diff --git a/library/common/src/main/java/com/google/android/exoplayer2/util/FrameProcessor.java b/library/common/src/main/java/com/google/android/exoplayer2/util/FrameProcessor.java
index cdf8d586fd..c63fd5e65f 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/util/FrameProcessor.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/util/FrameProcessor.java
@@ -137,6 +137,8 @@ public interface FrameProcessor {
    *
    * <p>The caller should update {@link FrameInfo#streamOffsetUs} when switching input streams to
    * ensure that frame timestamps are always monotonically increasing.
+   *
+   * <p>Can be called on any thread.
    */
   void setInputFrameInfo(FrameInfo inputFrameInfo);
 
@@ -216,6 +218,8 @@ public interface FrameProcessor {
    * ignored.
    *
    * <p>This method blocks until all resources are released or releasing times out.
+   *
+   * <p>Can be called on any thread.
    */
   void release();
 }