揭秘Android Camera2，开启实时帧图像捕捉之旅！

2024-01-07 23:30:37

Camera2：揭开安卓摄影新篇章

揭开Camera2的面纱

Camera2是安卓平台上用于摄像头开发的原生API，它比旧版的Camera1 API拥有更高的扩展性和灵活性，让你能够更深入地控制和发挥设备摄像头硬件的潜力。

Camera2入门指南

1. 启动Camera2 API

CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
String[] cameraIds = cameraManager.getCameraIdList();

// 选择要使用的摄像头
String cameraId = cameraIds[0]; // 一般情况下，后置摄像头是第一个
CameraCharacteristics characteristics = cameraManager.getCameraCharacteristics(cameraId);

2. 创建CameraDevice

CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
    @Override
    public void onOpened(@NonNull CameraDevice camera) {
        // 摄像头已打开，可以开始预览或拍照
    }

    @Override
    public void onDisconnected(@NonNull CameraDevice camera) {
        // 摄像头已断开连接
    }

    @Override
    public void onError(@NonNull CameraDevice camera, int error) {
        // 摄像头出错
    }
};

cameraManager.openCamera(cameraId, stateCallback, null);

3. 创建CameraCaptureSession

SurfaceTexture surfaceTexture = textureView.getSurfaceTexture();
Surface surface = new Surface(surfaceTexture);

CaptureRequest.Builder requestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
requestBuilder.addTarget(surface);

cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
    @Override
    public void onConfigured(@NonNull CameraCaptureSession session) {
        // CameraCaptureSession已配置好，可以开始预览或拍照
    }

    @Override
    public void onConfigureFailed(@NonNull CameraCaptureSession session) {
        // CameraCaptureSession配置失败
    }
}, null);

4. 开始预览

captureSession.setRepeatingRequest(requestBuilder.build(), null, null);

5. 拍照

CaptureRequest.Builder requestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
requestBuilder.addTarget(imageReader.getSurface());

cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE).build().capture(imageReader.getCaptureCallback(), null);

Camera2中的要点