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Support layer skipping in L3T1 scalability structure

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Bug: webrtc:11999
Change-Id: Id60d28cf54e35b23f5da0f05bb94c1d9dcc356b6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/185806
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32269}
This commit is contained in:
Danil Chapovalov
2020-09-30 18:25:11 +02:00
committed by Commit Bot
parent 281fb1ed7b
commit b3a83ba8a4
3 changed files with 81 additions and 34 deletions
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101
modules/video_coding/codecs/av1/scalability_structure_l3t1.cc
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@ -24,22 +24,27 @@ constexpr auto kNotPresent = DecodeTargetIndication::kNotPresent;
constexpr auto kSwitch = DecodeTargetIndication::kSwitch;
constexpr auto kRequired = DecodeTargetIndication::kRequired;
constexpr DecodeTargetIndication kDtis[5][3] = {
{kSwitch, kSwitch, kSwitch}, // Key, S0
{kNotPresent, kSwitch, kSwitch}, // Key, S1
{kNotPresent, kNotPresent, kSwitch}, // Key and Delta, S2
{kSwitch, kRequired, kRequired}, // Delta, S0
{kNotPresent, kSwitch, kRequired}, // Delta, S1
constexpr DecodeTargetIndication kKeyFrameDtis[3][3] = {
{kSwitch, kSwitch, kSwitch}, // S0
{kNotPresent, kSwitch, kSwitch}, // S1
{kNotPresent, kNotPresent, kSwitch}, // S2
};
constexpr DecodeTargetIndication kDeltaFrameDtis[3][3] = {
{kSwitch, kRequired, kRequired}, // S0
{kNotPresent, kSwitch, kRequired}, // S1
{kNotPresent, kNotPresent, kSwitch}, // S2
};
} // namespace
constexpr int ScalabilityStructureL3T1::kNumSpatialLayers;
ScalabilityStructureL3T1::~ScalabilityStructureL3T1() = default;
ScalableVideoController::StreamLayersConfig
ScalabilityStructureL3T1::StreamConfig() const {
StreamLayersConfig result;
result.num_spatial_layers = 3;
result.num_spatial_layers = kNumSpatialLayers;
result.num_temporal_layers = 1;
result.scaling_factor_num[0] = 1;
result.scaling_factor_den[0] = 4;
@ -50,8 +55,8 @@ ScalabilityStructureL3T1::StreamConfig() const {
FrameDependencyStructure ScalabilityStructureL3T1::DependencyStructure() const {
FrameDependencyStructure structure;
structure.num_decode_targets = 3;
structure.num_chains = 3;
structure.num_decode_targets = kNumSpatialLayers;
structure.num_chains = kNumSpatialLayers;
structure.decode_target_protected_by_chain = {0, 1, 2};
auto& templates = structure.templates;
templates.resize(6);
@ -66,47 +71,79 @@ FrameDependencyStructure ScalabilityStructureL3T1::DependencyStructure() const {
std::vector<ScalableVideoController::LayerFrameConfig>
ScalabilityStructureL3T1::NextFrameConfig(bool restart) {
std::vector<LayerFrameConfig> config(3);
std::vector<LayerFrameConfig> configs;
configs.reserve(kNumSpatialLayers);
// Buffer i keeps latest frame for spatial layer i
if (restart || keyframe_) {
config[0].Id(0).S(0).Keyframe().Update(0);
config[1].Id(1).S(1).Update(1).Reference(0);
config[2].Id(2).S(2).Update(2).Reference(1);
keyframe_ = false;
} else {
config[0].Id(3).S(0).ReferenceAndUpdate(0);
config[1].Id(4).S(1).ReferenceAndUpdate(1).Reference(0);
config[2].Id(2).S(2).ReferenceAndUpdate(2).Reference(1);
if (next_pattern_ == kKeyFrame || restart) {
for (int sid = 0; sid < kNumSpatialLayers; ++sid) {
use_temporal_dependency_[sid] = false;
}
next_pattern_ = kKeyFrame;
}
return config;
absl::optional<int> spatial_dependency_buffer_id;
for (int sid = 0; sid < kNumSpatialLayers; ++sid) {
if (!active_decode_targets_[sid]) {
// Next frame from the spatial layer `sid` shouldn't depend on potentially
// very old previous frame from the spatial layer `sid`.
use_temporal_dependency_[sid] = false;
continue;
}
configs.emplace_back();
ScalableVideoController::LayerFrameConfig& config = configs.back().S(sid);
config.Id(next_pattern_);
if (spatial_dependency_buffer_id) {
config.Reference(*spatial_dependency_buffer_id);
} else if (next_pattern_ == kKeyFrame) {
config.Keyframe();
}
if (use_temporal_dependency_[sid]) {
config.ReferenceAndUpdate(sid);
} else {
// TODO(bugs.webrtc.org/11999): Propagate chain restart on delta frame to
// ChainDiffCalculator
config.Update(sid);
}
spatial_dependency_buffer_id = sid;
use_temporal_dependency_[sid] = true;
}
next_pattern_ = kDeltaFrame;
return configs;
}
absl::optional<GenericFrameInfo> ScalabilityStructureL3T1::OnEncodeDone(
LayerFrameConfig config) {
absl::optional<GenericFrameInfo> frame_info;
if (config.IsKeyframe() && config.Id() != 0) {
// Encoder generated a key frame without asking to.
if (config.SpatialId() > 0) {
RTC_LOG(LS_WARNING) << "Unexpected spatial id " << config.SpatialId()
<< " for key frame.";
}
config = LayerFrameConfig().Id(0).S(0).Keyframe().Update(0);
}
const auto& dtis = (config.IsKeyframe() || config.Id() == kKeyFrame)
? kKeyFrameDtis
: kDeltaFrameDtis;
if (config.Id() < 0 || config.Id() >= int{ABSL_ARRAYSIZE(kDtis)}) {
RTC_LOG(LS_ERROR) << "Unexpected config id " << config.Id();
if (config.SpatialId() < 0 ||
config.SpatialId() >= int{ABSL_ARRAYSIZE(dtis)}) {
RTC_LOG(LS_ERROR) << "Unexpected layer frame config id " << config.Id()
<< ", spatial id: " << config.SpatialId();
return frame_info;
}
frame_info.emplace();
frame_info->spatial_id = config.SpatialId();
frame_info->temporal_id = config.TemporalId();
frame_info->encoder_buffers = config.Buffers();
frame_info->decode_target_indications.assign(std::begin(kDtis[config.Id()]),
std::end(kDtis[config.Id()]));
frame_info->decode_target_indications.assign(
std::begin(dtis[config.SpatialId()]), std::end(dtis[config.SpatialId()]));
frame_info->part_of_chain = {config.SpatialId() == 0, config.SpatialId() <= 1,
true};
frame_info->active_decode_targets = active_decode_targets_;
return frame_info;
}
void ScalabilityStructureL3T1::OnRatesUpdated(
const VideoBitrateAllocation& bitrates) {
for (int sid = 0; sid < kNumSpatialLayers; ++sid) {
active_decode_targets_.set(sid, bitrates.GetBitrate(sid, 0) > 0);
}
}
} // namespace webrtc

