<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.manos.videoviewmetrics.MainActivity">

    <RelativeLayout
        android:layout_alignParentTop="true"
        android:id="@+id/topLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <ImageView
            android:layout_centerVertical="true"
            android:layout_centerHorizontal="true"
            android:background="@mipmap/ic_wallpaper1"
            android:id="@+id/imageView1"
            android:layout_width="1920dp"
            android:layout_height="1080dp" />

    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/bottomLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/topLayout">

        <ImageView
            android:background="@mipmap/ic_wallpaper2"
            android:id="@+id/imageView2"
            android:layout_width="1280dp"
            android:layout_height="720dp" />

    </RelativeLayout>


</RelativeLayout>

public class MainActivity extends AppCompatActivity {

    private RelativeLayout topLayout, bottomLayout;
    private ImageView topImageView, bottomImageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        topLayout = (RelativeLayout) findViewById(R.id.topLayout);
        bottomLayout = (RelativeLayout) findViewById(R.id.bottomLayout);
        topImageView = (ImageView) findViewById(R.id.imageView1);
        bottomImageView = (ImageView) findViewById(R.id.imageView2);


        DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);

        int wantedHeight = displaymetrics.heightPixels / 2;
        //int wantedWidth = displaymetrics.widthPixels;

        int currentHeight = 1080;
        int currentWidth = 1920;


        float scaleFactor = (float) wantedHeight/ (float) currentHeight  ;

        int newWidth = (int) (scaleFactor * currentWidth);
        int newHeight = (int) (scaleFactor * currentHeight);

        topLayout.getLayoutParams().height = newHeight;
        topLayout.getLayoutParams().width = newWidth;
    }

}