modules/video_coding/svc/scalability_structure_full_svc.h

/*
 *  Copyright (c) 2020 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 MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_FULL_SVC_H_
#define MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_FULL_SVC_H_

#include <bitset>
#include <vector>

#include "api/transport/rtp/dependency_descriptor.h"
#include "common_video/generic_frame_descriptor/generic_frame_info.h"
#include "modules/video_coding/svc/scalable_video_controller.h"

namespace webrtc {

class ScalabilityStructureFullSvc : public ScalableVideoController {
 public:
  ScalabilityStructureFullSvc(int num_spatial_layers, int num_temporal_layers);
  ~ScalabilityStructureFullSvc() override;

  StreamLayersConfig StreamConfig() const override;

  std::vector<LayerFrameConfig> NextFrameConfig(bool restart) override;
  GenericFrameInfo OnEncodeDone(const LayerFrameConfig& config) override;
  void OnRatesUpdated(const VideoBitrateAllocation& bitrates) override;

 private:
  enum FramePattern {
    kNone,
    kDeltaT2A,
    kDeltaT1,
    kDeltaT2B,
    kDeltaT0,
  };
  static constexpr absl::string_view kFramePatternNames[] = {
      "None", "DeltaT2A", "DeltaT1", "DeltaT2B", "DeltaT0"};
  static constexpr int kMaxNumSpatialLayers = 3;
  static constexpr int kMaxNumTemporalLayers = 3;

  // Index of the buffer to store last frame for layer (`sid`, `tid`)
  int BufferIndex(int sid, int tid) const {
    return tid * num_spatial_layers_ + sid;
  }
  bool DecodeTargetIsActive(int sid, int tid) const {
    return active_decode_targets_[sid * num_temporal_layers_ + tid];
  }
  void SetDecodeTargetIsActive(int sid, int tid, bool value) {
    active_decode_targets_.set(sid * num_temporal_layers_ + tid, value);
  }
  FramePattern NextPattern() const;
  bool TemporalLayerIsActive(int tid) const;
  static DecodeTargetIndication Dti(int sid,
                                    int tid,
                                    const LayerFrameConfig& frame);

  const int num_spatial_layers_;
  const int num_temporal_layers_;

  FramePattern last_pattern_ = kNone;
  std::bitset<kMaxNumSpatialLayers> can_reference_t0_frame_for_spatial_id_ = 0;
  std::bitset<kMaxNumSpatialLayers> can_reference_t1_frame_for_spatial_id_ = 0;
  std::bitset<32> active_decode_targets_;
};

}  // namespace webrtc

#endif  // MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_FULL_SVC_H_