Support tts:textEmphasis in TTML parser and WebView output

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

+/*
+ * Copyright (C) 2021 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.text.span;
+
+import static java.lang.annotation.RetentionPolicy.SOURCE;
+
+import androidx.annotation.IntDef;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+
+public final class TextEmphasisSpan {
+  /**
+   * <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/text-emphasis-position">Text Emphasis Position</a>
+   */
+
+  /**
+   * The text emphasis position is unknown. If an implementation does not recognize or otherwise
+   * distinguish an annotation position value, then it must be interpreted as if a position of
+   * before were specified; as such, an implementation that supports text annotation marks must
+   * minimally support the before value.
+   */
+  public static final int POSITION_UNKNOWN = -1;
+
+  /**
+   * The emphasis marks should be positioned above the base text in horizontal writing mode The
+   * emphasis marks should be positioned to the right of the base text in vertical writing mode
+   */
+  public static final int POSITION_BEFORE = 1;
+
+  /**
+   * The emphasis marks should be positioned below the base text in horizontal writing mode The
+   * emphasis marks should be positioned to the left of the base text in vertical writing mode
+   */
+  public static final int POSITION_AFTER = 2;
+
+  /**
+   * The text emphasis should be positioned in following way:
+   *
+   * <ul>
+   *   <li>Equivalent to {@link #POSITION_BEFORE} for (1) the only line area of or (2) the first line
+   *   area of the last block area generated by a p element which contains annotated text
+   *   <li>otherwise, equivalent to {@link #POSITION_AFTER}
+   * </ul>
+   */
+  public static final int POSITION_OUTSIDE = 3;
+
+  /**
+   * The possible positions of the emphasis marks relative to the base text.
+   *
+   * <p>One of:
+   *
+   * <ul>
+   *   <li>{@link #POSITION_UNKNOWN}
+   *   <li>{@link #POSITION_BEFORE}
+   *   <li>{@link #POSITION_AFTER}
+   *   <li>{@link #POSITION_OUTSIDE}
+   * </ul>
+   */
+  @Documented
+  @Retention(SOURCE)
+  @IntDef({POSITION_UNKNOWN, POSITION_BEFORE, POSITION_AFTER, POSITION_OUTSIDE})
+  public @interface Position {
+
+  }
+
+  /**
+   * The text emphasis position is unknown.
+   */
+  public static final int MARK_UNKNOWN = -1;
+
+  public static final int MARK_AUTO = 1;
+  public static final int MARK_FILLED_CIRCLE = 2;
+  public static final int MARK_FILLED_DOT = 3;
+  public static final int MARK_FILLED_SESAME = 4;
+  public static final int MARK_OPEN_CIRCLE = 5;
+  public static final int MARK_OPEN_DOT = 6;
+  public static final int MARK_OPEN_SESAME = 7;
+
+  /**
+   * The possible types of annotations used.
+   *
+   * <p>One of:
+   *
+   * <ul>
+   *   <li>{@link #MARK_UNKNOWN}
+   *   <li>{@link #MARK_AUTO}
+   *   <li>{@link #MARK_FILLED_CIRCLE}
+   *   <li>{@link #MARK_FILLED_DOT}
+   *   <li>{@link #MARK_FILLED_SESAME}
+   *   <li>{@link #MARK_OPEN_CIRCLE}
+   *   <li>{@link #MARK_OPEN_DOT}
+   *   <li>{@link #MARK_OPEN_SESAME}
+   * </ul>
+   */
+  @Documented
+  @Retention(SOURCE)
+  @IntDef({MARK_UNKNOWN, MARK_AUTO, MARK_FILLED_CIRCLE, MARK_FILLED_DOT, MARK_FILLED_SESAME,
+      MARK_OPEN_CIRCLE, MARK_OPEN_DOT, MARK_OPEN_SESAME})
+  public @interface Mark {
+
+  }
+
+  /**
+   * The position of the text emphasis relative to the base text
+   */
+  @TextEmphasisSpan.Position
+  public final int position;
+
+  /**
+   * The text emphasis mark
+   */
+  @TextEmphasisSpan.Mark
+  public final int mark;
+
+  public TextEmphasisSpan(@TextEmphasisSpan.Mark int mark,
+      @TextEmphasisSpan.Position int position) {
+    this.mark = mark;
+    this.position = position;
+  }
+}

