diff --git a/library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformationRequest.java b/library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformationRequest.java
index 958e340e1b..03bf3edc77 100644
--- a/library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformationRequest.java
+++ b/library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformationRequest.java
@@ -213,7 +213,7 @@ public final class TransformationRequest {
     }
 
     /**
-     * Sets the output resolution using the output height.
+     * Sets the output resolution using the output height of the displayed video.
      *
      * <p>Output width of the displayed video will scale to preserve the video's aspect ratio after
      * other transformations.
@@ -224,6 +224,10 @@ public final class TransformationRequest {
      * {@linkplain #setScale(float,float) scaling} or @linkplain #setRotationDegrees(float)
      * rotation} are requested.
      *
+     * <p>Note that the output encoded video's dimensions may be swapped from the displayed video's
+     * dimensions, if the displayed video's height > width. This is to improve compatibility among
+     * different device encoders.
+     *
      * @param outputHeight The output height of the displayed video, in pixels.
      * @return This builder.
      */