Use SimpleDecoder for subtitles.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117543706

library/src/androidTest/java/com/google/android/exoplayer/text/subrip/SubripParserTest.java

@@ -37,7 +37,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
   public void testParseEmpty() throws IOException {
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), EMPTY_FILE);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
     // Assert that the subtitle is empty.
     assertEquals(0, subtitle.getEventTimeCount());
     assertTrue(subtitle.getCues(0).isEmpty());
@@ -46,7 +46,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
   public void testParseTypical() throws IOException {
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_FILE);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
     assertEquals(6, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue2(subtitle, 2);
@@ -56,7 +56,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
   public void testParseTypicalWithByteOrderMark() throws IOException {
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_WITH_BYTE_ORDER_MARK);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
     assertEquals(6, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue2(subtitle, 2);
@@ -66,7 +66,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
   public void testParseTypicalExtraBlankLine() throws IOException {
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_EXTRA_BLANK_LINE);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
     assertEquals(6, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue2(subtitle, 2);
@@ -77,7 +77,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
     // Parsing should succeed, parsing the first and third cues only.
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_MISSING_TIMECODE);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
     assertEquals(4, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue3(subtitle, 2);
@@ -87,7 +87,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
     // Parsing should succeed, parsing the first and third cues only.
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_MISSING_SEQUENCE);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
     assertEquals(4, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue3(subtitle, 2);
@@ -96,7 +96,7 @@ public final class SubripParserTest extends InstrumentationTestCase {
   public void testParseNoEndTimecodes() throws IOException {
     SubripParser parser = new SubripParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), NO_END_TIMECODES_FILE);
-    SubripSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    SubripSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // Test event count.
     assertEquals(3, subtitle.getEventTimeCount());

library/src/androidTest/java/com/google/android/exoplayer/text/ttml/TtmlParserTest.java

@@ -472,6 +472,6 @@ public final class TtmlParserTest extends InstrumentationTestCase {
   private TtmlSubtitle getSubtitle(String file) throws IOException {
     TtmlParser ttmlParser = new TtmlParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), file);
-    return ttmlParser.parse(bytes, 0, bytes.length);
+    return ttmlParser.decode(bytes, bytes.length);
   }
 }

library/src/androidTest/java/com/google/android/exoplayer/text/webvtt/Mp4WebvttParserTest.java

@@ -18,16 +18,11 @@ package com.google.android.exoplayer.text.webvtt;
 import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.text.Cue;
 import com.google.android.exoplayer.text.Subtitle;
-import com.google.android.exoplayer.util.Util;
-
-import android.util.ArraySet;
 
 import junit.framework.TestCase;
 
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.List;
-import java.util.Set;
 
 /**
  * Unit test for {@link Mp4WebvttParser}.
@@ -96,20 +91,20 @@ public final class Mp4WebvttParserTest extends TestCase {
   // Positive tests.
 
   public void testSingleCueSample() throws ParserException {
-    Subtitle result = parser.parse(SINGLE_CUE_SAMPLE, 0, SINGLE_CUE_SAMPLE.length);
+    Subtitle result = parser.decode(SINGLE_CUE_SAMPLE, SINGLE_CUE_SAMPLE.length);
     Cue expectedCue = new Cue("Hello World"); // Line feed must be trimmed by the parser
     assertMp4WebvttSubtitleEquals(result, expectedCue);
   }
 
   public void testTwoCuesSample() throws ParserException {
-    Subtitle result = parser.parse(DOUBLE_CUE_SAMPLE, 0, DOUBLE_CUE_SAMPLE.length);
+    Subtitle result = parser.decode(DOUBLE_CUE_SAMPLE, DOUBLE_CUE_SAMPLE.length);
     Cue firstExpectedCue = new Cue("Hello World");
     Cue secondExpectedCue = new Cue("Bye Bye");
     assertMp4WebvttSubtitleEquals(result, firstExpectedCue, secondExpectedCue);
   }
 
   public void testNoCueSample() throws IOException {
-    Subtitle result = parser.parse(NO_CUE_SAMPLE, 0, NO_CUE_SAMPLE.length);
+    Subtitle result = parser.decode(NO_CUE_SAMPLE, NO_CUE_SAMPLE.length);
     assertMp4WebvttSubtitleEquals(result, new Cue[] {});
   }
 
@@ -117,7 +112,7 @@ public final class Mp4WebvttParserTest extends TestCase {
 
   public void testSampleWithIncompleteHeader() {
     try {
-      parser.parse(INCOMPLETE_HEADER_SAMPLE, 0, INCOMPLETE_HEADER_SAMPLE.length);
+      parser.decode(INCOMPLETE_HEADER_SAMPLE, INCOMPLETE_HEADER_SAMPLE.length);
     } catch (ParserException e) {
       return;
     }
@@ -130,55 +125,31 @@ public final class Mp4WebvttParserTest extends TestCase {
    * Asserts that the Subtitle's cues (which are all part of the event at t=0) are equal to the
    * expected Cues.
    *
-   * @param sub The parsed {@link Subtitle} to check.
-   * @param expectedCues Expected {@link Cue}s in order of appearance.
+   * @param subtitle The {@link Subtitle} to check.
+   * @param expectedCues The expected {@link Cue}s.
    */
-  private static void assertMp4WebvttSubtitleEquals(Subtitle sub, Cue... expectedCues) {
-    assertEquals(1, sub.getEventTimeCount());
-    assertEquals(0, sub.getEventTime(0));
-    List<Cue> subtitleCues = sub.getCues(0);
+  private static void assertMp4WebvttSubtitleEquals(Subtitle subtitle, Cue... expectedCues) {
+    assertEquals(1, subtitle.getEventTimeCount());
+    assertEquals(0, subtitle.getEventTime(0));
+    List<Cue> subtitleCues = subtitle.getCues(0);
     assertEquals(expectedCues.length, subtitleCues.size());
     for (int i = 0; i < subtitleCues.size(); i++) {
-      Set<String> differences = getCueDifferences(subtitleCues.get(i), expectedCues[i]);
-      assertTrue("Cues at position " + i + " are not equal. Different fields are "
-          + Arrays.toString(differences.toArray()), differences.isEmpty());
+      assertCueEquals(expectedCues[i], subtitleCues.get(i));
     }
   }
 