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

+/*
+ * Copyright (C) 2021 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.text.ttml;
+
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_AUTO;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_FILLED_CIRCLE;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_FILLED_DOT;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_FILLED_SESAME;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_OPEN_CIRCLE;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_OPEN_DOT;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_OPEN_SESAME;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.POSITION_AFTER;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.POSITION_BEFORE;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.POSITION_OUTSIDE;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.POSITION_UNKNOWN;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
+
+/**
+ * This class is used to emphasize text using markers above or below the text. For example, markers
+ * known as boutens are commonly used in Japanese texts. Boutens are dots placed above or below a
+ * word or phrase that act as literal points of emphasis, equivalent to the use of italics in
+ * English. Boutens can help express implied meanings which provide a richer and more dynamic
+ * translation.
+ */
+/* package */ final class TextEmphasis {
+
+  /**
+   * The position of the text emphasis relative to the base text.
+   */
+  @TextEmphasisSpan.Position
+  public final int position;
+
+  /**
+   * The desired emphasis mark
+   */
+  @TextEmphasisSpan.Mark
+  public final int mark;
+
+  private TextEmphasis(@TextEmphasisSpan.Mark int mark, @TextEmphasisSpan.Position int position) {
+    this.mark = mark;
+    this.position = position;
+  }
+
+  @Override
+  public String toString() {
+    return "TextEmphasis{" +
+        "position=" + position +
+        ", mark=" + mark +
+        '}';
+  }
+
+  public static TextEmphasis createTextEmphasis(@Nullable String value) {
+    if (value == null) {
+      return null;
+    }
+
+    String parsingValue = value.toLowerCase().trim();
+    if ("".equals(parsingValue)) {
+      return null;
+    }
+
+    String[] nodes = parsingValue.split("\\s+");
+
+    switch (nodes.length) {
+      case 0:
+        return null;
+      case 1:
+        return handleOneNode(nodes[0]);
+      case 2:
+        return handleTwoNodes(nodes[0], nodes[1]);
+      default:
+        // We ignore anything after third entry in value
+        return handleThreeNodes(nodes[0], nodes[1], nodes[2]);
+    }
+  }
+
+  private static @Nullable
+  TextEmphasis handleOneNode(@NonNull String value) {
+
+    if (TtmlNode.TEXT_EMPHASIS_NONE.equals(value)) {
+      return null;
+    }
+
+    // Handle "auto" or unknown value
+    // If an implementation does not recognize or otherwise distinguish an emphasis style value,
+    // then it must be interpreted as if a style of auto were specified; as such, an implementation
+    // that supports text emphasis marks must minimally support the auto value.
+    return new TextEmphasis(MARK_AUTO, POSITION_UNKNOWN);
+  }
+
+  private static @Nullable
+  TextEmphasis handleTwoNodes(@NonNull String mark, @NonNull String position) {
+
+    @TextEmphasisSpan.Position int positionEntry = getPosition(position);
+    @TextEmphasisSpan.Mark int markEntry;
+    switch (mark) {
+      case TtmlNode.TEXT_EMPHASIS_AUTO:
+        markEntry = MARK_AUTO;
+        break;
+      // If only circle, dot, or sesame is specified, then it is equivalent to filled circle,
+      // filled dot, and filled sesame, respectively.
+      case TtmlNode.TEXT_EMPHASIS_MARK_DOT:
+        markEntry = MARK_FILLED_DOT;
+        break;
+      case TtmlNode.TEXT_EMPHASIS_MARK_SESAME:
+        markEntry = MARK_FILLED_SESAME;
+        break;
+      case TtmlNode.TEXT_EMPHASIS_MARK_CIRCLE:
+        markEntry = MARK_FILLED_CIRCLE;
+        break;
+      default:
+        // This is use case for: "filled dot" when position is not specified.
+        return handleWithPosition(mark, position, POSITION_UNKNOWN);
+    }
+
+    return new TextEmphasis(markEntry, positionEntry);
+  }
+
+  private static @Nullable
+  TextEmphasis handleWithPosition(@NonNull String markStyle, @Nullable String mark,
+      @TextEmphasisSpan.Position int position) {
+
+    switch (mark) {
+
+      case TtmlNode.TEXT_EMPHASIS_MARK_DOT:
+        if (TtmlNode.TEXT_EMPHASIS_MARK_FILLED.equals(markStyle)) {
+          return new TextEmphasis(MARK_FILLED_DOT, position);
+        } else if (TtmlNode.TEXT_EMPHASIS_MARK_OPEN.equals(markStyle)) {
+          return new TextEmphasis(MARK_OPEN_DOT, position);
+        } else {
+          return new TextEmphasis(MARK_FILLED_DOT, position);
+        }
+
+      case TtmlNode.TEXT_EMPHASIS_MARK_SESAME:
+        if (TtmlNode.TEXT_EMPHASIS_MARK_FILLED.equals(markStyle)) {
+          return new TextEmphasis(MARK_FILLED_SESAME, position);
+        } else if (TtmlNode.TEXT_EMPHASIS_MARK_OPEN.equals(markStyle)) {
+          return new TextEmphasis(MARK_OPEN_SESAME, position);
+        } else {
+          return new TextEmphasis(MARK_FILLED_SESAME, position);
+        }
+
+      case TtmlNode.TEXT_EMPHASIS_MARK_CIRCLE:
+        if (TtmlNode.TEXT_EMPHASIS_MARK_FILLED.equals(markStyle)) {
+          return new TextEmphasis(MARK_FILLED_CIRCLE, position);
+        } else if (TtmlNode.TEXT_EMPHASIS_MARK_OPEN.equals(markStyle)) {
+          return new TextEmphasis(MARK_OPEN_CIRCLE, position);
+        } else {
+          return new TextEmphasis(MARK_FILLED_CIRCLE, position);
+        }
+
+      default:
+        // Not supported, default to AUTO.
+        break;
+    }
+
+    return new TextEmphasis(MARK_AUTO, POSITION_UNKNOWN);
+  }
+
+  private static @Nullable
+  TextEmphasis handleThreeNodes(@NonNull String markStyle, @NonNull String mark,
+      @NonNull String position) {
+
+    @TextEmphasisSpan.Position int positionEntry = getPosition(position);
+    return handleWithPosition(markStyle, mark, positionEntry);
+  }
+
+  private static @TextEmphasisSpan.Position
+  int getPosition(@NonNull String value) {
+
+    switch (value) {
+      case TtmlNode.TEXT_EMPHASIS_POSITION_AFTER:
+        return POSITION_AFTER;
+      case TtmlNode.TEXT_EMPHASIS_POSITION_BEFORE:
+        return POSITION_BEFORE;
+      case TtmlNode.TEXT_EMPHASIS_POSITION_OUTSIDE:
+        return POSITION_OUTSIDE;
+      default:
+        // ignore
+        break;
+    }
+    return POSITION_UNKNOWN;
+  }
+}

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

@@ -609,6 +609,10 @@ public final class TtmlDecoder extends SimpleSubtitleDecoder {
               break;
               break;
           }
           }
           break;
           break;
+        case TtmlNode.ATTR_TTS_TEXT_EMPHASIS:
+          style = createIfNull(style).setTextEmphasis(
+              TextEmphasis.createTextEmphasis(Util.toLowerInvariant(attributeValue)));
+          break;
         default:
         default:
           // ignore
           // ignore
           break;
           break;

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

@@ -69,6 +69,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   public static final String ATTR_TTS_TEXT_DECORATION = "textDecoration";
   public static final String ATTR_TTS_TEXT_DECORATION = "textDecoration";
   public static final String ATTR_TTS_TEXT_ALIGN = "textAlign";
   public static final String ATTR_TTS_TEXT_ALIGN = "textAlign";
   public static final String ATTR_TTS_TEXT_COMBINE = "textCombine";
   public static final String ATTR_TTS_TEXT_COMBINE = "textCombine";
+  public static final String ATTR_TTS_TEXT_EMPHASIS = "textEmphasis";
   public static final String ATTR_TTS_WRITING_MODE = "writingMode";
   public static final String ATTR_TTS_WRITING_MODE = "writingMode";
 
 
   // Values for ruby
   // Values for ruby
@@ -106,6 +107,19 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   public static final String VERTICAL_LR = "tblr";
   public static final String VERTICAL_LR = "tblr";
   public static final String VERTICAL_RL = "tbrl";
   public static final String VERTICAL_RL = "tbrl";
 
 
+  // Values for textEmphasis
+  public static final String TEXT_EMPHASIS_NONE = "none";
+  public static final String TEXT_EMPHASIS_AUTO = "auto";
+  public static final String TEXT_EMPHASIS_MARK_DOT = "dot";
+  public static final String TEXT_EMPHASIS_MARK_SESAME = "sesame";
+  public static final String TEXT_EMPHASIS_MARK_CIRCLE = "circle";
+  public static final String TEXT_EMPHASIS_MARK_FILLED = "filled";
+  public static final String TEXT_EMPHASIS_MARK_OPEN = "open";
+
+  public static final String TEXT_EMPHASIS_POSITION_AFTER = "after";
+  public static final String TEXT_EMPHASIS_POSITION_BEFORE = "before";
+  public static final String TEXT_EMPHASIS_POSITION_OUTSIDE = "outside";
+
   @Nullable public final String tag;
   @Nullable public final String tag;
   @Nullable public final String text;
   @Nullable public final String text;
   public final boolean isTextNode;
   public final boolean isTextNode;
@@ -243,7 +257,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 
     TreeMap<String, Cue.Builder> regionTextOutputs = new TreeMap<>();
     TreeMap<String, Cue.Builder> regionTextOutputs = new TreeMap<>();
     traverseForText(timeUs, false, regionId, regionTextOutputs);
     traverseForText(timeUs, false, regionId, regionTextOutputs);
-    traverseForStyle(timeUs, globalStyles, regionTextOutputs);
+    traverseForStyle(timeUs, globalStyles, regionMap, regionId, regionTextOutputs);
 
 
     List<Cue> cues = new ArrayList<>();
     List<Cue> cues = new ArrayList<>();
 
