webrtc/modules/video_coding/svc/scalability_structure_full_svc.cc
Danil Chapovalov f91f8b517a Consolidate full svc structures in one source file
Keeping structures in the same file makes it clearer which are missing
and makes it easier to see if structures are consistent with one another.

No-Try: True
Bug: None
Change-Id: I4e5e6971054dd28dd326c68369ee57b6df62725e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/206987
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33256}
2021-02-13 16:17:54 +00:00

392 lines
15 KiB
C++

/*
* 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_full_svc.h"
#include <utility>
#include <vector>
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "api/transport/rtp/dependency_descriptor.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
namespace webrtc {
namespace {
enum : int { kKey, kDelta };
} // namespace
constexpr int ScalabilityStructureFullSvc::kMaxNumSpatialLayers;
constexpr int ScalabilityStructureFullSvc::kMaxNumTemporalLayers;
constexpr absl::string_view ScalabilityStructureFullSvc::kFramePatternNames[];
ScalabilityStructureFullSvc::ScalabilityStructureFullSvc(
int num_spatial_layers,
int num_temporal_layers,
ScalingFactor resolution_factor)
: num_spatial_layers_(num_spatial_layers),
num_temporal_layers_(num_temporal_layers),
resolution_factor_(resolution_factor),
active_decode_targets_(
(uint32_t{1} << (num_spatial_layers * num_temporal_layers)) - 1) {
RTC_DCHECK_LE(num_spatial_layers, kMaxNumSpatialLayers);
RTC_DCHECK_LE(num_temporal_layers, kMaxNumTemporalLayers);
}
ScalabilityStructureFullSvc::~ScalabilityStructureFullSvc() = default;
ScalabilityStructureFullSvc::StreamLayersConfig
ScalabilityStructureFullSvc::StreamConfig() const {
StreamLayersConfig result;
result.num_spatial_layers = num_spatial_layers_;
result.num_temporal_layers = num_temporal_layers_;
result.scaling_factor_num[num_spatial_layers_ - 1] = 1;
result.scaling_factor_den[num_spatial_layers_ - 1] = 1;
for (int sid = num_spatial_layers_ - 1; sid > 0; --sid) {
result.scaling_factor_num[sid - 1] =
resolution_factor_.num * result.scaling_factor_num[sid];
result.scaling_factor_den[sid - 1] =
resolution_factor_.den * result.scaling_factor_den[sid];
}
return result;
}
bool ScalabilityStructureFullSvc::TemporalLayerIsActive(int tid) const {
if (tid >= num_temporal_layers_) {
return false;
}
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
if (DecodeTargetIsActive(sid, tid)) {
return true;
}
}
return false;
}
DecodeTargetIndication ScalabilityStructureFullSvc::Dti(
int sid,
int tid,
const LayerFrameConfig& config) {
if (sid < config.SpatialId() || tid < config.TemporalId()) {
return DecodeTargetIndication::kNotPresent;
}
if (sid == config.SpatialId()) {
if (tid == 0) {
RTC_DCHECK_EQ(config.TemporalId(), 0);
return DecodeTargetIndication::kSwitch;
}
if (tid == config.TemporalId()) {
return DecodeTargetIndication::kDiscardable;
}
if (tid > config.TemporalId()) {
RTC_DCHECK_GT(tid, config.TemporalId());
return DecodeTargetIndication::kSwitch;
}
}
RTC_DCHECK_GT(sid, config.SpatialId());
RTC_DCHECK_GE(tid, config.TemporalId());
if (config.IsKeyframe() || config.Id() == kKey) {
return DecodeTargetIndication::kSwitch;
}
return DecodeTargetIndication::kRequired;
}
ScalabilityStructureFullSvc::FramePattern
ScalabilityStructureFullSvc::NextPattern() const {
switch (last_pattern_) {
case kNone:
case kDeltaT2B:
return kDeltaT0;
case kDeltaT2A:
if (TemporalLayerIsActive(1)) {
return kDeltaT1;
}
return kDeltaT0;
case kDeltaT1:
if (TemporalLayerIsActive(2)) {
return kDeltaT2B;
}
return kDeltaT0;
case kDeltaT0:
if (TemporalLayerIsActive(2)) {
return kDeltaT2A;
}
if (TemporalLayerIsActive(1)) {
return kDeltaT1;
}
return kDeltaT0;
}
}
std::vector<ScalableVideoController::LayerFrameConfig>
ScalabilityStructureFullSvc::NextFrameConfig(bool restart) {
std::vector<LayerFrameConfig> configs;
if (active_decode_targets_.none()) {
last_pattern_ = kNone;
return configs;
}
configs.reserve(num_spatial_layers_);
if (last_pattern_ == kNone || restart) {
can_reference_t0_frame_for_spatial_id_.reset();
last_pattern_ = kNone;
}
FramePattern current_pattern = NextPattern();
absl::optional<int> spatial_dependency_buffer_id;
switch (current_pattern) {
case kDeltaT0:
// Disallow temporal references cross T0 on higher temporal layers.
