WAV: Don't output data beyond the data limit

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=211446207

RELEASENOTES.md

@@ -2,6 +2,8 @@
 
 ### dev-v2 (not yet released) ###
 
+* WAV: Fix issue where white noise would be output at the end of playback
+  ([#4724](https://github.com/google/ExoPlayer/issues/4724)).
 * Add a flag to opt-in to automatic audio focus handling via
   `SimpleExoPlayer.setAudioAttributes`.
 * Distribute Cronet extension via jCenter.

library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavExtractor.java

@@ -24,6 +24,7 @@
 import com.google.android.exoplayer2.extractor.ExtractorsFactory;
 import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MimeTypes;
 import java.io.IOException;
 
@@ -88,7 +89,16 @@ public int read(ExtractorInput input, PositionHolder seekPosition)
       extractorOutput.seekMap(wavHeader);
     }
 
-    int bytesAppended = trackOutput.sampleData(input, MAX_INPUT_SIZE - pendingBytes, true);
+    long dataLimit = wavHeader.getDataLimit();
+    Assertions.checkState(dataLimit != C.POSITION_UNSET);
+
+    long bytesLeft = dataLimit - input.getPosition();
+    if (bytesLeft <= 0) {
+      return Extractor.RESULT_END_OF_INPUT;
+    }
+
+    int maxBytesToRead = (int) Math.min(MAX_INPUT_SIZE - pendingBytes, bytesLeft);
+    int bytesAppended = trackOutput.sampleData(input, maxBytesToRead, true);
     if (bytesAppended != RESULT_END_OF_INPUT) {
       pendingBytes += bytesAppended;
     }

library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavHeader.java

@@ -52,7 +52,7 @@ public WavHeader(int numChannels, int sampleRateHz, int averageBytesPerSecond, i
     this.encoding = encoding;
   }
 
-  // Setting bounds.
+  // Data bounds.
 
   /**
    * Sets the data start position and size in bytes of sample data in this WAV.
@@ -65,6 +65,11 @@ public void setDataBounds(long dataStartPosition, long dataSize) {
     this.dataSize = dataSize;
   }
 
+  /** Returns the data limit, or {@link C#POSITION_UNSET} if the data bounds have not been set. */
+  public long getDataLimit() {
+    return hasDataBounds() ? (dataStartPosition + dataSize) : C.POSITION_UNSET;
+  }
+
   /** Returns whether the data start position and size have been set. */
   public boolean hasDataBounds() {
     return dataStartPosition != 0 && dataSize != 0;

library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavHeaderReader.java

@@ -97,13 +97,15 @@ public static WavHeader peek(ExtractorInput input) throws IOException, Interrupt
   }
 
   /**
-   * Skips to the data in the given WAV input stream and returns its data size. After calling, the
-   * input stream's position will point to the start of sample data in the WAV.
-   * <p>
-   * If an exception is thrown, the input position will be left pointing to a chunk header.
+   * Skips to the data in the given WAV input stream. After calling, the input stream's position
+   * will point to the start of sample data in the WAV, and the data bounds of the provided {@link
+   * WavHeader} will have been set.
    *
-   * @param input Input stream to skip to the data chunk in. Its peek position must be pointing to
-   *     a valid chunk header.
+   * <p>If an exception is thrown, the input position will be left pointing to a chunk header and
+   * the bounds of the provided {@link WavHeader} will not have been set.
+   *
+   * @param input Input stream to skip to the data chunk in. Its peek position must be pointing to a
+   *     valid chunk header.
    * @param wavHeader WAV header to populate with data bounds.
    * @throws ParserException If an error occurs parsing chunks.
    * @throws IOException If reading from the input fails.