1 files changed, 350 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/text/TextRenderer.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/text/TextRenderer.java
new file mode 100644
index 0000000000..428b106fcd
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/text/TextRenderer.java
@@ -0,0 +1,350 @@
+/*
+ * 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;
+
+import android.os.Handler;
+import android.os.Handler.Callback;
+import android.os.Looper;
+import android.os.Message;
+import androidx.annotation.IntDef;
+import androidx.annotation.Nullable;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.BaseRenderer;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.Format;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.FormatHolder;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.RendererCapabilities;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Log;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.MimeTypes;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A renderer for text.
+ * <p>
+ * {@link Subtitle}s are decoded from sample data using {@link SubtitleDecoder} instances obtained
+ * from a {@link SubtitleDecoderFactory}. The actual rendering of the subtitle {@link Cue}s is
+ * delegated to a {@link TextOutput}.
+ */
+public final class TextRenderer extends BaseRenderer implements Callback {
+
+  private static final String TAG = "TextRenderer";
+
+  @Documented
+  @Retention(RetentionPolicy.SOURCE)
+  @IntDef({
+    REPLACEMENT_STATE_NONE,
+    REPLACEMENT_STATE_SIGNAL_END_OF_STREAM,
+    REPLACEMENT_STATE_WAIT_END_OF_STREAM
+  })
+  private @interface ReplacementState {}
+  /**
+   * The decoder does not need to be replaced.
+   */
+  private static final int REPLACEMENT_STATE_NONE = 0;
+  /**
+   * The decoder needs to be replaced, but we haven't yet signaled an end of stream to the existing
+   * decoder. We need to do so in order to ensure that it outputs any remaining buffers before we
+   * release it.
+   */
+  private static final int REPLACEMENT_STATE_SIGNAL_END_OF_STREAM = 1;
+  /**
+   * The decoder needs to be replaced, and we've signaled an end of stream to the existing decoder.
+   * We're waiting for the decoder to output an end of stream signal to indicate that it has output
+   * any remaining buffers before we release it.
+   */
+  private static final int REPLACEMENT_STATE_WAIT_END_OF_STREAM = 2;
+
+  private static final int MSG_UPDATE_OUTPUT = 0;
+
+  @Nullable private final Handler outputHandler;
+  private final TextOutput output;
+  private final SubtitleDecoderFactory decoderFactory;
+  private final FormatHolder formatHolder;
+
+  private boolean inputStreamEnded;
+  private boolean outputStreamEnded;
+  @ReplacementState private int decoderReplacementState;
+  @Nullable private Format streamFormat;
+  @Nullable private SubtitleDecoder decoder;
+  @Nullable private SubtitleInputBuffer nextInputBuffer;
+  @Nullable private SubtitleOutputBuffer subtitle;
+  @Nullable private SubtitleOutputBuffer nextSubtitle;
+  private int nextSubtitleEventIndex;
+
+  /**
+   * @param output The output.
+   * @param outputLooper The looper associated with the thread on which the output should be called.
+   *     If the output makes use of standard Android UI components, then this should normally be the
+   *     looper associated with the application's main thread, which can be obtained using {@link
+   *     android.app.Activity#getMainLooper()}. Null may be passed if the output should be called
+   *     directly on the player's internal rendering thread.
+   */
+  public TextRenderer(TextOutput output, @Nullable Looper outputLooper) {
+    this(output, outputLooper, SubtitleDecoderFactory.DEFAULT);
+  }
+
+  /**
+   * @param output The output.
+   * @param outputLooper The looper associated with the thread on which the output should be called.
+   *     If the output makes use of standard Android UI components, then this should normally be the
+   *     looper associated with the application's main thread, which can be obtained using {@link
+   *     android.app.Activity#getMainLooper()}. Null may be passed if the output should be called
+   *     directly on the player's internal rendering thread.
+   * @param decoderFactory A factory from which to obtain {@link SubtitleDecoder} instances.
