。。。
  Producer* producer1 = new Producer(profile,"avformat", "/Users/linximing/Movies/55_1726454285_raw.mp4");
 producer1->set_in_and_out(400, 440);
        {
            Mlt::Filter f =  Mlt::Filter(profile,"affine");
            f.set("transition.rect", "0/0:50%x50% 1");
            f.set("transition.valign", "m");
            f.set("transition.halign", "c");
            f.set("transition.distort", 0);
            f.set("transition.fill", 1);
            producer1->attach(f);
        }
 Producer producer3 = Producer(profile,"color", "#995000");
    producer3.set_in_and_out(0, 20);
    Mlt::Playlist playlist(profile);
      playlist.append(producer3);  
  playlist.append(*producer1); 

  Mlt::Transition transition2(profile, "luma");
    int targetIndex = 0;
    playlist.mix(targetIndex, 10);
    playlist.mix_add(targetIndex   1, &transition2);
。。。