app_mp3.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <[email protected]>
 *
 * 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 <[email protected]>
 *
 * \note Add feature to play local M3U playlist file
 * Vincent Li <[email protected]>
 *
 * \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 http://en.wikipedia.org/wiki/M3U
 to see how M3U playlist file format is like, Example usage would be
 exten => 1234,1,MP3Player(/var/lib/asterisk/playlist.m3u)
 User can exit by pressing any key on the dialpad, or by hanging up.</para>
 <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", "-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", "-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", "-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", "-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", "-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", "-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", "-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", "-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", "-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", "-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", "-q", "-s", "-f", "8192", "--mono", "-r", sampling_rate_str, filename, (char *)NULL);
 /* As a last-ditch effort, try to use PATH */
 execlp("mpg123", "mpg123", "-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;
 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;
 if (ast_write(chan, &myf.f) < 0) {
 res = -1;
 break;
 }
 } else {
 ast_debug(1, "No more mp3\n");
 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");