Clean up DVB support

- Removed the PES_STRIPPED flag. It's unnecessary. We can strip
  PES in the TS extractor instead.
- Made nearly all of the object classes in DvbParser immutable.
  Else it's non-obvious that none of this state can be mutated.
- Made a a lot of the methods in DvbParser static for the same
  reason.
- Removed unnecessary null checks, code that was never executed,
  unused fields etc.
- Add proper flushing of DvbParser, to prevent corrupt output
  following a seek.

library/core/proguard-rules.txt

@@ -7,4 +7,4 @@
 }
 -keepclassmembers class com.google.android.exoplayer2.text.dvb.DvbDecoder {
     public <init>(java.util.List);
-}
+}

library/core/src/androidTest/java/com/google/android/exoplayer2/text/subrip/SubripDecoderTest.java

@@ -36,7 +36,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
   public void testDecodeEmpty() throws IOException {
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), EMPTY_FILE);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     // Assert that the subtitle is empty.
     assertEquals(0, subtitle.getEventTimeCount());
     assertTrue(subtitle.getCues(0).isEmpty());
@@ -45,7 +45,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
   public void testDecodeTypical() throws IOException {
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_FILE);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     assertEquals(6, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue2(subtitle, 2);
@@ -55,7 +55,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
   public void testDecodeTypicalWithByteOrderMark() throws IOException {
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_WITH_BYTE_ORDER_MARK);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     assertEquals(6, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue2(subtitle, 2);
@@ -65,7 +65,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
   public void testDecodeTypicalExtraBlankLine() throws IOException {
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_EXTRA_BLANK_LINE);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     assertEquals(6, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue2(subtitle, 2);
@@ -76,7 +76,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
     // Parsing should succeed, parsing the first and third cues only.
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_MISSING_TIMECODE);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     assertEquals(4, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue3(subtitle, 2);
@@ -86,7 +86,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
     // Parsing should succeed, parsing the first and third cues only.
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_MISSING_SEQUENCE);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     assertEquals(4, subtitle.getEventTimeCount());
     assertTypicalCue1(subtitle, 0);
     assertTypicalCue3(subtitle, 2);
@@ -96,7 +96,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
     // Parsing should succeed, parsing the third cue only.
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), TYPICAL_NEGATIVE_TIMESTAMPS);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
     assertEquals(2, subtitle.getEventTimeCount());
     assertTypicalCue3(subtitle, 0);
   }
@@ -104,7 +104,7 @@ public final class SubripDecoderTest extends InstrumentationTestCase {
   public void testDecodeNoEndTimecodes() throws IOException {
     SubripDecoder decoder = new SubripDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), NO_END_TIMECODES_FILE);
-    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length);
+    SubripSubtitle subtitle = decoder.decode(bytes, bytes.length, false);
 
     // Test event count.
     assertEquals(3, subtitle.getEventTimeCount());

library/core/src/androidTest/java/com/google/android/exoplayer2/text/ttml/TtmlDecoderTest.java

@@ -482,7 +482,7 @@ public final class TtmlDecoderTest extends InstrumentationTestCase {
   private TtmlSubtitle getSubtitle(String file) throws IOException, SubtitleDecoderException {
     TtmlDecoder ttmlDecoder = new TtmlDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), file);
-    return ttmlDecoder.decode(bytes, bytes.length);
+    return ttmlDecoder.decode(bytes, bytes.length, false);
   }
 
 }

library/core/src/androidTest/java/com/google/android/exoplayer2/text/webvtt/Mp4WebvttDecoderTest.java

@@ -81,14 +81,14 @@ public final class Mp4WebvttDecoderTest extends TestCase {
 
   public void testSingleCueSample() throws SubtitleDecoderException {
     Mp4WebvttDecoder decoder = new Mp4WebvttDecoder();
-    Subtitle result = decoder.decode(SINGLE_CUE_SAMPLE, SINGLE_CUE_SAMPLE.length);
+    Subtitle result = decoder.decode(SINGLE_CUE_SAMPLE, SINGLE_CUE_SAMPLE.length, false);
     Cue expectedCue = new Cue("Hello World"); // Line feed must be trimmed by the decoder
     assertMp4WebvttSubtitleEquals(result, expectedCue);
   }
 
