!7

import org.jcodec.api.awt.AWTSequenceEncoder8Bit;

static int framesToEncode = 100000;

p {
  inputFilePath("Video to modify", voidfunc(final File video) {
    thread {
      invertVideo(video);
    }
  });
}

svoid invertVideo(File video) {
  File outFile = prepareProgramFile(addSuffix("inverted-" + video.getName(), ".mp4"));
  
  final LeftQueue lq = new LeftQueue(video);
  final RightQueue rq = new RightQueue(outFile);
  lq.rightQueue = rq;
  
  stepThread(lq);
  stepThread(rq);
}

svoid stepThread(Steppable s) {
  Thread thread = new Thread("Stepper Thread") {
    public void run() {
      s.step();
      while licensed {
        while (s.shouldStep) {
          s.shouldStep = false;
          s.step();
        }
        sleep();
      }
    }
  };
  s.thread = thread;
  thread.start();
}

abstract sclass Steppable {
  volatile bool shouldStep;
  Thread thread;
  
  void shouldStep() {
    shouldStep = true;
    if (thread != null) thread.interrupt();
  }
  
  abstract void step;
}

// decoding part
Steppable > LeftQueue {
  Iterator<BufferedImage> stream;
  RightQueue rightQueue;

  *(File video) {
    stream = framesFromVideo_reordering(video);
  }
  
  void step {
    if (stream != null && rightQueue.needImage())
      if (stream.hasNext()) {
        rightQueue.receive(stream.next());
        shouldStep();
      } else {
        stream = null;
        rightQueue.close();
      }
  }
}

// encoding part
Steppable > RightQueue {
  File outMP4;
  AWTSequenceEncoder8Bit enc;
  volatile BufferedImage img;
  int frames;
  volatile bool shouldClose;

  *(File *outMP4) {
    AWTSequenceEncoder8Bit enc = AWTSequenceEncoder8Bit.create25Fps(outMP4);
    enc.getEncoder().setKeyInterval(25);
  }
    
  void receive(BufferedImage img) {
    if (this.img != null) fail();
    this.img = img;
    shouldStep();
  }
  
  bool needImage() { ret img == null; }
  
  void step {
    if (img != null) {
      img = invertedImage(img);
      enc.encodeImage(img);
      img = null;
      ++frames;
      print("Frames: " + frames + "/" + framesToEncode);
      if (frames >= framesToEncode) shouldClose = true;
      else shouldStep();
    }
  }
  
  void close {
    enc.finish();
    print("Wrote " + f2s(outMP4) + " (" + frames + " frames)");
  }
}