   /**
-   * Checks whether two non null cues are equal. Check fails if any of the Cues are null.
-   *
-   * @return a set that contains the names of the different fields.
+   * Asserts that two cues are equal.
    */
-  private static Set<String> getCueDifferences(Cue aCue, Cue anotherCue) {
-    assertNotNull(aCue);
-    assertNotNull(anotherCue);
-    Set<String> differences = new ArraySet<>();
-    if (aCue.line != anotherCue.line) {
-      differences.add("line: " + aCue.line + " | " + anotherCue.line);
-    }
-    if (aCue.lineAnchor != anotherCue.lineAnchor) {
-      differences.add("lineAnchor: " + aCue.lineAnchor + " | " + anotherCue.lineAnchor);
-    }
-    if (aCue.lineType != anotherCue.lineType) {
-      differences.add("lineType: " + aCue.lineType + " | " + anotherCue.lineType);
-    }
-    if (aCue.position != anotherCue.position) {
-      differences.add("position: " + aCue.position + " | " + anotherCue.position);
-    }
-    if (aCue.positionAnchor != anotherCue.positionAnchor) {
-      differences.add("positionAnchor: " + aCue.positionAnchor + " | " + anotherCue.positionAnchor);
-    }
-    if (aCue.size != anotherCue.size) {
-      differences.add("size: " + aCue.size + " | " + anotherCue.size);
-    }
-    if (!Util.areEqual(aCue.text.toString(), anotherCue.text.toString())) {
-      differences.add("text: '" + aCue.text + "' | '" + anotherCue.text + '\'');
-    }
-    if (!Util.areEqual(aCue.textAlignment, anotherCue.textAlignment)) {
-      differences.add("textAlignment: " + aCue.textAlignment + " | " + anotherCue.textAlignment);
-    }
-    return differences;
+  private static void assertCueEquals(Cue expected, Cue actual) {
+    assertEquals(expected.line, actual.line);
+    assertEquals(expected.lineAnchor, actual.lineAnchor);
+    assertEquals(expected.lineType, actual.lineType);
+    assertEquals(expected.position, actual.position);
+    assertEquals(expected.positionAnchor, actual.positionAnchor);
+    assertEquals(expected.size, actual.size);
+    assertEquals(expected.text.toString(), actual.text.toString());
+    assertEquals(expected.textAlignment, actual.textAlignment);
   }
 
 }

library/src/androidTest/java/com/google/android/exoplayer/text/webvtt/WebvttParserTest.java

@@ -42,7 +42,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), EMPTY_FILE);
     try {
-      parser.parse(bytes, 0, bytes.length);
+      parser.decode(bytes, bytes.length);
       fail("Expected ParserException");
     } catch (ParserException expected) {
       // Do nothing.
@@ -52,7 +52,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
   public void testParseTypical() throws IOException {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_FILE);
-    WebvttSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    WebvttSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // test event count
     assertEquals(4, subtitle.getEventTimeCount());
@@ -65,7 +65,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
   public void testParseTypicalWithIds() throws IOException {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_WITH_IDS_FILE);
-    WebvttSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    WebvttSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // test event count
     assertEquals(4, subtitle.getEventTimeCount());
@@ -78,7 +78,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
   public void testParseTypicalWithComments() throws IOException {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_WITH_COMMENTS_FILE);
-    WebvttSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    WebvttSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // test event count
     assertEquals(4, subtitle.getEventTimeCount());
@@ -91,7 +91,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
   public void testParseWithTags() throws IOException {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), WITH_TAGS_FILE);
-    WebvttSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    WebvttSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // test event count
     assertEquals(8, subtitle.getEventTimeCount());
@@ -106,7 +106,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
   public void testParseWithPositioning() throws IOException {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), WITH_POSITIONING_FILE);
-    WebvttSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    WebvttSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // test event count
     assertEquals(12, subtitle.getEventTimeCount());
@@ -134,7 +134,7 @@ public class WebvttParserTest extends InstrumentationTestCase {
   public void testParseWithBadCueHeader() throws IOException {
     WebvttParser parser = new WebvttParser();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), WITH_BAD_CUE_HEADER_FILE);
-    WebvttSubtitle subtitle = parser.parse(bytes, 0, bytes.length);
+    WebvttSubtitle subtitle = parser.decode(bytes, bytes.length);
 
     // test event count
     assertEquals(4, subtitle.getEventTimeCount());

library/src/main/java/com/google/android/exoplayer/text/SubtitleInputBuffer.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.text;
+
+import com.google.android.exoplayer.SampleHolder;
+import com.google.android.exoplayer.util.extensions.InputBuffer;
+
+/**
+ * An input buffer for {@link SubtitleParser}.
+ */
+/* package */ final class SubtitleInputBuffer extends InputBuffer {
+
+  public long subsampleOffsetUs;
+
+  public SubtitleInputBuffer() {
+    super(SampleHolder.BUFFER_REPLACEMENT_MODE_NORMAL);
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/text/PlayableSubtitle.java → library/src/main/java/com/google/android/exoplayer/text/SubtitleOutputBuffer.java

-package com.google.android.exoplayer.text;
-
 /*
  * Copyright (C) 2014 The Android Open Source Project
  *
@@ -15,36 +13,32 @@ package com.google.android.exoplayer.text;
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package com.google.android.exoplayer.text;
+
+import com.google.android.exoplayer.Format;
+import com.google.android.exoplayer.util.extensions.OutputBuffer;
+
 import java.util.List;
 