   public void testTwoCuesSample() throws SubtitleDecoderException {
     Mp4WebvttDecoder decoder = new Mp4WebvttDecoder();
-    Subtitle result = decoder.decode(DOUBLE_CUE_SAMPLE, DOUBLE_CUE_SAMPLE.length);
+    Subtitle result = decoder.decode(DOUBLE_CUE_SAMPLE, DOUBLE_CUE_SAMPLE.length, false);
     Cue firstExpectedCue = new Cue("Hello World");
     Cue secondExpectedCue = new Cue("Bye Bye");
     assertMp4WebvttSubtitleEquals(result, firstExpectedCue, secondExpectedCue);
@@ -96,7 +96,7 @@ public final class Mp4WebvttDecoderTest extends TestCase {
 
   public void testNoCueSample() throws SubtitleDecoderException {
     Mp4WebvttDecoder decoder = new Mp4WebvttDecoder();
-    Subtitle result = decoder.decode(NO_CUE_SAMPLE, NO_CUE_SAMPLE.length);
+    Subtitle result = decoder.decode(NO_CUE_SAMPLE, NO_CUE_SAMPLE.length, false);
     assertMp4WebvttSubtitleEquals(result);
   }
 
@@ -105,7 +105,7 @@ public final class Mp4WebvttDecoderTest extends TestCase {
   public void testSampleWithIncompleteHeader() {
     Mp4WebvttDecoder decoder = new Mp4WebvttDecoder();
     try {
-      decoder.decode(INCOMPLETE_HEADER_SAMPLE, INCOMPLETE_HEADER_SAMPLE.length);
+      decoder.decode(INCOMPLETE_HEADER_SAMPLE, INCOMPLETE_HEADER_SAMPLE.length, false);
     } catch (SubtitleDecoderException e) {
       return;
     }

library/core/src/androidTest/java/com/google/android/exoplayer2/text/webvtt/WebvttDecoderTest.java

@@ -49,7 +49,7 @@ public class WebvttDecoderTest extends InstrumentationTestCase {
     WebvttDecoder decoder = new WebvttDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), EMPTY_FILE);
     try {
-      decoder.decode(bytes, bytes.length);
+      decoder.decode(bytes, bytes.length, false);
       fail();
     } catch (SubtitleDecoderException expected) {
       // Do nothing.
@@ -194,7 +194,7 @@ public class WebvttDecoderTest extends InstrumentationTestCase {
       SubtitleDecoderException {
     WebvttDecoder decoder = new WebvttDecoder();
     byte[] bytes = TestUtil.getByteArray(getInstrumentation(), asset);
-    return decoder.decode(bytes, bytes.length);
+    return decoder.decode(bytes, bytes.length, false);
   }
 
   private Spanned getUniqueSpanTextAt(WebvttSubtitle sub, long timeUs) {

library/core/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java

@@ -1465,8 +1465,9 @@ public final class MatroskaExtractor implements Extractor {
           break;
         case CODEC_ID_DVBSUB:
           mimeType = MimeTypes.APPLICATION_DVBSUBS;
-          initializationData = Collections.singletonList(new byte[] {
+          // Init data: composition_page (2), ancillary_page (2)
-              (byte) 0x01, codecPrivate[0], codecPrivate[1], codecPrivate[2], codecPrivate[3]});
+          initializationData = Collections.singletonList(new byte[] {codecPrivate[0],
+              codecPrivate[1], codecPrivate[2], codecPrivate[3]});
           break;
         default:
           throw new ParserException("Unrecognized codec identifier.");

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/DefaultTsPayloadReaderFactory.java

@@ -110,7 +110,8 @@ public final class DefaultTsPayloadReaderFactory implements TsPayloadReader.Fact
       case TsExtractor.TS_STREAM_TYPE_ID3:
         return new PesReader(new Id3Reader());
       case TsExtractor.TS_STREAM_TYPE_DVBSUBS:
-        return new PesReader(new DvbSubtitlesReader(esInfo));
+        return new PesReader(
+            new DvbSubtitleReader(esInfo.language, esInfo.dvbSubtitleInitializationData));
       default:
         return null;
     }

