Add support for SSA (V4+) PrimaryColour style

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

@@ -19,6 +19,8 @@
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 
 import android.text.Layout;
+import android.text.SpannableString;
+import android.text.style.ForegroundColorSpan;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.text.Cue;
@@ -301,8 +303,17 @@ private static Cue createCue(
       SsaStyle.Overrides styleOverrides,
       float screenWidth,
       float screenHeight) {
-    Cue.Builder cue = new Cue.Builder().setText(text);
-
+    SpannableString spannableText = new SpannableString(text);
+    Cue.Builder cue = new Cue.Builder().setText(spannableText);
+
+    // Apply primary color.
+    if (style != null) {
+      if (style.primaryColor.isSet()) {
+        spannableText.setSpan(new ForegroundColorSpan(style.primaryColor.getColor()),
+            0, spannableText.length(), SpannableString.SPAN_EXCLUSIVE_EXCLUSIVE);
+      }
+    }
+    // Apply alignment.
     @SsaStyle.SsaAlignment int alignment;
     if (styleOverrides.alignment != SsaStyle.SSA_ALIGNMENT_UNKNOWN) {
       alignment = styleOverrides.alignment;

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

@@ -21,14 +21,17 @@
 
 import android.graphics.PointF;
 import android.text.TextUtils;
+import androidx.annotation.ColorInt;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.android.exoplayer2.util.ColorParser;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
+import java.util.NoSuchElementException;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -85,10 +88,12 @@
 
   public final String name;
   @SsaAlignment public final int alignment;
+  public SsaColor primaryColor;
 
-  private SsaStyle(String name, @SsaAlignment int alignment) {
+  private SsaStyle(String name, @SsaAlignment int alignment, SsaColor primaryColor) {
     this.name = name;
     this.alignment = alignment;
+    this.primaryColor = primaryColor;
   }
 
   @Nullable
@@ -105,7 +110,9 @@ public static SsaStyle fromStyleLine(String styleLine, Format format) {
     }
     try {
       return new SsaStyle(
-          styleValues[format.nameIndex].trim(), parseAlignment(styleValues[format.alignmentIndex]));
+          styleValues[format.nameIndex].trim(),
+          parseAlignment(styleValues[format.alignmentIndex]),
+          parsePrimaryColor(styleValues[format.primaryColorIndex]));
     } catch (RuntimeException e) {
       Log.w(TAG, "Skipping malformed 'Style:' line: '" + styleLine + "'", e);
       return null;
@@ -144,6 +151,46 @@ private static boolean isValidAlignment(@SsaAlignment int alignment) {
     }
   }
 
+  private static SsaColor parsePrimaryColor(String primaryColorStr) {
+    try {
+      return SsaColor.from(ColorParser.parseSsaColor(primaryColorStr.trim()));
+    } catch (IllegalArgumentException ex) {
+      Log.w(TAG, "Failed parsing color value: " + primaryColorStr);
+    }
+    return SsaColor.UNSET;
+  }
+
+  /**
+   * Represents an SSA V4+ style color in ARGB format.
+   */
+  /* package */ static final class SsaColor {
+
+    public static SsaColor UNSET = new SsaColor(0, false);
+
+    private final @ColorInt int color;
+    private final boolean isSet;
+
+    private SsaColor(@ColorInt int color, boolean isSet) {
+      this.color = color;
+      this.isSet = isSet;
+    }
+
+    public @ColorInt int getColor() {
+      if (!isSet) {
+        throw new NoSuchElementException("No color is present");
+      }
+      return color;
+    }
+
+    public boolean isSet() {
+      return isSet;
+    }
+
+    public static SsaColor from(@ColorInt int value) {
+      return new SsaColor(value, true);
+    }
+  }
+
   /**
    * Represents a {@code Format:} line from the {@code [V4+ Styles]} section
    *
@@ -154,11 +201,13 @@ private static boolean isValidAlignment(@SsaAlignment int alignment) {
 
     public final int nameIndex;
     public final int alignmentIndex;
+    public final int primaryColorIndex;
     public final int length;
 
