A simple service to loop RTMP VOD streaming

rtmp_loop.c

/*
 * loop_rtmp.c: A simple service to loop RTMP VOD streaming
 *
 * Usage:
 *   loop_rtmp <playlist> <channel>
 *
 */

#include <unistd.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "rtmp_config.h"
#include "sys_utils.h"
#include "task_exec.h"

#define LOCAL_LOG_IDENTIFY  "loop_rtmp/loop_rtmp"

static int check_playlist(const char *playlist)
{
    FILE *fp = fopen(playlist, "r");
    char *buffer,*p, *ptr;
    char line[2048] = {0};
    char filename[2048];
    int total_size = 1024*2048;
    int len = 0;
    struct stat file_stat;

    if (!fp)
        return -1;

    buffer = malloc(total_size);
    if (!buffer) {
        fclose(fp);
        return -2;
    }
    p = buffer;

    //
    // the playlist format:
    // ....
    // file /main_disk/live_record/imbatv_1500K-1422099849.mp4
    // file /main_disk/live_record/imbatv_1500K-1422171768.mp4
    // ....
    //
    while (fgets(line, sizeof(line) - 1 , fp) != NULL) {
        // Only work for *nix
        ptr = strchr(line, '/');
        if (ptr) {
            strcpy(filename, ptr);
            ptr = filename;
            while(*ptr) {
                // remove tail "\n" or "\r"
                if (*ptr == '\n' || *ptr == '\r') {
                    *ptr = '\0';
                    break;
                }
                ptr++;
            }
            // check if file is available
            // MUST check the path is a regular file, not a directory
            if (access(filename, F_OK) != -1 &&
                (stat(filename, &file_stat) == 0 && S_ISREG(file_stat.st_mode))) {
                int n = strlen(line);

                if (len + n >  total_size)
                    break;
                strncpy(p, line, n);
                len += n;
                p += n;
            }
        }
    }
    fclose(fp);

    fp = fopen(playlist, "w");
    if (fp) {
        fwrite(buffer, 1, len, fp);
        fclose(fp);
    }
    free(buffer);

    return 0;
}

//
// The playlist is published to "rtmp://127.0.0.1/vod/$channel"
//
int main(int argc, const char *argv[])
{
    pid_t pid = 0;
    char input_url[MAX_URL_LENGTH] = {0};
    char rtmp_url[MAX_URL_LENGTH] = {0};
    char channel[128] = {0};
    char logfile[256] = {0};
    char cmd[2048] = {0};
    int i=0, max_loop_count = 256;

    if (argc != 3) {
        fprintf(stderr, "Usage: loop_rtmp <playlist> <channel>\n");
        exit(1);
    }
    snprintf(channel, sizeof(channel), "%s", argv[2]);
    ptr = strstr(channel, PLATFORM_MAGIC_CODE);
    if (!ptr) {
        fprintf(stderr, "Channel code(%s) is wrong\n", channel);
        return -1;
    }
    *ptr = '\0';

    snprintf(input_url, MAX_URL_LENGTH, "%s", argv[1]);
    snprintf(rtmp_url, MAX_URL_LENGTH, "rtmp://127.0.0.1/vod/%s", channel);

    fprintf(stderr, "input_url: %s\n", input_url);
    fprintf(stderr, "loop_channel: %s\n", rtmp_url);

    fprintf(stderr, "\n");

    while (i < max_loop_count) {
        //
        // kill all subscribers which are listening to current channel
        // otherwise, the timestamp is wrong when re-loop, we will get the following huge warnings:
        //
        // DTS 4203501128, next:2082712000 st:0 invalid dropping
        // PTS 4203501208, next:2082712000 invalid dropping st:0
        // DTS 4203501168, next:2082752000 st:0 invalid dropping
        // PTS 4203501368, next:2082752000 invalid dropping st:0
        // ....
        //
        // until the remote publish server close client's connection
        //
        // Another solution: repeat/extend contents in the playlist to 21 days
        //
        kill_apps(FFMPEG_APP, rtmp_url);

        make_log_name(LOG_BASE_PATH, LOCAL_LOG_IDENTIFY, channel, logfile, sizeof(logfile));

        //
        // Make sure the files in playlist are available, otherwise, we will get the following error:
        //
        // [concat @ 0x29f60c0] Impossible to open '/main_disk/live_record/imbatv_1500K-1421920601.mp4'
        // /main_disk/logs/mp4_1500K_playlist.txt: No such file or directory
        //
        check_playlist(input_url);

        snprintf(cmd, sizeof(cmd), "/usr/local/bin/%s -loglevel warning -xerror -re -f concat -i '%s' -c copy -metadata title='loop_%s' -f flv '%s' &> '%s'", FFMPEG_APP, inp
ut_url, argv[2], rtmp_url, logfile);
        fprintf(stderr, "ffmpeg_cmd: %s\n", cmd);
        pid = task_exec(cmd, 0);
        // TODO: playlist refresh automatically
        waitpid(pid, &status, 0);
        // can not capture: SIGKILL and SIGSTOP
        if (WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV) {
            fprintf(stderr, "terminated forcely");
            break;
        }

        i++;
        // Must sleep, because playlist list is a local file which will not be blocked by network IO
        sleep(1);
        fprintf(stderr, "\n***** loop playlist: count=%d *****\n", i);
    }

    fprintf(stderr, "The App has been terminated: loop_count=%d\n", i);

    return 0;
}