11
modules/video_coding/codecs/av1/scalability_structure_l3t1.h
View File

@ -35,9 +35,18 @@ class ScalabilityStructureL3T1 : public ScalableVideoController {
std::vector<LayerFrameConfig> NextFrameConfig(bool restart) override;
absl::optional<GenericFrameInfo> OnEncodeDone(
LayerFrameConfig config) override;
void OnRatesUpdated(const VideoBitrateAllocation& bitrates) override;
private:
bool keyframe_ = true;
enum FramePattern {
kKeyFrame,
kDeltaFrame,
};
static constexpr int kNumSpatialLayers = 3;
FramePattern next_pattern_ = kKeyFrame;
bool use_temporal_dependency_[kNumSpatialLayers] = {false, false, false};
std::bitset<32> active_decode_targets_ = 0b111;
};
} // namespace webrtc

3
modules/video_coding/codecs/av1/scalability_structure_unittest.cc
View File

@ -347,7 +347,8 @@ INSTANTIATE_TEST_SUITE_P(
INSTANTIATE_TEST_SUITE_P(Svc,
ScalabilityStructureSetRatesTest,
Values(SvcTestParam{"L1T2",
/*num_temporal_units=*/4}),
/*num_temporal_units=*/4},
SvcTestParam{"L3T1", /*num_temporal_units=*/3}),
[](const testing::TestParamInfo<SvcTestParam>& info) {
return info.param.name;
});