using_vhook = 1;
static void add_frame_hooker(const char *arg){    int argc = 0;    char *argv[64];    int i;    char *args = av_strdup(arg);    argv[0] = strtok(args, " ");    while (argc < 62 && (argv[++argc] = strtok(NULL, " "))) {    }    i = frame_hook_add(argc, argv);    if (i != 0) {        fprintf(stderr, "Failed to add video hook function: %s\n", arg);        exit(1);    }}