can_reference_t1_frame_for_spatial_id_.reset();
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
if (!DecodeTargetIsActive(sid, /*tid=*/0)) {
// Next frame from the spatial layer `sid` shouldn't depend on
// potentially old previous frame from the spatial layer `sid`.
can_reference_t0_frame_for_spatial_id_.reset(sid);
continue;
}
configs.emplace_back();
ScalableVideoController::LayerFrameConfig& config = configs.back();
config.Id(last_pattern_ == kNone ? kKey : kDelta).S(sid).T(0);
if (spatial_dependency_buffer_id) {
config.Reference(*spatial_dependency_buffer_id);
} else if (last_pattern_ == kNone) {
config.Keyframe();
}
if (can_reference_t0_frame_for_spatial_id_[sid]) {
config.ReferenceAndUpdate(BufferIndex(sid, /*tid=*/0));
} else {
// TODO(bugs.webrtc.org/11999): Propagate chain restart on delta frame
// to ChainDiffCalculator
config.Update(BufferIndex(sid, /*tid=*/0));
}
can_reference_t0_frame_for_spatial_id_.set(sid);
spatial_dependency_buffer_id = BufferIndex(sid, /*tid=*/0);
}
break;
case kDeltaT1:
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
if (!DecodeTargetIsActive(sid, /*tid=*/1) ||
!can_reference_t0_frame_for_spatial_id_[sid]) {
continue;
}
configs.emplace_back();
ScalableVideoController::LayerFrameConfig& config = configs.back();
config.Id(kDelta).S(sid).T(1);
// Temporal reference.
config.Reference(BufferIndex(sid, /*tid=*/0));
// Spatial reference unless this is the lowest active spatial layer.
if (spatial_dependency_buffer_id) {
config.Reference(*spatial_dependency_buffer_id);
}
// No frame reference top layer frame, so no need save it into a buffer.
if (num_temporal_layers_ > 2 || sid < num_spatial_layers_ - 1) {
config.Update(BufferIndex(sid, /*tid=*/1));
}
spatial_dependency_buffer_id = BufferIndex(sid, /*tid=*/1);
}
break;
case kDeltaT2A:
case kDeltaT2B:
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
if (!DecodeTargetIsActive(sid, /*tid=*/2) ||
!can_reference_t0_frame_for_spatial_id_[sid]) {
continue;
}
configs.emplace_back();
ScalableVideoController::LayerFrameConfig& config = configs.back();
config.Id(kDelta).S(sid).T(2);
// Temporal reference.
if (current_pattern == kDeltaT2B &&
can_reference_t1_frame_for_spatial_id_[sid]) {
config.Reference(BufferIndex(sid, /*tid=*/1));
} else {
config.Reference(BufferIndex(sid, /*tid=*/0));
}
// Spatial reference unless this is the lowest active spatial layer.
if (spatial_dependency_buffer_id) {
config.Reference(*spatial_dependency_buffer_id);
}
// No frame reference top layer frame, so no need save it into a buffer.
