webrtc/modules/video_coding/codecs/vp8/screenshare_layers.h

/* Copyright (c) 2013 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_CODECS_VP8_SCREENSHARE_LAYERS_H_
#define WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_SCREENSHARE_LAYERS_H_

#include <list>

#include "vpx/vpx_encoder.h"

#include "webrtc/base/timeutils.h"
#include "webrtc/modules/video_coding/codecs/vp8/temporal_layers.h"
#include "webrtc/modules/video_coding/utility/include/frame_dropper.h"
#include "webrtc/typedefs.h"

namespace webrtc {

struct CodecSpecificInfoVP8;

class ScreenshareLayers : public TemporalLayers {
 public:
  static const double kMaxTL0FpsReduction;
  static const double kAcceptableTargetOvershoot;
  static const int kTl0Flags;
  static const int kTl1Flags;
  static const int kTl1SyncFlags;

  ScreenshareLayers(int num_temporal_layers, uint8_t initial_tl0_pic_idx);
  virtual ~ScreenshareLayers() {}

  // Returns the recommended VP8 encode flags needed. May refresh the decoder
  // and/or update the reference buffers.
  int EncodeFlags(uint32_t timestamp) override;

  bool ConfigureBitrates(int bitrate_kbps,
                         int max_bitrate_kbps,
                         int framerate,
                         vpx_codec_enc_cfg_t* cfg) override;

  void PopulateCodecSpecific(bool base_layer_sync,
                             CodecSpecificInfoVP8* vp8_info,
                             uint32_t timestamp) override;

  void FrameEncoded(unsigned int size, uint32_t timestamp, int qp) override;

  int CurrentLayerId() const override;

  // Allows the layers adapter to update the encoder configuration prior to a
  // frame being encoded. Return true if the configuration should be updated
  // and false if now change is needed.
  bool UpdateConfiguration(vpx_codec_enc_cfg_t* cfg) override;

 private:
  bool TimeToSync(int64_t timestamp) const;

  int number_of_temporal_layers_;
  bool last_base_layer_sync_;
  uint8_t tl0_pic_idx_;
  int active_layer_;
  int64_t last_timestamp_;
  int64_t last_sync_timestamp_;
  rtc::TimestampWrapAroundHandler time_wrap_handler_;
  int min_qp_;
  int max_qp_;
  uint32_t max_debt_bytes_;
  int frame_rate_;

  static const int kMaxNumTemporalLayers = 2;
  struct TemporalLayer {
    TemporalLayer()
        : state(State::kNormal),
          enhanced_max_qp(-1),
          last_qp(-1),
          debt_bytes_(0),
          target_rate_kbps_(0) {}

    enum class State {
      kNormal,
      kDropped,
      kReencoded,
      kQualityBoost,
    } state;

    int enhanced_max_qp;
    int last_qp;
    uint32_t debt_bytes_;
    uint32_t target_rate_kbps_;

    void UpdateDebt(int64_t delta_ms);
  } layers_[kMaxNumTemporalLayers];
};
}  // namespace webrtc

#endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_SCREENSHARE_LAYERS_H_