sprintf(cmd, "--start=%d", _time, _lv_demo_music_get_track_length(track_id));
// execlp.../music", NULL);
// execlp("play", "play", "-p", buf, "trim", cmd, NULL);
// execlp...LOG_D("child pid:%d\n", getpid());
prctl(PR_SET_PDEATHSIG, SIGKILL);
execlp