1 files changed, 125 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/text/webvtt/WebvttDecoder.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/text/webvtt/WebvttDecoder.java
new file mode 100644
index 0000000000..a70a49e82e
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/text/webvtt/WebvttDecoder.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.text.webvtt;
+
+import android.text.TextUtils;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.ParserException;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.text.SimpleSubtitleDecoder;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.text.Subtitle;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.text.SubtitleDecoderException;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A {@link SimpleSubtitleDecoder} for WebVTT.
+ * <p>
+ * @see <a href="http://dev.w3.org/html5/webvtt">WebVTT specification</a>
+ */
+public final class WebvttDecoder extends SimpleSubtitleDecoder {
+
+  private static final int EVENT_NONE = -1;
+  private static final int EVENT_END_OF_FILE = 0;
+  private static final int EVENT_COMMENT = 1;
+  private static final int EVENT_STYLE_BLOCK = 2;
+  private static final int EVENT_CUE = 3;
+
+  private static final String COMMENT_START = "NOTE";
+  private static final String STYLE_START = "STYLE";
+
+  private final WebvttCueParser cueParser;
+  private final ParsableByteArray parsableWebvttData;
+  private final WebvttCue.Builder webvttCueBuilder;
+  private final CssParser cssParser;
+  private final List<WebvttCssStyle> definedStyles;
+
+  public WebvttDecoder() {
+    super("WebvttDecoder");
+    cueParser = new WebvttCueParser();
+    parsableWebvttData = new ParsableByteArray();
+    webvttCueBuilder = new WebvttCue.Builder();
+    cssParser = new CssParser();
+    definedStyles = new ArrayList<>();
+  }
+
+  @Override
+  protected Subtitle decode(byte[] bytes, int length, boolean reset)
+      throws SubtitleDecoderException {
+    parsableWebvttData.reset(bytes, length);
+    // Initialization for consistent starting state.
+    webvttCueBuilder.reset();
+    definedStyles.clear();
+
+    // Validate the first line of the header, and skip the remainder.
+    try {
+      WebvttParserUtil.validateWebvttHeaderLine(parsableWebvttData);
+    } catch (ParserException e) {
+      throw new SubtitleDecoderException(e);
+    }
+    while (!TextUtils.isEmpty(parsableWebvttData.readLine())) {}
+
+    int event;
+    ArrayList<WebvttCue> subtitles = new ArrayList<>();
+    while ((event = getNextEvent(parsableWebvttData)) != EVENT_END_OF_FILE) {
+      if (event == EVENT_COMMENT) {
+        skipComment(parsableWebvttData);
+      } else if (event == EVENT_STYLE_BLOCK) {
+        if (!subtitles.isEmpty()) {
+          throw new SubtitleDecoderException("A style block was found after the first cue.");
+        }
+        parsableWebvttData.readLine(); // Consume the "STYLE" header.
+        definedStyles.addAll(cssParser.parseBlock(parsableWebvttData));
+      } else if (event == EVENT_CUE) {
+        if (cueParser.parseCue(parsableWebvttData, webvttCueBuilder, definedStyles)) {
+          subtitles.add(webvttCueBuilder.build());
+          webvttCueBuilder.reset();
+        }
+      }
+    }
+    return new WebvttSubtitle(subtitles);
+  }
+
+  /**
+   * Positions the input right before the next event, and returns the kind of event found. Does not
+   * consume any data from such event, if any.
+   *
+   * @return The kind of event found.
+   */
+  private static int getNextEvent(ParsableByteArray parsableWebvttData) {
+    int foundEvent = EVENT_NONE;
+    int currentInputPosition = 0;
+    while (foundEvent == EVENT_NONE) {
+      currentInputPosition = parsableWebvttData.getPosition();
+      String line = parsableWebvttData.readLine();
+      if (line == null) {
+        foundEvent = EVENT_END_OF_FILE;
+      } else if (STYLE_START.equals(line)) {
+        foundEvent = EVENT_STYLE_BLOCK;
+      } else if (line.startsWith(COMMENT_START)) {
+        foundEvent = EVENT_COMMENT;
+      } else {
+        foundEvent = EVENT_CUE;
+      }
+    }
+    parsableWebvttData.setPosition(currentInputPosition);
+    return foundEvent;
+  }
+
+  private static void skipComment(ParsableByteArray parsableWebvttData) {
+    while (!TextUtils.isEmpty(parsableWebvttData.readLine())) {}
+  }
+
+}