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webrtc / src / 93734c342a1eea60edd424f1ed4539e7b417ab02 / . / video / video_stream_encoder.cc
blob: b4b5af556df417a4c3a29672da9b4cc9b2969fa9 [file] [log] [blame]
/*
* Copyright (c) 2012 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 "video/video_stream_encoder.h"
#include <algorithm>
#include <limits>
#include <numeric>
#include <utility>
#include "absl/memory/memory.h"
#include "api/video/encoded_image.h"
#include "api/video/i420_buffer.h"
#include "api/video/video_bitrate_allocator_factory.h"
#include "modules/video_coding/codecs/vp9/svc_rate_allocator.h"
#include "modules/video_coding/include/video_codec_initializer.h"
#include "modules/video_coding/include/video_coding.h"
#include "modules/video_coding/utility/default_video_bitrate_allocator.h"
#include "rtc_base/arraysize.h"
#include "rtc_base/checks.h"
#include "rtc_base/experiments/quality_scaling_experiment.h"
#include "rtc_base/location.h"
#include "rtc_base/logging.h"
#include "rtc_base/strings/string_builder.h"
#include "rtc_base/system/fallthrough.h"
#include "rtc_base/time_utils.h"
#include "rtc_base/trace_event.h"
#include "system_wrappers/include/field_trial.h"
#include "video/overuse_frame_detector.h"
namespace webrtc {
namespace {
// Time interval for logging frame counts.
const int64_t kFrameLogIntervalMs = 60000;
const int kMinFramerateFps = 2;
// Time to keep a single cached pending frame in paused state.
const int64_t kPendingFrameTimeoutMs = 1000;
const char kInitialFramedropFieldTrial[] = "WebRTC-InitialFramedrop";
constexpr char kFrameDropperFieldTrial[] = "WebRTC-FrameDropper";
// The maximum number of frames to drop at beginning of stream
// to try and achieve desired bitrate.
const int kMaxInitialFramedrop = 4;
// When the first change in BWE above this threshold occurs,
// enable DropFrameDueToSize logic.
const float kFramedropThreshold = 0.3;
// Averaging window spanning 90 frames at default 30fps, matching old media
// optimization module defaults.
const int64_t kFrameRateAvergingWindowSizeMs = (1000 / 30) * 90;
// Initial limits for BALANCED degradation preference.
int MinFps(int pixels) {
if (pixels <= 320 * 240) {
return 7;
} else if (pixels <= 480 * 270) {
return 10;
} else if (pixels <= 640 * 480) {
return 15;
} else {
return std::numeric_limits<int>::max();
}
}
int MaxFps(int pixels) {
if (pixels <= 320 * 240) {
return 10;
} else if (pixels <= 480 * 270) {
return 15;
} else {
return std::numeric_limits<int>::max();
}
}
uint32_t abs_diff(uint32_t a, uint32_t b) {
return (a < b) ? b - a : a - b;
}
bool IsResolutionScalingEnabled(DegradationPreference degradation_preference) {
return degradation_preference == DegradationPreference::MAINTAIN_FRAMERATE ||
degradation_preference == DegradationPreference::BALANCED;
}
bool IsFramerateScalingEnabled(DegradationPreference degradation_preference) {
return degradation_preference == DegradationPreference::MAINTAIN_RESOLUTION ||
degradation_preference == DegradationPreference::BALANCED;
}
// TODO(pbos): Lower these thresholds (to closer to 100%) when we handle
// pipelining encoders better (multiple input frames before something comes
// out). This should effectively turn off CPU adaptations for systems that
// remotely cope with the load right now.