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/DvbSubtitleReader.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2017 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.exoplayer2.extractor.ts;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Parses DVB subtitle data and extracts individual frames.
+ */
+public final class DvbSubtitleReader implements ElementaryStreamReader {
+
+  private final String language;
+  private final List<byte[]> initializationData;
+
+  private TrackOutput output;
+  private boolean writingSample;
+  private int bytesToCheck;
+  private int sampleBytesWritten;
+  private long sampleTimeUs;
+
+  /**
+   * @param language The subtitle language code.
+   * @param initializationData Initialization data to be included in the track {@link Format}.
+   */
+  public DvbSubtitleReader(String language, byte[] initializationData) {
+    this.language = language;
+    this.initializationData = Collections.singletonList(initializationData);
+  }
+
+  @Override
+  public void seek() {
+    writingSample = false;
+  }
+
+  @Override
+  public void createTracks(ExtractorOutput extractorOutput, TrackIdGenerator idGenerator) {
+    idGenerator.generateNewId();
+    this.output = extractorOutput.track(idGenerator.getTrackId(), C.TRACK_TYPE_TEXT);
+    output.format(Format.createImageSampleFormat(idGenerator.getFormatId(),
+        MimeTypes.APPLICATION_DVBSUBS, null, Format.NO_VALUE, initializationData, language, null));
+  }
+
+  @Override
+  public void packetStarted(long pesTimeUs, boolean dataAlignmentIndicator) {
+    if (!dataAlignmentIndicator) {
+      return;
+    }
+    writingSample = true;
+    sampleTimeUs = pesTimeUs;
+    sampleBytesWritten = 0;
+    bytesToCheck = 2;
+  }
+
+  @Override
+  public void packetFinished() {
+    if (writingSample) {
+      output.sampleMetadata(sampleTimeUs, C.BUFFER_FLAG_KEY_FRAME, sampleBytesWritten, 0, null);
+      writingSample = false;
+    }
+  }
+
+  @Override
+  public void consume(ParsableByteArray data) {
+    if (writingSample) {
+      if (bytesToCheck == 2 && !checkNextByte(data, 0x20)) {
+        // Failed to check data_identifier
+        return;
+      }
+      if (bytesToCheck == 1 && !checkNextByte(data, 0x00)) {
+        // Check and discard the subtitle_stream_id
+        return;
+      }
+      int bytesAvailable = data.bytesLeft();
+      output.sampleData(data, bytesAvailable);
+      sampleBytesWritten += bytesAvailable;
+    }
+  }
+
+  private boolean checkNextByte(ParsableByteArray data, int expectedValue) {
+    if (data.bytesLeft() == 0) {
+      return false;
+    }
+    if (data.readUnsignedByte() != expectedValue) {
+      writingSample = false;
+    }
+    bytesToCheck--;
+    return writingSample;
+  }
+
+}

