1 files changed, 104 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/StandaloneMediaClock.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/StandaloneMediaClock.java
new file mode 100644
index 0000000000..f72867694d
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/StandaloneMediaClock.java
@@ -0,0 +1,104 @@
+/*
+ * 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.util;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.PlaybackParameters;
+
+/**
+ * A {@link MediaClock} whose position advances with real time based on the playback parameters when
+ * started.
+ */
+public final class StandaloneMediaClock implements MediaClock {
+
+  private final Clock clock;
+
+  private boolean started;
+  private long baseUs;
+  private long baseElapsedMs;
+  private PlaybackParameters playbackParameters;
+
+  /**
+   * Creates a new standalone media clock using the given {@link Clock} implementation.
+   *
+   * @param clock A {@link Clock}.
+   */
+  public StandaloneMediaClock(Clock clock) {
+    this.clock = clock;
+    this.playbackParameters = PlaybackParameters.DEFAULT;
+  }
+
+  /**
+   * Starts the clock. Does nothing if the clock is already started.
+   */
+  public void start() {
+    if (!started) {
+      baseElapsedMs = clock.elapsedRealtime();
+      started = true;
+    }
+  }
+
+  /**
+   * Stops the clock. Does nothing if the clock is already stopped.
+   */
+  public void stop() {
+    if (started) {
+      resetPosition(getPositionUs());
+      started = false;
+    }
+  }
+
+  /**
+   * Resets the clock's position.
+   *
+   * @param positionUs The position to set in microseconds.
+   */
+  public void resetPosition(long positionUs) {
+    baseUs = positionUs;
+    if (started) {
+      baseElapsedMs = clock.elapsedRealtime();
+    }
+  }
+
+  @Override
+  public long getPositionUs() {
+    long positionUs = baseUs;
+    if (started) {
+      long elapsedSinceBaseMs = clock.elapsedRealtime() - baseElapsedMs;
+      if (playbackParameters.speed == 1f) {
+        positionUs += C.msToUs(elapsedSinceBaseMs);
+      } else {
+        positionUs += playbackParameters.getMediaTimeUsForPlayoutTimeMs(elapsedSinceBaseMs);
+      }
+    }
+    return positionUs;
+  }
+
+  @Override
+  public void setPlaybackParameters(PlaybackParameters playbackParameters) {
+    // Store the current position as the new base, in case the playback speed has changed.
+    if (started) {
+      resetPosition(getPositionUs());
+    }
+    this.playbackParameters = playbackParameters;
+  }
+
+  @Override
+  public PlaybackParameters getPlaybackParameters() {
+    return playbackParameters;
+  }
+
+}