CpuOveruseOptions GetCpuOveruseOptions(
const VideoStreamEncoderSettings& settings,
bool full_overuse_time) {
CpuOveruseOptions options;
if (full_overuse_time) {
options.low_encode_usage_threshold_percent = 150;
options.high_encode_usage_threshold_percent = 200;
}
if (settings.experiment_cpu_load_estimator) {
options.filter_time_ms = 5 * rtc::kNumMillisecsPerSec;
}
return options;
}
} // namespace
// VideoSourceProxy is responsible ensuring thread safety between calls to
// VideoStreamEncoder::SetSource that will happen on libjingle's worker thread
// when a video capturer is connected to the encoder and the encoder task queue
// (encoder_queue_) where the encoder reports its VideoSinkWants.
class VideoStreamEncoder::VideoSourceProxy {
public:
explicit VideoSourceProxy(VideoStreamEncoder* video_stream_encoder)
: video_stream_encoder_(video_stream_encoder),
degradation_preference_(DegradationPreference::DISABLED),
source_(nullptr),
max_framerate_(std::numeric_limits<int>::max()) {}
void SetSource(rtc::VideoSourceInterface<VideoFrame>* source,
const DegradationPreference& degradation_preference) {
// Called on libjingle's worker thread.
RTC_DCHECK_CALLED_SEQUENTIALLY(&main_checker_);
rtc::VideoSourceInterface<VideoFrame>* old_source = nullptr;
rtc::VideoSinkWants wants;
{
rtc::CritScope lock(&crit_);
degradation_preference_ = degradation_preference;
old_source = source_;
source_ = source;
wants = GetActiveSinkWantsInternal();
}
if (old_source != source && old_source != nullptr) {
old_source->RemoveSink(video_stream_encoder_);
}
if (!source) {
return;
}
source->AddOrUpdateSink(video_stream_encoder_, wants);
}
void SetMaxFramerate(int max_framerate) {
RTC_DCHECK_GT(max_framerate, 0);
rtc::CritScope lock(&crit_);
if (max_framerate == max_framerate_)
return;
RTC_LOG(LS_INFO) << "Set max framerate: " << max_framerate;
max_framerate_ = max_framerate;
if (source_) {
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
}
}
void SetWantsRotationApplied(bool rotation_applied) {
rtc::CritScope lock(&crit_);
sink_wants_.rotation_applied = rotation_applied;
if (source_) {
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
}
}
rtc::VideoSinkWants GetActiveSinkWants() {
rtc::CritScope lock(&crit_);
return GetActiveSinkWantsInternal();
}
void ResetPixelFpsCount() {
rtc::CritScope lock(&crit_);
sink_wants_.max_pixel_count = std::numeric_limits<int>::max();
sink_wants_.target_pixel_count.reset();
sink_wants_.max_framerate_fps = std::numeric_limits<int>::max();
if (source_)
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
}
bool RequestResolutionLowerThan(int pixel_count,
int min_pixels_per_frame,
bool* min_pixels_reached) {
// Called on the encoder task queue.
rtc::CritScope lock(&crit_);
if (!source_ || !IsResolutionScalingEnabled(degradation_preference_)) {
// This can happen since |degradation_preference_| is set on libjingle's
// worker thread but the adaptation is done on the encoder task queue.
return false;
}
// The input video frame size will have a resolution less than or equal to
// |max_pixel_count| depending on how the source can scale the frame size.
const int pixels_wanted = (pixel_count * 3) / 5;
if (pixels_wanted >= sink_wants_.max_pixel_count) {
return false;
}
if (pixels_wanted < min_pixels_per_frame) {
*min_pixels_reached = true;
return false;
}
RTC_LOG(LS_INFO) << "Scaling down resolution, max pixels: "
<< pixels_wanted;
sink_wants_.max_pixel_count = pixels_wanted;
sink_wants_.target_pixel_count = absl::nullopt;
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
return true;
}
int RequestFramerateLowerThan(int fps) {
// Called on the encoder task queue.
