| /* |
| * 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. |
| */ |
| #include "modules/video_coding/svc/scalability_structure_l2t2_key_shift.h" |
| |
| #include <utility> |
| #include <vector> |
| |
| #include "absl/base/macros.h" |
| #include "api/transport/rtp/dependency_descriptor.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/logging.h" |
| |
| namespace webrtc { |
| namespace { |
| |
| DecodeTargetIndication |
| Dti(int sid, int tid, const ScalableVideoController::LayerFrameConfig& config) { |
| if (config.IsKeyframe()) { |
| RTC_DCHECK_EQ(config.TemporalId(), 0); |
| return sid < config.SpatialId() ? DecodeTargetIndication::kNotPresent |
| : DecodeTargetIndication::kSwitch; |
| } |
| |
| if (sid != config.SpatialId() || tid < config.TemporalId()) { |
| return DecodeTargetIndication::kNotPresent; |
| } |
| if (tid == config.TemporalId() && tid > 0) { |
| return DecodeTargetIndication::kDiscardable; |
| } |
| return DecodeTargetIndication::kSwitch; |
| } |
| |
| } // namespace |
| |
| constexpr int ScalabilityStructureL2T2KeyShift::kNumSpatialLayers; |
| constexpr int ScalabilityStructureL2T2KeyShift::kNumTemporalLayers; |
| |
| ScalabilityStructureL2T2KeyShift::~ScalabilityStructureL2T2KeyShift() = default; |
| |
| ScalableVideoController::StreamLayersConfig |
| ScalabilityStructureL2T2KeyShift::StreamConfig() const { |
| StreamLayersConfig result; |
| result.num_spatial_layers = 2; |
| result.num_temporal_layers = 2; |
| result.scaling_factor_num[0] = 1; |
| result.scaling_factor_den[0] = 2; |
| return result; |
| } |
| |
| FrameDependencyStructure ScalabilityStructureL2T2KeyShift::DependencyStructure() |
| const { |
| FrameDependencyStructure structure; |
| structure.num_decode_targets = 4; |
| structure.num_chains = 2; |
| structure.decode_target_protected_by_chain = {0, 0, 1, 1}; |
| structure.templates.resize(7); |
| auto& templates = structure.templates; |
| templates[0].S(0).T(0).Dtis("SSSS").ChainDiffs({0, 0}); |
| templates[1].S(0).T(0).Dtis("SS--").ChainDiffs({2, 1}).FrameDiffs({2}); |
| templates[2].S(0).T(0).Dtis("SS--").ChainDiffs({4, 1}).FrameDiffs({4}); |
| templates[3].S(0).T(1).Dtis("-D--").ChainDiffs({2, 3}).FrameDiffs({2}); |
| templates[4].S(1).T(0).Dtis("--SS").ChainDiffs({1, 1}).FrameDiffs({1}); |
| templates[5].S(1).T(0).Dtis("--SS").ChainDiffs({3, 4}).FrameDiffs({4}); |
| templates[6].S(1).T(1).Dtis("---D").ChainDiffs({1, 2}).FrameDiffs({2}); |
| return structure; |
| } |
| |
| std::vector<ScalableVideoController::LayerFrameConfig> |
| ScalabilityStructureL2T2KeyShift::NextFrameConfig(bool restart) { |
| std::vector<LayerFrameConfig> configs; |
| configs.reserve(2); |
| if (restart) { |
| next_pattern_ = kKey; |
| } |
| |
| // Buffer0 keeps latest S0T0 frame, |
| // Buffer1 keeps latest S1T0 frame. |
| switch (next_pattern_) { |
| case kKey: |
| if (DecodeTargetIsActive(/*sid=*/0, /*tid=*/0)) { |
| configs.emplace_back(); |
| configs.back().S(0).T(0).Update(0).Keyframe(); |
| } |
| if (DecodeTargetIsActive(/*sid=*/1, /*tid=*/0)) { |
| configs.emplace_back(); |
| configs.back().S(1).T(0).Update(1); |
| if (DecodeTargetIsActive(/*sid=*/0, /*tid=*/0)) { |
| configs.back().Reference(0); |
| } else { |
| configs.back().Keyframe(); |
| } |
| } |
| next_pattern_ = kDelta0; |
| break; |
| case kDelta0: |
| if (DecodeTargetIsActive(/*sid=*/0, /*tid=*/0)) { |
| configs.emplace_back(); |
| configs.back().S(0).T(0).ReferenceAndUpdate(0); |
| } |
| if (DecodeTargetIsActive(/*sid=*/1, /*tid=*/1)) { |
| configs.emplace_back(); |
| configs.back().S(1).T(1).Reference(1); |
| } |
| if (configs.empty() && DecodeTargetIsActive(/*sid=*/1, /*tid=*/0)) { |
| configs.emplace_back(); |
| configs.back().S(1).T(0).ReferenceAndUpdate(1); |
| } |
| next_pattern_ = kDelta1; |
| break; |
| case kDelta1: |
| if (DecodeTargetIsActive(/*sid=*/0, /*tid=*/1)) { |
| configs.emplace_back(); |
| configs.back().S(0).T(1).Reference(0); |
| } |
| if (DecodeTargetIsActive(/*sid=*/1, /*tid=*/0)) { |
| configs.emplace_back(); |
| configs.back().S(1).T(0).ReferenceAndUpdate(1); |
| } |
| if (configs.empty() && DecodeTargetIsActive(/*sid=*/0, /*tid=*/0)) { |
| configs.emplace_back(); |
| configs.back().S(0).T(0).ReferenceAndUpdate(0); |
| } |
| next_pattern_ = kDelta0; |
| break; |
| } |
| |
| RTC_DCHECK(!configs.empty() || active_decode_targets_.none()); |
| return configs; |
| } |
| |
| GenericFrameInfo ScalabilityStructureL2T2KeyShift::OnEncodeDone( |
| const LayerFrameConfig& config) { |
| GenericFrameInfo frame_info; |
| frame_info.spatial_id = config.SpatialId(); |
| frame_info.temporal_id = config.TemporalId(); |
| frame_info.encoder_buffers = config.Buffers(); |
| for (int sid = 0; sid < kNumSpatialLayers; ++sid) { |
| for (int tid = 0; tid < kNumTemporalLayers; ++tid) { |
| frame_info.decode_target_indications.push_back(Dti(sid, tid, config)); |
| } |
| } |
| if (config.IsKeyframe()) { |
| frame_info.part_of_chain = {true, true}; |
| } else if (config.TemporalId() == 0) { |
| frame_info.part_of_chain = {config.SpatialId() == 0, |
| config.SpatialId() == 1}; |
| } else { |
| frame_info.part_of_chain = {false, false}; |
| } |
| return frame_info; |
| } |
| |
| void ScalabilityStructureL2T2KeyShift::OnRatesUpdated( |
| const VideoBitrateAllocation& bitrates) { |
| for (int sid = 0; sid < kNumSpatialLayers; ++sid) { |
| // Enable/disable spatial layers independetely. |
| bool active = bitrates.GetBitrate(sid, /*tid=*/0) > 0; |
| if (!DecodeTargetIsActive(sid, /*tid=*/0) && active) { |
| // Key frame is required to reenable any spatial layer. |
| next_pattern_ = kKey; |
| } |
| |
| SetDecodeTargetIsActive(sid, /*tid=*/0, active); |
| SetDecodeTargetIsActive(sid, /*tid=*/1, |
| active && bitrates.GetBitrate(sid, /*tid=*/1) > 0); |
| } |
| } |
| |
| } // namespace webrtc |