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/DvbSubtitlesReader.java

@@ -1,133 +0,0 @@
-/*
- * Copyright (C) 2017 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.exoplayer2.extractor.ts;
-
-
-import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.Format;
-import com.google.android.exoplayer2.extractor.ExtractorOutput;
-import com.google.android.exoplayer2.extractor.TrackOutput;
-import com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
-import com.google.android.exoplayer2.util.MimeTypes;
-import com.google.android.exoplayer2.util.ParsableByteArray;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-
-/**
- * Output PES packets to a {@link TrackOutput}.
- */
-public final class DvbSubtitlesReader implements ElementaryStreamReader {
-
-  private class SubtitleTrack {
-    private String language;
-    private List<byte[]> initializationData;
-  }
-
-  private List<SubtitleTrack> subtitles = new ArrayList<>();
-
-  private long sampleTimeUs;
-  private int sampleBytesWritten;
-  private boolean writingSample;
-
-  private List<TrackOutput> outputTracks = new ArrayList<>();
-
-  public DvbSubtitlesReader(TsPayloadReader.EsInfo esInfo) {
-    int pos = 2;
-
-    while (pos < esInfo.descriptorBytes.length) {
-      SubtitleTrack subtitle = new SubtitleTrack();
-      subtitle.language = new String(new byte[] {
-              esInfo.descriptorBytes[pos],
-              esInfo.descriptorBytes[pos + 1],
-              esInfo.descriptorBytes[pos + 2]});
-
-      if (((esInfo.descriptorBytes[pos + 3] & 0xF0 ) >> 4 ) == 2 ) {
-        subtitle.language += " for hard of hearing";
-      }
-
-      subtitle.initializationData = Collections.singletonList(new byte[] {(byte) 0x00,
-          esInfo.descriptorBytes[pos + 4], esInfo.descriptorBytes[pos + 5],
-          esInfo.descriptorBytes[pos + 6], esInfo.descriptorBytes[pos + 7]});
-
-      subtitles.add(subtitle);
-      pos += 8;
-    }
-  }
-
-
-  @Override
-  public void seek() {
-    writingSample = false;
-  }
-
-  @Override
-  public void createTracks(ExtractorOutput extractorOutput, TrackIdGenerator idGenerator) {
-    TrackOutput output;
-    SubtitleTrack subtitle;
-
-    for (int i = 0; i < subtitles.size(); i++) {
-      subtitle = subtitles.get(i);
-      idGenerator.generateNewId();
-      output = extractorOutput.track(idGenerator.getTrackId(), C.TRACK_TYPE_TEXT);
-      output.format(Format.createImageSampleFormat(idGenerator.getFormatId(),
-              MimeTypes.APPLICATION_DVBSUBS, null, Format.NO_VALUE,
-              subtitle.initializationData, subtitle.language, null));
-      outputTracks.add(output);
-    }
-  }
-
-
-  @Override
-  public void packetStarted(long pesTimeUs, boolean dataAlignmentIndicator) {
-    if (!dataAlignmentIndicator) {
-      return;
-    }
-    writingSample = true;
-    sampleTimeUs = pesTimeUs;
-    sampleBytesWritten = 0;
-  }
-
-  @Override
-  public void packetFinished() {
-    TrackOutput output;
-
-    for (int i = 0; i < outputTracks.size(); i++) {
-      output = outputTracks.get(i);
-      output.sampleMetadata(sampleTimeUs, C.BUFFER_FLAG_KEY_FRAME, sampleBytesWritten, 0, null);
-    }
-    writingSample = false;
-  }
-
-  @Override
-  public void consume(ParsableByteArray data) {
-    if (writingSample) {
-      int bytesAvailable = data.bytesLeft();
-      TrackOutput output;
-      int dataPosition = data.getPosition();
-
-      for (int i = 0; i < outputTracks.size(); i++) {
-        data.setPosition(dataPosition);
-        output = outputTracks.get(i);
-        output.sampleData(data, bytesAvailable);
-      }
-
-      sampleBytesWritten += bytesAvailable;
-    }
-  }
-}

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/TsExtractor.java

@@ -92,7 +92,7 @@ public final class TsExtractor implements Extractor {
   public static final int TS_STREAM_TYPE_H265 = 0x24;
   public static final int TS_STREAM_TYPE_ID3 = 0x15;
   public static final int TS_STREAM_TYPE_SPLICE_INFO = 0x86;
-  public static final int TS_STREAM_TYPE_DVBSUBS   = 0x59;
+  public static final int TS_STREAM_TYPE_DVBSUBS = 0x59;
 
   private static final int TS_PACKET_SIZE = 188;
   private static final int TS_SYNC_BYTE = 0x47; // First byte of each TS packet.
@@ -408,7 +408,7 @@ public final class TsExtractor implements Extractor {
       if (mode == MODE_HLS && id3Reader == null) {
         // Setup an ID3 track regardless of whether there's a corresponding entry, in case one
         // appears intermittently during playback. See [Internal: b/20261500].
-        EsInfo dummyEsInfo = new EsInfo(TS_STREAM_TYPE_ID3, null, new byte[0]);
+        EsInfo dummyEsInfo = new EsInfo(TS_STREAM_TYPE_ID3, null, null, new byte[0]);
         id3Reader = payloadReaderFactory.createPayloadReader(TS_STREAM_TYPE_ID3, dummyEsInfo);
         id3Reader.init(timestampAdjuster, output,
             new TrackIdGenerator(programNumber, TS_STREAM_TYPE_ID3, MAX_PID_PLUS_ONE));
@@ -478,6 +478,7 @@ public final class TsExtractor implements Extractor {
       int descriptorsEndPosition = descriptorsStartPosition + length;
       int streamType = -1;
       String language = null;
+      byte[] dvbSubtitleInitializationData = null;
       while (data.getPosition() < descriptorsEndPosition) {
         int descriptorTag = data.readUnsignedByte();
         int descriptorLength = data.readUnsignedByte();
@@ -503,12 +504,16 @@ public final class TsExtractor implements Extractor {
         } else if (descriptorTag == TS_PMT_DESC_DVBSUBS) {
           streamType = TS_STREAM_TYPE_DVBSUBS;
           language = new String(data.data, data.getPosition(), 3).trim();
+          data.skipBytes(4); // Skip language (3) + subtitling_type (1)
+          // Init data: composition_page (2), ancillary_page (2)
+          dvbSubtitleInitializationData = new byte[4];
+          data.readBytes(dvbSubtitleInitializationData, 0, 4);
         }
         // Skip unused bytes of current descriptor.
         data.skipBytes(positionOfNextDescriptor - data.getPosition());
       }
       data.setPosition(descriptorsEndPosition);
-      return new EsInfo(streamType, language,
+      return new EsInfo(streamType, language, dvbSubtitleInitializationData,
           Arrays.copyOfRange(data.data, descriptorsStartPosition, descriptorsEndPosition));
     }
 