// The input video frame rate will be scaled down to 2/3, rounding down.
int framerate_wanted = (fps * 2) / 3;
return RestrictFramerate(framerate_wanted) ? framerate_wanted : -1;
}
bool RequestHigherResolutionThan(int pixel_count) {
// Called on the encoder task queue.
rtc::CritScope lock(&crit_);
if (!source_ || !IsResolutionScalingEnabled(degradation_preference_)) {
// This can happen since |degradation_preference_| is set on libjingle's
// worker thread but the adaptation is done on the encoder task queue.
return false;
}
int max_pixels_wanted = pixel_count;
if (max_pixels_wanted != std::numeric_limits<int>::max())
max_pixels_wanted = pixel_count * 4;
if (max_pixels_wanted <= sink_wants_.max_pixel_count)
return false;
sink_wants_.max_pixel_count = max_pixels_wanted;
if (max_pixels_wanted == std::numeric_limits<int>::max()) {
// Remove any constraints.
sink_wants_.target_pixel_count.reset();
} else {
// On step down we request at most 3/5 the pixel count of the previous
// resolution, so in order to take "one step up" we request a resolution
// as close as possible to 5/3 of the current resolution. The actual pixel
// count selected depends on the capabilities of the source. In order to
// not take a too large step up, we cap the requested pixel count to be at
// most four time the current number of pixels.
sink_wants_.target_pixel_count = (pixel_count * 5) / 3;
}
RTC_LOG(LS_INFO) << "Scaling up resolution, max pixels: "
<< max_pixels_wanted;
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
return true;
}
// Request upgrade in framerate. Returns the new requested frame, or -1 if
// no change requested. Note that maxint may be returned if limits due to
// adaptation requests are removed completely. In that case, consider
// |max_framerate_| to be the current limit (assuming the capturer complies).
int RequestHigherFramerateThan(int fps) {
// Called on the encoder task queue.
// The input frame rate will be scaled up to the last step, with rounding.
int framerate_wanted = fps;
if (fps != std::numeric_limits<int>::max())
framerate_wanted = (fps * 3) / 2;
return IncreaseFramerate(framerate_wanted) ? framerate_wanted : -1;
}
bool RestrictFramerate(int fps) {
// Called on the encoder task queue.
rtc::CritScope lock(&crit_);
if (!source_ || !IsFramerateScalingEnabled(degradation_preference_))
return false;
const int fps_wanted = std::max(kMinFramerateFps, fps);
if (fps_wanted >= sink_wants_.max_framerate_fps)
return false;
RTC_LOG(LS_INFO) << "Scaling down framerate: " << fps_wanted;
sink_wants_.max_framerate_fps = fps_wanted;
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
return true;
}
bool IncreaseFramerate(int fps) {
// Called on the encoder task queue.
rtc::CritScope lock(&crit_);
if (!source_ || !IsFramerateScalingEnabled(degradation_preference_))
return false;
const int fps_wanted = std::max(kMinFramerateFps, fps);
if (fps_wanted <= sink_wants_.max_framerate_fps)
return false;
RTC_LOG(LS_INFO) << "Scaling up framerate: " << fps_wanted;
sink_wants_.max_framerate_fps = fps_wanted;
source_->AddOrUpdateSink(video_stream_encoder_,
GetActiveSinkWantsInternal());
return true;
}
private:
rtc::VideoSinkWants GetActiveSinkWantsInternal()
RTC_EXCLUSIVE_LOCKS_REQUIRED(&crit_) {
rtc::VideoSinkWants wants = sink_wants_;
// Clear any constraints from the current sink wants that don't apply to
// the used degradation_preference.
switch (degradation_preference_) {
case DegradationPreference::BALANCED:
break;
case DegradationPreference::MAINTAIN_FRAMERATE:
wants.max_framerate_fps = std::numeric_limits<int>::max();
break;
case DegradationPreference::MAINTAIN_RESOLUTION:
wants.max_pixel_count = std::numeric_limits<int>::max();
wants.target_pixel_count.reset();
break;
case DegradationPreference::DISABLED:
wants.max_pixel_count = std::numeric_limits<int>::max();
wants.target_pixel_count.reset();
wants.max_framerate_fps = std::numeric_limits<int>::max();
}
// Limit to configured max framerate.
