_get_format(ast_channel_nativeformats(chan), 0);
    sampling_rate = ast_format_get_sample_rate(native_format);
    write_format = ast_format_cache_get_slin_by_rate(sampling_rate);
 
    owriteformat = ao2_bump(ast_channel_writeformat(chan));
    res = ast_set_write_format(chan, write_format);
    if (res < 0) {
        ast_log(LOG_WARNING, "Unable to set write format to signed linear\n");
        return -1;
    }
 
    myf.f.frametype = AST_FRAME_VOICE;
    myf.f.subclass.format = write_format;
    myf.f.mallocd = 0;
    myf.f.offset = AST_FRIENDLY_OFFSET;
    myf.f.src = __PRETTY_FUNCTION__;
    myf.f.delivery.tv_sec = 0;
    myf.f.delivery.tv_usec = 0;
    myf.f.data.ptr = myf.frdata;
 
    res = mp3play(data, sampling_rate, fds[1]);
    if (!strncasecmp(data, "http://", 7)) {
        timeout = 10;
    }
    /* Wait 1000 ms first */
    next = ast_tvnow();
    next.tv_sec += 1;
    if (res >= 0) {
        pid = res;
        /* Order is important -- there's almost always going to be mp3...  we want to prioritize the
           user */
        for (;;) {
            ms = ast_tvdiff_ms(next, ast_tvnow());
            if (ms <= 0) {
                res = timed_read(fds[0], myf.frdata, sizeof(myf.frdata), timeout, pid);
                if (res > 0) {
                    myf.f.datalen = res;
                    myf.f.samples = res / 2;
                    startedmp3 = 1;
                    if (ast_write(chan, &myf.f) < 0) {
                        res = -1;
                        break;
                    }
                } else {
                    ast_debug(1, "No more mp3\n");
                    if (!startedmp3) { /* we couldn't do anything, which means this stream doesn't work */
                        if (!strncasecmp(data, "https://", 8)) {
                            ast_log(LOG_WARNING, "%s() does not support HTTPS streams. Use HTTP instead.\n", app);
                        }
                        ast_log(LOG_WARNING, "MP3 stream '%s' is broken or nonexistent\n", data);
                    }
                    res = 0;
                    break;
                }
                next = ast_tvadd(next, ast_samp2tv(myf.f.samples, sampling_rate));
            } else {
                ms = ast_waitfor(chan, ms);
                if (ms < 0) {
                    ast_debug(1, "Hangup detected\n");
                    res = -1;
                    break;
                }
                if (ms) {
                    f = ast_read(chan);
                    if (!f) {
                        ast_debug(1, "Null frame == hangup() detected\n");
                        res = -1;
                        break;
                    }
                    if (f->frametype == AST_FRAME_DTMF) {
                        ast_debug(1, "User pressed a key\n");
                        ast_frfree(f);
                        res = 0;
                        break;
                    }
                    ast_frfree(f);
                }
            }
        }
    }
    close(fds[0]);
    close(fds[1]);
 
    if (pid > -1)
        kill(pid, SIGKILL);
    if (!res && owriteformat)
        ast_set_write_format(chan, owriteformat);
 
    ast_frfree(&myf.f);
 
    return res;
}
 
static int unload_module(void)
{
    return ast_unregister_application(app);
}
 
static int load_module(void)
{
    return ast_register_application_xml(app, mp3_exec);
}
 
AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "Silly MP3 Application");