 
@@ -354,26 +368,32 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   }
   }
 
 
   private void traverseForStyle(
   private void traverseForStyle(
-      long timeUs, Map<String, TtmlStyle> globalStyles, Map<String, Cue.Builder> regionOutputs) {
+      long timeUs, Map<String, TtmlStyle> globalStyles, Map<String, TtmlRegion> regionMaps,
+      String inheritedRegion, Map<String, Cue.Builder> regionOutputs) {
     if (!isActive(timeUs)) {
     if (!isActive(timeUs)) {
       return;
       return;
     }
     }
+    String resolvedRegionId = ANONYMOUS_REGION_ID.equals(regionId) ? inheritedRegion : regionId;
+
     for (Map.Entry<String, Integer> entry : nodeEndsByRegion.entrySet()) {
     for (Map.Entry<String, Integer> entry : nodeEndsByRegion.entrySet()) {
       String regionId = entry.getKey();
       String regionId = entry.getKey();
       int start = nodeStartsByRegion.containsKey(regionId) ? nodeStartsByRegion.get(regionId) : 0;
       int start = nodeStartsByRegion.containsKey(regionId) ? nodeStartsByRegion.get(regionId) : 0;
       int end = entry.getValue();
       int end = entry.getValue();
       if (start != end) {
       if (start != end) {
         Cue.Builder regionOutput = Assertions.checkNotNull(regionOutputs.get(regionId));
         Cue.Builder regionOutput = Assertions.checkNotNull(regionOutputs.get(regionId));
-        applyStyleToOutput(globalStyles, regionOutput, start, end);
+        @Cue.VerticalType int verticalType = Assertions
+            .checkNotNull(regionMaps.get(resolvedRegionId)).verticalType;
+        applyStyleToOutput(globalStyles, regionOutput, start, end, verticalType);
       }
       }
     }
     }
     for (int i = 0; i < getChildCount(); ++i) {
     for (int i = 0; i < getChildCount(); ++i) {
-      getChild(i).traverseForStyle(timeUs, globalStyles, regionOutputs);
+      getChild(i).traverseForStyle(timeUs, globalStyles, regionMaps, resolvedRegionId, regionOutputs);
     }
     }
   }
   }
 
 
   private void applyStyleToOutput(
   private void applyStyleToOutput(
-      Map<String, TtmlStyle> globalStyles, Cue.Builder regionOutput, int start, int end) {
+      Map<String, TtmlStyle> globalStyles, Cue.Builder regionOutput, int start, int end,
+      @Cue.VerticalType int verticalType) {
     @Nullable TtmlStyle resolvedStyle = TtmlRenderUtil.resolveStyle(style, styleIds, globalStyles);
     @Nullable TtmlStyle resolvedStyle = TtmlRenderUtil.resolveStyle(style, styleIds, globalStyles);
     @Nullable SpannableStringBuilder text = (SpannableStringBuilder) regionOutput.getText();
     @Nullable SpannableStringBuilder text = (SpannableStringBuilder) regionOutput.getText();
     if (text == null) {
     if (text == null) {
@@ -381,7 +401,8 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       regionOutput.setText(text);
       regionOutput.setText(text);
     }
     }
     if (resolvedStyle != null) {
     if (resolvedStyle != null) {
-      TtmlRenderUtil.applyStylesToSpan(text, start, end, resolvedStyle, parent, globalStyles);
+      TtmlRenderUtil
+          .applyStylesToSpan(text, start, end, resolvedStyle, parent, globalStyles, verticalType);
       regionOutput.setTextAlignment(resolvedStyle.getTextAlign());
       regionOutput.setTextAlignment(resolvedStyle.getTextAlign());
     }
     }
   }
   }

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

@@ -27,9 +27,11 @@ import android.text.style.StyleSpan;
 import android.text.style.TypefaceSpan;
 import android.text.style.TypefaceSpan;
 import android.text.style.UnderlineSpan;
 import android.text.style.UnderlineSpan;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.SpanUtil;
 import com.google.android.exoplayer2.text.span.SpanUtil;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayDeque;
 import java.util.ArrayDeque;
@@ -83,7 +85,8 @@ import java.util.Map;
       int end,
       int end,
       TtmlStyle style,
       TtmlStyle style,
       @Nullable TtmlNode parent,
       @Nullable TtmlNode parent,
-      Map<String, TtmlStyle> globalStyles) {
+      Map<String, TtmlStyle> globalStyles,
+      @Cue.VerticalType int verticalType) {
 
 
     if (style.getStyle() != TtmlStyle.UNSPECIFIED) {
     if (style.getStyle() != TtmlStyle.UNSPECIFIED) {
       builder.setSpan(new StyleSpan(style.getStyle()), start, end,
       builder.setSpan(new StyleSpan(style.getStyle()), start, end,
@@ -119,6 +122,27 @@ import java.util.Map;
           end,
           end,
           Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
           Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
     }
     }
+    if (style.getTextEmphasis() != null) {
+      TextEmphasis textEmphasis = style.getTextEmphasis();
+      // https://www.w3.org/TR/ttml2/#style-value-emphasis-style
+      // If an implementation does not recognize or otherwise distinguish an emphasis style value,
+      // then it must be interpreted as if a style of auto were specified; as such, an
+      // implementation that supports text emphasis marks must minimally support the auto value.
+      // If a vertical writing mode applies, then equivalent to filled sesame; otherwise, equivalent
+      // to filled circle.
+      @TextEmphasisSpan.Mark int mark = textEmphasis.mark;
+      if (textEmphasis.mark == TextEmphasisSpan.MARK_AUTO
+          || textEmphasis.mark == TextEmphasisSpan.MARK_UNKNOWN) {
+        mark = (verticalType == Cue.VERTICAL_TYPE_LR || verticalType == Cue.VERTICAL_TYPE_RL) ?
+            TextEmphasisSpan.MARK_FILLED_SESAME : TextEmphasisSpan.MARK_FILLED_CIRCLE;
+      }
+      SpanUtil.addOrReplaceSpan(
+          builder,
+          new TextEmphasisSpan(mark, textEmphasis.position),
+          start,
+          end,
+          Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+    }
     switch (style.getRubyType()) {
     switch (style.getRubyType()) {
       case TtmlStyle.RUBY_TYPE_BASE:
       case TtmlStyle.RUBY_TYPE_BASE:
         // look for the sibling RUBY_TEXT and add it as span between start & end.
         // look for the sibling RUBY_TEXT and add it as span between start & end.