wants.max_framerate_fps = std::min(max_framerate_, wants.max_framerate_fps);
wants.partial_frames = true;
return wants;
}
rtc::CriticalSection crit_;
rtc::SequencedTaskChecker main_checker_;
VideoStreamEncoder* const video_stream_encoder_;
rtc::VideoSinkWants sink_wants_ RTC_GUARDED_BY(&crit_);
DegradationPreference degradation_preference_ RTC_GUARDED_BY(&crit_);
rtc::VideoSourceInterface<VideoFrame>* source_ RTC_GUARDED_BY(&crit_);
int max_framerate_ RTC_GUARDED_BY(&crit_);
RTC_DISALLOW_COPY_AND_ASSIGN(VideoSourceProxy);
};
VideoStreamEncoder::VideoStreamEncoder(
uint32_t number_of_cores,
VideoStreamEncoderObserver* encoder_stats_observer,
const VideoStreamEncoderSettings& settings,
std::unique_ptr<OveruseFrameDetector> overuse_detector)
: shutdown_event_(true /* manual_reset */, false),
number_of_cores_(number_of_cores),
initial_framedrop_(0),
initial_framedrop_on_bwe_enabled_(
webrtc::field_trial::IsEnabled(kInitialFramedropFieldTrial)),
quality_scaling_experiment_enabled_(QualityScalingExperiment::Enabled()),
source_proxy_(new VideoSourceProxy(this)),
sink_(nullptr),
settings_(settings),
video_sender_(Clock::GetRealTimeClock(), this),
overuse_detector_(std::move(overuse_detector)),
encoder_stats_observer_(encoder_stats_observer),
max_framerate_(-1),
pending_encoder_reconfiguration_(false),
pending_encoder_creation_(false),
crop_width_(0),
crop_height_(0),
encoder_start_bitrate_bps_(0),
max_data_payload_length_(0),
last_observed_bitrate_bps_(0),
encoder_paused_and_dropped_frame_(false),
clock_(Clock::GetRealTimeClock()),
degradation_preference_(DegradationPreference::DISABLED),
posted_frames_waiting_for_encode_(0),
last_captured_timestamp_(0),
delta_ntp_internal_ms_(clock_->CurrentNtpInMilliseconds() -
clock_->TimeInMilliseconds()),
last_frame_log_ms_(clock_->TimeInMilliseconds()),
captured_frame_count_(0),
dropped_frame_count_(0),
pending_frame_post_time_us_(0),
bitrate_observer_(nullptr),
force_disable_frame_dropper_(false),
input_framerate_(kFrameRateAvergingWindowSizeMs, 1000),
pending_frame_drops_(0),
encoder_queue_("EncoderQueue") {
RTC_DCHECK(encoder_stats_observer);
RTC_DCHECK(overuse_detector_);
}
VideoStreamEncoder::~VideoStreamEncoder() {
RTC_DCHECK_RUN_ON(&thread_checker_);
RTC_DCHECK(shutdown_event_.Wait(0))
<< "Must call ::Stop() before destruction.";
}
void VideoStreamEncoder::Stop() {
RTC_DCHECK_RUN_ON(&thread_checker_);
source_proxy_->SetSource(nullptr, DegradationPreference());
encoder_queue_.PostTask([this] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
overuse_detector_->StopCheckForOveruse();
rate_allocator_.reset();
bitrate_observer_ = nullptr;
video_sender_.RegisterExternalEncoder(nullptr, false);
quality_scaler_ = nullptr;
shutdown_event_.Set();
});
shutdown_event_.Wait(rtc::Event::kForever);
}
void VideoStreamEncoder::SetBitrateAllocationObserver(
VideoBitrateAllocationObserver* bitrate_observer) {
RTC_DCHECK_RUN_ON(&thread_checker_);
encoder_queue_.PostTask([this, bitrate_observer] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
RTC_DCHECK(!bitrate_observer_);
bitrate_observer_ = bitrate_observer;
});
}
void VideoStreamEncoder::SetSource(
rtc::VideoSourceInterface<VideoFrame>* source,
const DegradationPreference& degradation_preference) {
RTC_DCHECK_RUN_ON(&thread_checker_);
source_proxy_->SetSource(source, degradation_preference);
encoder_queue_.PostTask([this, degradation_preference] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (degradation_preference_ != degradation_preference) {
// Reset adaptation state, so that we're not tricked into thinking there's
// an already pending request of the same type.
