android exoplayer not fitted properly and not stretched across devices

Question

I have a screen on Portrait, I want the video to fit properly and cover the entire view without showing the background by the side,am currently using app:resize_mode="fit", this works well, but it shows the background by the side, considering other devices I don't want it to stretch, I have also tried using zoom for the app:resize_mode="zoom", but the video-stream cuts off at the top also, how do I make the video-stream fit perfectly without stretching or pixelating across other devices.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/login_hintcolor"
android:weightSum="6.8">

  <LinearLayout
    android:id="@+id/main_ll"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

 <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="2.8"
    android:orientation="vertical">

    <FrameLayout
        android:id="@+id/main_media_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="50dp">

        <com.google.android.exoplayer2.ui.PlayerView
            android:id="@+id/exoplayer"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/login_graycolor"
            app:resize_mode="fit"
            android:keepScreenOn="true" />


        <ProgressBar
            android:id="@+id/progressBar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:gravity="center" />

        <ImageView
            android:id="@+id/image_whole_video"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/playing"
            android:gravity="center"
            android:visibility="gone" />
    </FrameLayout>
    </LinearLayout>
    <LinearLayout
        android:id="@+id/ll_coomment_sec"
        android:visibility="visible"
        android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="4"
        android:background="@color/white_dull"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:weightSum="2">

            <android.support.v7.widget.RecyclerView
                android:layout_marginTop="5dp"
                android:layout_marginLeft="5dp"
                android:layout_marginRight="10dp"
                android:layout_weight="1.7"
                android:id="@+id/recyclerv_comment"
                android:visibility="visible"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:nestedScrollingEnabled="false"
                />


            <RelativeLayout
                android:visibility="gone"
                android:layout_marginBottom="10dp"
                android:id="@+id/llCommentBox"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:background="@color/white"
                android:orientation="horizontal"
                android:padding="5dp">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                android:weightSum="3"
                android:gravity="center">

                <ProgressBar
                    android:id="@+id/progressBarComment"
                    android:layout_weight="0.5"
                    android:layout_width="30dp"
                    android:layout_height="30dp"
                    android:layout_gravity="center"
                    android:visibility="gone"
                    android:gravity="center" />

                <org.xxxxx[ ][1].com.utils.CommentEditText
                    android:id="@+id/etComment"
                    android:layout_weight="2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                 android:background="@drawable/commet_edittext_background"
                    android:hint="@string/leave_a_comment"
                    android:inputType="textMultiLine"
                    android:maxLength="200"
                    android:maxLines="3"
                    android:textColor="@color/black" />
                <Button
                    android:visibility="visible"
                    android:id="@+id/btn_postcomment"
                    android:layout_gravity="center"
                    android:layout_weight="0.5"
                    android:layout_width="40dp"
                    android:layout_height="wrap_content"
                    android:scaleType="fitXY"
                    android:text="Post"
                    android:textSize="10sp"
                    android:layout_marginRight="1dp"
                    android:textStyle="bold"
                    android:textColor="@color/white"
                    android:background="@color/comment_button"
                    />
            </LinearLayout>
            </RelativeLayout>

        </LinearLayout>
    </LinearLayout>
</RelativeLayout>[enter image description here][1]