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

@@ -87,6 +87,8 @@ import java.lang.annotation.RetentionPolicy;
   @Nullable private Layout.Alignment textAlign;
   @Nullable private Layout.Alignment textAlign;
   @OptionalBoolean private int textCombine;
   @OptionalBoolean private int textCombine;
 
 
+  private TextEmphasis textEmphasis;
+
   public TtmlStyle() {
   public TtmlStyle() {
     linethrough = UNSPECIFIED;
     linethrough = UNSPECIFIED;
     underline = UNSPECIFIED;
     underline = UNSPECIFIED;
@@ -238,6 +240,9 @@ import java.lang.annotation.RetentionPolicy;
         fontSizeUnit = ancestor.fontSizeUnit;
         fontSizeUnit = ancestor.fontSizeUnit;
         fontSize = ancestor.fontSize;
         fontSize = ancestor.fontSize;
       }
       }
+      if (textEmphasis == null) {
+        textEmphasis = ancestor.textEmphasis;
+      }
       // attributes not inherited as of http://www.w3.org/TR/ttml1/
       // attributes not inherited as of http://www.w3.org/TR/ttml1/
       if (chaining && !hasBackgroundColor && ancestor.hasBackgroundColor) {
       if (chaining && !hasBackgroundColor && ancestor.hasBackgroundColor) {
         setBackgroundColor(ancestor.backgroundColor);
         setBackgroundColor(ancestor.backgroundColor);
@@ -299,6 +304,16 @@ import java.lang.annotation.RetentionPolicy;
     return this;
     return this;
   }
   }
 
 
+  @Nullable
+  public TextEmphasis getTextEmphasis() {
+    return textEmphasis;
+  }
+
+  public TtmlStyle setTextEmphasis(@Nullable TextEmphasis textEmphasis) {
+    this.textEmphasis = textEmphasis;
+    return this;
+  }
+
   public TtmlStyle setFontSize(float fontSize) {
   public TtmlStyle setFontSize(float fontSize) {
     this.fontSize = fontSize;
     this.fontSize = fontSize;
     return this;
     return this;

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

@@ -28,6 +28,7 @@ import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.text.Subtitle;
 import com.google.android.exoplayer2.text.Subtitle;
 import com.google.android.exoplayer2.text.SubtitleDecoderException;
 import com.google.android.exoplayer2.text.SubtitleDecoderException;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.ColorParser;
 import com.google.android.exoplayer2.util.ColorParser;
 import java.io.IOException;
 import java.io.IOException;
@@ -36,7 +37,9 @@ import java.util.Map;
 import org.junit.Test;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runner.RunWith;
 
 
-/** Unit test for {@link TtmlDecoder}. */
+/**
+ * Unit test for {@link TtmlDecoder}.
+ */
 @RunWith(AndroidJUnit4.class)
 @RunWith(AndroidJUnit4.class)
 public final class TtmlDecoderTest {
 public final class TtmlDecoderTest {
 
 
@@ -67,6 +70,7 @@ public final class TtmlDecoderTest {
   private static final String VERTICAL_TEXT_FILE = "media/ttml/vertical_text.xml";
   private static final String VERTICAL_TEXT_FILE = "media/ttml/vertical_text.xml";
   private static final String TEXT_COMBINE_FILE = "media/ttml/text_combine.xml";
   private static final String TEXT_COMBINE_FILE = "media/ttml/text_combine.xml";
   private static final String RUBIES_FILE = "media/ttml/rubies.xml";
   private static final String RUBIES_FILE = "media/ttml/rubies.xml";
+  private static final String TEXT_EMPHASIS_FILE = "media/ttml/text_emphasis.xml";
 
 
   @Test
   @Test
   public void inlineAttributes() throws IOException, SubtitleDecoderException {
   public void inlineAttributes() throws IOException, SubtitleDecoderException {
@@ -109,12 +113,10 @@ public final class TtmlDecoderTest {
    * framework level. Tests that <i>lime</i> resolves to <code>#FF00FF00</code> not <code>#00FF00
    * framework level. Tests that <i>lime</i> resolves to <code>#FF00FF00</code> not <code>#00FF00
    * </code>.
    * </code>.
    *
    *
-   * @see <a
-   *     href="https://github.com/android/platform_frameworks_base/blob/jb-mr2-release/graphics/java/android/graphics/Color.java#L414">
-   *     JellyBean Color</a> <a
-   *     href="https://github.com/android/platform_frameworks_base/blob/kitkat-mr2.2-release/graphics/java/android/graphics/Color.java#L414">
-   *     Kitkat Color</a>
    * @throws IOException thrown if reading subtitle file fails.
    * @throws IOException thrown if reading subtitle file fails.
+   * @see <a href="https://github.com/android/platform_frameworks_base/blob/jb-mr2-release/graphics/java/android/graphics/Color.java#L414">
+   * JellyBean Color</a> <a href="https://github.com/android/platform_frameworks_base/blob/kitkat-mr2.2-release/graphics/java/android/graphics/Color.java#L414">
+   * Kitkat Color</a>
    */
    */
   @Test
   @Test
   public void lime() throws IOException, SubtitleDecoderException {
   public void lime() throws IOException, SubtitleDecoderException {
@@ -674,6 +676,105 @@ public final class TtmlDecoderTest {
     assertThat(sixthCue).hasNoRubySpanBetween(0, sixthCue.length());
     assertThat(sixthCue).hasNoRubySpanBetween(0, sixthCue.length());
   }
   }
 
