diff --git a/library/core/src/main/java/com/google/android/exoplayer2/BaseRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/BaseRenderer.java
index 176eed140b..cc02417ef4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/BaseRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/BaseRenderer.java
@@ -345,12 +345,12 @@ public abstract class BaseRenderer implements Renderer, RendererCapabilities {
    * @param formatRequired Whether the caller requires that the format of the stream be read even if
    *     it's not changing. A sample will never be read if set to true, however it is still possible
    *     for the end of stream or nothing to be read.
-   * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ} or
-   *     {@link C#RESULT_BUFFER_READ}.
+   * @return The status of read, one of {@link SampleStream.ReadDataResult}.
    */
+  @SampleStream.ReadDataResult
   protected final int readSource(
       FormatHolder formatHolder, DecoderInputBuffer buffer, boolean formatRequired) {
-    int result = stream.readData(formatHolder, buffer, formatRequired);
+    @SampleStream.ReadDataResult int result = stream.readData(formatHolder, buffer, formatRequired);
     if (result == C.RESULT_BUFFER_READ) {
       if (buffer.isEndOfStream()) {
         readingPositionUs = C.TIME_END_OF_SOURCE;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/audio/SimpleDecoderAudioRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/audio/SimpleDecoderAudioRenderer.java
index d35d62e321..e7ab44fed4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/audio/SimpleDecoderAudioRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/audio/SimpleDecoderAudioRenderer.java
@@ -37,6 +37,7 @@ import com.google.android.exoplayer2.decoder.SimpleOutputBuffer;
 import com.google.android.exoplayer2.drm.DrmSession;
 import com.google.android.exoplayer2.drm.DrmSession.DrmSessionException;
 import com.google.android.exoplayer2.drm.ExoMediaCrypto;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MediaClock;
 import com.google.android.exoplayer2.util.MimeTypes;
@@ -231,7 +232,7 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
       // We don't have a format yet, so try and read one.
       FormatHolder formatHolder = getFormatHolder();
       flagsOnlyBuffer.clear();
-      int result = readSource(formatHolder, flagsOnlyBuffer, true);
+      @SampleStream.ReadDataResult int result = readSource(formatHolder, flagsOnlyBuffer, true);
       if (result == C.RESULT_FORMAT_READ) {
         onInputFormatChanged(formatHolder);
       } else if (result == C.RESULT_BUFFER_READ) {
@@ -392,7 +393,7 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
       return false;
     }
 
-    int result;
+    @SampleStream.ReadDataResult int result;
     FormatHolder formatHolder = getFormatHolder();
     if (waitingForKeys) {
       // We've already read an encrypted sample into buffer, and are waiting for keys.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java
index 3cbfe679c5..e2a67301da 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java
@@ -42,6 +42,7 @@ import com.google.android.exoplayer2.drm.DrmSession.DrmSessionException;
 import com.google.android.exoplayer2.drm.FrameworkMediaCrypto;
 import com.google.android.exoplayer2.mediacodec.MediaCodecUtil.DecoderQueryException;
 import com.google.android.exoplayer2.source.MediaPeriod;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.NalUnitUtil;
@@ -934,6 +935,7 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
   private boolean readToFlagsOnlyBuffer(boolean requireFormat) throws ExoPlaybackException {
     FormatHolder formatHolder = getFormatHolder();
     flagsOnlyBuffer.clear();
+    @SampleStream.ReadDataResult
     int result = readSource(formatHolder, flagsOnlyBuffer, requireFormat);
     if (result == C.RESULT_FORMAT_READ) {
       onInputFormatChanged(formatHolder);
@@ -1219,7 +1221,7 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
       return true;
     }
 
-    int result;
+    @SampleStream.ReadDataResult int result;
     FormatHolder formatHolder = getFormatHolder();
     int adaptiveReconfigurationBytes = 0;
     if (waitingForKeys) {
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataRenderer.java
index 1ffea4ad33..a832674fcd 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataRenderer.java
@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.RendererCapabilities;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayList;
@@ -118,7 +119,7 @@ public final class MetadataRenderer extends BaseRenderer implements Callback {
     if (!inputStreamEnded && pendingMetadataCount < MAX_PENDING_METADATA_COUNT) {
       buffer.clear();
       FormatHolder formatHolder = getFormatHolder();
-      int result = readSource(formatHolder, buffer, false);
+      @SampleStream.ReadDataResult int result = readSource(formatHolder, buffer, false);
       if (result == C.RESULT_BUFFER_READ) {
         if (buffer.isEndOfStream()) {
           inputStreamEnded = true;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaPeriod.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaPeriod.java
index 38e99bdeca..ab108d4db4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaPeriod.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaPeriod.java
@@ -310,7 +310,7 @@ public final class ClippingMediaPeriod implements MediaPeriod, MediaPeriod.Callb
         buffer.setFlags(C.BUFFER_FLAG_END_OF_STREAM);
         return C.RESULT_BUFFER_READ;
       }
-      int result = childStream.readData(formatHolder, buffer, requireFormat);
+      @ReadDataResult int result = childStream.readData(formatHolder, buffer, requireFormat);
       if (result == C.RESULT_FORMAT_READ) {
         Format format = Assertions.checkNotNull(formatHolder.format);
         if (format.encoderDelay != 0 || format.encoderPadding != 0) {
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/SampleStream.java b/library/core/src/main/java/com/google/android/exoplayer2/source/SampleStream.java
index 54293aa4c1..0c5e5045ef 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/SampleStream.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/SampleStream.java
@@ -15,16 +15,26 @@
  */
 package com.google.android.exoplayer2.source;
 
