Merge pull request #8133 from xufuji456:dev-v2

PiperOrigin-RevId: 340254878

RELEASENOTES.md

@@ -38,6 +38,9 @@
     *   Fix a bug that caused multiple ads in an ad pod to be skipped when one
         ad in the ad pod was skipped.
     *   Fix passing an ads response to the `ImaAdsLoader` builder.
+*   Text
+    *   Allow tx3g subtitles with `styl` boxes with start and/or end offsets
+        that lie outside the length of the cue text.
 
 ### 2.12.1 (2020-10-23) ###
 

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

@@ -31,6 +31,7 @@ import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.text.SimpleSubtitleDecoder;
 import com.google.android.exoplayer2.text.Subtitle;
 import com.google.android.exoplayer2.text.SubtitleDecoderException;
+import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Charsets;
@@ -43,6 +44,8 @@ import java.util.List;
  */
 public final class Tx3gDecoder extends SimpleSubtitleDecoder {
 
+  private static final String TAG = "Tx3gDecoder";
+
   private static final char BOM_UTF16_BE = '\uFEFF';
   private static final char BOM_UTF16_LE = '\uFFFE';
 
@@ -185,6 +188,16 @@ public final class Tx3gDecoder extends SimpleSubtitleDecoder {
     int fontFace = parsableByteArray.readUnsignedByte();
     parsableByteArray.skipBytes(1); // font size
     int colorRgba = parsableByteArray.readInt();
+
+    if (end > cueText.length()) {
+      Log.w(
+          TAG, "Truncating styl end (" + end + ") to cueText.length() (" + cueText.length() + ").");
+      end = cueText.length();
+    }
+    if (start >= end) {
+      Log.w(TAG, "Ignoring styl with start (" + start + ") >= end (" + end + ").");
+      return;
+    }
     attachFontFace(cueText, fontFace, defaultFontFace, start, end, SPAN_PRIORITY_HIGH);
     attachColor(cueText, colorRgba, defaultColorRgba, start, end, SPAN_PRIORITY_HIGH);
   }

library/core/src/test/java/com/google/android/exoplayer2/text/tx3g/Tx3gDecoderTest.java

@@ -38,6 +38,10 @@ public final class Tx3gDecoderTest {
   private static final String NO_SUBTITLE = "media/tx3g/no_subtitle";
   private static final String SAMPLE_JUST_TEXT = "media/tx3g/sample_just_text";
   private static final String SAMPLE_WITH_STYL = "media/tx3g/sample_with_styl";
+  private static final String SAMPLE_WITH_STYL_START_TOO_LARGE =
+      "media/tx3g/sample_with_styl_start_too_large";
+  private static final String SAMPLE_WITH_STYL_END_TOO_LARGE =
+      "media/tx3g/sample_with_styl_end_too_large";
   private static final String SAMPLE_WITH_STYL_ALL_DEFAULTS =
       "media/tx3g/sample_with_styl_all_defaults";
   private static final String SAMPLE_UTF16_BE_NO_STYL = "media/tx3g/sample_utf16_be_no_styl";
@@ -90,6 +94,52 @@ public final class Tx3gDecoderTest {
     assertFractionalLinePosition(subtitle.getCues(0).get(0), 0.85f);
   }
 
+  /**
+   * The 7-byte sample contains a 4-byte emoji. The start index (6) and end index (7) are valid as
+   * byte offsets, but not a UTF-16 code-unit offset, so they're both truncated to 5 (the length of
+   * the resulting the string in Java) and the spans end up empty (so we don't add them).
+   *
+   * <p>https://github.com/google/ExoPlayer/pull/8133
+   */
+  @Test
+  public void decodeWithStyl_startTooLarge_noSpanAdded() throws Exception {
+    Tx3gDecoder decoder = new Tx3gDecoder(ImmutableList.of());
+    byte[] bytes =
+        TestUtil.getByteArray(
+            ApplicationProvider.getApplicationContext(), SAMPLE_WITH_STYL_START_TOO_LARGE);
+
+    Subtitle subtitle = decoder.decode(bytes, bytes.length, false);
+    SpannedString text = new SpannedString(subtitle.getCues(0).get(0).text);
+
+    assertThat(text.toString()).isEqualTo("CC 🙂");
+    assertThat(text).hasNoSpans();
+    assertFractionalLinePosition(subtitle.getCues(0).get(0), 0.85f);
+  }
+
+  /**
+   * The 7-byte sample contains a 4-byte emoji. The end index (6) is valid as a byte offset, but not
+   * a UTF-16 code-unit offset, so it's truncated to 5 (the length of the resulting the string in
+   * Java).
+   *
+   * <p>https://github.com/google/ExoPlayer/pull/8133
+   */
+  @Test
+  public void decodeWithStyl_endTooLarge_clippedToEndOfText() throws Exception {
+    Tx3gDecoder decoder = new Tx3gDecoder(ImmutableList.of());
+    byte[] bytes =
+        TestUtil.getByteArray(
+            ApplicationProvider.getApplicationContext(), SAMPLE_WITH_STYL_END_TOO_LARGE);
+
+    Subtitle subtitle = decoder.decode(bytes, bytes.length, false);
+    SpannedString text = new SpannedString(subtitle.getCues(0).get(0).text);
+
+    assertThat(text.toString()).isEqualTo("CC 🙂");
+    assertThat(text).hasBoldItalicSpanBetween(0, 5);
+    assertThat(text).hasUnderlineSpanBetween(0, 5);
+    assertThat(text).hasForegroundColorSpanBetween(0, 5).withColor(Color.GREEN);
+    assertFractionalLinePosition(subtitle.getCues(0).get(0), 0.85f);
+  }
+
   @Test
   public void decodeWithStylAllDefaults() throws Exception {
     Tx3gDecoder decoder = new Tx3gDecoder(ImmutableList.of());