| /* |
| * Copyright 2015 Google Inc. All Rights Reserved. |
| * |
| * 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. |
| */ |
| |
| #ifndef MEDIA_BASE_SHELL_VIDEO_FRAME_PROVIDER_H_ |
| #define MEDIA_BASE_SHELL_VIDEO_FRAME_PROVIDER_H_ |
| |
| #include <vector> |
| |
| #include "base/callback.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/synchronization/lock.h" |
| #include "base/time.h" |
| #include "media/base/video_frame.h" |
| |
| namespace media { |
| |
| // TODO: Remove Shell prefix. |
| // The ShellVideoFrameProvider manages the backlog for video frames. It has the |
| // following functionalities: |
| // 1. It caches the video frames ready to be displayed. |
| // 2. It decides which frame to be displayed at the current time. |
| // 3. It removes frames that will no longer be displayed. |
| class ShellVideoFrameProvider |
| : public base::RefCountedThreadSafe<ShellVideoFrameProvider> { |
| public: |
| explicit ShellVideoFrameProvider(scoped_refptr<VideoFrame> punch_out = NULL); |
| |
| typedef base::Callback<base::TimeDelta()> MediaTimeCB; |
| // This class uses the media time to decide which frame is current. It |
| // retrieves the media time from the registered media_time_cb. There can only |
| // be one registered media_time_cb at a certain time, a call to |
| // RegisterMediaTimeCB() will overwrite the previously registered callback. |
| void RegisterMediaTimeCB(const MediaTimeCB& media_time_cb); |
| // This function unregisters the media time callback if it hasn't been |
| // overwritten by another callback. |
| void UnregisterMediaTimeCB(const MediaTimeCB& media_time_cb); |
| |
| // Returns the current frame to be displayed if there is one. Otherwise it |
| // returns NULL. |
| const scoped_refptr<VideoFrame>& GetCurrentFrame(); |
| |
| void AddFrame(const scoped_refptr<VideoFrame>& frame); |
| // Flush will clear all cached frames except the current frame. So the current |
| // frame can still be displayed during seek. |
| void Flush(); |
| // Stop will clear all cached frames including the current frame. |
| void Stop(); |
| size_t GetNumOfFramesCached() const; |
| |
| // Return true if VideoFrames have been released from the internal frames_ |
| // queue since the last time this was called. |
| bool QueryAndResetHasConsumedFrames(); |
| |
| // Return the value of |dropped_frames_| and reset it to 0. |
| int ResetAndReturnDroppedFrames(); |
| |
| private: |
| base::TimeDelta GetMediaTime_Locked() const; |
| |
| scoped_refptr<VideoFrame> punch_out_; |
| |
| mutable base::Lock frames_lock_; |
| MediaTimeCB media_time_cb_; |
| std::vector<scoped_refptr<VideoFrame> > frames_; |
| scoped_refptr<VideoFrame> current_frame_; |
| bool has_consumed_frames_; |
| int dropped_frames_; |
| |
| #if !defined(__LB_SHELL__FOR_RELEASE__) |
| int max_delay_in_microseconds_; |
| #endif // !defined(__LB_SHELL__FOR_RELEASE__) |
| |
| DISALLOW_COPY_AND_ASSIGN(ShellVideoFrameProvider); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_SHELL_VIDEO_FRAME_PROVIDER_H_ |