 /**
- * A subtitle that wraps another subtitle, making it playable by adjusting it to be correctly
- * aligned with the playback timebase.
+ * A {@link Subtitle} output from a {@link SubtitleParser}.
  */
-/* package */ final class PlayableSubtitle implements Subtitle {
+/* package */ final class SubtitleOutputBuffer extends OutputBuffer implements Subtitle {
 
-  /**
-   * The start time of the subtitle.
-   * <p>
-   * May be less than {@code getEventTime(0)}, since a subtitle may begin prior to the time of the
-   * first event.
-   */
-  public final long startTimeUs;
+  private final SubtitleParser owner;
 
-  private final Subtitle subtitle;
-  private final long offsetUs;
+  private Subtitle subtitle;
+  private long offsetUs;
 
-  /**
-   * @param subtitle The subtitle to wrap.
-   * @param isRelative True if the wrapped subtitle's timestamps are relative to the start time.
-   *     False if they are absolute.
-   * @param startTimeUs The start time of the subtitle.
-   * @param offsetUs An offset to add to the subtitle timestamps.
-   */
-  public PlayableSubtitle(Subtitle subtitle, boolean isRelative, long startTimeUs, long offsetUs) {
+  public SubtitleOutputBuffer(SubtitleParser owner) {
+    this.owner = owner;
+  }
+
+  public void setOutput(long timestampUs, Subtitle subtitle, long subsampleOffsetUs) {
+    this.timestampUs = timestampUs;
     this.subtitle = subtitle;
-    this.startTimeUs = startTimeUs;
-    this.offsetUs = (isRelative ? startTimeUs : 0) + offsetUs;
+    this.offsetUs = subsampleOffsetUs == Format.OFFSET_SAMPLE_RELATIVE ? timestampUs
+        : subsampleOffsetUs;
   }
 
   @Override
@@ -72,4 +66,9 @@ import java.util.List;
     return subtitle.getCues(timeUs - offsetUs);
   }
 
+  @Override
+  public void release() {
+    owner.releaseOutputBuffer(this);
+  }
+
 }

library/src/main/java/com/google/android/exoplayer/text/SubtitleParser.java

@@ -16,29 +16,48 @@
 package com.google.android.exoplayer.text;
 
 import com.google.android.exoplayer.ParserException;
+import com.google.android.exoplayer.util.extensions.SimpleDecoder;
 
 /**
- * Parses {@link Subtitle}s from a byte array.
+ * Parses {@link Subtitle}s from {@link SubtitleInputBuffer}s.
  */
-public interface SubtitleParser {
-
-  /**
-   * Checks whether the parser supports a given subtitle mime type.
-   *
-   * @param mimeType A subtitle mime type.
-   * @return Whether the mime type is supported.
-   */
-  public boolean canParse(String mimeType);
-
-  /**
-   * Parses a {@link Subtitle} from the provided {@code byte[]}.
-   *
-   * @param bytes The array holding the subtitle data.
-   * @param offset The offset of the subtitle data in bytes.
-   * @param length The length of the subtitle data in bytes.
-   * @return A parsed representation of the subtitle.
-   * @throws ParserException If a problem occurred parsing the subtitle data.
-   */
-  public Subtitle parse(byte[] bytes, int offset, int length) throws ParserException;
+public abstract class SubtitleParser extends
+    SimpleDecoder<SubtitleInputBuffer, SubtitleOutputBuffer, ParserException> {
+
+  protected SubtitleParser() {
+    super(new SubtitleInputBuffer[2], new SubtitleOutputBuffer[2]);
+    setInitialInputBufferSize(1024);
+  }
+
+  @Override
+  protected final SubtitleInputBuffer createInputBuffer() {
+    return new SubtitleInputBuffer();
+  }
+
+  @Override
+  protected final SubtitleOutputBuffer createOutputBuffer() {
+    return new SubtitleOutputBuffer(this);
+  }
+
+  @Override
+  protected final void releaseOutputBuffer(SubtitleOutputBuffer buffer) {
+    super.releaseOutputBuffer(buffer);
+  }
+
+  @Override
+  protected final ParserException decode(SubtitleInputBuffer inputBuffer,
+      SubtitleOutputBuffer outputBuffer) {
+    try {
+      Subtitle subtitle = decode(inputBuffer.sampleHolder.data.array(),
+          inputBuffer.sampleHolder.size);
+      outputBuffer.setOutput(inputBuffer.sampleHolder.timeUs, subtitle,
+          inputBuffer.subsampleOffsetUs);
+      return null;
+    } catch (ParserException e) {
+      return e;
+    }
+  }
+
+  protected abstract Subtitle decode(byte[] data, int size) throws ParserException;
 