 
+  @Test
+  public void textEmphasis() throws IOException, SubtitleDecoderException {
+    TtmlSubtitle subtitle = getSubtitle(TEXT_EMPHASIS_FILE);
+
+    Spanned firstCue = getOnlyCueTextAtTimeUs(subtitle, 10_000_000);
+    assertThat(firstCue)
+        .hasNoTextEmphasisSpanBetween("None ".length(), "None おはよ".length());
+
+    Spanned secondCue = getOnlyCueTextAtTimeUs(subtitle, 20_000_000);
+    assertThat(secondCue)
+        .hasTextEmphasisSpanBetween("Auto ".length(), "Auto ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_CIRCLE,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned thirdCue = getOnlyCueTextAtTimeUs(subtitle, 30_000_000);
+    assertThat(thirdCue)
+        .hasTextEmphasisSpanBetween("Filled circle ".length(), "Filled circle こんばんは".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_CIRCLE,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned fourthCue = getOnlyCueTextAtTimeUs(subtitle, 40_000_000);
+    assertThat(fourthCue)
+        .hasTextEmphasisSpanBetween("Filled dot ".length(), "Filled dot ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_DOT, TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned fifthCue = getOnlyCueTextAtTimeUs(subtitle, 50_000_000);
+    assertThat(fifthCue)
+        .hasTextEmphasisSpanBetween("Filled sesame ".length(), "Filled sesame おはよ".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_SESAME,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned sixthCue = getOnlyCueTextAtTimeUs(subtitle, 60_000_000);
+    assertThat(sixthCue)
+        .hasTextEmphasisSpanBetween("Open circle before ".length(),
+            "Open circle before ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_OPEN_CIRCLE, TextEmphasisSpan.POSITION_BEFORE);
+
+    Spanned seventhCue = getOnlyCueTextAtTimeUs(subtitle, 70_000_000);
+    assertThat(seventhCue)
+        .hasTextEmphasisSpanBetween("Open dot after ".length(), "Open dot after おはよ".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_OPEN_DOT, TextEmphasisSpan.POSITION_AFTER);
+
+    Spanned eighthCue = getOnlyCueTextAtTimeUs(subtitle, 80_000_000);
+    assertThat(eighthCue)
+        .hasTextEmphasisSpanBetween("Open sesame outside ".length(),
+            "Open sesame outside ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_OPEN_SESAME, TextEmphasisSpan.POSITION_OUTSIDE);
+
+    Spanned ninthCue = getOnlyCueTextAtTimeUs(subtitle, 90_000_000);
+    assertThat(ninthCue)
+        .hasTextEmphasisSpanBetween("Auto outside ".length(), "Auto outside おはよ".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_CIRCLE,
+            TextEmphasisSpan.POSITION_OUTSIDE);
+
+    Spanned tenthCue = getOnlyCueTextAtTimeUs(subtitle, 100_000_000);
+    assertThat(tenthCue)
+        .hasTextEmphasisSpanBetween("Circle before ".length(), "Circle before ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_BEFORE);
+
+    Spanned eleventhCue = getOnlyCueTextAtTimeUs(subtitle, 110_000_000);
+    assertThat(eleventhCue)
+        .hasTextEmphasisSpanBetween("Sesame after ".length(), "Sesame after おはよ".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_SESAME, TextEmphasisSpan.POSITION_AFTER);
+
+    Spanned twelfthCue = getOnlyCueTextAtTimeUs(subtitle, 120_000_000);
+    assertThat(twelfthCue)
+        .hasTextEmphasisSpanBetween("Dot outside ".length(), "Dot outside ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_DOT, TextEmphasisSpan.POSITION_OUTSIDE);
+
+    Spanned thirteenthCue = getOnlyCueTextAtTimeUs(subtitle, 130_000_000);
+    assertThat(thirteenthCue)
+        .hasNoTextEmphasisSpanBetween("No textEmphasis property ".length(),
+            "No textEmphasis property おはよ".length());
+
+    Spanned fourteenthCue = getOnlyCueTextAtTimeUs(subtitle, 140_000_000);
+    assertThat(fourteenthCue)
+        .hasTextEmphasisSpanBetween("Auto (TBLR) ".length(), "Auto (TBLR) ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_SESAME,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned fifteenthCue = getOnlyCueTextAtTimeUs(subtitle, 150_000_000);
+    assertThat(fifteenthCue)
+        .hasTextEmphasisSpanBetween("Auto (TBRL) ".length(), "Auto (TBRL) おはよ".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_SESAME,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned sixteenthCue = getOnlyCueTextAtTimeUs(subtitle, 160_000_000);
+    assertThat(sixteenthCue)
+        .hasTextEmphasisSpanBetween("Auto (TB) ".length(), "Auto (TB) ございます".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_SESAME,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+
+    Spanned seventeenthCue = getOnlyCueTextAtTimeUs(subtitle, 170_000_000);
+    assertThat(seventeenthCue)
+        .hasTextEmphasisSpanBetween("Auto (LR) ".length(), "Auto (LR) おはよ".length())
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_CIRCLE,
+            TextEmphasisSpan.POSITION_UNKNOWN);
+  }
+
   private static Spanned getOnlyCueTextAtTimeUs(Subtitle subtitle, long timeUs) {
   private static Spanned getOnlyCueTextAtTimeUs(Subtitle subtitle, long timeUs) {
     Cue cue = getOnlyCueAtTimeUs(subtitle, timeUs);
     Cue cue = getOnlyCueAtTimeUs(subtitle, timeUs);
     assertThat(cue.text).isInstanceOf(Spanned.class);
     assertThat(cue.text).isInstanceOf(Spanned.class);

library/core/src/test/java/com/google/android/exoplayer2/text/ttml/TtmlStyleTest.java

@@ -16,6 +16,10 @@
 package com.google.android.exoplayer2.text.ttml;
 package com.google.android.exoplayer2.text.ttml;
 
 
 import static android.graphics.Color.BLACK;
 import static android.graphics.Color.BLACK;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_FILLED_DOT;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.MARK_OPEN_SESAME;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.POSITION_AFTER;
+import static com.google.android.exoplayer2.text.span.TextEmphasisSpan.POSITION_BEFORE;
 import static com.google.android.exoplayer2.text.ttml.TtmlStyle.STYLE_BOLD;
 import static com.google.android.exoplayer2.text.ttml.TtmlStyle.STYLE_BOLD;
 import static com.google.android.exoplayer2.text.ttml.TtmlStyle.STYLE_BOLD_ITALIC;
 import static com.google.android.exoplayer2.text.ttml.TtmlStyle.STYLE_BOLD_ITALIC;
 import static com.google.android.exoplayer2.text.ttml.TtmlStyle.STYLE_ITALIC;
 import static com.google.android.exoplayer2.text.ttml.TtmlStyle.STYLE_ITALIC;
@@ -46,6 +50,7 @@ public final class TtmlStyleTest {
   private static final int RUBY_POSITION = RubySpan.POSITION_UNDER;
   private static final int RUBY_POSITION = RubySpan.POSITION_UNDER;
   private static final Layout.Alignment TEXT_ALIGN = Layout.Alignment.ALIGN_CENTER;
   private static final Layout.Alignment TEXT_ALIGN = Layout.Alignment.ALIGN_CENTER;
   private static final boolean TEXT_COMBINE = true;
   private static final boolean TEXT_COMBINE = true;
+  public static final String TEXT_EMPHASIS_STYLE="dot before";
 
 
   private final TtmlStyle populatedStyle =
   private final TtmlStyle populatedStyle =
       new TtmlStyle()
       new TtmlStyle()
@@ -62,7 +67,8 @@ public final class TtmlStyleTest {
           .setRubyType(RUBY_TYPE)
           .setRubyType(RUBY_TYPE)
           .setRubyPosition(RUBY_POSITION)
           .setRubyPosition(RUBY_POSITION)
           .setTextAlign(TEXT_ALIGN)
           .setTextAlign(TEXT_ALIGN)
-          .setTextCombine(TEXT_COMBINE);
+          .setTextCombine(TEXT_COMBINE)
+          .setTextEmphasis(TextEmphasis.createTextEmphasis(TEXT_EMPHASIS_STYLE));
 
 
   @Test
   @Test
   public void inheritStyle() {
   public void inheritStyle() {
@@ -86,6 +92,9 @@ public final class TtmlStyleTest {
     assertWithMessage("backgroundColor should not be inherited")
     assertWithMessage("backgroundColor should not be inherited")
         .that(style.hasBackgroundColor())
         .that(style.hasBackgroundColor())
         .isFalse();
         .isFalse();
+    assertThat(style.getTextEmphasis()).isNotNull();
+    assertThat(style.getTextEmphasis().mark).isEqualTo(MARK_FILLED_DOT);
+    assertThat(style.getTextEmphasis().position).isEqualTo(POSITION_BEFORE);
   }
   }
 
 
   @Test
   @Test
@@ -109,6 +118,9 @@ public final class TtmlStyleTest {
         .that(style.getBackgroundColor())
         .that(style.getBackgroundColor())
         .isEqualTo(BACKGROUND_COLOR);
         .isEqualTo(BACKGROUND_COLOR);
     assertWithMessage("rubyType should be chained").that(style.getRubyType()).isEqualTo(RUBY_TYPE);
     assertWithMessage("rubyType should be chained").that(style.getRubyType()).isEqualTo(RUBY_TYPE);
+    assertThat(style.getTextEmphasis()).isNotNull();
+    assertThat(style.getTextEmphasis().mark).isEqualTo(MARK_FILLED_DOT);
+    assertThat(style.getTextEmphasis().position).isEqualTo(POSITION_BEFORE);
   }
   }
 