+   */
+  public TextRenderer(
+      TextOutput output, @Nullable Looper outputLooper, SubtitleDecoderFactory decoderFactory) {
+    super(C.TRACK_TYPE_TEXT);
+    this.output = Assertions.checkNotNull(output);
+    this.outputHandler =
+        outputLooper == null ? null : Util.createHandler(outputLooper, /* callback= */ this);
+    this.decoderFactory = decoderFactory;
+    formatHolder = new FormatHolder();
+  }
+
+  @Override
+  @Capabilities
+  public int supportsFormat(Format format) {
+    if (decoderFactory.supportsFormat(format)) {
+      return RendererCapabilities.create(
+          supportsFormatDrm(null, format.drmInitData) ? FORMAT_HANDLED : FORMAT_UNSUPPORTED_DRM);
+    } else if (MimeTypes.isText(format.sampleMimeType)) {
+      return RendererCapabilities.create(FORMAT_UNSUPPORTED_SUBTYPE);
+    } else {
+      return RendererCapabilities.create(FORMAT_UNSUPPORTED_TYPE);
+    }
+  }
+
+  @Override
+  protected void onStreamChanged(Format[] formats, long offsetUs) {
+    streamFormat = formats[0];
+    if (decoder != null) {
+      decoderReplacementState = REPLACEMENT_STATE_SIGNAL_END_OF_STREAM;
+    } else {
+      decoder = decoderFactory.createDecoder(streamFormat);
+    }
+  }
+
+  @Override
+  protected void onPositionReset(long positionUs, boolean joining) {
+    inputStreamEnded = false;
+    outputStreamEnded = false;
+    resetOutputAndDecoder();
+  }
+
+  @Override
+  public void render(long positionUs, long elapsedRealtimeUs) {
+    if (outputStreamEnded) {
+      return;
+    }
+
+    if (nextSubtitle == null) {
+      decoder.setPositionUs(positionUs);
+      try {
+        nextSubtitle = decoder.dequeueOutputBuffer();
+      } catch (SubtitleDecoderException e) {
+        handleDecoderError(e);
+        return;
+      }
+    }
+
+    if (getState() != STATE_STARTED) {
+      return;
+    }
+
+    boolean textRendererNeedsUpdate = false;
+    if (subtitle != null) {
+      // We're iterating through the events in a subtitle. Set textRendererNeedsUpdate if we
+      // advance to the next event.
+      long subtitleNextEventTimeUs = getNextEventTime();
+      while (subtitleNextEventTimeUs <= positionUs) {
+        nextSubtitleEventIndex++;
+        subtitleNextEventTimeUs = getNextEventTime();
+        textRendererNeedsUpdate = true;
+      }
+    }
+
+    if (nextSubtitle != null) {
+      if (nextSubtitle.isEndOfStream()) {
+        if (!textRendererNeedsUpdate && getNextEventTime() == Long.MAX_VALUE) {
+          if (decoderReplacementState == REPLACEMENT_STATE_WAIT_END_OF_STREAM) {
+            replaceDecoder();
+          } else {
+            releaseBuffers();
+            outputStreamEnded = true;
+          }
+        }
+      } else if (nextSubtitle.timeUs <= positionUs) {
+        // Advance to the next subtitle. Sync the next event index and trigger an update.
+        if (subtitle != null) {
+          subtitle.release();
+        }
+        subtitle = nextSubtitle;
+        nextSubtitle = null;
+        nextSubtitleEventIndex = subtitle.getNextEventTimeIndex(positionUs);
+        textRendererNeedsUpdate = true;
+      }
+    }
+
+    if (textRendererNeedsUpdate) {
+      // textRendererNeedsUpdate is set and we're playing. Update the renderer.
+      updateOutput(subtitle.getCues(positionUs));
+    }
+
+    if (decoderReplacementState == REPLACEMENT_STATE_WAIT_END_OF_STREAM) {
+      return;
+    }
+
+    try {
+      while (!inputStreamEnded) {
+        if (nextInputBuffer == null) {
+          nextInputBuffer = decoder.dequeueInputBuffer();
+          if (nextInputBuffer == null) {
+            return;
+          }
+        }
+        if (decoderReplacementState == REPLACEMENT_STATE_SIGNAL_END_OF_STREAM) {
+          nextInputBuffer.setFlags(C.BUFFER_FLAG_END_OF_STREAM);
+          decoder.queueInputBuffer(nextInputBuffer);
+          nextInputBuffer = null;
+          decoderReplacementState = REPLACEMENT_STATE_WAIT_END_OF_STREAM;
+          return;
+        }
+        // Try and read the next subtitle from the source.