-    private Format(int nameIndex, int alignmentIndex, int length) {
+    private Format(int nameIndex, int alignmentIndex, int primaryColorIndex, int length) {
       this.nameIndex = nameIndex;
       this.alignmentIndex = alignmentIndex;
+      this.primaryColorIndex = primaryColorIndex;
       this.length = length;
     }
 
@@ -171,6 +220,7 @@ private Format(int nameIndex, int alignmentIndex, int length) {
     public static Format fromFormatLine(String styleFormatLine) {
       int nameIndex = C.INDEX_UNSET;
       int alignmentIndex = C.INDEX_UNSET;
+      int primaryColorIndex = C.INDEX_UNSET;
       String[] keys =
           TextUtils.split(styleFormatLine.substring(SsaDecoder.FORMAT_LINE_PREFIX.length()), ",");
       for (int i = 0; i < keys.length; i++) {
@@ -181,9 +231,14 @@ public static Format fromFormatLine(String styleFormatLine) {
           case "alignment":
             alignmentIndex = i;
             break;
+          case "primarycolour":
+            primaryColorIndex = i;
+            break;
         }
       }
-      return nameIndex != C.INDEX_UNSET ? new Format(nameIndex, alignmentIndex, keys.length) : null;
+      return nameIndex != C.INDEX_UNSET
+          ? new Format(nameIndex, alignmentIndex, primaryColorIndex, keys.length)
+          : null;
     }
   }
 

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

@@ -67,6 +67,45 @@ public static int parseCssColor(String colorExpression) {
     return parseColorInternal(colorExpression, true);
   }
 
+  /**
+   * Parses a SSA V4+ color expression.
+   *
+   * @param colorExpression The color expression.
+   * @return The parsed ARGB color.
+   */
+  @ColorInt
+  public static int parseSsaColor(String colorExpression) {
+    // The SSA V4+ color can be represented in hex (&HAABBGGRR) or in decimal format (byte order
+    // AABBGGRR) and in both cases the alpha channel's value needs to be inverted as in case of SSA
+    // the 0xFF alpha value means transparent and 0x00 means opaque which is the opposite from the
+    // @ColorInt representation.
+    int abgr;
+    try {
+      // Parse color from hex format (&HAABBGGRR).
+      if (colorExpression.startsWith("&H")) {
+        StringBuilder rgbaStringBuilder = new StringBuilder(colorExpression);
+        if (colorExpression.length() < 10) {
+          // Add leading zeros if necessary.
+          while (rgbaStringBuilder.length() != 10) {
+            rgbaStringBuilder.insert(2, "0");
+          }
+        }
+        abgr = (int) Long.parseLong(rgbaStringBuilder.substring(2), 16);
+      } else {
+        // Parse color from decimal format (bytes order AABBGGRR).
+        abgr = (int) Long.parseLong(colorExpression);
+      }
+    } catch (NumberFormatException ex) {
+      throw new IllegalArgumentException(ex);
+    }
+    // Convert ABGR to ARGB.
+    int a = ((abgr >> 24) & 0xFF) ^ 0xFF; // Flip alpha.
+    int b = (abgr >> 16) & 0xFF;
+    int g = (abgr >> 8) & 0xFF;
+    int r = abgr & 0xff;
+    return Color.argb(a, r, g, b);
+  }
+
   @ColorInt
   private static int parseColorInternal(String colorExpression, boolean alphaHasFloatFormat) {
     Assertions.checkArgument(!TextUtils.isEmpty(colorExpression));

library/core/src/test/java/com/google/android/exoplayer2/text/ssa/SsaDecoderTest.java

@@ -18,7 +18,10 @@
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
 
+import android.graphics.Color;
 import android.text.Layout;
+import android.text.SpannableString;
+import android.text.style.ForegroundColorSpan;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.testutil.TestUtil;
@@ -44,6 +47,7 @@ public final class SsaDecoderTest {
   private static final String INVALID_TIMECODES = "media/ssa/invalid_timecodes";
   private static final String INVALID_POSITIONS = "media/ssa/invalid_positioning";
   private static final String POSITIONS_WITHOUT_PLAYRES = "media/ssa/positioning_without_playres";
+  private static final String COLORS = "media/ssa/colors";
 