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/TsPayloadReader.java

@@ -60,17 +60,22 @@ public interface TsPayloadReader {
 
     public final int streamType;
     public final String language;
+    public final byte[] dvbSubtitleInitializationData;
     public final byte[] descriptorBytes;
 
     /**
      * @param streamType The type of the stream as defined by the
      *     {@link TsExtractor}{@code .TS_STREAM_TYPE_*}.
      * @param language The language of the stream, as defined by ISO/IEC 13818-1, section 2.6.18.
+     * @param dvbSubtitleInitializationData If the descriptors include a DVB subtitle tag, this is
+     *     the corresponding decoder initialization data. Null otherwise.
      * @param descriptorBytes The descriptor bytes associated to the stream.
      */
-    public EsInfo(int streamType, String language, byte[] descriptorBytes) {
+    public EsInfo(int streamType, String language, byte[] dvbSubtitleInitializationData,
+        byte[] descriptorBytes) {
       this.streamType = streamType;
       this.language = language;
+      this.dvbSubtitleInitializationData = dvbSubtitleInitializationData;
       this.descriptorBytes = descriptorBytes;
     }
 

library/core/src/main/java/com/google/android/exoplayer2/text/Cue.java

@@ -168,8 +168,9 @@ public class Cue {
   public final float size;
 
   /**
-   * The bitmap height as a fraction of the of the viewport size, or -1 if the bitmap should be
+   * The bitmap height as a fraction of the of the viewport size, or {@link #DIMEN_UNSET} if the
-   * displayed at its natural height given for its specified {@link #size}.
+   * bitmap should be displayed at its natural height given the bitmap dimensions and the specified
+   * {@link #size}.
    */
   public final float bitmapHeight;
 
@@ -195,14 +196,15 @@ public class Cue {
    *     fraction of the viewport height.
    * @param verticalPositionAnchor The vertical anchor. One of {@link #ANCHOR_TYPE_START},
    *     {@link #ANCHOR_TYPE_MIDDLE}, {@link #ANCHOR_TYPE_END} and {@link #TYPE_UNSET}.
-   * @param width The width of the cue, expressed as a fraction of the viewport width.
+   * @param width The width of the cue as a fraction of the viewport width.
-   * @param height The width of the cue, expressed as a fraction of the viewport width.
+   * @param height The height of the cue as a fraction of the viewport height, or
+   *     {@link #DIMEN_UNSET} if the bitmap should be displayed at its natural height for the
+   *     specified {@code width}.
    */
   public Cue(Bitmap bitmap, float horizontalPosition, @AnchorType int horizontalPositionAnchor,
-             float verticalPosition, @AnchorType int verticalPositionAnchor, float width, float
+      float verticalPosition, @AnchorType int verticalPositionAnchor, float width, float height) {
-                 height) {
     this(null, null, bitmap, verticalPosition, LINE_TYPE_FRACTION, verticalPositionAnchor,
-           horizontalPosition, horizontalPositionAnchor, width, height, false, Color.BLACK);
+        horizontalPosition, horizontalPositionAnchor, width, height, false, Color.BLACK);
   }
 