 }

library/src/main/java/com/google/android/exoplayer/text/SubtitleParserFactory.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.text;
+
+import com.google.android.exoplayer.Format;
+import com.google.android.exoplayer.util.MimeTypes;
+
+/**
+ * A factory for {@link SubtitleParser} instances.
+ */
+public interface SubtitleParserFactory {
+
+  /**
+   * Returns whether the factory is able to instantiate a {@link SubtitleParser} for the given
+   * {@link Format}.
+   *
+   * @param format The {@link Format}.
+   * @return True if the factory can instantiate a suitable {@link SubtitleParser}. False otherwise.
+   */
+  boolean supportsFormat(Format format);
+
+  /**
+   * Creates a {@link SubtitleParser} for the given {@link Format}.
+   *
+   * @param format The {@link Format}.
+   * @return A new {@link SubtitleParser}.
+   * @throws IllegalArgumentException If the {@link Format} is not supported.
+   */
+  SubtitleParser createParser(Format format);
+
+  /**
+   * Default {@link SubtitleParserFactory} implementation.
+   * <p>
+   * The formats supported by this factory are:
+   * <ul>
+   * <li>WebVTT ({@link com.google.android.exoplayer.text.webvtt.WebvttParser})</li>
+   * <li>WebVTT (MP4) ({@link com.google.android.exoplayer.text.webvtt.Mp4WebvttParser})</li>
+   * <li>TTML ({@link com.google.android.exoplayer.text.ttml.TtmlParser})</li>
+   * <li>SubRip ({@link com.google.android.exoplayer.text.subrip.SubripParser})</li>
+   * <li>TX3G ({@link com.google.android.exoplayer.text.tx3g.Tx3gParser})</li>
+   * </ul>
+   */
+  final SubtitleParserFactory DEFAULT = new SubtitleParserFactory() {
+
+    @Override
+    public boolean supportsFormat(Format format) {
+      return getParserClass(format.sampleMimeType) != null;
+    }
+
+    @Override
+    public SubtitleParser createParser(Format format) {
+      try {
+        Class<?> clazz = getParserClass(format.sampleMimeType);
+        if (clazz == null) {
+          throw new IllegalArgumentException("Attempted to create parser for unsupported format");
+        }
+        return clazz.asSubclass(SubtitleParser.class).newInstance();
+      } catch (InstantiationException | IllegalAccessException e) {
+        throw new IllegalStateException("Unexpected error instantiating parser", e);
+      }
+    }
+
+    private Class<?> getParserClass(String mimeType) {
+      try {
+        switch (mimeType) {
+          case MimeTypes.TEXT_VTT:
+            return Class.forName("com.google.android.exoplayer.text.webvtt.WebvttParser");
+          case MimeTypes.APPLICATION_TTML:
+            return Class.forName("com.google.android.exoplayer.text.ttml.TtmlParser");
+          case MimeTypes.APPLICATION_MP4VTT:
+            return Class.forName("com.google.android.exoplayer.text.webvtt.Mp4WebvttParser");
+          case MimeTypes.APPLICATION_SUBRIP:
+            return Class.forName("com.google.android.exoplayer.text.subrip.SubripParser");
+          case MimeTypes.APPLICATION_TX3G:
+            return Class.forName("com.google.android.exoplayer.text.tx3g.Tx3gParser");
+          default:
+            return null;
+        }
+      } catch (ClassNotFoundException e) {
+        return null;
+      }
+    }
+
+  };
+
+}

library/src/main/java/com/google/android/exoplayer/text/SubtitleParserHelper.java

-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.google.android.exoplayer.text;
-
-import com.google.android.exoplayer.Format;
-import com.google.android.exoplayer.ParserException;
-import com.google.android.exoplayer.SampleHolder;
-import com.google.android.exoplayer.util.Assertions;
-import com.google.android.exoplayer.util.Util;
-
-import android.media.MediaCodec;
-import android.os.Handler;
-import android.os.Looper;
-import android.os.Message;
-
-import java.io.IOException;
-
-/**
- * Wraps a {@link SubtitleParser}, exposing an interface similar to {@link MediaCodec} for
- * asynchronous parsing of subtitles.
- */
-/* package */ final class SubtitleParserHelper implements Handler.Callback {
-
-  private static final int MSG_FORMAT = 0;
-  private static final int MSG_SAMPLE = 1;
-
-  private final SubtitleParser parser;
-  private final Handler handler;
-
-  private SampleHolder sampleHolder;
-  private boolean parsing;
-  private PlayableSubtitle result;
-  private IOException error;
-  private RuntimeException runtimeError;
-
-  private boolean subtitlesAreRelative;
-  private long subtitleOffsetUs;
-
-  /**
-   * @param looper The {@link Looper} associated with the thread on which parsing should occur.
-   * @param parser The parser that should be used to parse the raw data.
-   */
-  public SubtitleParserHelper(Looper looper, SubtitleParser parser) {
-    this.handler = new Handler(looper, this);
-    this.parser = parser;
-    flush();
-  }
-
-  /**
-   * Flushes the helper, canceling the current parsing operation, if there is one.
-   */
-  public synchronized void flush() {
-    sampleHolder = new SampleHolder(SampleHolder.BUFFER_REPLACEMENT_MODE_NORMAL);
-    parsing = false;
-    result = null;
-    error = null;
-    runtimeError = null;
-  }
-
-  /**
-   * Whether the helper is currently performing a parsing operation.
-   *
-   * @return True if the helper is currently performing a parsing operation. False otherwise.
-   */
-  public synchronized boolean isParsing() {
-    return parsing;
-  }
-
-  /**
-   * Gets the holder that should be populated with data to be parsed.
-   * <p>
-   * The returned holder will remain valid unless {@link #flush()} is called. If {@link #flush()}
-   * is called the holder is replaced, and this method should be called again to obtain the new
-   * holder.
-   *
-   * @return The holder that should be populated with data to be parsed.
-   */
-  public synchronized SampleHolder getSampleHolder() {
-    return sampleHolder;
-  }
-
-  /**
-   * Sets the format of subsequent samples.
-   *
-   * @param format The format.
-   */
-  public void setFormat(Format format) {
-    handler.obtainMessage(MSG_FORMAT, format).sendToTarget();
-  }
-
-  /**
-   * Start a parsing operation.
-   * <p>
-   * The holder returned by {@link #getSampleHolder()} should be populated with the data to be
-   * parsed prior to calling this method.
-   */
-  public synchronized void startParseOperation() {
-    Assertions.checkState(!parsing);
-    parsing = true;
-    result = null;
-    error = null;
-    runtimeError = null;
-    handler.obtainMessage(MSG_SAMPLE, Util.getTopInt(sampleHolder.timeUs),
-        Util.getBottomInt(sampleHolder.timeUs), sampleHolder).sendToTarget();
-  }
-
-  /**
-   * Gets the result of the most recent parsing operation.
-   * <p>
-   * The result is cleared as a result of calling this method, and so subsequent calls will return
-   * null until a subsequent parsing operation has finished.
-   *
-   * @return The result of the parsing operation, or null.
-   * @throws IOException If the parsing operation failed.
-   */
-  public synchronized PlayableSubtitle getAndClearResult() throws IOException {
-    try {
-      if (error != null) {
-        throw error;
-      } else if (runtimeError != null) {
-        throw runtimeError;
-      } else {
-        return result;
-      }
-    } finally {
-      result = null;
-      error = null;
-      runtimeError = null;
-    }
-  }
-
-  @Override
-  public boolean handleMessage(Message msg) {
-    switch (msg.what) {
-      case MSG_FORMAT:
-        handleFormat((Format) msg.obj);
-        break;
-      case MSG_SAMPLE:
-        long sampleTimeUs = Util.getLong(msg.arg1, msg.arg2);
-        SampleHolder holder = (SampleHolder) msg.obj;
-        handleSample(sampleTimeUs, holder);
-        break;
-    }
-    return true;
-  }
-
-  private void handleFormat(Format format) {
-    subtitlesAreRelative = format.subsampleOffsetUs == Format.OFFSET_SAMPLE_RELATIVE;
-    subtitleOffsetUs = subtitlesAreRelative ? 0 : format.subsampleOffsetUs;
-  }
-
-  private void handleSample(long sampleTimeUs, SampleHolder holder) {
-    Subtitle parsedSubtitle = null;
-    ParserException error = null;
-    RuntimeException runtimeError = null;
-    try {
-      parsedSubtitle = parser.parse(holder.data.array(), 0, holder.size);
-    } catch (ParserException e) {
-      error = e;
-    } catch (RuntimeException e) {
-      runtimeError = e;
-    }
-    synchronized (this) {
-      if (sampleHolder != holder) {
-        // A flush has occurred since this holder was posted. Do nothing.
-      } else {
-        this.result = new PlayableSubtitle(parsedSubtitle, subtitlesAreRelative, sampleTimeUs,
-            subtitleOffsetUs);
-        this.error = error;
-        this.runtimeError = runtimeError;
-        this.parsing = false;
-      }
-    }
-  }
-
-}