if (sid < num_spatial_layers_ - 1) {
config.Update(BufferIndex(sid, /*tid=*/2));
}
spatial_dependency_buffer_id = BufferIndex(sid, /*tid=*/2);
}
break;
case kNone:
RTC_NOTREACHED();
break;
}
if (configs.empty() && !restart) {
RTC_LOG(LS_WARNING) << "Failed to generate configuration for L"
<< num_spatial_layers_ << "T" << num_temporal_layers_
<< " with active decode targets "
<< active_decode_targets_.to_string('-').substr(
active_decode_targets_.size() -
num_spatial_layers_ * num_temporal_layers_)
<< " and transition from "
<< kFramePatternNames[last_pattern_] << " to "
<< kFramePatternNames[current_pattern]
<< ". Resetting.";
return NextFrameConfig(/*restart=*/true);
}
last_pattern_ = current_pattern;
return configs;
}
GenericFrameInfo ScalabilityStructureFullSvc::OnEncodeDone(
const LayerFrameConfig& config) {
if (config.TemporalId() == 1) {
can_reference_t1_frame_for_spatial_id_.set(config.SpatialId());
}
GenericFrameInfo frame_info;
frame_info.spatial_id = config.SpatialId();
frame_info.temporal_id = config.TemporalId();
frame_info.encoder_buffers = config.Buffers();
frame_info.decode_target_indications.reserve(num_spatial_layers_ *
num_temporal_layers_);
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
for (int tid = 0; tid < num_temporal_layers_; ++tid) {
frame_info.decode_target_indications.push_back(Dti(sid, tid, config));
}
}
if (config.TemporalId() == 0) {
frame_info.part_of_chain.resize(num_spatial_layers_);
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
frame_info.part_of_chain[sid] = config.SpatialId() <= sid;
}
} else {
frame_info.part_of_chain.assign(num_spatial_layers_, false);
}
frame_info.active_decode_targets = active_decode_targets_;
return frame_info;
}
void ScalabilityStructureFullSvc::OnRatesUpdated(
const VideoBitrateAllocation& bitrates) {
for (int sid = 0; sid < num_spatial_layers_; ++sid) {
// Enable/disable spatial layers independetely.
bool active = true;
for (int tid = 0; tid < num_temporal_layers_; ++tid) {
// To enable temporal layer, require bitrates for lower temporal layers.
active = active && bitrates.GetBitrate(sid, tid) > 0;
SetDecodeTargetIsActive(sid, tid, active);
}
}
}
FrameDependencyStructure ScalabilityStructureL1T2::DependencyStructure() const {
FrameDependencyStructure structure;
structure.num_decode_targets = 2;
structure.num_chains = 1;
structure.decode_target_protected_by_chain = {0, 0};
structure.templates.resize(3);
structure.templates[0].T(0).Dtis("SS").ChainDiffs({0});
structure.templates[1].T(0).Dtis("SS").ChainDiffs({2}).FrameDiffs({2});
structure.templates[2].T(1).Dtis("-D").ChainDiffs({1}).FrameDiffs({1});
return structure;
}
FrameDependencyStructure ScalabilityStructureL1T3::DependencyStructure() const {
FrameDependencyStructure structure;
structure.num_decode_targets = 3;
structure.num_chains = 1;
structure.decode_target_protected_by_chain = {0, 0, 0};
structure.templates.resize(5);
structure.templates[0].T(0).Dtis("SSS").ChainDiffs({0});
structure.templates[1].T(0).Dtis("SSS").ChainDiffs({4}).FrameDiffs({4});
structure.templates[2].T(1).Dtis("-DS").ChainDiffs({2}).FrameDiffs({2});
structure.templates[3].T(2).Dtis("--D").ChainDiffs({1}).FrameDiffs({1});
structure.templates[4].T(2).Dtis("--D").ChainDiffs({3}).FrameDiffs({1});
return structure;
}
FrameDependencyStructure ScalabilityStructureL2T1::DependencyStructure() const {
FrameDependencyStructure structure;
structure.num_decode_targets = 2;
structure.num_chains = 2;
