/*******************************************************************************
# #
# MJPG-streamer allows to stream JPG frames from an input-plugin #
# to several output plugins #
# #
# Copyright (C) 2007 Tom Stöveken #
# #
# This program is free software; you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation; version 2 of the License. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program; if not, write to the Free Software #
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #
# #
*******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <linux/videodev.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <signal.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <getopt.h>
#include <pthread.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <syslog.h>
#include "utils.h"
#include "mjpg_streamer.h"
/* globals */
static globals global;
/******************************************************************************
Description.: Display a help message
Input Value.: argv[0] is the program name and the parameter progname
Return Value: -
******************************************************************************/
void help(char *progname)
{
fprintf(stderr, "-----------------------------------------------------------------------\n");
fprintf(stderr, "Usage: %s\n" \
" -i | --input \"<input-plugin.so> [parameters]\"\n" \
" -o | --output \"<output-plugin.so> [parameters]\"\n" \
" [-h | --help ]........: display this help\n" \
" [-v | --version ].....: display version information\n" \
" [-b | --background]...: fork to the background, daemon mode\n", progname);
fprintf(stderr, "-----------------------------------------------------------------------\n");
fprintf(stderr, "Example #1:\n" \
" To open an UVC webcam \"/dev/video1\" and stream it via HTTP:\n" \
" %s -i \"input_uvc.so -d /dev/video1\" -o \"output_http.so\"\n", progname);
fprintf(stderr, "-----------------------------------------------------------------------\n");
fprintf(stderr, "Example #2:\n" \
" To open an UVC webcam and stream via HTTP port 8090:\n" \
" %s -i \"input_uvc.so\" -o \"output_http.so -p 8090\"\n", progname);
fprintf(stderr, "-----------------------------------------------------------------------\n");
fprintf(stderr, "Example #3:\n" \
" To get help for a certain input plugin:\n" \
" %s -i \"input_uvc.so --help\"\n", progname);
fprintf(stderr, "-----------------------------------------------------------------------\n");
fprintf(stderr, "In case the modules (=plugins) can not be found:\n" \
" * Set the default search path for the modules with:\n" \
" export LD_LIBRARY_PATH=/path/to/plugins,\n" \
" * or put the plugins into the \"/lib/\" or \"/usr/lib\" folder,\n" \
" * or instead of just providing the plugin file name, use a complete\n" \
" path and filename:\n" \
" %s -i \"/path/to/modules/input_uvc.so\"\n", progname);
fprintf(stderr, "-----------------------------------------------------------------------\n");
}
/******************************************************************************
Description.: pressing CTRL+C sends signals to this process instead of just
killing it plugins can tidily shutdown and free allocated
ressources. The function prototype is defined by the system,
because it is a callback function.
