1 /*
2 * Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10 #include "modules/video_coding/codecs/av1/scalability_structure_l2t2_key_shift.h"
11
12 #include <utility>
13 #include <vector>
14
15 #include "absl/base/macros.h"
16 #include "api/transport/rtp/dependency_descriptor.h"
17 #include "rtc_base/checks.h"
18 #include "rtc_base/logging.h"
19
20 namespace webrtc {
21 namespace {
22
23 constexpr auto kNotPresent = DecodeTargetIndication::kNotPresent;
24 constexpr auto kDiscardable = DecodeTargetIndication::kDiscardable;
25 constexpr auto kSwitch = DecodeTargetIndication::kSwitch;
26
27 constexpr DecodeTargetIndication kDtis[6][4] = {
28 {kSwitch, kSwitch, kSwitch, kSwitch}, // kKey, S0T0
29 {kNotPresent, kNotPresent, kSwitch, kSwitch}, // kKey, S1T0
30 {kSwitch, kSwitch, kNotPresent, kNotPresent}, // kDelta0, S0T0
31 {kNotPresent, kNotPresent, kNotPresent, kDiscardable}, // kDelta0, S1T1
32 {kNotPresent, kDiscardable, kNotPresent, kNotPresent}, // kDelta1, S0T1
33 {kNotPresent, kNotPresent, kSwitch, kSwitch}, // kDelta1, S1T0
34 };
35
36 } // namespace
37
38 ScalabilityStructureL2T2KeyShift::~ScalabilityStructureL2T2KeyShift() = default;
39
40 ScalableVideoController::StreamLayersConfig
StreamConfig() const41 ScalabilityStructureL2T2KeyShift::StreamConfig() const {
42 StreamLayersConfig result;
43 result.num_spatial_layers = 2;
44 result.num_temporal_layers = 2;
45 result.scaling_factor_num[0] = 1;
46 result.scaling_factor_den[0] = 2;
47 return result;
48 }
49
DependencyStructure() const50 FrameDependencyStructure ScalabilityStructureL2T2KeyShift::DependencyStructure()
51 const {
52 FrameDependencyStructure structure;
53 structure.num_decode_targets = 4;
54 structure.num_chains = 2;
55 structure.decode_target_protected_by_chain = {0, 0, 1, 1};
56 structure.templates.resize(7);
57 auto& templates = structure.templates;
58 templates[0].S(0).T(0).Dtis("SSSS").ChainDiffs({0, 0});
59 templates[1].S(0).T(0).Dtis("SS--").ChainDiffs({2, 1}).FrameDiffs({2});
60 templates[2].S(0).T(0).Dtis("SS--").ChainDiffs({4, 1}).FrameDiffs({4});
61 templates[3].S(0).T(1).Dtis("-D--").ChainDiffs({2, 3}).FrameDiffs({2});
62 templates[4].S(1).T(0).Dtis("--SS").ChainDiffs({1, 1}).FrameDiffs({1});
63 templates[5].S(1).T(0).Dtis("--SS").ChainDiffs({3, 4}).FrameDiffs({4});
64 templates[6].S(1).T(1).Dtis("---D").ChainDiffs({1, 2}).FrameDiffs({2});
65 return structure;
66 }
67
68 ScalableVideoController::LayerFrameConfig
KeyFrameConfig() const69 ScalabilityStructureL2T2KeyShift::KeyFrameConfig() const {
70 return LayerFrameConfig().Id(0).Keyframe().S(0).T(0).Update(0);
71 }
72
73 std::vector<ScalableVideoController::LayerFrameConfig>
NextFrameConfig(bool restart)74 ScalabilityStructureL2T2KeyShift::NextFrameConfig(bool restart) {
75 if (restart) {
76 next_pattern_ = kKey;
77 }
78 std::vector<LayerFrameConfig> result(2);
79
80 // Buffer0 keeps latest S0T0 frame,
81 // Buffer1 keeps latest S1T0 frame.
82 switch (next_pattern_) {
83 case kKey:
84 result[0] = KeyFrameConfig();
85 result[1].Id(1).S(1).T(0).Reference(0).Update(1);
86 next_pattern_ = kDelta0;
87 break;
88 case kDelta0:
89 result[0].Id(2).S(0).T(0).ReferenceAndUpdate(0);
90 result[1].Id(3).S(1).T(1).Reference(1);
91 next_pattern_ = kDelta1;
92 break;
93 case kDelta1:
94 result[0].Id(4).S(0).T(1).Reference(0);
95 result[1].Id(5).S(1).T(0).ReferenceAndUpdate(1);
96 next_pattern_ = kDelta0;
97 break;
98 }
99 return result;
100 }
101
OnEncodeDone(LayerFrameConfig config)102 absl::optional<GenericFrameInfo> ScalabilityStructureL2T2KeyShift::OnEncodeDone(
103 LayerFrameConfig config) {
104 if (config.IsKeyframe()) {
105 config = KeyFrameConfig();
106 }
107
108 absl::optional<GenericFrameInfo> frame_info;
109 if (config.Id() < 0 || config.Id() >= int{ABSL_ARRAYSIZE(kDtis)}) {
110 RTC_LOG(LS_ERROR) << "Unexpected config id " << config.Id();
111 return frame_info;
112 }
113 frame_info.emplace();
114 frame_info->spatial_id = config.SpatialId();
115 frame_info->temporal_id = config.TemporalId();
116 frame_info->encoder_buffers = config.Buffers();
117 frame_info->decode_target_indications.assign(std::begin(kDtis[config.Id()]),
118 std::end(kDtis[config.Id()]));
119 if (config.IsKeyframe()) {
120 frame_info->part_of_chain = {true, true};
121 } else if (config.TemporalId() == 0) {
122 frame_info->part_of_chain = {config.SpatialId() == 0,
123 config.SpatialId() == 1};
124 } else {
125 frame_info->part_of_chain = {false, false};
126 }
127 return frame_info;
128 }
129
130 } // namespace webrtc
131