How can I scale video in ExoPlayer-V2 - Play Video In Full Screen

Following two lines helped me to play video in full-screen mode.

Using app:resize_mode in layout file this somehow help but it stretches the video as mentioned in the question picture.

<com.google.android.exoplayer2.ui.PlayerView
      android:layout_width="match_parent"
      app:resize_mode="...."
      android:layout_height="match_parent" />

Try changing AspectRatioFrameLayout to FILL,FIT,ZOOM... as per yout requirement, changing below line worked for me.

exoVideoPlayerView.setResizeMode(AspectRatioFrameLayout.RESIZE_MODE_FILL);

Bellow line will ensure that aspect ratio is correctly maintained even for 4:3 videos.

exoPlayer.setResizeMode(AspectRatioFrameLayout.RESIZE_MODE_FIT);

Also you can try changing VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING in exoplayer

To maintain center crop in exo player below code worked for me:

Java code:

playerView.setResizeMode(AspectRatioFrameLayout.RESIZE_MODE_ZOOM);

or you can use from xml:

<com.google.android.exoplayer2.ui.PlayerView
    android:id="@+id/playerView"
    android:layout_width="match_parent"
    app:resize_mode="zoom"
    android:layout_height="match_parent" />

Following are the Resize Mode options to play around with

app:resize_mode="fixed_width"
app:resize_mode="fixed_height"
app:resize_mode="fill"
app:resize_mode="fit"
app:resize_mode="zoom"

You can try each one to see its affect on your container.