   /**
@@ -248,10 +250,10 @@ public class Cue {
    * @param windowColor See {@link #windowColor}.
    */
   public Cue(CharSequence text, Alignment textAlignment, float line, @LineType int lineType,
-             @AnchorType int lineAnchor, float position, @AnchorType int positionAnchor, float size,
+      @AnchorType int lineAnchor, float position, @AnchorType int positionAnchor, float size,
-             boolean windowColorSet, int windowColor) {
+      boolean windowColorSet, int windowColor) {
     this(text, textAlignment, null, line, lineType, lineAnchor, position, positionAnchor, size,
-        -1, windowColorSet, windowColor);
+        DIMEN_UNSET, windowColorSet, windowColor);
   }
 
   private Cue(CharSequence text, Alignment textAlignment, Bitmap bitmap, float line,

library/core/src/main/java/com/google/android/exoplayer2/text/SimpleSubtitleDecoder.java

@@ -67,7 +67,7 @@ public abstract class SimpleSubtitleDecoder extends
       SubtitleOutputBuffer outputBuffer, boolean reset) {
     try {
       ByteBuffer inputData = inputBuffer.data;
-      Subtitle subtitle = decode(inputData.array(), inputData.limit());
+      Subtitle subtitle = decode(inputData.array(), inputData.limit(), reset);
       outputBuffer.setContent(inputBuffer.timeUs, subtitle, inputBuffer.subsampleOffsetUs);
       // Clear BUFFER_FLAG_DECODE_ONLY (see [Internal: b/27893809]).
       outputBuffer.clearFlag(C.BUFFER_FLAG_DECODE_ONLY);
@@ -82,9 +82,11 @@ public abstract class SimpleSubtitleDecoder extends
    *
    * @param data An array holding the data to be decoded, starting at position 0.
    * @param size The size of the data to be decoded.
+   * @param reset Whether the decoder must be reset before decoding.
    * @return The decoded {@link Subtitle}.
    * @throws SubtitleDecoderException If a decoding error occurs.
    */
-  protected abstract Subtitle decode(byte[] data, int size) throws SubtitleDecoderException;
+  protected abstract Subtitle decode(byte[] data, int size, boolean reset)
+      throws SubtitleDecoderException;
 
 }

library/core/src/main/java/com/google/android/exoplayer2/text/SubtitleDecoderFactory.java

@@ -24,7 +24,6 @@ import com.google.android.exoplayer2.text.tx3g.Tx3gDecoder;
 import com.google.android.exoplayer2.text.webvtt.Mp4WebvttDecoder;
 import com.google.android.exoplayer2.text.webvtt.WebvttDecoder;
 import com.google.android.exoplayer2.util.MimeTypes;
-
 import java.util.List;
 
 /**
@@ -86,7 +85,8 @@ public interface SubtitleDecoderFactory {
           return clazz.asSubclass(SubtitleDecoder.class).getConstructor(Integer.TYPE)
               .newInstance(format.accessibilityChannel);
         } else if (format.sampleMimeType.equals(MimeTypes.APPLICATION_DVBSUBS)) {
-          return clazz.asSubclass(SubtitleDecoder.class).getConstructor(List.class).newInstance(format.initializationData);
+          return clazz.asSubclass(SubtitleDecoder.class).getConstructor(List.class)
+              .newInstance(format.initializationData);
         } else {
           return clazz.asSubclass(SubtitleDecoder.class).getConstructor().newInstance();
         }

library/core/src/main/java/com/google/android/exoplayer2/text/dvb/DvbDecoder.java

@@ -16,7 +16,7 @@
 package com.google.android.exoplayer2.text.dvb;
 
 import com.google.android.exoplayer2.text.SimpleSubtitleDecoder;
-
+import com.google.android.exoplayer2.util.ParsableByteArray;
 import java.util.List;
 
 /**
@@ -26,27 +26,25 @@ public final class DvbDecoder extends SimpleSubtitleDecoder {
 
   private final DvbParser parser;
 
+  /**
+   * @param initializationData The initialization data for the decoder. The initialization data
+   *     must consist of a single byte array containing 5 bytes: flag_pes_stripped (1),
+   *     composition_page (2), ancillary_page (2).
+   */
   public DvbDecoder(List<byte[]> initializationData) {
     super("DvbDecoder");
-
+    ParsableByteArray data = new ParsableByteArray(initializationData.get(0));
-    int subtitleCompositionPage = 1;
+    int subtitleCompositionPage = data.readUnsignedShort();
-    int subtitleAncillaryPage = 1;
+    int subtitleAncillaryPage = data.readUnsignedShort();
-    int flags = 0;
+    parser = new DvbParser(subtitleCompositionPage, subtitleAncillaryPage);
-    byte[] tempByteArray;
-
-    if ((tempByteArray = initializationData.get(0)) != null && tempByteArray.length == 5) {
-      if (tempByteArray[0] == 0x01) {
-        flags |= DvbParser.FLAG_PES_STRIPPED_DVBSUB;
-      }
-      subtitleCompositionPage = ((tempByteArray[1] & 0xFF) << 8) | (tempByteArray[2] & 0xFF);
-      subtitleAncillaryPage = ((tempByteArray[3] & 0xFF) << 8) | (tempByteArray[4] & 0xFF);
-    }
-
-    parser = new DvbParser(subtitleCompositionPage, subtitleAncillaryPage, flags);
   }
 
