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_l2t1.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 kSwitch = DecodeTargetIndication::kSwitch;
25 constexpr auto kRequired = DecodeTargetIndication::kRequired;
26
27 constexpr DecodeTargetIndication kDtis[4][2] = {
28 {kSwitch, kSwitch}, // Key, S0
29 {kNotPresent, kSwitch}, // Key, S1
30 {kSwitch, kRequired}, // Delta, S0
31 {kNotPresent, kRequired}, // Delta, S1
32 };
33
34 } // namespace
35
36 ScalabilityStructureL2T1::~ScalabilityStructureL2T1() = default;
37
38 ScalableVideoController::StreamLayersConfig
StreamConfig() const39 ScalabilityStructureL2T1::StreamConfig() const {
40 StreamLayersConfig result;
41 result.num_spatial_layers = 2;
42 result.num_temporal_layers = 1;
43 result.scaling_factor_num[0] = 1;
44 result.scaling_factor_den[0] = 2;
45 return result;
46 }
47
DependencyStructure() const48 FrameDependencyStructure ScalabilityStructureL2T1::DependencyStructure() const {
49 FrameDependencyStructure structure;
50 structure.num_decode_targets = 2;
51 structure.num_chains = 2;
52 structure.decode_target_protected_by_chain = {0, 1};
53 structure.templates.resize(4);
54 structure.templates[0].S(0).Dtis("SR").ChainDiffs({2, 1}).FrameDiffs({2});
55 structure.templates[1].S(0).Dtis("SS").ChainDiffs({0, 0});
56 structure.templates[2].S(1).Dtis("-R").ChainDiffs({1, 1}).FrameDiffs({2, 1});
57 structure.templates[3].S(1).Dtis("-S").ChainDiffs({1, 1}).FrameDiffs({1});
58 return structure;
59 }
60
61 ScalableVideoController::LayerFrameConfig
KeyFrameConfig() const62 ScalabilityStructureL2T1::KeyFrameConfig() const {
63 return LayerFrameConfig().Id(0).S(0).Keyframe().Update(0);
64 }
65
66 std::vector<ScalableVideoController::LayerFrameConfig>
NextFrameConfig(bool restart)67 ScalabilityStructureL2T1::NextFrameConfig(bool restart) {
68 std::vector<LayerFrameConfig> result(2);
69 // Buffer0 keeps latest S0 frame, Buffer1 keeps latest S1 frame.
70 if (restart || keyframe_) {
71 result[0] = KeyFrameConfig();
72 result[1].Id(1).S(1).Reference(0).Update(1);
73 keyframe_ = false;
74 } else {
75 result[0].Id(2).S(0).ReferenceAndUpdate(0);
76 result[1].Id(3).S(1).Reference(0).ReferenceAndUpdate(1);
77 }
78 return result;
79 }
80
OnEncodeDone(LayerFrameConfig config)81 absl::optional<GenericFrameInfo> ScalabilityStructureL2T1::OnEncodeDone(
82 LayerFrameConfig config) {
83 absl::optional<GenericFrameInfo> frame_info;
84 if (config.IsKeyframe()) {
85 config = KeyFrameConfig();
86 }
87
88 if (config.Id() < 0 || config.Id() >= int{ABSL_ARRAYSIZE(kDtis)}) {
89 RTC_LOG(LS_ERROR) << "Unexpected config id " << config.Id();
90 return frame_info;
91 }
92 frame_info.emplace();
93 frame_info->spatial_id = config.SpatialId();
94 frame_info->temporal_id = config.TemporalId();
95 frame_info->encoder_buffers = std::move(config.Buffers());
96 frame_info->decode_target_indications.assign(std::begin(kDtis[config.Id()]),
97 std::end(kDtis[config.Id()]));
98 frame_info->part_of_chain = {config.SpatialId() == 0, true};
99 return frame_info;
100 }
101
102 } // namespace webrtc
103