library/src/main/java/com/google/android/exoplayer/text/TextTrackRenderer.java

@@ -18,6 +18,7 @@ package com.google.android.exoplayer.text;
 import com.google.android.exoplayer.ExoPlaybackException;
 import com.google.android.exoplayer.Format;
 import com.google.android.exoplayer.FormatHolder;
+import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.SampleHolder;
 import com.google.android.exoplayer.SampleSourceTrackRenderer;
 import com.google.android.exoplayer.TrackRenderer;
@@ -28,158 +29,97 @@ import com.google.android.exoplayer.util.MimeTypes;
 import android.annotation.TargetApi;
 import android.os.Handler;
 import android.os.Handler.Callback;
-import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Message;
 
 import java.io.IOException;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
 /**
- * A {@link TrackRenderer} for subtitles. Text is parsed from sample data using a
- * {@link SubtitleParser}. The actual rendering of each line of text is delegated to a
- * {@link TextRenderer}.
+ * A {@link TrackRenderer} for subtitles.
  * <p>
- * If no {@link SubtitleParser} instances are passed to the constructor, the subtitle type will be
- * detected automatically for the following supported formats:
- *
- * <ul>
- * <li>WebVTT ({@link com.google.android.exoplayer.text.webvtt.WebvttParser})</li>
- * <li>TTML
- * ({@link com.google.android.exoplayer.text.ttml.TtmlParser})</li>
- * <li>SubRip
- * ({@link com.google.android.exoplayer.text.subrip.SubripParser})</li>
- * <li>TX3G
- * ({@link com.google.android.exoplayer.text.tx3g.Tx3gParser})</li>
- * </ul>
- *
- * <p>To override the default parsers, pass one or more {@link SubtitleParser} instances to the
- * constructor. The first {@link SubtitleParser} that returns {@code true} from
- * {@link SubtitleParser#canParse(String)} will be used.
+ * Text is parsed from sample data using {@link SubtitleParser} instances obtained from a
+ * {@link SubtitleParserFactory}. The actual rendering of each line of text is delegated to a
+ * {@link TextRenderer}.
  */
 @TargetApi(16)
 public final class TextTrackRenderer extends SampleSourceTrackRenderer implements Callback {
 
   private static final int MSG_UPDATE_OVERLAY = 0;
 
-  /**
-   * Default parser classes in priority order. They are referred to indirectly so that it is
-   * possible to remove unused parsers.
-   */
-  private static final List<Class<? extends SubtitleParser>> DEFAULT_PARSER_CLASSES;
-  static {
-    DEFAULT_PARSER_CLASSES = new ArrayList<>();
-    // Load parsers using reflection so that they can be deleted cleanly.
-    // Class.forName(<class name>) appears for each parser so that automated tools like proguard
-    // can detect the use of reflection (see http://proguard.sourceforge.net/FAQ.html#forname).
-    try {
-      DEFAULT_PARSER_CLASSES.add(
-          Class.forName("com.google.android.exoplayer.text.webvtt.WebvttParser")
-              .asSubclass(SubtitleParser.class));
-    } catch (ClassNotFoundException e) {
-      // Parser not found.
-    }
-    try {
-      DEFAULT_PARSER_CLASSES.add(
-          Class.forName("com.google.android.exoplayer.text.ttml.TtmlParser")
-              .asSubclass(SubtitleParser.class));
-    } catch (ClassNotFoundException e) {
-      // Parser not found.
-    }
-    try {
-      DEFAULT_PARSER_CLASSES.add(
-          Class.forName("com.google.android.exoplayer.text.webvtt.Mp4WebvttParser")
-              .asSubclass(SubtitleParser.class));
-    } catch (ClassNotFoundException e) {
-      // Parser not found.
-    }
-    try {
-      DEFAULT_PARSER_CLASSES.add(
-          Class.forName("com.google.android.exoplayer.text.subrip.SubripParser")
-              .asSubclass(SubtitleParser.class));
-    } catch (ClassNotFoundException e) {
-      // Parser not found.
-    }
-    try {
-      DEFAULT_PARSER_CLASSES.add(
-          Class.forName("com.google.android.exoplayer.text.tx3g.Tx3gParser")
-              .asSubclass(SubtitleParser.class));
-    } catch (ClassNotFoundException e) {
-      // Parser not found.
-    }
-  }
-
   private final Handler textRendererHandler;
   private final TextRenderer textRenderer;
+  private final SubtitleParserFactory parserFactory;
   private final FormatHolder formatHolder;
-  private final SubtitleParser[] subtitleParsers;
 
