Deliver video frames on Android, on the decode thread.

webrtc/modules/video_coding/generic_decoder.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_CODING_GENERIC_DECODER_H_
 #define WEBRTC_MODULES_VIDEO_CODING_GENERIC_DECODER_H_
 
 #include <memory>
 
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/modules/video_coding/encoded_frame.h"
 #include "webrtc/modules/video_coding/include/video_codec_interface.h"
 #include "webrtc/modules/video_coding/timestamp_map.h"
 #include "webrtc/modules/video_coding/timing.h"
-#include "webrtc/rtc_base/criticalsection.h"
 #include "webrtc/rtc_base/thread_checker.h"
 
 namespace webrtc {
 
 class VCMReceiveCallback;
 
 enum { kDecoderFrameMemoryLength = 10 };
 
 struct VCMFrameInformation {
   int64_t renderTimeMs;
   int64_t decodeStartTimeMs;
   void* userData;
   VideoRotation rotation;
   VideoContentType content_type;
   EncodedImage::Timing timing;
 };
 
 class VCMDecodedFrameCallback : public DecodedImageCallback {
  public:
   VCMDecodedFrameCallback(VCMTiming* timing, Clock* clock);
   ~VCMDecodedFrameCallback() override;
+
   void SetUserReceiveCallback(VCMReceiveCallback* receiveCallback);
   VCMReceiveCallback* UserReceiveCallback();
 
   int32_t Decoded(VideoFrame& decodedImage) override;
   int32_t Decoded(VideoFrame& decodedImage, int64_t decode_time_ms) override;
   void Decoded(VideoFrame& decodedImage,
                rtc::Optional<int32_t> decode_time_ms,
                rtc::Optional<uint8_t> qp) override;
   int32_t ReceivedDecodedReferenceFrame(const uint64_t pictureId) override;
   int32_t ReceivedDecodedFrame(const uint64_t pictureId) override;
 
   uint64_t LastReceivedPictureID() const;
   void OnDecoderImplementationName(const char* implementation_name);
 
   void Map(uint32_t timestamp, VCMFrameInformation* frameInfo);
   int32_t Pop(uint32_t timestamp);
 
  private:
   rtc::ThreadChecker construction_thread_;
-  // Protect |_timestampMap|.
+  rtc::ThreadChecker decoder_thread_;
   Clock* const _clock;
   // This callback must be set before the decoder thread starts running
   // and must only be unset when external threads (e.g decoder thread)
   // have been stopped. Due to that, the variable should regarded as const
   // while there are more than one threads involved, it must be set
   // from the same thread, and therfore a lock is not required to access it.
   VCMReceiveCallback* _receiveCallback = nullptr;
-  VCMTiming* _timing;
-  rtc::CriticalSection lock_;
-  VCMTimestampMap _timestampMap GUARDED_BY(lock_);
-  uint64_t _lastReceivedPictureID;
+  VCMTiming* _timing ACCESS_ON(decoder_thread_);
+  VCMTimestampMap _timestampMap ACCESS_ON(decoder_thread_);
+  uint64_t _lastReceivedPictureID ACCESS_ON(decoder_thread_);
   int64_t ntp_offset_;
 };
 
 class VCMGenericDecoder {
  public:
   explicit VCMGenericDecoder(VideoDecoder* decoder, bool isExternal = false);
   ~VCMGenericDecoder();
 
   /**
   * Initialize the decoder with the information from the VideoCodec
   */
   int32_t InitDecode(const VideoCodec* settings, int32_t numberOfCores);
 
   /**
   * Decode to a raw I420 frame,
   *
   * inputVideoBuffer reference to encoded video frame
   */
   int32_t Decode(const VCMEncodedFrame& inputFrame, int64_t nowMs);
 
   /**
   * Set decode callback. Deregistering while decoding is illegal.
   */
   int32_t RegisterDecodeCompleteCallback(VCMDecodedFrameCallback* callback);
 
-  bool External() const;
   bool PrefersLateDecoding() const;
   bool IsSameDecoder(VideoDecoder* decoder) const {
     return decoder_.get() == decoder;
   }
 
+#if defined(WEBRTC_ANDROID)
+  // See https://bugs.chromium.org/p/webrtc/issues/detail?id=7361
+  void PollDecodedFrames();
+#endif
+
  private:
-  VCMDecodedFrameCallback* _callback;
-  VCMFrameInformation _frameInfos[kDecoderFrameMemoryLength];
-  uint32_t _nextFrameInfoIdx;
+  rtc::ThreadChecker decoder_thread_;
+  VCMDecodedFrameCallback* _callback ACCESS_ON(decoder_thread_);
+  VCMFrameInformation _frameInfos[kDecoderFrameMemoryLength] ACCESS_ON(
+      decoder_thread_);
+  uint32_t _nextFrameInfoIdx ACCESS_ON(decoder_thread_);
   std::unique_ptr<VideoDecoder> decoder_;
-  VideoCodecType _codecType;
+  VideoCodecType _codecType ACCESS_ON(decoder_thread_);
   const bool _isExternal;
   VideoContentType _last_keyframe_content_type;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_GENERIC_DECODER_H_