Android camera1 支持4:3

// Import necessary packages
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

// Define class that implements SurfaceHolder.Callback
public class CustomCamera implements SurfaceHolder.Callback {

    // Declare variables
    private Camera mCamera;
    private SurfaceHolder mHolder;

    // Constructor
    public CustomCamera(SurfaceView surfaceView) {
        // Get SurfaceHolder from SurfaceView
        mHolder = surfaceView.getHolder();
        // Set this class as the callback for SurfaceHolder events
        mHolder.addCallback(this);
    }

    // Implement SurfaceHolder.Callback methods
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // Open camera and set preview display
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        // Set camera parameters for preview size and aspect ratio
        Camera.Parameters parameters = mCamera.getParameters();
        Camera.Size previewSize = getOptimalPreviewSize(parameters.getSupportedPreviewSizes(), 4, 3);
        parameters.setPreviewSize(previewSize.width, previewSize.height);
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }

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

    // Define method to get optimal preview size based on aspect ratio
    private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int width, int height) {
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio = (double) width / height;
        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;
        int targetHeight = height;

        // Try to find a size that matches the target aspect ratio and has the closest height
        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);
            }
        }

        // If no size matches the target aspect ratio, choose the one with the closest aspect ratio
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                double ratio = (double) size.width / size.height;
                if (Math.abs(ratio - targetRatio) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(ratio - targetRatio);
                }
            }
        }

        return optimalSize;
    }
}

// To get a 4:3 aspect ratio, we need to find the optimal preview size with a width-to-height ratio of 4:3. 
// We can do this by iterating through the list of supported preview sizes and finding the one with the closest height to the target height (which is 3/4 of the target width). 
// If there is no size with a 4:3 aspect ratio, we choose the one with the closest aspect ratio. 
// We then set the camera parameters to use this preview size.