Input Value.: sig tells us which signal was received
Return Value: -
******************************************************************************/
void signal_handler(int sig)
{
int i;
/* signal "stop" to threads */
LOG("setting signal to stop\n");
global.stop = 1;
usleep(1000*1000);
/* clean up threads */
LOG("force cancelation of threads and cleanup ressources\n");
global.in.stop();
for(i=0; i<global.outcnt; i++) {
global.out
.stop(global.out.param.id);
}
usleep(1000*1000);
/* close handles of input plugins */
dlclose(&global.in.handle);
for(i=0; i<global.outcnt; i++) {
/* skip = 0;
DBG("about to decrement usage counter for handle of %s, id #%02d, handle: %p\n", \
global.out.plugin, global.out.param.id, global.out.handle);
for(j=i+1; j<global.outcnt; j++) {
if ( global.out.handle == global.out[j].handle ) {
DBG("handles are pointing to the same destination (%p == %p)\n", global.out.handle, global.out[j].handle);
skip = 1;
}
}
if ( skip ) {
continue;
}
DBG("closing handle %p\n", global.out.handle);
*/
dlclose(global.out.handle);
}
DBG("all plugin handles closed\n");
pthread_cond_destroy(&global.db_update);
pthread_mutex_destroy(&global.db);
LOG("done\n");
closelog();
exit(0);
return;
}
/******************************************************************************
Description.:
Input Value.:
Return Value:
******************************************************************************/
int control(int command, char *details) {
switch(command) {
case CONTROL_CMD_RECONFIGURE_INPUT:
printf("will reload input plugin: %s\n", details);
break;
default:
LOG("unknown control command received\n");
}
return 0;
}
/******************************************************************************
Description.:
Input Value.:
Return Value:
******************************************************************************/
int main(int argc, char *argv[])
{
char *input = "input_uvc.so --resolution 640x480 --fps 5 --device /dev/video0";
char *output[MAX_OUTPUT_PLUGINS];
int daemon=0, i;
size_t tmp=0;
output[0] = "output_http.so --port 8080";
global.outcnt = 0;
global.control = control;
/* parameter parsing */
while(1) {
int option_index = 0, c=0;
static struct option long_options[] = \
{
{"h", no_argument, 0, 0},
{"help", no_argument, 0, 0},
{"i", required_argument, 0, 0},
{"input", required_argument, 0, 0},
{"o", required_argument, 0, 0},
{"output", required_argument, 0, 0},
{"v", no_argument, 0, 0},
{"version", no_argument, 0, 0},
{"b", no_argument, 0, 0},
{"background", no_argument, 0, 0},
{0, 0, 0, 0}
};
c = getopt_long_only(argc, argv, "", long_options, &option_index);
/* no more options to parse */
if (c == -1) break;
/* unrecognized option */
if(c=='?'){ help(argv[0]); return 0; }
switch (option_index) {
/* h, help */
case 0:
case 1:
help(argv[0]);
return 0;
break;
/* i, input */
case 2:
case 3:
input = strdup(optarg);
break;
/* o, output */
case 4:
case 5:
output[global.outcnt++] = strdup(optarg);
break;
/* v, version */
case 6:
case 7:
printf("MJPG Streamer Version: %s\n" \
"Compilation Date.....: %s\n" \
"Compilation Time.....: %s\n", SOURCE_VERSION, __DATE__, __TIME__);
return 0;
break;
/* b, background */
case 8:
case 9:
daemon=1;
break;
default:
help(argv[0]);
return 0;
}
}
openlog("MJPG-streamer ", LOG_PID|LOG_CONS, LOG_USER);
//openlog("MJPG-streamer ", LOG_PID|LOG_CONS|LOG_PERROR, LOG_USER);
syslog(LOG_INFO, "starting application");
/* fork to the background */
if ( daemon ) {
LOG("enabling daemon mode");
daemon_mode();
}
/* initialise the global variables */
global.stop = 0;
global.buf = NULL;
global.size = 0;
global.in.plugin = NULL;
/* this mutex and the conditional variable are used to synchronize access to the global picture buffer */
if( pthread_mutex_init(&global.db, NULL) != 0 ) {