 
   @Test
   @Test
@@ -245,4 +257,13 @@ public final class TtmlStyleTest {
     style.setTextCombine(true);
     style.setTextCombine(true);
     assertThat(style.getTextCombine()).isTrue();
     assertThat(style.getTextCombine()).isTrue();
   }
   }
+
+  @Test
+  public void textEmphasis() {
+    TtmlStyle style = new TtmlStyle();
+    assertThat(style.getTextEmphasis()).isNull();
+    style.setTextEmphasis(TextEmphasis.createTextEmphasis("open sesame after"));
+    assertThat(style.getTextEmphasis().mark).isEqualTo(MARK_OPEN_SESAME);
+    assertThat(style.getTextEmphasis().position).isEqualTo(POSITION_AFTER);
+  }
 }
 }

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

@@ -31,6 +31,7 @@ import android.util.SparseArray;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableMap;
@@ -197,6 +198,14 @@ import java.util.regex.Pattern;
       }
       }
     } else if (span instanceof UnderlineSpan) {
     } else if (span instanceof UnderlineSpan) {
       return "<u>";
       return "<u>";
+    } else if (span instanceof TextEmphasisSpan) {
+      TextEmphasisSpan textEmphasisSpan = (TextEmphasisSpan) span;
+      String style = getTextEmphasisStyle(textEmphasisSpan.mark);
+      String position = getTextEmphasisPosition(textEmphasisSpan.position);
+      return Util
+          .formatInvariant("<span style='-webkit-text-emphasis-style: %s; text-emphasis-style: %s; "
+                  + "-webkit-text-emphasis-position: %s; text-emphasis-position: %s;'>",
+              style, style, position, position);
     } else {
     } else {
       return null;
       return null;
     }
     }
@@ -209,7 +218,8 @@ import java.util.regex.Pattern;
         || span instanceof BackgroundColorSpan
         || span instanceof BackgroundColorSpan
         || span instanceof HorizontalTextInVerticalContextSpan
         || span instanceof HorizontalTextInVerticalContextSpan
         || span instanceof AbsoluteSizeSpan
         || span instanceof AbsoluteSizeSpan
-        || span instanceof RelativeSizeSpan) {
+        || span instanceof RelativeSizeSpan
+        || span instanceof TextEmphasisSpan) {
       return "</span>";
       return "</span>";
     } else if (span instanceof TypefaceSpan) {
     } else if (span instanceof TypefaceSpan) {
       @Nullable String fontFamily = ((TypefaceSpan) span).getFamily();
       @Nullable String fontFamily = ((TypefaceSpan) span).getFamily();
@@ -232,6 +242,47 @@ import java.util.regex.Pattern;
     return null;
     return null;
   }
   }
 
 
+  private static String getTextEmphasisStyle(@TextEmphasisSpan.Mark int mark) {
+    switch (mark) {
+      case TextEmphasisSpan.MARK_FILLED_CIRCLE:
+        return "filled circle";
+      case TextEmphasisSpan.MARK_FILLED_DOT:
+        return "filled dot";
+      case TextEmphasisSpan.MARK_FILLED_SESAME:
+        return "filled sesame";
+      case TextEmphasisSpan.MARK_OPEN_CIRCLE:
+        return "open circle";
+      case TextEmphasisSpan.MARK_OPEN_DOT:
+        return "open dot";
+      case TextEmphasisSpan.MARK_OPEN_SESAME:
+        return "open sesame";
+      case TextEmphasisSpan.MARK_AUTO: // TODO
+        // https://www.w3.org/TR/ttml2/#style-value-emphasis-style
+        // If a vertical writing mode applies, then equivalent to filled sesame; otherwise,
+        // equivalent to filled circle.
+      case TextEmphasisSpan.MARK_UNKNOWN:
+      default:
+        return "unset";
+    }
+  }
+
+  private static String getTextEmphasisPosition(@TextEmphasisSpan.Position int position){
+    switch (position) {
+      case TextEmphasisSpan.POSITION_AFTER:
+        return "under left";
+      case TextEmphasisSpan.POSITION_UNKNOWN:
+      case TextEmphasisSpan.POSITION_BEFORE:
+      case TextEmphasisSpan.POSITION_OUTSIDE: /* Not supported, fallback to "before" */
+      default:
+        // https://www.w3.org/TR/ttml2/#style-value-annotation-position
+        // If an implementation does not recognize or otherwise distinguish an annotation position
+        // value, then it must be interpreted as if a position of before were specified; as such,
+        // an implementation that supports text annotation marks must minimally support the before
+        // value.
+        return "over right";
+    }
+  }
+
   private static Transition getOrCreate(SparseArray<Transition> transitions, int key) {
   private static Transition getOrCreate(SparseArray<Transition> transitions, int key) {
     @Nullable Transition transition = transitions.get(key);
     @Nullable Transition transition = transitions.get(key);
     if (transition == null) {
     if (transition == null) {

library/ui/src/test/java/com/google/android/exoplayer2/ui/SpannedToHtmlConverterTest.java

@@ -34,6 +34,7 @@ import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
 import org.junit.Test;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runner.RunWith;
 import org.robolectric.annotation.Config;
 import org.robolectric.annotation.Config;
@@ -280,6 +281,37 @@ public class SpannedToHtmlConverterTest {
   }
   }
 
 
   @Test
   @Test
+  public void convert_supportsTextEmphasisSpan() {
+    SpannableString spanned = new SpannableString("Text emphasis おはよ ございます ");
+    spanned.setSpan(
+        new TextEmphasisSpan(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_BEFORE),
+        "Text emphasis ".length(),
+        "Text emphasis おはよ".length(),
+        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+
+    spanned.setSpan(
+        new TextEmphasisSpan(TextEmphasisSpan.MARK_OPEN_SESAME, TextEmphasisSpan.POSITION_AFTER),
+        "Text emphasis おはよ ".length(),
+        "Text emphasis おはよ ございます ".length(),
+        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+
+    SpannedToHtmlConverter.HtmlAndCss htmlAndCss =
+        SpannedToHtmlConverter.convert(spanned, displayDensity);
+
+    assertThat(htmlAndCss.cssRuleSets).isEmpty();
+    assertThat(htmlAndCss.html)
+        .isEqualTo(
+            "Text emphasis <span style='"
+                + "-webkit-text-emphasis-style: filled circle; text-emphasis-style: filled circle; "
+                + "-webkit-text-emphasis-position: over right; text-emphasis-position: over right;"
+                + "'>&#12362;&#12399;&#12424;</span> "
+                + "<span style='"
+                + "-webkit-text-emphasis-style: open sesame; text-emphasis-style: open sesame; "
+                + "-webkit-text-emphasis-position: under left; text-emphasis-position: under left;"
+                + "'>&#12372;&#12374;&#12356;&#12414;&#12377; </span>");
+  }
+
+  @Test
   public void convert_supportsUnderlineSpan() {
   public void convert_supportsUnderlineSpan() {
     SpannableString spanned = new SpannableString("String with underlined section.");
     SpannableString spanned = new SpannableString("String with underlined section.");
     spanned.setSpan(
     spanned.setSpan(