last_adaptation_request_.reset();
if (degradation_preference == DegradationPreference::BALANCED ||
degradation_preference_ == DegradationPreference::BALANCED) {
// TODO(asapersson): Consider removing |adapt_counters_| map and use one
// AdaptCounter for all modes.
source_proxy_->ResetPixelFpsCount();
adapt_counters_.clear();
}
}
degradation_preference_ = degradation_preference;
if (encoder_)
ConfigureQualityScaler();
if (!IsFramerateScalingEnabled(degradation_preference) &&
max_framerate_ != -1) {
// If frame rate scaling is no longer allowed, remove any potential
// allowance for longer frame intervals.
overuse_detector_->OnTargetFramerateUpdated(max_framerate_);
}
});
}
void VideoStreamEncoder::SetSink(EncoderSink* sink, bool rotation_applied) {
source_proxy_->SetWantsRotationApplied(rotation_applied);
encoder_queue_.PostTask([this, sink] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
sink_ = sink;
});
}
void VideoStreamEncoder::SetStartBitrate(int start_bitrate_bps) {
encoder_queue_.PostTask([this, start_bitrate_bps] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
encoder_start_bitrate_bps_ = start_bitrate_bps;
});
}
void VideoStreamEncoder::ConfigureEncoder(VideoEncoderConfig config,
size_t max_data_payload_length) {
// TODO(srte): This struct should be replaced by a lambda with move capture
// when C++14 lambda is allowed.
struct ConfigureEncoderTask {
void operator()() {
encoder->ConfigureEncoderOnTaskQueue(std::move(config),
max_data_payload_length);
}
VideoStreamEncoder* encoder;
VideoEncoderConfig config;
size_t max_data_payload_length;
};
encoder_queue_.PostTask(
ConfigureEncoderTask{this, std::move(config), max_data_payload_length});
}
void VideoStreamEncoder::ConfigureEncoderOnTaskQueue(
VideoEncoderConfig config,
size_t max_data_payload_length) {
RTC_DCHECK_RUN_ON(&encoder_queue_);
RTC_DCHECK(sink_);
RTC_LOG(LS_INFO) << "ConfigureEncoder requested.";
max_data_payload_length_ = max_data_payload_length;
pending_encoder_creation_ =
(!encoder_ || encoder_config_.video_format != config.video_format);
encoder_config_ = std::move(config);
pending_encoder_reconfiguration_ = true;
// Reconfigure the encoder now if the encoder has an internal source or
// if the frame resolution is known. Otherwise, the reconfiguration is
// deferred until the next frame to minimize the number of reconfigurations.
// The codec configuration depends on incoming video frame size.
if (last_frame_info_) {
ReconfigureEncoder();
} else if (settings_.encoder_factory
->QueryVideoEncoder(encoder_config_.video_format)
.has_internal_source) {
last_frame_info_ = VideoFrameInfo(176, 144, false);
ReconfigureEncoder();
}
}
// TODO(bugs.webrtc.org/8807): Currently this always does a hard
// reconfiguration, but this isn't always necessary. Add in logic to only update
// the VideoBitrateAllocator and call OnEncoderConfigurationChanged with a
// "soft" reconfiguration.
void VideoStreamEncoder::ReconfigureEncoder() {
RTC_DCHECK(pending_encoder_reconfiguration_);
std::vector<VideoStream> streams =
encoder_config_.video_stream_factory->CreateEncoderStreams(
last_frame_info_->width, last_frame_info_->height, encoder_config_);
// TODO(ilnik): If configured resolution is significantly less than provided,
// e.g. because there are not enough SSRCs for all simulcast streams,
// signal new resolutions via SinkWants to video source.
