之前每一秒鐘擷取一張圖片，發現有些圖片報了“[mpeg4 @ 05938aa0] warning: first frame is no keyframe”這個警告，而且截出的圖片都是灰屏，根本沒有圖片。後來在網上找了很久，終於弄明白了，原來是ffmpeg它有“關鍵幀”這個說法，所以如果設定的幀的位置不是關鍵幀的位置的話，就可能截出的圖片有問題。後來經過改進，終於搞定了。

	public static void main(String[] args) {
		System.out.println(System.getProperty("java.library.path"));
//		 System.out.println("Welcome to OpenCV " + Core.VERSION);
//		 System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
//		 Mat m = Mat.eye(3, 3, CvType.CV_8UC1);
//		 System.out.println("m = " + m.dump());

		// 載入本地的OpenCV庫，這樣就可以用它來呼叫Java API
		System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
		Test t = new Test();
//		t.test();
//		t.run();
//		t.run2();
		t.run3();
//		System.out.println(t.CmpPic("d:/img/219.jpg"));
	}
 

	public void run3() {
		CvCapture capture = opencv_highgui.cvCreateFileCapture("D:/085402.crf");
		
		//幀率
		int fps = (int) opencv_highgui.cvGetCaptureProperty(capture, opencv_highgui.CV_CAP_PROP_FPS);
		System.out.println("幀率:"+fps);
		
		IplImage frame = null;
		double pos1 = 0;
		
		int rootCount = 0;

		while (true) {
			
			//讀取關鍵幀
			frame = opencv_highgui.cvQueryFrame(capture);
			
			rootCount = fps;
			while(rootCount > 0 ){
				//這一段的目的是跳過每一秒鐘的幀數,也就是說fps是幀率(一秒鐘有多少幀),在讀取一幀後,跳過fps數量的幀就相當於跳過了1秒鐘。
				frame = opencv_highgui.cvQueryFrame(capture);
				rootCount--;
			}

			//獲取當前幀的位置
			pos1 = opencv_highgui.cvGetCaptureProperty(capture,opencv_highgui.CV_CAP_PROP_POS_FRAMES);
			System.out.println(pos1);

			if (null == frame)
				break;
			
			opencv_highgui.cvSaveImage("d:/img/" + pos1 + ".jpg",frame);
			
		}

		opencv_highgui.cvReleaseCapture(capture);
	}