-  private int parserIndex;
   private boolean inputStreamEnded;
-  private PlayableSubtitle subtitle;
-  private PlayableSubtitle nextSubtitle;
-  private SubtitleParserHelper parserHelper;
-  private HandlerThread parserThread;
+  private SubtitleParser parser;
+  private SubtitleInputBuffer nextInputBuffer;
+  private SubtitleOutputBuffer subtitle;
+  private SubtitleOutputBuffer nextSubtitle;
   private int nextSubtitleEventIndex;
 
   /**
    * @param textRenderer The text renderer.
    * @param textRendererLooper The looper associated with the thread on which textRenderer should be
    *     invoked. If the renderer makes use of standard Android UI components, then this should
-   *     normally be the looper associated with the applications' main thread, which can be
-   *     obtained using {@link android.app.Activity#getMainLooper()}. Null may be passed if the
-   *     renderer should be invoked directly on the player's internal rendering thread.
-   * @param subtitleParsers {@link SubtitleParser}s to parse text samples, in order of decreasing
-   *     priority. If omitted, the default parsers will be used.
+   *     normally be the looper associated with the application's main thread, which can be obtained
+   *     using {@link android.app.Activity#getMainLooper()}. Null may be passed if the renderer
+   *     should be invoked directly on the player's internal rendering thread.
+   */
+  public TextTrackRenderer(TextRenderer textRenderer, Looper textRendererLooper) {
+    this(textRenderer, textRendererLooper, SubtitleParserFactory.DEFAULT);
+  }
+
+  /**
+   * @param textRenderer The text renderer.
+   * @param textRendererLooper The looper associated with the thread on which textRenderer should be
+   *     invoked. If the renderer makes use of standard Android UI components, then this should
+   *     normally be the looper associated with the application's main thread, which can be obtained
+   *     using {@link android.app.Activity#getMainLooper()}. Null may be passed if the renderer
+   *     should be invoked directly on the player's internal rendering thread.
+   * @param parserFactory A factory from which to obtain {@link SubtitleParser} instances.
    */
   public TextTrackRenderer(TextRenderer textRenderer, Looper textRendererLooper,
-      SubtitleParser... subtitleParsers) {
+      SubtitleParserFactory parserFactory) {
     this.textRenderer = Assertions.checkNotNull(textRenderer);
     this.textRendererHandler = textRendererLooper == null ? null
         : new Handler(textRendererLooper, this);
-    if (subtitleParsers == null || subtitleParsers.length == 0) {
-      subtitleParsers = new SubtitleParser[DEFAULT_PARSER_CLASSES.size()];
-      for (int i = 0; i < subtitleParsers.length; i++) {
-        try {
-          subtitleParsers[i] = DEFAULT_PARSER_CLASSES.get(i).newInstance();
-        } catch (InstantiationException e) {
-          throw new IllegalStateException("Unexpected error creating default parser", e);
-        } catch (IllegalAccessException e) {
-          throw new IllegalStateException("Unexpected error creating default parser", e);
-        }
-      }
-    }
-    this.subtitleParsers = subtitleParsers;
+    this.parserFactory = parserFactory;
     formatHolder = new FormatHolder();
   }
 
   @Override
   protected int supportsFormat(Format format) {
-    return getParserIndex(format.sampleMimeType) != -1 ? TrackRenderer.FORMAT_HANDLED
+    return parserFactory.supportsFormat(format) ? TrackRenderer.FORMAT_HANDLED
         : (MimeTypes.isText(format.sampleMimeType) ? FORMAT_UNSUPPORTED_SUBTYPE
-            : FORMAT_UNSUPPORTED_TYPE);
+        : FORMAT_UNSUPPORTED_TYPE);
   }
 
   @Override
   protected void onEnabled(Format[] formats, TrackStream trackStream, long positionUs,
       boolean joining) throws ExoPlaybackException {
     super.onEnabled(formats, trackStream, positionUs, joining);
-    parserIndex = getParserIndex(formats[0].sampleMimeType);
-    parserThread = new HandlerThread("textParser");
-    parserThread.start();
-    parserHelper = new SubtitleParserHelper(parserThread.getLooper(), subtitleParsers[parserIndex]);
+    parser = parserFactory.createParser(formats[0]);
+    parser.start();
   }
 
   @Override
   protected void reset(long positionUs) {
     inputStreamEnded = false;
-    subtitle = null;
-    nextSubtitle = null;
+    if (subtitle != null) {
+      subtitle.release();
+      subtitle = null;
+    }
+    if (nextSubtitle != null) {
+      nextSubtitle.release();
+      nextSubtitle = null;
+    }
+    nextInputBuffer = null;
     clearTextRenderer();
-    if (parserHelper != null) {
-      parserHelper.flush();
+    if (parser != null) {
+      parser.flush();
     }
   }
 
