Source code
Revision control
Copy as Markdown
Other Tools
/*
* Copyright (c) 2021 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_SIMULCAST_H_
#define MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_SIMULCAST_H_
#include <vector>
#include "api/transport/rtp/dependency_descriptor.h"
#include "api/video/video_bitrate_allocation.h"
#include "common_video/generic_frame_descriptor/generic_frame_info.h"
#include "modules/video_coding/svc/scalable_video_controller.h"
namespace webrtc {
// Scalability structure with multiple independent spatial layers each with the
// same temporal layering.
class ScalabilityStructureSimulcast : public ScalableVideoController {
public:
struct ScalingFactor {
int num = 1;
int den = 2;
};
ScalabilityStructureSimulcast(int num_spatial_layers,
int num_temporal_layers,
ScalingFactor resolution_factor);
~ScalabilityStructureSimulcast() 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 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;
const int num_spatial_layers_;
const int num_temporal_layers_;
const ScalingFactor resolution_factor_;
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_;
};
// S1 0--0--0-
// ...
// S0 0--0--0-
class ScalabilityStructureS2T1 : public ScalabilityStructureSimulcast {
public:
explicit ScalabilityStructureS2T1(ScalingFactor resolution_factor = {})
: ScalabilityStructureSimulcast(2, 1, resolution_factor) {}
~ScalabilityStructureS2T1() override = default;
FrameDependencyStructure DependencyStructure() const override;
};
class ScalabilityStructureS2T2 : public ScalabilityStructureSimulcast {
public:
explicit ScalabilityStructureS2T2(ScalingFactor resolution_factor = {})
: ScalabilityStructureSimulcast(2, 2, resolution_factor) {}
~ScalabilityStructureS2T2() override = default;
FrameDependencyStructure DependencyStructure() const override;
};
// S1T2 3 7
// | /
// S1T1 / 5
// |_/
// S1T0 1-------9...
//
// S0T2 2 6
// | /
// S0T1 / 4
// |_/
// S0T0 0-------8...
// Time-> 0 1 2 3 4
class ScalabilityStructureS2T3 : public ScalabilityStructureSimulcast {
public:
explicit ScalabilityStructureS2T3(ScalingFactor resolution_factor = {})
: ScalabilityStructureSimulcast(2, 3, resolution_factor) {}
~ScalabilityStructureS2T3() override = default;
FrameDependencyStructure DependencyStructure() const override;
};
class ScalabilityStructureS3T1 : public ScalabilityStructureSimulcast {
public:
explicit ScalabilityStructureS3T1(ScalingFactor resolution_factor = {})
: ScalabilityStructureSimulcast(3, 1, resolution_factor) {}
~ScalabilityStructureS3T1() override = default;
FrameDependencyStructure DependencyStructure() const override;
};
class ScalabilityStructureS3T2 : public ScalabilityStructureSimulcast {
public:
explicit ScalabilityStructureS3T2(ScalingFactor resolution_factor = {})
: ScalabilityStructureSimulcast(3, 2, resolution_factor) {}
~ScalabilityStructureS3T2() override = default;
FrameDependencyStructure DependencyStructure() const override;
};
class ScalabilityStructureS3T3 : public ScalabilityStructureSimulcast {
public:
explicit ScalabilityStructureS3T3(ScalingFactor resolution_factor = {})
: ScalabilityStructureSimulcast(3, 3, resolution_factor) {}
~ScalabilityStructureS3T3() override = default;
FrameDependencyStructure DependencyStructure() const override;
};
} // namespace webrtc
#endif // MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_SIMULCAST_H_