   @Override
-  protected DvbSubtitle decode(byte[] data, int length) {
+  protected DvbSubtitle decode(byte[] data, int length, boolean reset) {
-    return new DvbSubtitle(parser.dvbSubsDecode(data, length));
+    if (reset) {
+      parser.reset();
+    }
+    return new DvbSubtitle(parser.decode(data, length));
   }
-}
+
+}

library/core/src/main/java/com/google/android/exoplayer2/text/dvb/DvbSubtitle.java

@@ -18,41 +18,37 @@ package com.google.android.exoplayer2.text.dvb;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.text.Subtitle;
-
-import java.util.Collections;
 import java.util.List;
 
 /**
  * A representation of a DVB subtitle.
  */
 /* package */ final class DvbSubtitle implements Subtitle {
-    private final List<Cue> cues;
 
-    public DvbSubtitle(List<Cue> cues) {
+  private final List<Cue> cues;
-        if (cues == null) {
-            this.cues = Collections.emptyList();
-        } else {
-            this.cues = cues;
-        }
-    }
 
-    @Override
+  public DvbSubtitle(List<Cue> cues) {
-    public int getNextEventTimeIndex(long timeUs) {
+    this.cues = cues;
-        return C.INDEX_UNSET;
+  }
-    }
 
-    @Override
+  @Override
-    public int getEventTimeCount() {
+  public int getNextEventTimeIndex(long timeUs) {
-        return 1;
+    return C.INDEX_UNSET;
-    }
+  }
 
-    @Override
+  @Override
-    public long getEventTime(int index) {
+  public int getEventTimeCount() {
-        return 0;
+    return 1;
-    }
+  }
 
-    @Override
+  @Override
-    public List<Cue> getCues(long timeUs) {
+  public long getEventTime(int index) {
-        return cues;
+    return 0;
-    }
+  }
-}
+
+  @Override
+  public List<Cue> getCues(long timeUs) {
+    return cues;
+  }
+
+}

library/core/src/main/java/com/google/android/exoplayer2/text/subrip/SubripDecoder.java

@@ -46,7 +46,7 @@ public final class SubripDecoder extends SimpleSubtitleDecoder {
   }
 
   @Override
-  protected SubripSubtitle decode(byte[] bytes, int length) {
+  protected SubripSubtitle decode(byte[] bytes, int length, boolean reset) {
     ArrayList<Cue> cues = new ArrayList<>();
     LongArray cueTimesUs = new LongArray();
     ParsableByteArray subripData = new ParsableByteArray(bytes, length);

library/core/src/main/java/com/google/android/exoplayer2/text/ttml/TtmlDecoder.java

@@ -94,7 +94,8 @@ public final class TtmlDecoder extends SimpleSubtitleDecoder {
   }
 
   @Override
-  protected TtmlSubtitle decode(byte[] bytes, int length) throws SubtitleDecoderException {
+  protected TtmlSubtitle decode(byte[] bytes, int length, boolean reset)
+      throws SubtitleDecoderException {
     try {
       XmlPullParser xmlParser = xmlParserFactory.newPullParser();
       Map<String, TtmlStyle> globalStyles = new HashMap<>();

library/core/src/main/java/com/google/android/exoplayer2/text/tx3g/Tx3gDecoder.java

@@ -35,7 +35,7 @@ public final class Tx3gDecoder extends SimpleSubtitleDecoder {
   }
 
   @Override
-  protected Subtitle decode(byte[] bytes, int length) {
+  protected Subtitle decode(byte[] bytes, int length, boolean reset) {
     parsableByteArray.reset(bytes, length);
     int textLength = parsableByteArray.readUnsignedShort();
     if (textLength == 0) {

library/core/src/main/java/com/google/android/exoplayer2/text/webvtt/Mp4WebvttDecoder.java

