1 files changed, 95 insertions, 0 deletions
diff --git a/dom/media/NextFrameSeekTask.h b/dom/media/NextFrameSeekTask.h
new file mode 100644
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+++ b/dom/media/NextFrameSeekTask.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NEXTFRAME_SEEK_TASK_H
+#define NEXTFRAME_SEEK_TASK_H
+
+#include "SeekTask.h"
+#include "MediaDecoderReader.h"
+
+namespace mozilla {
+namespace media {
+
+/*
+ * While invoking a NextFrameSeekTask, we don't know the seek target time, what
+ * we know is the media's currant position. We use the media's currant position
+ * to find out what the next frame is, by traversing through the video queue or
+ * asking the decoder to decode more video frames. Once we confirm the next
+ * frame, we then know the target time of the NextFrameSeekTask and we update it
+ * so that the MDSM will be able to update the media element's position.
+ */
+
+class NextFrameSeekTask final : public SeekTask {
+public:
+  NextFrameSeekTask(const void* aDecoderID,
+                   AbstractThread* aThread,
+                   MediaDecoderReaderWrapper* aReader,
+                   const SeekTarget& aTarget,
+                   const MediaInfo& aInfo,
+                   const media::TimeUnit& aDuration,
+                   int64_t aCurrentTime,
+                   MediaQueue<MediaData>& aAudioQueue,
+                   MediaQueue<MediaData>& aVideoQueue);
+
+  void Discard() override;
+
+  RefPtr<SeekTaskPromise> Seek(const media::TimeUnit& aDuration) override;
+
+  bool NeedToResetMDSM() const override;
+
+private:
+  ~NextFrameSeekTask();
+
+  void RequestVideoData();
+
+  bool NeedMoreVideo() const;
+
+  bool IsVideoRequestPending() const;
+
+  bool IsAudioSeekComplete() const;
+
+  bool IsVideoSeekComplete() const;
+
+  void MaybeFinishSeek();
+
+  void OnAudioDecoded(MediaData* aAudioSample);
+
+  void OnAudioNotDecoded(const MediaResult& aError);
+
+  void OnVideoDecoded(MediaData* aVideoSample);
+
+  void OnVideoNotDecoded(const MediaResult& aError);
+
+  void SetCallbacks();
+
+  void CancelCallbacks();
+
+  // Update the seek target's time before resolving this seek task, the updated
+  // time will be used in the MDSM::SeekCompleted() to update the MDSM's position.
+  void UpdateSeekTargetTime();
+
+  /*
+   * Data shared with MDSM.
+   */
+  MediaQueue<MediaData>& mAudioQueue;
+  MediaQueue<MediaData>& mVideoQueue;
+
+  /*
+   * Internal state.
+   */
+  const int64_t mCurrentTime;
+  media::TimeUnit mDuration;
+
+  MediaEventListener mAudioCallback;
+  MediaEventListener mVideoCallback;
+  MediaEventListener mAudioWaitCallback;
+  MediaEventListener mVideoWaitCallback;
+};
+
+} // namespace media
+} // namespace mozilla
+
+#endif /* NEXTFRAME_SEEK_TASK_H */