   @Test
   public void decodeEmpty() throws IOException {
@@ -267,6 +271,46 @@ public void decodeInvalidTimecodes() throws IOException {
     assertTypicalCue3(subtitle, 0);
   }
 
+  @Test
+  public void decodeColors() throws IOException {
+    SsaDecoder decoder = new SsaDecoder();
+    byte[] bytes = TestUtil.getByteArray(ApplicationProvider.getApplicationContext(), COLORS);
+    Subtitle subtitle = decoder.decode(bytes, bytes.length, false);
+    assertThat(subtitle.getEventTimeCount()).isEqualTo(12);
+    // &H000000FF (AABBGGRR) -> #FFFF0000 (AARRGGBB)
+    Cue firstCue = Iterables.getOnlyElement(subtitle.getCues(subtitle.getEventTime(0)));
+    ForegroundColorSpan firstSpan = getSpan(firstCue, ForegroundColorSpan.class);
+    assertThat(firstSpan.getForegroundColor()).isEqualTo(Color.RED);
+    // &H0000FFFF (AABBGGRR) -> #FFFFFF00 (AARRGGBB)
+    Cue secondCue = Iterables.getOnlyElement(subtitle.getCues(subtitle.getEventTime(2)));
+    ForegroundColorSpan secondSpan = getSpan(secondCue, ForegroundColorSpan.class);
+    assertThat(secondSpan.getForegroundColor()).isEqualTo(Color.YELLOW);
+    // &HFF00 (GGRR) -> #FF00FF00 (AARRGGBB)
+    Cue thirdClue = Iterables.getOnlyElement(subtitle.getCues(subtitle.getEventTime(4)));
+    ForegroundColorSpan thirdSpan = getSpan(thirdClue, ForegroundColorSpan.class);
+    assertThat(thirdSpan.getForegroundColor()).isEqualTo(Color.GREEN);
+    // &H400000FF (AABBGGRR) -> #BFFF0000 (AARRGGBB) -> -1073807360
+    Cue forthClue = Iterables.getOnlyElement(subtitle.getCues(subtitle.getEventTime(6)));
+    ForegroundColorSpan forthSpan = getSpan(forthClue, ForegroundColorSpan.class);
+    assertThat(forthSpan.getForegroundColor()).isEqualTo(-1073807360);
+    // 16711680 (AABBGGRR) -> &H00FF0000 (AABBGGRR) -> #FF0000FF (AARRGGBB) -> -16776961
+    Cue fifthClue = Iterables.getOnlyElement(subtitle.getCues(subtitle.getEventTime(8)));
+    ForegroundColorSpan fifthSpan = getSpan(fifthClue, ForegroundColorSpan.class);
+    assertThat(fifthSpan.getForegroundColor()).isEqualTo(-16776961);
+    // 2164195328 (AABBGGRR) -> &H80FF0000 (AABBGGRR) -> #7F0000FF (AARRGGBB) -> 2130706687
+    Cue sixthClue = Iterables.getOnlyElement(subtitle.getCues(subtitle.getEventTime(10)));
+    ForegroundColorSpan sixthSpan = getSpan(sixthClue, ForegroundColorSpan.class);
+    assertThat(sixthSpan.getForegroundColor()).isEqualTo(2130706687);
+  }
+
+  private static <T> T getSpan(Cue cue, Class<T> clazz) {
+    return getSpan(cue, 0, cue.text.length(), clazz);
+  }
+
+  private static <T> T getSpan(Cue cue, int start, int end, Class<T> clazz) {
+    return SpannableString.valueOf(cue.text).getSpans(start, end, clazz)[0];
+  }
+
   private static void assertTypicalCue1(Subtitle subtitle, int eventIndex) {
     assertThat(subtitle.getEventTime(eventIndex)).isEqualTo(0);
     assertThat(subtitle.getCues(subtitle.getEventTime(eventIndex)).get(0).text.toString())

library/core/src/test/java/com/google/android/exoplayer2/util/ColorParserTest.java