@@ -188,7 +128,7 @@ public final class TextTrackRenderer extends SampleSourceTrackRenderer implement
       throws ExoPlaybackException {
     if (nextSubtitle == null) {
       try {
-        nextSubtitle = parserHelper.getAndClearResult();
+        nextSubtitle = parser.dequeueOutputBuffer();
       } catch (IOException e) {
         throw ExoPlaybackException.createForRenderer(e, getIndex());
       }
@@ -211,8 +151,11 @@ public final class TextTrackRenderer extends SampleSourceTrackRenderer implement
       }
     }
 
-    if (nextSubtitle != null && nextSubtitle.startTimeUs <= positionUs) {
+    if (nextSubtitle != null && nextSubtitle.timestampUs <= positionUs) {
       // Advance to the next subtitle. Sync the next event index and trigger an update.
+      if (subtitle != null) {
+        subtitle.release();
+      }
       subtitle = nextSubtitle;
       nextSubtitle = null;
       nextSubtitleEventIndex = subtitle.getNextEventTimeIndex(positionUs);
@@ -224,26 +167,45 @@ public final class TextTrackRenderer extends SampleSourceTrackRenderer implement
       updateTextRenderer(subtitle.getCues(positionUs));
     }
 
-    if (!inputStreamEnded && nextSubtitle == null && !parserHelper.isParsing()) {
-      // Try and read the next subtitle from the source.
-      SampleHolder sampleHolder = parserHelper.getSampleHolder();
-      sampleHolder.clearData();
-      int result = readSource(formatHolder, sampleHolder);
-      if (result == TrackStream.SAMPLE_READ) {
-        parserHelper.startParseOperation();
-      } else if (result == TrackStream.END_OF_STREAM) {
-        inputStreamEnded = true;
+    try {
+      if (!inputStreamEnded && nextSubtitle == null) {
+        if (nextInputBuffer == null) {
+          nextInputBuffer = parser.dequeueInputBuffer();
+          if (nextInputBuffer == null) {
+            return;
+          }
+        }
+        // Try and read the next subtitle from the source.
+        SampleHolder sampleHolder = nextInputBuffer.sampleHolder;
+        sampleHolder.clearData();
+        int result = readSource(formatHolder, sampleHolder);
+        if (result == TrackStream.SAMPLE_READ) {
+          nextInputBuffer.subsampleOffsetUs = formatHolder.format.subsampleOffsetUs;
+          parser.queueInputBuffer(nextInputBuffer);
+        } else if (result == TrackStream.END_OF_STREAM) {
+          inputStreamEnded = true;
+        }
       }
+    } catch (ParserException e) {
+      throw ExoPlaybackException.createForRenderer(e, getIndex());
     }
   }
 
   @Override
   protected void onDisabled() throws ExoPlaybackException {
-    subtitle = null;
-    nextSubtitle = null;
-    parserThread.quit();
-    parserThread = null;
-    parserHelper = null;
+    if (subtitle != null) {
+      subtitle.release();
+      subtitle = null;
+    }
+    if (nextSubtitle != null) {
+      nextSubtitle.release();
+      nextSubtitle = null;
+    }
+    if (parser != null) {
+      parser.release();
+      parser = null;
+    }
+    nextInputBuffer = null;
     clearTextRenderer();
     super.onDisabled();
   }
@@ -293,13 +255,4 @@ public final class TextTrackRenderer extends SampleSourceTrackRenderer implement
     textRenderer.onCues(cues);
   }
 
-  private int getParserIndex(String sampleMimeType) {
-    for (int i = 0; i < subtitleParsers.length; i++) {
-      if (subtitleParsers[i].canParse(sampleMimeType)) {
-        return i;
-      }
-    }
-    return -1;
-  }
-
 }

library/src/main/java/com/google/android/exoplayer/text/subrip/SubripParser.java

@@ -18,7 +18,6 @@ package com.google.android.exoplayer.text.subrip;
 import com.google.android.exoplayer.text.Cue;
 import com.google.android.exoplayer.text.SubtitleParser;
 import com.google.android.exoplayer.util.LongArray;
-import com.google.android.exoplayer.util.MimeTypes;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
 import android.text.Html;
@@ -33,7 +32,7 @@ import java.util.regex.Pattern;
 /**
  * A simple SubRip parser.
  */
-public final class SubripParser implements SubtitleParser {
+public final class SubripParser extends SubtitleParser {
 
   private static final String TAG = "SubripParser";
 
@@ -48,16 +47,10 @@ public final class SubripParser implements SubtitleParser {
   }
 
   @Override
-  public boolean canParse(String mimeType) {
-    return MimeTypes.APPLICATION_SUBRIP.equals(mimeType);
-  }
-
-  @Override
-  public SubripSubtitle parse(byte[] bytes, int offset, int length) {
+  protected SubripSubtitle decode(byte[] bytes, int length) {
     ArrayList<Cue> cues = new ArrayList<>();
     LongArray cueTimesUs = new LongArray();
-    ParsableByteArray subripData = new ParsableByteArray(bytes, offset + length);
-    subripData.setPosition(offset);
+    ParsableByteArray subripData = new ParsableByteArray(bytes, length);
     boolean haveEndTimecode;
     String currentLine;
 

library/src/main/java/com/google/android/exoplayer/text/ttml/TtmlParser.java

@@ -18,7 +18,6 @@ package com.google.android.exoplayer.text.ttml;
 import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.text.SubtitleParser;
-import com.google.android.exoplayer.util.MimeTypes;
 import com.google.android.exoplayer.util.ParserUtil;
 import com.google.android.exoplayer.util.Util;
 
@@ -58,7 +57,7 @@ import java.util.regex.Pattern;
  * </p>
  * @see <a href="http://www.w3.org/TR/ttaf1-dfxp/">TTML specification</a>
  */
-public final class TtmlParser implements SubtitleParser {
+public final class TtmlParser extends SubtitleParser {
 
   private static final String TAG = "TtmlParser";
 
