text: /*
   *  Copyright (c) 2014 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 MEDIA_ENGINE_SIMULCAST_ENCODER_ADAPTER_H_
  #define MEDIA_ENGINE_SIMULCAST_ENCODER_ADAPTER_H_
  
  #include <memory>
  #include <stack>
  #include <string>
  #include <utility>
  #include <vector>
  
  #include "absl/types/optional.h"
  #include "api/video_codecs/sdp_video_format.h"
  #include "modules/video_coding/include/video_codec_interface.h"
  #include "rtc_base/atomic_ops.h"
  #include "rtc_base/sequenced_task_checker.h"
  
  namespace webrtc {
  
  class SimulcastRateAllocator;
  class VideoEncoderFactory;
  
  // SimulcastEncoderAdapter implements simulcast support by creating multiple
  // webrtc::VideoEncoder instances with the given VideoEncoderFactory.
  // The object is created and destroyed on the worker thread, but all public
  // interfaces should be called from the encoder task queue.
  class SimulcastEncoderAdapter : public VideoEncoder {
   public:
    explicit SimulcastEncoderAdapter(VideoEncoderFactory* factory,
                                     const SdpVideoFormat& format);
    virtual ~SimulcastEncoderAdapter();
  
    // Implements VideoEncoder.
    int Release() override;
    int InitEncode(const VideoCodec* inst,
                   int number_of_cores,
                   size_t max_payload_size) override;
    int Encode(const VideoFrame& input_image,
               const CodecSpecificInfo* codec_specific_info,
               const std::vector<FrameType>* frame_types) override;
    int RegisterEncodeCompleteCallback(EncodedImageCallback* callback) override;
    int SetRateAllocation(const VideoBitrateAllocation& bitrate,
                          uint32_t new_framerate) override;
  
    // Eventual handler for the contained encoders' EncodedImageCallbacks, but
    // called from an internal helper that also knows the correct stream
    // index.
    EncodedImageCallback::Result OnEncodedImage(
        size_t stream_idx,
        const EncodedImage& encoded_image,
        const CodecSpecificInfo* codec_specific_info,
        const RTPFragmentationHeader* fragmentation);
  
    EncoderInfo GetEncoderInfo() const override;
  
   private:
    struct StreamInfo {
      StreamInfo(std::unique_ptr<VideoEncoder> encoder,
                 std::unique_ptr<EncodedImageCallback> callback,
                 uint16_t width,
                 uint16_t height,
                 bool send_stream)
          : encoder(std::move(encoder)),
            callback(std::move(callback)),
            width(width),
            height(height),
            key_frame_request(false),
            send_stream(send_stream) {}
      std::unique_ptr<VideoEncoder> encoder;
      std::unique_ptr<EncodedImageCallback> callback;
      uint16_t width;
      uint16_t height;
      bool key_frame_request;
      bool send_stream;
    };
  
    enum class StreamResolution {
      OTHER,
      HIGHEST,
      LOWEST,
    };
  
    // Populate the codec settings for each simulcast stream.
    void PopulateStreamCodec(const webrtc::VideoCodec& inst,
                             int stream_index,
                             uint32_t start_bitrate_kbps,
                             StreamResolution stream_resolution,
                             webrtc::VideoCodec* stream_codec);
  
    bool Initialized() const;
  
    void DestroyStoredEncoders();
  
    volatile int inited_;  // Accessed atomically.
    VideoEncoderFactory* const factory_;
    const SdpVideoFormat video_format_;
    VideoCodec codec_;
    std::vector<StreamInfo> streaminfos_;
    EncodedImageCallback* encoded_complete_callback_;
    EncoderInfo encoder_info_;
  
    // Used for checking the single-threaded access of the encoder interface.
    rtc::SequencedTaskChecker encoder_queue_;
  
    // Store encoders in between calls to Release and InitEncode, so they don't
    // have to be recreated. Remaining encoders are destroyed by the destructor.
    std::stack<std::unique_ptr<VideoEncoder>> stored_encoders_;
  
    const absl::optional<unsigned int> experimental_boosted_screenshare_qp_;
  };
  
  }  // namespace webrtc
  
  #endif  // MEDIA_ENGINE_SIMULCAST_ENCODER_ADAPTER_H_
  