我正在尝试从java应用程序中捕获视频屏幕截图。我已经下载了 sarxos / webcam-capture 库。我已将可执行jar添加到我的项目中。这有点乱。我想从我创建的简单javafx接口捕获视频。问题是在安装了lib和slf4后，它还需要安装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());
但是我收到以下内容：
Caused by: java.lang.UnsatisfiedLinkError: no xuggle-ferry in java.library.path
EDIT2 我也试过了jxcapture库。我在项目中添加了所有必需的库我运行以下代码：enter link description here，代码工作正常我设法存储视频，但最后我收到以下错误：
8614 [JNIWrapper.ShutdownHook] ERROR com.jniwrapper.NativeResourceCollector - com.jniwrapper.FunctionExecutionException：回调参数类型或其计数不正确 at com.jniwrapper.Function.invokeVirtualFunc（Native Method）
知道这个错误是什么意思吗？什么是JNIWrapper.ShutdownHook？我尝试了3台不同的机器中的代码，这只发生在其中一台机器上？我该如何处理这个例外？
EDIT3：我试过@whitesite提案EDIT3。 gui开始了，我有两个按钮启动和停止启动按钮打开相机，当我试图停止时，我收到以下内容：
java.lang.NullPointerException：参数0的指针地址为NULL。 at org.bytedeco.javacpp.opencv_videoio $ VideoWriter.write（Native Method） 在org.bytedeco.javacv.OpenCVFrameRecorder.record（OpenCVFrameRecorder.java:105） 在Test1.lambda $ 0（Test1.java:52） 在java.lang.Thread.run（未知来源）
答案 0 :(得分：4)
您在类路径中缺少slf4-api-ver.jar。但是只添加api是不够的，你还需要像slf4j-simple-ver.jar这样的提供者。最新版本为1.7.21版本，可从此处下载http://www.slf4j.org/download.html
答案 1 :(得分：4)
好的，这就是我使用这个JavaCV library及其示例所得到的：
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);
}
}
它从网络摄像头捕获视频并实时翻译，同时写入文件。您需要使用maven或手动安装以及来自二进制zip存档的所有jar包在classpath中包含它们的库。也许你不需要所有这些，但我没有深入挖掘
您可以使用设置并调查示例和来源。从我所看到的它是非常强大的图书馆
的修改
只是视频处理部分：
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();
}
}
});
您需要在某处开始处理videoProcessor.start()，然后将其中断以停止录制videoProcessor.interrupt()。您可能还需要设置适当的录像机帧速率，以将其调整为相机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
如果摄像头捕获工作，你可以使用它来捕获图像并使用javaCV将这些图像记录到视频文件中（就像你在问题中的exapmle，只是javaCV而不是xuggler）。这是一个小型的javafx应用程序，它有两个按钮：'Start'启动videoProcessing线程捕获视频，'Stop'中断此线程：
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);
}
}