java使用摄像头录制

要在 Java 中使用摄像头录制视频，你可以使用 Java 的 OpenCV 库或者 Java Media Framework（JMF）。

使用 OpenCV 库：

1. 安装 OpenCV 库并配置环境变量。
2. 在 Java 代码中导入 OpenCV 库。
3. 初始化摄像头并打开视频流。
4. 读取视频流中的每一帧，并将其显示在窗口中或者保存为视频文件。

以下是示例代码：

import org.opencv.core.*;
import org.opencv.videoio.VideoCapture;

public class VideoRecorder {
    public static void main(String[] args) {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        
        VideoCapture camera = new VideoCapture(0);
        if (!camera.isOpened()) {
            System.out.println("Failed to open camera!");
            return;
        }
        
        Mat frame = new Mat();
        Size frameSize = new Size((int) camera.get(Videoio.CAP_PROP_FRAME_WIDTH), (int) camera.get(Videoio.CAP_PROP_FRAME_HEIGHT));
        VideoWriter videoWriter = new VideoWriter("output.avi", VideoWriter.fourcc('M','J','P','G'), 30, frameSize, true);
        
        while (camera.read(frame)) {
            // Display the frame
            HighGui.imshow("Camera", frame);
            
            // Save the frame to video file
            videoWriter.write(frame);
            
            if (HighGui.waitKey(1) == 27) {
                break;
            }
        }
        
        camera.release();
        videoWriter.release();
        HighGui.destroyAllWindows();
    }
}

使用 JMF：

1. 下载并安装 JMF。
2. 在 Java 代码中导入 JMF 库。
3. 创建一个 Player 对象并指定视频源。
4. 创建一个 DataSource 对象并将其连接到 Player 对象。
5. 创建一个 Processor 对象并连接到 DataSource 对象。
6. 将 Processor 对象的输出连接到一个 FileWriter 对象，用于保存视频文件。
7. 开始录制并停止录制时关闭所有对象。

以下是示例代码：

import java.io.File;
import java.io.IOException;
import javax.media.*;
import javax.media.format.VideoFormat;
import javax.media.protocol.DataSource;
import javax.media.protocol.FileTypeDescriptor;

public class VideoRecorder {
    public static void main(String[] args) {
        String outputFile = "output.avi";
        int width = 640;
        int height = 480;
        int frameRate = 30;
        
        File file = new File(outputFile);
        try {
            file.createNewFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        // Create a player for the video source
        Player player = null;
        try {
            MediaLocator locator = new MediaLocator("vfw://0");
            player = Manager.createRealizedPlayer(locator);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        // Create a data source for the player
        DataSource dataSource = player.getDataSource();
        
        // Create a processor for the data source
        Processor processor = null;
        try {
            processor = Manager.createProcessor(dataSource);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        // Configure the processor
        processor.configure();
        while (processor.getState() < Processor.Configured) {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        
        // Set the output format
        TrackControl trackControl = (TrackControl) processor.getTrackControls()[0];
        VideoFormat videoFormat = new VideoFormat(VideoFormat.MJPG, new Dimension(width, height), Format.NOT_SPECIFIED, Format.byteArray, (float) frameRate);
        trackControl.setFormat(videoFormat);
        
        // Create a file writer for the processor
        FileTypeDescriptor outputFileType = new FileTypeDescriptor(FileTypeDescriptor.QUICKTIME);
        outputFileType.appendSuffix("avi");
        DataSource outputDataSource = null;
        try {
            outputDataSource = Manager.createDataSource(new MediaLocator("file:" + outputFile));
        } catch (Exception e) {
            e.printStackTrace();
        }
        DataSink dataSink = null;
        try {
            dataSink = Manager.createDataSink(processor.getDataOutput(), outputDataSource);
            dataSink.open();
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        // Connect the processor to the file writer
        processor.setContentDescriptor(new ContentDescriptor(outputFileType));
        processor.realize();
        while (processor.getState() < Processor.Realized) {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        processor.start();
        dataSink.start();
        System.out.println("Recording...");
        
        // Wait for the user to stop recording
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        
        // Stop recording and close all objects
        System.out.println("Stopping recording...");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        dataSink.stop();
        dataSink.close();
        processor.stop();
        processor.close();
        player.stop();
        player.close();
        System.out.println("Done.");
    }
}