diff --git a/libraries/common/src/main/java/androidx/media3/common/VideoGraph.java b/libraries/common/src/main/java/androidx/media3/common/VideoGraph.java
index 89142f922f..d542d22c0f 100644
--- a/libraries/common/src/main/java/androidx/media3/common/VideoGraph.java
+++ b/libraries/common/src/main/java/androidx/media3/common/VideoGraph.java
@@ -75,7 +75,8 @@ public interface VideoGraph {
    *
    * <p>If the method throws, the caller must call {@link #release}.
    *
-   * @param sequenceIndex The sequence index of the input which can aid ordering of the inputs.
+   * @param sequenceIndex The sequence index of the input which can aid ordering of the inputs. The
+   *     index must start from 0.
    */
   void registerInput(int sequenceIndex) throws VideoFrameProcessingException;
 
diff --git a/libraries/effect/src/main/java/androidx/media3/effect/MultipleInputVideoGraph.java b/libraries/effect/src/main/java/androidx/media3/effect/MultipleInputVideoGraph.java
index 851375ffa1..e4dbd5433b 100644
--- a/libraries/effect/src/main/java/androidx/media3/effect/MultipleInputVideoGraph.java
+++ b/libraries/effect/src/main/java/androidx/media3/effect/MultipleInputVideoGraph.java
@@ -47,6 +47,8 @@ import androidx.media3.common.VideoFrameProcessor;
 import androidx.media3.common.VideoGraph;
 import androidx.media3.common.util.GlUtil;
 import androidx.media3.common.util.UnstableApi;
+import androidx.media3.common.util.Util;
+
 import com.google.common.util.concurrent.MoreExecutors;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
@@ -261,7 +263,7 @@ public abstract class MultipleInputVideoGraph implements VideoGraph {
 
   @Override
   public VideoFrameProcessor getProcessor(int inputId) {
-    checkState(preProcessors.indexOfKey(inputId) >= 0);
+    checkState(Util.contains(preProcessors, inputId));
     return preProcessors.get(inputId);
   }
 
diff --git a/libraries/effect/src/main/java/androidx/media3/effect/SingleInputVideoGraph.java b/libraries/effect/src/main/java/androidx/media3/effect/SingleInputVideoGraph.java
index 789e3674e1..02433043c6 100644
--- a/libraries/effect/src/main/java/androidx/media3/effect/SingleInputVideoGraph.java
+++ b/libraries/effect/src/main/java/androidx/media3/effect/SingleInputVideoGraph.java
@@ -38,7 +38,7 @@ import java.util.concurrent.Executor;
 @UnstableApi
 public abstract class SingleInputVideoGraph implements VideoGraph {
 
-  /** The ID {@link #registerInput(int)} returns. */
+  /** The index of the only {@linkplain #registerInput(int) registered} input. */
   public static final int SINGLE_INPUT_INDEX = 0;
 
   private final Context context;
diff --git a/libraries/effect/src/main/java/androidx/media3/effect/VideoCompositor.java b/libraries/effect/src/main/java/androidx/media3/effect/VideoCompositor.java
index 348b9c6fad..783a3f33bf 100644
--- a/libraries/effect/src/main/java/androidx/media3/effect/VideoCompositor.java
+++ b/libraries/effect/src/main/java/androidx/media3/effect/VideoCompositor.java
@@ -49,8 +49,8 @@ public interface VideoCompositor extends GlTextureProducer {
    * Registers a new input source, and returns a unique {@code inputId} corresponding to this
    * source, to be used in {@link #queueInputTexture}.
    *
-   * @param sequenceIndex The sequence index of the input source, which is can be used to determine
-   *     the order of the input sources.
+   * @param sequenceIndex The sequence index of the input source which is used to determine the
+   *     order of the input sources.
    */
   void registerInputSource(int sequenceIndex);
 
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java b/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java
index 478923af76..eb5a5fba51 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java
@@ -64,7 +64,7 @@ import java.util.List;
    *
    * @param editedMediaItem The initial {@link EditedMediaItem} of the input.
    * @param format The initial {@link Format} of the input.
-   * @param sequenceIndex The sequence index of the input.
+   * @param sequenceIndex The index of the input sequence.
    * @throws ExportException If an error occurs getting the input.
    */
   public abstract GraphInput getInput(