+import androidx.annotation.IntDef;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
 import java.io.IOException;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 
 /**
  * A stream of media samples (and associated format information).
  */
 public interface SampleStream {
 
+  /** Return values of {@link #readData(FormatHolder, DecoderInputBuffer, boolean)}. */
+  @Documented
+  @Retention(RetentionPolicy.SOURCE)
+  @IntDef({C.RESULT_NOTHING_READ, C.RESULT_FORMAT_READ, C.RESULT_BUFFER_READ})
+  @interface ReadDataResult {}
+
   /**
    * Returns whether data is available to be read.
    * <p>
@@ -62,9 +72,9 @@ public interface SampleStream {
    * @param formatRequired Whether the caller requires that the format of the stream be read even if
    *     it's not changing. A sample will never be read if set to true, however it is still possible
    *     for the end of stream or nothing to be read.
-   * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ} or
-   *     {@link C#RESULT_BUFFER_READ}.
+   * @return The status of read, one of {@link ReadDataResult}.
    */
+  @ReadDataResult
   int readData(FormatHolder formatHolder, DecoderInputBuffer buffer, boolean formatRequired);
 
   /**
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/text/TextRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/text/TextRenderer.java
index fc34a1422b..8d16583b1c 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/text/TextRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/text/TextRenderer.java
@@ -26,6 +26,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.RendererCapabilities;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.MimeTypes;
@@ -229,7 +230,7 @@ public final class TextRenderer extends BaseRenderer implements Callback {
           return;
         }
         // Try and read the next subtitle from the source.
-        int result = readSource(formatHolder, nextInputBuffer, false);
+        @SampleStream.ReadDataResult int result = readSource(formatHolder, nextInputBuffer, false);
         if (result == C.RESULT_BUFFER_READ) {
           if (nextInputBuffer.isEndOfStream()) {
             inputStreamEnded = true;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/video/SimpleDecoderVideoRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/video/SimpleDecoderVideoRenderer.java
index afc53b90fe..44d019f57b 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/video/SimpleDecoderVideoRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/video/SimpleDecoderVideoRenderer.java
@@ -32,6 +32,7 @@ import com.google.android.exoplayer2.decoder.SimpleDecoder;
 import com.google.android.exoplayer2.drm.DrmSession;
 import com.google.android.exoplayer2.drm.DrmSession.DrmSessionException;
 import com.google.android.exoplayer2.drm.ExoMediaCrypto;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.TimedValueQueue;
 import com.google.android.exoplayer2.util.TraceUtil;
@@ -153,7 +154,7 @@ public abstract class SimpleDecoderVideoRenderer extends BaseRenderer {
       // We don't have a format yet, so try and read one.
       FormatHolder formatHolder = getFormatHolder();
       flagsOnlyBuffer.clear();
-      int result = readSource(formatHolder, flagsOnlyBuffer, true);
+      @SampleStream.ReadDataResult int result = readSource(formatHolder, flagsOnlyBuffer, true);
       if (result == C.RESULT_FORMAT_READ) {
         onInputFormatChanged(formatHolder);
       } else if (result == C.RESULT_BUFFER_READ) {
@@ -678,7 +679,7 @@ public abstract class SimpleDecoderVideoRenderer extends BaseRenderer {
       return false;
     }
 
-    int result;
+    @SampleStream.ReadDataResult int result;
     FormatHolder formatHolder = getFormatHolder();
     if (waitingForKeys) {
       // We've already read an encrypted sample into buffer, and are waiting for keys.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/video/spherical/CameraMotionRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/video/spherical/CameraMotionRenderer.java
index 0333b0b896..2a8978fd18 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/video/spherical/CameraMotionRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/video/spherical/CameraMotionRenderer.java
@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.Renderer;
 import com.google.android.exoplayer2.RendererCapabilities;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
@@ -86,6 +87,7 @@ public class CameraMotionRenderer extends BaseRenderer {
     while (!hasReadStreamToEnd() && lastTimestampUs < positionUs + SAMPLE_WINDOW_DURATION_US) {
       buffer.clear();
       FormatHolder formatHolder = getFormatHolder();
+      @SampleStream.ReadDataResult
       int result = readSource(formatHolder, buffer, /* formatRequired= */ false);
       if (result != C.RESULT_BUFFER_READ || buffer.isEndOfStream()) {
         return;
diff --git a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeRenderer.java b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeRenderer.java
index 74349b3ed0..fab3c4ef26 100644
--- a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeRenderer.java
+++ b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeRenderer.java
@@ -25,6 +25,7 @@ import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.Renderer;
 import com.google.android.exoplayer2.RendererCapabilities;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
+import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MimeTypes;
 import java.util.Arrays;
@@ -83,6 +84,7 @@ public class FakeRenderer extends BaseRenderer {
       if (!hasPendingBuffer) {
         FormatHolder formatHolder = getFormatHolder();
         buffer.clear();
+        @SampleStream.ReadDataResult
         int result = readSource(formatHolder, buffer, /* formatRequired= */ false);
         if (result == C.RESULT_FORMAT_READ) {
           formatReadCount++;