public void processVideo() throws Exception {
        if (converterThread != null && converterThread.isAlive()) {
            throw new Exception("Convert is already running");
        }

        if (videoInputPath == null) {
            throw new Exception("Video input is not specified.");
        }

        if (videoOutputPath == null) {
            throw new Exception("Video output is not specified.");
        }

        delegate.disableRenderButton();
        converterThread = new ConverterThread(this, videoInputPath, videoOutputPath);
        converterThread.start();
    }