structure.decode_target_protected_by_chain = {0, 1};
structure.templates.resize(4);
structure.templates[0].S(0).Dtis("SR").ChainDiffs({2, 1}).FrameDiffs({2});
structure.templates[1].S(0).Dtis("SS").ChainDiffs({0, 0});
structure.templates[2].S(1).Dtis("-S").ChainDiffs({1, 1}).FrameDiffs({2, 1});
structure.templates[3].S(1).Dtis("-S").ChainDiffs({1, 1}).FrameDiffs({1});
return structure;
}
FrameDependencyStructure ScalabilityStructureL2T2::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(6);
auto& templates = structure.templates;
templates[0].S(0).T(0).Dtis("SSSS").ChainDiffs({0, 0});
templates[1].S(0).T(0).Dtis("SSRR").ChainDiffs({4, 3}).FrameDiffs({4});
templates[2].S(0).T(1).Dtis("-D-R").ChainDiffs({2, 1}).FrameDiffs({2});
templates[3].S(1).T(0).Dtis("--SS").ChainDiffs({1, 1}).FrameDiffs({1});
templates[4].S(1).T(0).Dtis("--SS").ChainDiffs({1, 1}).FrameDiffs({4, 1});
templates[5].S(1).T(1).Dtis("---D").ChainDiffs({3, 2}).FrameDiffs({2, 1});
return structure;
}
FrameDependencyStructure ScalabilityStructureL3T1::DependencyStructure() const {
FrameDependencyStructure structure;
structure.num_decode_targets = 3;
structure.num_chains = 3;
structure.decode_target_protected_by_chain = {0, 1, 2};
auto& templates = structure.templates;
templates.resize(6);
templates[0].S(0).Dtis("SRR").ChainDiffs({3, 2, 1}).FrameDiffs({3});
templates[1].S(0).Dtis("SSS").ChainDiffs({0, 0, 0});
templates[2].S(1).Dtis("-SR").ChainDiffs({1, 1, 1}).FrameDiffs({3, 1});
templates[3].S(1).Dtis("-SS").ChainDiffs({1, 1, 1}).FrameDiffs({1});
templates[4].S(2).Dtis("--S").ChainDiffs({2, 1, 1}).FrameDiffs({3, 1});
templates[5].S(2).Dtis("--S").ChainDiffs({2, 1, 1}).FrameDiffs({1});
return structure;
}
FrameDependencyStructure ScalabilityStructureL3T3::DependencyStructure() const {
FrameDependencyStructure structure;
structure.num_decode_targets = 9;
structure.num_chains = 3;
structure.decode_target_protected_by_chain = {0, 0, 0, 1, 1, 1, 2, 2, 2};
auto& t = structure.templates;
t.resize(15);
// Templates are shown in the order frames following them appear in the
// stream, but in `structure.templates` array templates are sorted by
// (`spatial_id`, `temporal_id`) since that is a dependency descriptor
// requirement. Indexes are written in hex for nicer alignment.
t[0x1].S(0).T(0).Dtis("SSSSSSSSS").ChainDiffs({0, 0, 0});
t[0x6].S(1).T(0).Dtis("---SSSSSS").ChainDiffs({1, 1, 1}).FrameDiffs({1});
t[0xB].S(2).T(0).Dtis("------SSS").ChainDiffs({2, 1, 1}).FrameDiffs({1});
t[0x3].S(0).T(2).Dtis("--D--R--R").ChainDiffs({3, 2, 1}).FrameDiffs({3});
t[0x8].S(1).T(2).Dtis("-----D--R").ChainDiffs({4, 3, 2}).FrameDiffs({3, 1});
t[0xD].S(2).T(2).Dtis("--------D").ChainDiffs({5, 4, 3}).FrameDiffs({3, 1});
t[0x2].S(0).T(1).Dtis("-DS-RR-RR").ChainDiffs({6, 5, 4}).FrameDiffs({6});
t[0x7].S(1).T(1).Dtis("----DS-RR").ChainDiffs({7, 6, 5}).FrameDiffs({6, 1});
t[0xC].S(2).T(1).Dtis("-------DS").ChainDiffs({8, 7, 6}).FrameDiffs({6, 1});
t[0x4].S(0).T(2).Dtis("--D--R--R").ChainDiffs({9, 8, 7}).FrameDiffs({3});
t[0x9].S(1).T(2).Dtis("-----D--R").ChainDiffs({10, 9, 8}).FrameDiffs({3, 1});
t[0xE].S(2).T(2).Dtis("--------D").ChainDiffs({11, 10, 9}).FrameDiffs({3, 1});
t[0x0].S(0).T(0).Dtis("SSSRRRRRR").ChainDiffs({12, 11, 10}).FrameDiffs({12});
t[0x5].S(1).T(0).Dtis("---SSSRRR").ChainDiffs({1, 1, 1}).FrameDiffs({12, 1});
t[0xA].S(2).T(0).Dtis("------SSS").ChainDiffs({2, 1, 1}).FrameDiffs({12, 1});
return structure;
}
} // namespace webrtc