@@ -91,16 +90,11 @@ public final class TtmlParser implements SubtitleParser {
   }
 
   @Override
-  public boolean canParse(String mimeType) {
-    return MimeTypes.APPLICATION_TTML.equals(mimeType);
-  }
-
-  @Override
-  public TtmlSubtitle parse(byte[] bytes, int offset, int length) throws ParserException {
+  protected TtmlSubtitle decode(byte[] bytes, int length) throws ParserException {
     try {
       XmlPullParser xmlParser = xmlParserFactory.newPullParser();
       Map<String, TtmlStyle> globalStyles = new HashMap<>();
-      ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes, offset, length);
+      ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes, 0, length);
       xmlParser.setInput(inputStream, null);
       TtmlSubtitle ttmlSubtitle = null;
       LinkedList<TtmlNode> nodeStack = new LinkedList<>();

library/src/main/java/com/google/android/exoplayer/text/tx3g/Tx3gParser.java

@@ -18,23 +18,17 @@ package com.google.android.exoplayer.text.tx3g;
 import com.google.android.exoplayer.text.Cue;
 import com.google.android.exoplayer.text.Subtitle;
 import com.google.android.exoplayer.text.SubtitleParser;
-import com.google.android.exoplayer.util.MimeTypes;
 
 /**
  * A {@link SubtitleParser} for tx3g.
  * <p>
  * Currently only supports parsing of a single text track.
  */
-public final class Tx3gParser implements SubtitleParser {
+public final class Tx3gParser extends SubtitleParser {
 
   @Override
-  public boolean canParse(String mimeType) {
-    return MimeTypes.APPLICATION_TX3G.equals(mimeType);
-  }
-
-  @Override
-  public Subtitle parse(byte[] bytes, int offset, int length) {
-    String cueText = new String(bytes, offset, length);
+  protected Subtitle decode(byte[] bytes, int length) {
+    String cueText = new String(bytes, 0, length);
     return new Tx3gSubtitle(new Cue(cueText));
   }
 

library/src/main/java/com/google/android/exoplayer/text/webvtt/Mp4WebvttParser.java

@@ -18,7 +18,6 @@ package com.google.android.exoplayer.text.webvtt;
 import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.text.Cue;
 import com.google.android.exoplayer.text.SubtitleParser;
-import com.google.android.exoplayer.util.MimeTypes;
 import com.google.android.exoplayer.util.ParsableByteArray;
 import com.google.android.exoplayer.util.Util;
 
@@ -28,7 +27,7 @@ import java.util.List;
 /**
  * A {@link SubtitleParser} for Webvtt embedded in a Mp4 container file.
  */
-public final class Mp4WebvttParser implements SubtitleParser {
+public final class Mp4WebvttParser extends SubtitleParser {
 
   private static final int BOX_HEADER_SIZE = 8;
 
@@ -45,16 +44,10 @@ public final class Mp4WebvttParser implements SubtitleParser {
   }
 
   @Override
-  public boolean canParse(String mimeType) {
-    return MimeTypes.APPLICATION_MP4VTT.equals(mimeType);
-  }
-
-  @Override
-  public Mp4WebvttSubtitle parse(byte[] bytes, int offset, int length) throws ParserException {
+  protected Mp4WebvttSubtitle decode(byte[] bytes, int length) throws ParserException {
     // Webvtt in Mp4 samples have boxes inside of them, so we have to do a traditional box parsing:
     // first 4 bytes size and then 4 bytes type.
-    sampleData.reset(bytes, offset + length);
-    sampleData.setPosition(offset);
+    sampleData.reset(bytes, length);
     List<Cue> resultingCueList = new ArrayList<>();
     while (sampleData.bytesLeft() > 0) {
       if (sampleData.bytesLeft() < BOX_HEADER_SIZE) {

library/src/main/java/com/google/android/exoplayer/text/webvtt/WebvttParser.java

@@ -17,7 +17,6 @@ package com.google.android.exoplayer.text.webvtt;
 
 import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.text.SubtitleParser;
-import com.google.android.exoplayer.util.MimeTypes;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
 import android.text.TextUtils;
@@ -29,7 +28,7 @@ import java.util.ArrayList;
  * <p>
  * @see <a href="http://dev.w3.org/html5/webvtt">WebVTT specification</a>
  */
-public final class WebvttParser implements SubtitleParser {
+public final class WebvttParser extends SubtitleParser {
 
   private final WebvttCueParser cueParser;
   private final ParsableByteArray parsableWebvttData;
@@ -42,14 +41,8 @@ public final class WebvttParser implements SubtitleParser {
   }
 
   @Override
-  public final boolean canParse(String mimeType) {
-    return MimeTypes.TEXT_VTT.equals(mimeType);
-  }
-
-  @Override
-  public final WebvttSubtitle parse(byte[] bytes, int offset, int length) throws ParserException {
-    parsableWebvttData.reset(bytes, offset + length);
-    parsableWebvttData.setPosition(offset);
+  protected final WebvttSubtitle decode(byte[] bytes, int length) throws ParserException {
+    parsableWebvttData.reset(bytes, length);
     webvttCueBuilder.reset(); // In case a previous parse run failed with a ParserException.
 
     // Validate the first line of the header, and skip the remainder.

library/src/main/java/com/google/android/exoplayer/util/extensions/InputBuffer.java

@@ -25,7 +25,11 @@ public class InputBuffer extends Buffer {
   public final SampleHolder sampleHolder;
 
   public InputBuffer() {
-    sampleHolder = new SampleHolder(SampleHolder.BUFFER_REPLACEMENT_MODE_DIRECT);
+    this(SampleHolder.BUFFER_REPLACEMENT_MODE_DIRECT);
+  }
+
+  public InputBuffer(int bufferReplacementMode) {
+    sampleHolder = new SampleHolder(bufferReplacementMode);
   }
 
   @Override