+        int result = readSource(formatHolder, nextInputBuffer, false);
+        if (result == C.RESULT_BUFFER_READ) {
+          if (nextInputBuffer.isEndOfStream()) {
+            inputStreamEnded = true;
+          } else {
+            nextInputBuffer.subsampleOffsetUs = formatHolder.format.subsampleOffsetUs;
+            nextInputBuffer.flip();
+          }
+          decoder.queueInputBuffer(nextInputBuffer);
+          nextInputBuffer = null;
+        } else if (result == C.RESULT_NOTHING_READ) {
+          return;
+        }
+      }
+    } catch (SubtitleDecoderException e) {
+      handleDecoderError(e);
+      return;
+    }
+  }
+
+  @Override
+  protected void onDisabled() {
+    streamFormat = null;
+    clearOutput();
+    releaseDecoder();
+  }
+
+  @Override
+  public boolean isEnded() {
+    return outputStreamEnded;
+  }
+
+  @Override
+  public boolean isReady() {
+    // Don't block playback whilst subtitles are loading.
+    // Note: To change this behavior, it will be necessary to consider [Internal: b/12949941].
+    return true;
+  }
+
+  private void releaseBuffers() {
+    nextInputBuffer = null;
+    nextSubtitleEventIndex = C.INDEX_UNSET;
+    if (subtitle != null) {
+      subtitle.release();
+      subtitle = null;
+    }
+    if (nextSubtitle != null) {
+      nextSubtitle.release();
+      nextSubtitle = null;
+    }
+  }
+
+  private void releaseDecoder() {
+    releaseBuffers();
+    decoder.release();
+    decoder = null;
+    decoderReplacementState = REPLACEMENT_STATE_NONE;
+  }
+
+  private void replaceDecoder() {
+    releaseDecoder();
+    decoder = decoderFactory.createDecoder(streamFormat);
+  }
+
+  private long getNextEventTime() {
+    return nextSubtitleEventIndex == C.INDEX_UNSET
+        || nextSubtitleEventIndex >= subtitle.getEventTimeCount()
+        ? Long.MAX_VALUE : subtitle.getEventTime(nextSubtitleEventIndex);
+  }
+
+  private void updateOutput(List<Cue> cues) {
+    if (outputHandler != null) {
+      outputHandler.obtainMessage(MSG_UPDATE_OUTPUT, cues).sendToTarget();
+    } else {
+      invokeUpdateOutputInternal(cues);
+    }
+  }
+
+  private void clearOutput() {
+    updateOutput(Collections.emptyList());
+  }
+
+  @SuppressWarnings("unchecked")
+  @Override
+  public boolean handleMessage(Message msg) {
+    switch (msg.what) {
+      case MSG_UPDATE_OUTPUT:
+        invokeUpdateOutputInternal((List<Cue>) msg.obj);
+        return true;
+      default:
+        throw new IllegalStateException();
+    }
+  }
+
+  private void invokeUpdateOutputInternal(List<Cue> cues) {
+    output.onCues(cues);
+  }
+
+  /**
+   * Called when {@link #decoder} throws an exception, so it can be logged and playback can
+   * continue.
+   *
+   * <p>Logs {@code e} and resets state to allow decoding the next sample.
+   */
+  private void handleDecoderError(SubtitleDecoderException e) {
+    Log.e(TAG, "Subtitle decoding failed. streamFormat=" + streamFormat, e);
+    resetOutputAndDecoder();
+  }
+
+  private void resetOutputAndDecoder() {
+    clearOutput();
+    if (decoderReplacementState != REPLACEMENT_STATE_NONE) {
+      replaceDecoder();
+    } else {
+      releaseBuffers();
+      decoder.flush();
+    }
+  }
+}