Prevent flipping of the front facing camera

问题:

I'm attempting to access the raw feed of android's front facing camera. By default, the front facing camera's preview is flipped horizontally so users can see themselves as if looking into a mirror - that's great, but not what I need. What's the best way to get the raw feed? Is there some way to disable the automatic flipping, or should I attempt to flip it in code myself? My application needs to display a real-time feed of the front facing camera without it being flipped like a mirror.

回答1:

If you want to use a front-facing camera for barcode scanning you can use TextureView and apply a transformation matrix to it. When the texture is updated you can read the image data and use that.

See https://github.com/hadders/camera-reverse

Specifically from MainActivity.java

mCamera.setDisplayOrientation(90);
Matrix matrix = new Matrix();
matrix.setScale(-1, 1);
matrix.postTranslate(width, 0);
mTextureView.setTransform(matrix);

回答2:

The data from the front camera is as the camera the sees it, looking at you. The left side of its image is your right side. I think this is what you want already? When put onto a SurfaceView it is flipped so it acts as you say, but that's a separate cosmetic transformation.

At least, this is how every device I've seen works and I've looked hard at this to implement front camera support in Barcode Scanner / Barcode Scanner+.