testdata/src/test/assets/media/ttml/text_emphasis.xml

+<tt xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
+  xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter"
+  xmlns:tts="http://www.w3.org/2006/10/ttaf1#style"
+  xmlns="http://www.w3.org/ns/ttml">
+  <head>
+    <region xml:id="region1" tts:extent="80.000% 80.000%" tts:origin="10.000% 10.000%" tts:writingMode="tbrl"/>
+    <region xml:id="region2" tts:extent="80.000% 80.000%" tts:origin="10.000% 10.000%" tts:writingMode="tblr"/>
+    <region xml:id="region3" tts:extent="80.000% 80.000%" tts:origin="10.000% 10.000%" tts:writingMode="tb"/>
+    <region xml:id="region4" tts:extent="80.000% 80.000%" tts:origin="10.000% 10.000%" tts:writingMode="lr"/>
+  </head>
+  <body>
+    <div>
+      <p begin="10s" end="18s">None <span tts:textEmphasis="none">おはよ</span></p>
+    </div>
+    <div>
+      <p begin="20s" end="28s">Auto <span tts:textEmphasis="auto">ございます</span></p>
+    </div>
+    <div>
+      <p begin="30s" end="38s">Filled circle <span tts:textEmphasis="filled circle">こんばんは</span></p>
+    </div>
+    <div>
+      <p begin="40s" end="48s">Filled dot <span tts:textEmphasis="filled dot">ございます</span></p>
+    </div>
+    <div>
+      <p begin="50s" end="58s">Filled sesame <span tts:textEmphasis="filled sesame">おはよ</span></p>
+    </div>
+    <div>
+      <p begin="60s" end="68s">Open circle before <span tts:textEmphasis="open circle before">ございます</span></p>
+    </div>
+    <div>
+      <p begin="70s" end="78s">Open dot after <span tts:textEmphasis="open dot after">おはよ</span></p>
+    </div>
+    <div>
+      <p begin="80s" end="88s">Open sesame outside <span tts:textEmphasis="open sesame outside">ございます</span></p>
+    </div>
+    <div>
+      <p begin="90s" end="98s">Auto outside <span tts:textEmphasis="auto outside">おはよ</span></p>
+    </div>
+    <div>
+      <p begin="100s" end="108s">Circle before <span tts:textEmphasis="circle before">ございます</span></p>
+    </div>
+    <div>
+      <p begin="110s" end="118s">Sesame after <span tts:textEmphasis="sesame after">おはよ</span></p>
+    </div>
+    <div>
+      <p begin="120s" end="128s">Dot outside <span tts:textEmphasis="dot outside">ございます</span></p>
+    </div>
+    <div>
+      <p begin="130s" end="138s">No textEmphasis property <span>おはよ</span></p>
+    </div>
+    <div>
+      <p begin="140s" end="148s" region="region1">Auto (TBLR) <span tts:textEmphasis="auto">ございます</span></p>
+    </div>
+    <div>
+      <p begin="150s" end="158s" region="region2">Auto (TBRL) <span tts:textEmphasis="auto">おはよ</span></p>
+    </div>
+    <div>
+      <p begin="160s" end="168s" region="region3">Auto (TB) <span tts:textEmphasis="auto">ございます</span></p>
+    </div>
+    <div>
+      <p begin="170s" end="178s" region="region4">Auto (LR) <span tts:textEmphasis="auto">おはよ</span></p>
+    </div>
+
+  </body>
+</tt>

testutils/src/main/java/com/google/android/exoplayer2/testutil/truth/SpannedSubject.java

@@ -38,6 +38,7 @@ import androidx.annotation.ColorInt;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.truth.Fact;
 import com.google.common.truth.Fact;
 import com.google.common.truth.FailureMetadata;
 import com.google.common.truth.FailureMetadata;
@@ -579,6 +580,47 @@ public final class SpannedSubject extends Subject {
   }
   }
 
 
   /**
   /**
+   * Checks that the subject has an {@link TextEmphasisSpan} from {@code start}
+   * to {@code end}.
+   *
+   * @param start The start of the expected span.
+   * @param end The end of the expected span.
+   * @return A {@link WithSpanFlags} object for optional additional assertions on the flags.
+   */
+  public TextEmphasisDescription hasTextEmphasisSpanBetween(int start, int end) {
+    if (actual == null) {
+      failWithoutActual(simpleFact("Spanned must not be null"));
+      return ALREADY_FAILED_WITH_MARK;
+    }
+
+    List<TextEmphasisSpan> textEmphasisSpans =
+        findMatchingSpans(start, end, TextEmphasisSpan.class);
+    if (textEmphasisSpans.size() == 1) {
+      return check("TextEmphasisSpan (start=%s,end=%s)", start, end).about(textEmphasisSubjects(actual)).that(textEmphasisSpans);
+    }
+    failWithExpectedSpan(
+        start,
+        end,
+        TextEmphasisSpan.class,
+        actual.toString().substring(start, end));
+    return ALREADY_FAILED_WITH_MARK;
+  }
+
+  /**
+   * Checks that the subject has no {@link TextEmphasisSpan}s on any of the text between
+   * {@code start} and {@code end}.
+   *
+   * <p>This fails even if the start and end indexes don't exactly match.
+   *
+   * @param start The start index to start searching for spans.
+   * @param end The end index to stop searching for spans.
+   */
+  public void hasNoTextEmphasisSpanBetween(int start, int end) {
+    hasNoSpansOfTypeBetween(TextEmphasisSpan.class, start, end);
+  }
+
+
+  /**
    * Checks that the subject has no {@link HorizontalTextInVerticalContextSpan}s on any of the text
    * Checks that the subject has no {@link HorizontalTextInVerticalContextSpan}s on any of the text
    * between {@code start} and {@code end}.
    * between {@code start} and {@code end}.
    *
    *
@@ -1110,4 +1152,95 @@ public final class SpannedSubject extends Subject {
       }
       }
     }
     }
   }
   }
+
+  /** Allows assertions about a span's textEmphasis mark and its position. */
+  public interface TextEmphasisDescription {
+
+    /**
+     * Checks that at least one of the matched spans has the expected {@code mark} and {@code position}.
+     *
+     * @param mark The expected mark
+     * @param position The expected position of the mark
+     * @return A {@link WithSpanFlags} object for optional additional assertions on the flags.
+     */
+    AndSpanFlags withMarkAndPosition(@TextEmphasisSpan.Mark int mark,
+        @TextEmphasisSpan.Position int position);
+  }
+
+  private static final TextEmphasisDescription ALREADY_FAILED_WITH_MARK =
+      (mark, position) -> ALREADY_FAILED_AND_FLAGS;
+
+  private static Factory<TextEmphasisSubject, List<TextEmphasisSpan>> textEmphasisSubjects(Spanned actualSpanned) {
+    return (FailureMetadata metadata, List<TextEmphasisSpan> spans) ->
+        new TextEmphasisSubject(metadata, spans, actualSpanned);
+  }
+
+  private static final class TextEmphasisSubject extends Subject implements TextEmphasisDescription {
+
+    private final List<TextEmphasisSpan> actualSpans;
+    private final Spanned actualSpanned;
+
+    private TextEmphasisSubject(
+        FailureMetadata metadata, List<TextEmphasisSpan> actualSpans, Spanned actualSpanned) {
+      super(metadata, actualSpans);
+      this.actualSpans = actualSpans;
+      this.actualSpanned = actualSpanned;
+    }
+
+    @Override
+    public AndSpanFlags withMarkAndPosition(@TextEmphasisSpan.Mark int mark,
+        @TextEmphasisSpan.Position int position) {
+      List<Integer> matchingSpanFlags = new ArrayList<>();
+      List<MarkAndPosition> textEmphasisMarksAndPositions = new ArrayList<>();
+      for (TextEmphasisSpan span : actualSpans) {
+        textEmphasisMarksAndPositions.add(new MarkAndPosition(span.mark, span.position));
+        if (span.mark == mark && span.position == position) {
+          matchingSpanFlags.add(actualSpanned.getSpanFlags(span));
+        }
+      }
+      check("textEmphasisMarkAndPosition")
+          .that(textEmphasisMarksAndPositions)
+          .containsExactly(new MarkAndPosition(mark, position));
+      return check("flags").about(spanFlags()).that(matchingSpanFlags);
+    }
+
+    private static final class MarkAndPosition {
+
+      @TextEmphasisSpan.Mark
+      private final int mark;
+      @TextEmphasisSpan.Position
+      private final int position;
+
+      private MarkAndPosition(@TextEmphasisSpan.Mark int mark,
+          @TextEmphasisSpan.Position int position) {
+        this.mark = mark;
+        this.position = position;
+      }
+
+      @Override
+      public boolean equals(@Nullable Object o) {
+        if (this == o) {
+          return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+          return false;
+        }
+
+        TextEmphasisSubject.MarkAndPosition that = (TextEmphasisSubject.MarkAndPosition) o;
+        return (position == that.position) && (mark == that.mark);
+      }
+
+      @Override
+      public int hashCode() {
+        int result = 34613 * mark + position;
+        return result;
+      }
+
+      @Override
+      public String toString() {
+        return String.format("{mark=%s,position=%s}", mark, position);
+      }
+    }
+  }
+
 }
 }

