camera view is upside down in my android application for Nexus 5X?

Question

I am developing an android application which uses camera preview in the background. It is working fine across different devices.

But when tested on Nexus 5X, the camera preview is upside down. I am using these permission in manifest

<uses-permission android:name="android.permission.CAMERA" />

My camera code is as follows

public void startCamera(int myTexture)
  {
    surface = new SurfaceTexture(myTexture);

    try {
      camera = Camera.open();


    } catch (Exception e) {
      Log.e("MainActivity", "failed to open Camera");
      e.printStackTrace();
    }
    try
    {
      camera1.setPreviewTexture(surface);
      camera1.startPreview();
    }
    catch (IOException ioe)
    {
      Log.w("MainActivity","Camera launch failed");
    }
  }

Tried camera.setDisplayOrientation(180); But didn't work. Please Help!

Answer 1

As explained in this pro-tip, you need to use setDisplayOrientation() to properly rotate the preview to match the device orientation.

The full code from the documentation (which works on the Nexus 5X) is:

public static void setCameraDisplayOrientation(Activity activity,
     int cameraId, android.hardware.Camera camera) {
   android.hardware.Camera.CameraInfo info =
       new android.hardware.Camera.CameraInfo();
   android.hardware.Camera.getCameraInfo(cameraId, info);
   int rotation = activity.getWindowManager().getDefaultDisplay()
       .getRotation();
   int degrees = 0;
   switch (rotation) {
     case Surface.ROTATION_0: degrees = 0; break;
     case Surface.ROTATION_90: degrees = 90; break;
     case Surface.ROTATION_180: degrees = 180; break;
     case Surface.ROTATION_270: degrees = 270; break;
   }

   int result;
   if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
     result = (info.orientation + degrees) % 360;
     result = (360 - result) % 360;  // compensate the mirror
   } else {  // back-facing
     result = (info.orientation - degrees + 360) % 360;
   }
   camera.setDisplayOrientation(result);
}

Answer 2

Since you are using a SurfaceTexture you will have to handle the rotation yourself. As stated in the documentation the method does not affect the order of the bytes:

This does not affect the order of byte array passed in onPreviewFrame(byte[], Camera), JPEG pictures, or recorded videos.

That said you can manually rotate the bytes directly on the GPU performing the action on the OpenGL Texture. Note that rotation of 180° is equivalent to flip bytes once vertically and once horizontally, which on OpenGL means that can either:

• Rotate 180° the plane drawing the camera texture
• Scale by -1 the x and y of the plane drawing the camera texture
• Change the UV of the camera plane