@@ -16,10 +16,14 @@
 package com.google.android.exoplayer2.util;
 
 import static android.graphics.Color.BLACK;
+import static android.graphics.Color.BLUE;
+import static android.graphics.Color.GREEN;
 import static android.graphics.Color.RED;
 import static android.graphics.Color.WHITE;
+import static android.graphics.Color.YELLOW;
 import static android.graphics.Color.argb;
 import static android.graphics.Color.parseColor;
+import static com.google.android.exoplayer2.util.ColorParser.parseSsaColor;
 import static com.google.android.exoplayer2.util.ColorParser.parseTtmlColor;
 import static com.google.common.truth.Truth.assertThat;
 
@@ -66,6 +70,21 @@ public void hexCodeParsing() {
     assertThat(parseTtmlColor("#12345678")).isEqualTo(parseColor("#78123456"));
   }
 
+  @Test
+  public void ssaColorParsing() {
+    // Hex format (&HAABBGGRR).
+    assertThat(parseSsaColor("&H000000FF")).isEqualTo(RED);
+    assertThat(parseSsaColor("&H0000FFFF")).isEqualTo(YELLOW);
+    assertThat(parseSsaColor("&H400000FF")).isEqualTo(parseColor("#BFFF0000"));
+    // Leading zeros.
+    assertThat(parseSsaColor("&HFF")).isEqualTo(RED);
+    assertThat(parseSsaColor("&HFF00")).isEqualTo(GREEN);
+    assertThat(parseSsaColor("&HFF0000")).isEqualTo(BLUE);
+    // Decimal format (AABBGGRR byte order).
+    assertThat(parseSsaColor(/*#000000FF*/"255")).isEqualTo(parseColor("#FFFF0000"));
+    assertThat(parseSsaColor(/*#FF0000FF*/"4278190335")).isEqualTo(parseColor("#00FF0000"));
+  }
+
   @Test
   public void rgbColorParsing() {
     assertThat(parseTtmlColor("rgb(255,255,255)")).isEqualTo(WHITE);

testdata/src/test/assets/media/ssa/colors

@@ -0,0 +1,24 @@
+[Script Info]
+Title: Coloring
+Script Type: V4.00+
+PlayResX: 1280
+PlayResY: 720
+
+[V4+ Styles]
+Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
+Style: PrimaryColourStyleHexRed        ,Roboto,50,&H000000FF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Style: PrimaryColourStyleHexYellow     ,Roboto,50,&H0000FFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Style: PrimaryColourStyleHexGreen      ,Roboto,50,&HFF00    ,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Style: PrimaryColourStyleHexAlpha      ,Roboto,50,&H400000FF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Style: PrimaryColourStyleDecimal       ,Roboto,50,16711680  ,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Style: PrimaryColourStyleDecimalAlpha  ,Roboto,50,2164195328,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+
+
+[Events]
+Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
+Dialogue: 0,0:00:00.95,0:00:03.11,PrimaryColourStyleHexRed         ,Arnold,0,0,0,,First line in RED (&H000000FF).
+Dialogue: 0,0:00:04.50,0:00:07.50,PrimaryColourStyleHexYellow      ,Arnold,0,0,0,,Second line in YELLOW (&H0000FFFF).
+Dialogue: 0,0:00:08.50,0:00:11.50,PrimaryColourStyleHexGreen       ,Arnold,0,0,0,,Third line in GREEN (leading zeros &HFF00).
+Dialogue: 0,0:00:12.50,0:00:15.50,PrimaryColourStyleHexAlpha       ,Arnold,0,0,0,,Fourth line in RED with alpha (&H400000FF).
+Dialogue: 0,0:00:16.50,0:00:19.50,PrimaryColourStyleDecimal        ,Arnold,0,0,0,,Fifth line in BLUE (16711680).
+Dialogue: 0,0:00:20.70,0:00:23.00,PrimaryColourStyleDecimalAlpha   ,Arnold,0,0,0,,Sixth line in BLUE with alpha (2164195328).