LOG("could not initialize mutex variable\n");
closelog();
exit(EXIT_FAILURE);
}
if( pthread_cond_init(&global.db_update, NULL) != 0 ) {
LOG("could not initialize condition variable\n");
closelog();
exit(EXIT_FAILURE);
}
/* ignore SIGPIPE (send by OS if transmitting to closed TCP sockets) */
signal(SIGPIPE, SIG_IGN);
/* register signal handler for <CTRL>+C in order to clean up */
if (signal(SIGINT, signal_handler) == SIG_ERR) {
LOG("could not register signal handler\n");
closelog();
exit(EXIT_FAILURE);
}
/*
* messages like the following will only be visible on your terminal
* if not running in daemon mode
*/
LOG("MJPG Streamer Version.: %s\n", SOURCE_VERSION);
/* check if at least one output plugin was selected */
if ( global.outcnt == 0 ) {
/* no? Then use the default plugin instead */
global.outcnt = 1;
}
/* open input plugin */
tmp = (size_t)(strchr(input, ' ')-input);
global.in.plugin = (tmp > 0)?strndup(input, tmp):strdup(input);
global.in.handle = dlopen(global.in.plugin, RTLD_LAZY);
if ( !global.in.handle ) {
LOG("ERROR: could not find input plugin\n");
LOG(" Perhaps you want to adjust the search path with:\n");
LOG(" # export LD_LIBRARY_PATH=/path/to/plugin/folder\n");
LOG(" dlopen: %s\n", dlerror() );
closelog();
exit(EXIT_FAILURE);
}
global.in.init = dlsym(global.in.handle, "input_init");
if ( global.in.init == NULL ) {
LOG("%s\n", dlerror());
exit(EXIT_FAILURE);
}
global.in.stop = dlsym(global.in.handle, "input_stop");
if ( global.in.stop == NULL ) {
LOG("%s\n", dlerror());
exit(EXIT_FAILURE);
}
global.in.run = dlsym(global.in.handle, "input_run");
if ( global.in.run == NULL ) {
LOG("%s\n", dlerror());
exit(EXIT_FAILURE);
}
/* try to find optional command */
global.in.cmd = dlsym(global.in.handle, "input_cmd");
global.in.param.parameter_string = strchr(input, ' ');
global.in.param.global = &global;
if ( global.in.init(&global.in.param) ) {
LOG("input_init() return value signals to exit");
closelog();
exit(0);
}
/* open output plugin */
for (i=0; i<global.outcnt; i++) {
tmp = (size_t)(strchr(output, ' ')-output);
global.out.plugin = (tmp > 0)?strndup(output, tmp):strdup(output);
global.out.handle = dlopen(global.out.plugin, RTLD_LAZY);
if ( !global.out.handle ) {
LOG("ERROR: could not find output plugin %s\n", global.out.plugin);
LOG(" Perhaps you want to adjust the search path with:\n");
LOG(" # export LD_LIBRARY_PATH=/path/to/plugin/folder\n");
LOG(" dlopen: %s\n", dlerror() );
closelog();
exit(EXIT_FAILURE);
}
global.out.init = dlsym(global.out.handle, "output_init");
if ( global.out.init == NULL ) {
LOG("%s\n", dlerror());
exit(EXIT_FAILURE);
}
global.out.stop = dlsym(global.out.handle, "output_stop");
if ( global.out.stop == NULL ) {
LOG("%s\n", dlerror());
exit(EXIT_FAILURE);
}
global.out.run = dlsym(global.out.handle, "output_run");
if ( global.out.run == NULL ) {
LOG("%s\n", dlerror());
exit(EXIT_FAILURE);
}
/* try to find optional command */
global.out.cmd = dlsym(global.out.handle, "output_cmd");
global.out.param.parameter_string = strchr(output, ' ');
global.out.param.global = &global;
global.out.param.id = i;
if ( global.out.init(&global.out.param) ) {
LOG("output_init() return value signals to exit");
closelog();
exit(0);
}
}
/* start to read the input, push pictures into global buffer */
DBG("starting input plugin\n");
syslog(LOG_INFO, "starting input plugin");
if ( global.in.run() ) {
LOG("can not run input plugin\n");
closelog();
return 1;
}
DBG("starting %d output plugin(s)\n", global.outcnt);
for(i=0; i<global.outcnt; i++) {
syslog(LOG_INFO, "starting output plugin: %s (ID: %02d)", global.out.plugin, global.out.param.id);
global.out.run(global.out.param.id);
}
/* wait for signals */
pause();
return 0;
}
求此程序的流程图，还有大概解释，此程序是web网页视频监控项目里的，小弟真的毕设急需但是，看着它毫无办法，求高手解答，请好心人加qq275397124解救我，非常感谢！小弟在此跪了！
