用Java摄像头捕捉视频

Question

我正在尝试从一个java应用程序中捕获视频屏幕截图。我没有加载sarxos/webcam-capture库。我在我的项目中添加了可执行的jar。有点乱。我想从我创建的一个简单的javafx界面上捕获视频。问题是，在安装了lib和slf4之后，它就需要安装xuggle。我在路径中添加了xuggle，我的代码如下：

File file = new File("output.ts");

IMediaWriter writer = ToolFactory.makeWriter(file.getName());
Dimension size = WebcamResolution.QVGA.getSize();

writer.addVideoStream(0, 0, ICodec.ID.CODEC_ID_H264, size.width, size.height);

Webcam webcam = Webcam.getDefault();
webcam.setViewSize(size);
webcam.open(true);

long start = System.currentTimeMillis();

for (int i = 0; i < 50; i++) {

    System.out.println("Capture frame " + i);

    BufferedImage image = ConverterFactory.convertToType(webcam.getImage(), BufferedImage.TYPE_3BYTE_BGR);
    IConverter converter = ConverterFactory.createConverter(image, IPixelFormat.Type.YUV420P);

    IVideoPicture frame = converter.toPicture(image, (System.currentTimeMillis() - start) * 1000);
    frame.setKeyFrame(i == 0);
    frame.setQuality(0);

    writer.encodeVideo(0, frame);

    // 10 FPS
    Thread.sleep(100);
}

writer.close();

System.out.println("Video recorded in file: " + file.getAbsolutePath());

不过，我收到以下资料：

Caused by: java.lang.UnsatisfiedLinkError: no xuggle-ferry in java.library.path

EDIT2 --我也尝试了jxcapture库。我在我的项目中添加了所有必需的库，我运行了以下代码：在这里输入链接描述，代码运行良好--我设法存储视频，但是最终我收到了以下错误：

8614 JNIWrapper.ShutdownHook ERROR com.jniwrapper.NativeResourceCollector - com.jniwrapper.FunctionExecutionException:回调参数类型或其计数在com.jniwrapper.NativeResourceCollector方法中不正确)

知道这个错误是关于什么的吗？JNIWrapper.ShutdownHook是什么？我在3台不同的机器上尝试了这些代码，而这只发生在其中一台机器上？我如何处理这个异常？

EDIT3:我试过@whitesite求婚EDIT3。gui启动了，我有两个按钮开始和停止，开始按钮打开相机，当我试图停止时，我收到以下消息：

java.lang.NullPointerException:参数0的指针地址为NULL。在org.bytedeco.javacpp.opencv_videoio$VideoWriter.write(Native方法上)在org.bytedeco.javacv.OpenCVFrameRecorder.record(OpenCVFrameRecorder.java:105) at Test1.lambda$0(Test1.java:52)在java.lang.Thread.run(未知源)

Answer 1

类路径中缺少slf4-api-ver.jar。但是，仅仅添加api是不够的，您还需要像slf4j这样的提供程序-simple-ver.jar。最新版本为1.7.21，可从此处下载http://www.slf4j.org/download.html

Answer 2

好的，这就是我使用这个JavaCV库和他们的例子所得到的：

public class Test extends Application {

public void start(Stage primaryStage) throws Exception {

    OpenCVFrameGrabber capture = OpenCVFrameGrabber.createDefault(0);
    capture.start();

    OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();
    Java2DFrameConverter javaConverter = new Java2DFrameConverter();

    VBox root = new VBox();
    Canvas canvas = new Canvas();
    canvas.setHeight(capture.getImageHeight());
    canvas.setWidth(capture.getImageWidth());
    root.getChildren().add(canvas);
    Scene scene = new Scene(root, capture.getImageWidth(), capture.getImageHeight());

    primaryStage.setTitle("Live video");
    primaryStage.setScene(scene);
    primaryStage.show();

    Thread videoProcessor = new Thread(() -> {
        File output = new File("C:/Work/test.avi");
        OpenCVFrameRecorder recorder = new OpenCVFrameRecorder(output, capture.getImageWidth(), capture.getImageHeight());
        try {
            recorder.setVideoCodec(opencv_videoio.CV_FOURCC((byte) 'M', (byte) 'J', (byte) 'P', (byte) 'G'));
            recorder.start();
            while (true) {
                if(Thread.currentThread().isInterrupted()){
                    break;
                }
                Frame frame = capture.grab();
                Platform.runLater(()->{
                    BufferedImage image = javaConverter.getBufferedImage(frame, 1.0, false, null);
                    canvas.getGraphicsContext2D().drawImage(SwingFXUtils.toFXImage(image, null),0,0);
                });
                recorder.record(frame);
            }
            recorder.stop();
            capture.release();
            recorder.release();
        } catch (Exception e) {
            e.printStackTrace();
        }
    });

    primaryStage.setOnCloseRequest(e->{
        videoProcessor.interrupt();
    });

    videoProcessor.start();

