Fix review comments

Author: icbaker

libraries/common/src/main/java/androidx/media3/common/util/Util.java

@@ -2233,7 +2233,21 @@ public static byte[] getBytesFromHexString(String hexString) {
    */
   @UnstableApi
   public static String toHexString(byte[] bytes) {
-    return BaseEncoding.base16().lowerCase().encode(bytes);
+    return toHexString(bytes, 0, bytes.length);
+  }
+
+  /**
+   * Returns a string containing a lower-case hex representation of the bytes provided.
+   *
+   * @param bytes The byte data to convert to hex.
+   * @param offset The offset into data to read from.
+   * @param length The number of bytes to read from data.
+   * @return A String containing the hex representation of {@code bytes} (considering {@code offset}
+   *     and {@code length}).
+   */
+  @UnstableApi
+  public static String toHexString(byte[] bytes, int offset, int length) {
+    return BaseEncoding.base16().lowerCase().encode(bytes, offset, length);
   }
 
   @UnstableApi

libraries/common/src/test/java/androidx/media3/common/util/UtilTest.java

@@ -1066,6 +1066,13 @@ public void toHexString_returnsHexString() {
     assertThat(Util.toHexString(bytes)).isEqualTo("12fc06");
   }
 
+  @Test
+  public void toHexString_withOffsetAndLength_returnsHexString() {
+    byte[] bytes = createByteArray(0x12, 0xFC, 0x06, 0x2B);
+
+    assertThat(Util.toHexString(bytes, /* offset= */ 1, /* length= */ 2)).isEqualTo("fc06");
+  }
+
   @Test
   public void getCodecsOfType_withNull_returnsNull() {
     assertThat(getCodecsOfType(null, C.TRACK_TYPE_VIDEO)).isNull();

libraries/extractor/src/main/java/androidx/media3/extractor/mp3/XingFrame.java

@@ -147,7 +147,7 @@ public static XingFrame parse(MpegAudioUtil.Header mpegAudioHeader, ParsableByte
   public long computeDurationUs() {
     if (frameCount == C.LENGTH_UNSET || frameCount == 0) {
       // If the frame count is missing/invalid, the header can't be used to determine the duration.
-      return C.LENGTH_UNSET;
+      return C.TIME_UNSET;
     }
     long sampleCount = frameCount * header.samplesPerFrame;
     if (encoderDelay != C.LENGTH_UNSET && encoderPadding != C.LENGTH_UNSET) {

libraries/extractor/src/test/java/androidx/media3/extractor/mp3/Mp3ExtractorTest.java

@@ -469,6 +469,7 @@ private static int findMpegFramePositionBeforeTag(ByteBuffer data, int tagOffset
         return framePosition;
       }
     }
-    throw new IllegalArgumentException("No tag found in " + Util.toHexString(data.array()));
+    throw new IllegalArgumentException(
+        "No tag found in " + Util.toHexString(data.array(), data.arrayOffset(), data.limit()));
   }
 }