testutils/src/test/java/com/google/android/exoplayer2/testutil/truth/SpannedSubjectTest.java

@@ -41,6 +41,8 @@ import com.google.android.exoplayer2.testutil.truth.SpannedSubject.AndSpanFlags;
 import com.google.android.exoplayer2.testutil.truth.SpannedSubject.WithSpanFlags;
 import com.google.android.exoplayer2.testutil.truth.SpannedSubject.WithSpanFlags;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.HorizontalTextInVerticalContextSpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
 import com.google.android.exoplayer2.text.span.RubySpan;
+import com.google.android.exoplayer2.text.span.TextEmphasisSpan;
+import com.google.android.exoplayer2.util.Util;
 import com.google.common.truth.ExpectFailure;
 import com.google.common.truth.ExpectFailure;
 import org.junit.Test;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runner.RunWith;
@@ -680,6 +682,104 @@ public class SpannedSubjectTest {
   }
   }
 
 
   @Test
   @Test
+  public void textEmphasis_success() {
+    SpannableString spannable =
+        createSpannable(
+            new TextEmphasisSpan(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_AFTER));
+
+    assertThat(spannable)
+        .hasTextEmphasisSpanBetween(SPAN_START, SPAN_END)
+        .withMarkAndPosition(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_AFTER)
+        .andFlags(Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+  }
+
+  @Test
+  public void textEmphasis_wrongIndex() {
+    checkHasSpanFailsDueToIndexMismatch(
+        new TextEmphasisSpan(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_AFTER),
+        SpannedSubject::hasTextEmphasisSpanBetween);
+  }
+
+
+  @Test
+  public void textEmphasis_wrongMark() {
+    SpannableString spannable =
+        createSpannable(
+            new TextEmphasisSpan(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_AFTER));
+
+    AssertionError expected =
+        expectFailure(
+            whenTesting ->
+                whenTesting
+                    .that(spannable)
+                    .hasTextEmphasisSpanBetween(SPAN_START, SPAN_END)
+                    .withMarkAndPosition(TextEmphasisSpan.MARK_OPEN_DOT,
+                        TextEmphasisSpan.POSITION_AFTER));
+
+    assertThat(expected).factValue("value of").contains("textEmphasisMarkAndPosition");
+    assertThat(expected).factValue("expected").contains(Util.formatInvariant(
+        "{mark=%d,position=%d}", TextEmphasisSpan.MARK_OPEN_DOT,
+        TextEmphasisSpan.POSITION_AFTER));
+    assertThat(expected).factValue("but was").contains(Util.formatInvariant(
+        "{mark=%d,position=%d}", TextEmphasisSpan.MARK_FILLED_CIRCLE,
+        TextEmphasisSpan.POSITION_AFTER));
+
+  }
+
+  @Test
+  public void textEmphasis_wrongPosition() {
+    SpannableString spannable =
+        createSpannable(
+            new TextEmphasisSpan(TextEmphasisSpan.MARK_OPEN_SESAME, TextEmphasisSpan.POSITION_BEFORE));
+
+    AssertionError expected =
+        expectFailure(
+            whenTesting ->
+                whenTesting
+                    .that(spannable)
+                    .hasTextEmphasisSpanBetween(SPAN_START, SPAN_END)
+                    .withMarkAndPosition(TextEmphasisSpan.MARK_OPEN_SESAME,
+                        TextEmphasisSpan.POSITION_AFTER));
+
+    assertThat(expected).factValue("value of").contains("textEmphasisMarkAndPosition");
+    assertThat(expected).factValue("expected").contains(Util.formatInvariant(
+        "{mark=%d,position=%d}", TextEmphasisSpan.MARK_OPEN_SESAME,
+        TextEmphasisSpan.POSITION_AFTER));
+    assertThat(expected).factValue("but was").contains(Util.formatInvariant(
+        "{mark=%d,position=%d}", TextEmphasisSpan.MARK_OPEN_SESAME,
+        TextEmphasisSpan.POSITION_BEFORE));
+  }
+
+  @Test
+  public void textEmphasis_wrongFlags() {
+    checkHasSpanFailsDueToFlagMismatch(
+        new TextEmphasisSpan(TextEmphasisSpan.MARK_OPEN_SESAME, TextEmphasisSpan.POSITION_BEFORE),
+        (subject, start, end) ->
+            subject
+                .hasTextEmphasisSpanBetween(start, end)
+                .withMarkAndPosition(TextEmphasisSpan.MARK_OPEN_SESAME,
+                    TextEmphasisSpan.POSITION_BEFORE));
+  }
+
+
+  @Test
+  public void noTextEmphasis_success() {
+    SpannableString spannable =
+        createSpannableWithUnrelatedSpanAnd(
+            new TextEmphasisSpan(TextEmphasisSpan.MARK_FILLED_CIRCLE,
+                TextEmphasisSpan.POSITION_AFTER));
+
+    assertThat(spannable).hasNoTextEmphasisSpanBetween(UNRELATED_SPAN_START, UNRELATED_SPAN_END);
+  }
+
+  @Test
+  public void noTextEmphasis_failure() {
+    checkHasNoSpanFails(
+        new TextEmphasisSpan(TextEmphasisSpan.MARK_FILLED_CIRCLE, TextEmphasisSpan.POSITION_AFTER),
+        SpannedSubject::hasNoTextEmphasisSpanBetween);
+  }
+
+  @Test
   public void horizontalTextInVerticalContextSpan_success() {
   public void horizontalTextInVerticalContextSpan_success() {
     SpannableString spannable =
     SpannableString spannable =
         createSpannable(
         createSpannable(