@@ -45,7 +45,8 @@ public final class Mp4WebvttDecoder extends SimpleSubtitleDecoder {
   }
 
   @Override
-  protected Mp4WebvttSubtitle decode(byte[] bytes, int length) throws SubtitleDecoderException {
+  protected Mp4WebvttSubtitle decode(byte[] bytes, int length, boolean reset)
+      throws SubtitleDecoderException {
     // 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, length);

library/core/src/main/java/com/google/android/exoplayer2/text/webvtt/WebvttDecoder.java

@@ -54,7 +54,8 @@ public final class WebvttDecoder extends SimpleSubtitleDecoder {
   }
 
   @Override
-  protected WebvttSubtitle decode(byte[] bytes, int length) throws SubtitleDecoderException {
+  protected WebvttSubtitle decode(byte[] bytes, int length, boolean reset)
+      throws SubtitleDecoderException {
     parsableWebvttData.reset(bytes, length);
     // Initialization for consistent starting state.
     webvttCueBuilder.reset();

library/core/src/main/java/com/google/android/exoplayer2/util/ParsableBitArray.java

@@ -89,6 +89,16 @@ public final class ParsableBitArray {
     return byteOffset * 8 + bitOffset;
   }
 
+  /**
+   * Returns the current byte offset. Must only be called when the position is byte aligned.
+   *
+   * @throws IllegalStateException If the position isn't byte aligned.
+   */
+  public int getBytePosition() {
+    Assertions.checkState(bitOffset == 0);
+    return byteOffset;
+  }
+
   /**
    * Sets the current bit offset.
    *
@@ -177,6 +187,47 @@ public final class ParsableBitArray {
     return returnValue;
   }
 
+  /**
+   * Aligns the position to the next byte boundary. Does nothing if the position is already aligned.
+   */
+  public void byteAlign() {
+    if (bitOffset == 0) {
+      return;
+    }
+    bitOffset = 0;
+    byteOffset++;
+    assertValidOffset();
+  }
+
+  /**
+   * Reads the next {@code length} bytes into {@code buffer}. Must only be called when the position
+   * is byte aligned.
+   *
+   * @see System#arraycopy(Object, int, Object, int, int)
+   * @param buffer The array into which the read data should be written.
+   * @param offset The offset in {@code buffer} at which the read data should be written.
+   * @param length The number of bytes to read.
+   * @throws IllegalStateException If the position isn't byte aligned.
+   */
+  public void readBytes(byte[] buffer, int offset, int length) {
+    Assertions.checkState(bitOffset == 0);
+    System.arraycopy(data, byteOffset, buffer, offset, length);
+    byteOffset += length;
+    assertValidOffset();
+  }
+
+  /**
+   * Skips the next {@code length} bytes. Must only be called when the position is byte aligned.
+   *
+   * @param length The number of bytes to read.
+   * @throws IllegalStateException If the position isn't byte aligned.
+   */
+  public void skipBytes(int length) {
+    Assertions.checkState(bitOffset == 0);
+    byteOffset += length;
+    assertValidOffset();
+  }
+
   private void assertValidOffset() {
     // It is fine for position to be at the end of the array, but no further.
     Assertions.checkState(byteOffset >= 0

library/ui/src/main/java/com/google/android/exoplayer2/ui/SubtitlePainter.java

@@ -315,7 +315,7 @@ import com.google.android.exoplayer2.util.Util;
     float anchorX = parentLeft + (parentWidth * cuePosition);
     float anchorY = parentTop + (parentHeight * cueLine);
     int width = Math.round(parentWidth * cueSize);
-    int height = cueBitmapHeight != -1 ? Math.round(parentHeight * cueBitmapHeight)
+    int height = cueBitmapHeight != Cue.DIMEN_UNSET ? Math.round(parentHeight * cueBitmapHeight)
         : Math.round(width * ((float) cueBitmap.getHeight() / cueBitmap.getWidth()));
     int x = Math.round(cueLineAnchor == Cue.ANCHOR_TYPE_END ? (anchorX - width)
         : cueLineAnchor == Cue.ANCHOR_TYPE_MIDDLE ? (anchorX - (width / 2)) : anchorX);