Android摄像头previewCallback不会调用4.1 [英] Android Camera PreviewCallback not called in 4.1

问题描述

我有一个应用程序来获得相机preVIEW帧与表面。这是工作在Android 4.0.4，但它确实与果冻豆，4.1.2在同一台设备上的更新后无法正常工作。简单地说，回调是从来没有叫回来。这里是code：剪断一点：

I have an application to get camera preview frames with a surface. It was working on Android 4.0.4 but it does not work with Jelly Bean, 4.1.2 on the same device after the update. Simply, the callback is never called back. Here is the code: Snipped a little bit:

public class Panel extends Activity {
    Camera myCamera;
    int cameraId = -1;
    MyCameraSurfaceView myCameraSurfaceView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_panel);

        myCamera = getCameraInstance();
        myCamera.setPreviewCallback(new Camera.PreviewCallback() {
            @Override
            public void onPreviewFrame(byte[] data, Camera camera) {
                Log.d("Camera Preview", data.length + "");
            }
        });

        myCameraSurfaceView = new MyCameraSurfaceView(this, myCamera);
        FrameLayout myCameraPreview = (FrameLayout) findViewById(R.id.videoview);
        myCameraPreview.addView(myCameraSurfaceView);
    }

    private Camera getCameraInstance() {
        Camera c = null;
        try {
            c = Camera.open();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return c;
    }


    public class MyCameraSurfaceView extends SurfaceView implements
            SurfaceHolder.Callback {

        private SurfaceHolder mHolder;
        private Camera mCamera;

        public MyCameraSurfaceView(Context context, Camera camera) {
            super(context);
            mCamera = camera;
            mHolder = getHolder();
            mHolder.addCallback(this);
        }

        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            try {
                mCamera.setPreviewDisplay(holder);
                mCamera.startPreview();
            } catch (IOException e) {
            }
        }
    }
}

该视频帧被显示在活动，所以我不能找出我做错了。

The video frames are being displayed on the activity, so I cannot figure out what I am doing wrong.

推荐答案

我已经通过其他的教程改写了code。它的工作原理，但现在更慢。我不知道确切的原因（这可能是由于泄漏的N7000 ROM我用的，它可能有错误或这是在4.1的实现方式不同，不知道）

I have rewrote the code by using another tutorial. It works, but now slower. I don't know the exact reason (it may be due to leaked N7000 ROM I use, it may have a bug or this is implemented differently in 4.1, not sure)

相机preview.java

CameraPreview.java

public class CameraPreview implements SurfaceHolder.Callback,
        Camera.PreviewCallback {
    int PreviewSizeWidth;
    int PreviewSizeHeight;
    SurfaceHolder mSurfHolder;
    Camera mCamera;

    public CameraPreview(int PreviewlayoutWidth, int PreviewlayoutHeight) {
        PreviewSizeWidth = PreviewlayoutWidth;
        PreviewSizeHeight = PreviewlayoutHeight;
    }



    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        Parameters p = camera.getParameters();  
        int width = p.getPreviewSize().width;
        int height = p.getPreviewSize().height;

        ByteArrayOutputStream outstr = new ByteArrayOutputStream();
        Rect rect = new Rect(0, 0, width, height);
        YuvImage yuvimage = new YuvImage(data, ImageFormat.NV21, width,
                height, null);
        yuvimage.compressToJpeg(rect, 80, outstr); // outstr contains image in jpeg  
        String encodedImage = Base64.encodeToString(
                outstr.toByteArray(), Base64.DEFAULT); // this is base64 encoding of image


    }

    @Override
    public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
        Parameters parameters;
        mSurfHolder = arg0;

        parameters = mCamera.getParameters();
        parameters.setPreviewSize(PreviewSizeWidth, PreviewSizeHeight);

        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }

    public void surfaceCreated(SurfaceHolder arg0) {
        mCamera = Camera.open();
        try {
            // If did not set the SurfaceHolder, the preview area will be black.
            mCamera.setPreviewDisplay(arg0);
            mCamera.setPreviewCallback(this);
            Parameters p = mCamera.getParameters();
            p.setPreviewSize(PreviewSizeWidth, PreviewSizeHeight);
            mCamera.setParameters(p);
        } catch (IOException e) {
            mCamera.release();
            mCamera = null;
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder arg0) {
        mCamera.setPreviewCallback(null);
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }
}

PanelActivity.java

PanelActivity.java

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_panel);


    SurfaceView camView = new SurfaceView(this);
    SurfaceHolder camHolder = camView.getHolder();
    int width = 352; // must set a compatible value, otherwise it gets the default width and height
    int height = 288;

    camPreview = new CameraPreview(width, height);

    camHolder.addCallback(camPreview);
    camHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    mainLayout = (FrameLayout) findViewById(R.id.videoview);
    mainLayout.addView(camView, new LayoutParams(width, height));

}

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