}

public static void main(String[] args) throws Exception {
    launch(args);
}

}

它捕获视频从网络摄像头和翻译它的现场和在同一时间写入文件。您需要使用maven或手动安装将它们的库包含在类路径中，还需要使用二进制zip存档中的所有jars。也许你不需要所有的，但我并没有深入挖掘。

你可以玩设置和调查的例子和来源。据我所见，它是一个非常强大的图书馆。

编辑

视频处理部分：

Thread videoProcessor = new Thread(() -> {
        OpenCVFrameGrabber capture = null;
        FrameRecorder recorder = null;
        try {

            File output = new File("C:/Work/test2.avi");
            capture = OpenCVFrameGrabber.createDefault(0);
            capture.start();
            recorder = FrameRecorder.createDefault(output, capture.getImageWidth(), capture.getImageHeight());
            recorder.setFrameRate(8);
            recorder.setVideoCodec(opencv_videoio.CV_FOURCC((byte) 'M', (byte) 'J', (byte) 'P', (byte) 'G'));
            recorder.start();
            long l = System.currentTimeMillis();
            while (true) {
                if(Thread.currentThread().isInterrupted()){
                    break;
                }
                recorder.record(capture.grab());

            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                recorder.stop();
                capture.release();
                recorder.release();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });

您需要在某个地方启动处理videoProcessor.start()，然后中断它以停止录制videoProcessor.interrupt()。您还可能需要设置适当的记录器帧速率，以调整它到您的相机fps。

编辑2

输出可用设备的代码：

int n = org.bytedeco.javacpp.videoInputLib.videoInput.listDevices();
for (int i = 0; i < n; i++) {
    System.out.println(i + " = " + org.bytedeco.javacpp.videoInputLib.videoInput.getDeviceName(i));
}  

编辑3

如果网络摄像头-捕获工作，你可以用它来捕获图像并使用javaCV将这些图像记录到视频文件中(就像你的问题中的exapmle，只是javaCV而不是xuggler)。这是一个小型javafx应用程序，它有两个按钮：'Start‘启动videoProcessing线程来捕获视频，'Stop’打断这个线程：

import com.github.sarxos.webcam.Webcam;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import org.bytedeco.javacpp.opencv_videoio;
import org.bytedeco.javacv.Java2DFrameConverter;
import org.bytedeco.javacv.OpenCVFrameRecorder;


import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.io.File;

public class Test1 extends Application {

public void start(Stage primaryStage) throws Exception {

    final double FPS = 25;
    final int WIDTH = 640;
    final int HEIGHT = 480;
    Webcam webcam = Webcam.getDefault();
    webcam.setViewSize(new Dimension(WIDTH, HEIGHT));

    Java2DFrameConverter javaConverter = new Java2DFrameConverter();

    VBox root = new VBox();
    Button b1 = new Button("Start");
    Button b2 = new Button("Stop");

    root.getChildren().addAll(b1, b2);
    Scene scene = new Scene(root, 300,200);
    primaryStage.setTitle("Test");
    primaryStage.setScene(scene);

    Runnable r = () -> {
        File output = new File("C:/Work/test.avi");
        OpenCVFrameRecorder recorder = new OpenCVFrameRecorder(output, WIDTH, HEIGHT);
        recorder.setFrameRate(FPS);
        try {
            recorder.setVideoCodec(opencv_videoio.CV_FOURCC((byte) 'M', (byte) 'J', (byte) 'P', (byte) 'G'));
            recorder.start();
            webcam.open();
            while (true) {
                if(Thread.currentThread().isInterrupted()){
                    break;
                }
                BufferedImage image = webcam.getImage();
                recorder.record(javaConverter.getFrame(image));
                try {
                    Thread.sleep(1000 / (long)FPS);
                } catch (InterruptedException ie) {
                    break;
                }
            }
            recorder.stop();
            recorder.release();
            webcam.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    };

    b1.setOnAction(e->{
        Thread t = new Thread(r);
        t.start();
        b2.setOnAction(e2->t.interrupt());
    });

    primaryStage.show();
}

public static void main(String[] args) throws Exception {
    launch(args);
}

}