android - 拍的照片比预览大

Question

我正在尝试为我的应用程序添加摄像头支持，我有以下用于摄像头的代码，图像要么被拉伸(stretch)要么预览被扭曲，

1- I tried the below and it shows a stretched preview image  

2- I tried the below with this mCamera.setDisplayOrientation, it shows the preview image fine but the taken picture is bigger than the one on the SurfaceView on portrait, but the image taken in landscape is fine.

3- I tried with getOptimalPreviewSize and I'm getting RuntimeException error as shown in the comment in the code below

4- I tried this http://stackoverflow.com/questions/26958110/android-taken-photo-is-bigger-than-the-preview and it's showing a white surfaceview and the landscape taken picture is stretched

我该怎么办？

class Preview extends ViewGroup implements SurfaceHolder.Callback {
    private final String TAG = "Preview";
    SurfaceView mSurfaceView;
    SurfaceHolder mHolder;
    Camera.Size mPreviewSize;
    List<Camera.Size> mSupportedPreviewSizes;
    Camera mCamera;
    Preview(Context context, SurfaceView sv) {
        super(context);
        mSurfaceView = sv;
        mHolder = mSurfaceView.getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }
    public void setCamera(Camera camera) {
        mCamera = camera;
        if (mCamera != null) {
            mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
            requestLayout();
            Camera.Parameters params = mCamera.getParameters();
            List<String> focusModes = params.getSupportedFocusModes();
            if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
                // set the focus mode
                params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                // set Camera parameters
                mCamera.setParameters(params);
            }
        }
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // We purposely disregard child measurements because act as a
        // wrapper to a SurfaceView that centers the camera preview instead
        // of stretching it.
        final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
        setMeasuredDimension(width, height);
        if (mSupportedPreviewSizes != null) {
            mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
        }
    }
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        if (changed && getChildCount() > 0) {
            final View child = getChildAt(0);
            final int width = r - l;
            final int height = b - t;
            int previewWidth = width;
            int previewHeight = height;
            if (mPreviewSize != null) {
                previewWidth = mPreviewSize.width;
                previewHeight = mPreviewSize.height;
            }
            // Center the child SurfaceView within the parent.
            if (width * previewHeight > height * previewWidth) {
                final int scaledChildWidth = previewWidth * height / previewHeight;
                child.layout((width - scaledChildWidth) / 2, 0,
                        (width + scaledChildWidth) / 2, height);
            } else {
                final int scaledChildHeight = previewHeight * width / previewWidth;
                child.layout(0, (height - scaledChildHeight) / 2,
                        width, (height + scaledChildHeight) / 2);
            }
        }
    }
    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where
        // to draw.
        try {
            if (mCamera != null) {
                mCamera.setPreviewDisplay(holder);
            }
        } catch (IOException exception) {
            Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
        }
    }
    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        if (mCamera != null) {
            mCamera.stopPreview();
        }
    }
    private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio = (double) w / h;
        if (sizes == null) return null;
        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;
        int targetHeight = h;
        // Try to find an size match aspect ratio and size
        for (Camera.Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
        // Cannot find the one match the aspect ratio, ignore the requirement
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }
    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        if(mCamera != null) {
//            mCamera.setDisplayOrientation(90);
            Camera.Parameters parameters = mCamera.getParameters();
    //The below is getting error RuntimeException: setParameters failed
            parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
            requestLayout();
            mCamera.setParameters(parameters);
            mCamera.startPreview();
        }
    }

}

Answer 1

看看来自 Google 的示例代码: https://github.com/googlesamples/android-Camera2Basic

无论是预览还是图片格式，都需要自己抓取请求单独处理。