如何正确设置 Android 相机方向? [英] How to set Android camera orientation properly?

问题描述

我想根据 Android 中的设备方向设置相机方向，但似乎没有任何效果.我尝试旋转 Surface 以及相机参数，但纵向模式下的相机预览总是颠倒过来.我需要将它顺时针旋转 90 度才能正确.这是我现在使用的代码，它只在横向模式下工作.

I want to set the camera orientation according to the device orientation in Android but nothing seems to be working. I tried to rotate the Surface as well as the camera parameters but the camera preview in portrait mode always comes upside down. I would need to rotate it by 90 degree clockwise for it to be correct. Here is the code I am using right now which works in landscape mode only.

    SurfaceHolder.Callback surfaceCallback = new SurfaceHolder.Callback() {

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        camera.stopPreview();
        camera.release();
        camera = null;
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {          
        initCamera();           
    }

    private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.2;
        double targetRatio = (double) w / h;
        if (sizes == null)
            return null;

        Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        int targetHeight = h;

        // Try to find an size match aspect ratio and size
        for (Size size : sizes) {
            Log.d(TAG, "Checking size " + size.width + "w " + size.height
                    + "h");
            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 (Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        Camera.Parameters parameters = camera.getParameters();

        List<Size> sizes = parameters.getSupportedPreviewSizes();
        Size optimalSize = getOptimalPreviewSize(sizes, width, height);         
        Log.d(TAG, "Surface size is " + width + "w " + height + "h");
        Log.d(TAG, "Optimal size is " + optimalSize.width + "w " + optimalSize.height + "h");           
        parameters.setPreviewSize(optimalSize.width, optimalSize.height);           
        // parameters.setPreviewSize(width, height);            
        camera.setParameters(parameters);
        camera.startPreview();
    }
};  

推荐答案

我终于用谷歌的相机应用解决了这个问题.它通过使用传感器获取手机的方向，然后适当地设置 EXIF 标签.从相机出来的 JPEG 不是自动定向的.

I finally fixed this using the Google's camera app. It gets the phone's orientation by using a sensor and then sets the EXIF tag appropriately. The JPEG which comes out of the camera is not oriented automatically.

此外，相机预览仅在横向模式下才能正常工作.如果您需要将活动布局定向为纵向，则必须使用来自方向传感器的值手动完成.

Also, the camera preview works properly only in the landscape mode. If you need your activity layout to be oriented in portrait, you will have to do it manually using the value from the orientation sensor.

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