// Stream dimensions may be not equal to given because of a simulcast
// restrictions.
auto highest_stream = std::max_element(
streams.begin(), streams.end(),
[](const webrtc::VideoStream& a, const webrtc::VideoStream& b) {
return std::tie(a.width, a.height) < std::tie(b.width, b.height);
});
int highest_stream_width = static_cast<int>(highest_stream->width);
int highest_stream_height = static_cast<int>(highest_stream->height);
// Dimension may be reduced to be, e.g. divisible by 4.
RTC_CHECK_GE(last_frame_info_->width, highest_stream_width);
RTC_CHECK_GE(last_frame_info_->height, highest_stream_height);
crop_width_ = last_frame_info_->width - highest_stream_width;
crop_height_ = last_frame_info_->height - highest_stream_height;
VideoCodec codec;
if (!VideoCodecInitializer::SetupCodec(encoder_config_, streams, &codec)) {
RTC_LOG(LS_ERROR) << "Failed to create encoder configuration.";
}
rate_allocator_ =
settings_.bitrate_allocator_factory->CreateVideoBitrateAllocator(codec);
// Set min_bitrate_bps, max_bitrate_bps, and max padding bit rate for VP9.
if (encoder_config_.codec_type == kVideoCodecVP9) {
// Lower max bitrate to the level codec actually can produce.
streams[0].max_bitrate_bps = std::min<int>(
streams[0].max_bitrate_bps, SvcRateAllocator::GetMaxBitrateBps(codec));
streams[0].min_bitrate_bps = codec.spatialLayers[0].minBitrate * 1000;
// target_bitrate_bps specifies the maximum padding bitrate.
streams[0].target_bitrate_bps =
SvcRateAllocator::GetPaddingBitrateBps(codec);
}
codec.startBitrate =
std::max(encoder_start_bitrate_bps_ / 1000, codec.minBitrate);
codec.startBitrate = std::min(codec.startBitrate, codec.maxBitrate);
codec.expect_encode_from_texture = last_frame_info_->is_texture;
max_framerate_ = codec.maxFramerate;
// Inform source about max configured framerate.
int max_framerate = 0;
for (const auto& stream : streams) {
max_framerate = std::max(stream.max_framerate, max_framerate);
}
source_proxy_->SetMaxFramerate(max_framerate);
// Keep the same encoder, as long as the video_format is unchanged.
// Encoder creation block is split in two since EncoderInfo needed to start
// CPU adaptation with the correct settings should be polled after
// encoder_->InitEncode().
if (pending_encoder_creation_) {
if (encoder_) {
video_sender_.RegisterExternalEncoder(nullptr, false);
}
encoder_ = settings_.encoder_factory->CreateVideoEncoder(
encoder_config_.video_format);
// TODO(nisse): What to do if creating the encoder fails? Crash,
// or just discard incoming frames?
RTC_CHECK(encoder_);
const webrtc::VideoEncoderFactory::CodecInfo info =
settings_.encoder_factory->QueryVideoEncoder(
encoder_config_.video_format);
video_sender_.RegisterExternalEncoder(encoder_.get(),
info.has_internal_source);
}
// RegisterSendCodec implies an unconditional call to
// encoder_->InitEncode().
bool success = video_sender_.RegisterSendCodec(
&codec, number_of_cores_,
static_cast<uint32_t>(max_data_payload_length_)) == VCM_OK;
if (!success) {
RTC_LOG(LS_ERROR) << "Failed to configure encoder.";
rate_allocator_.reset();
}
if (pending_encoder_creation_) {
overuse_detector_->StopCheckForOveruse();
overuse_detector_->StartCheckForOveruse(
GetCpuOveruseOptions(
settings_, encoder_->GetEncoderInfo().is_hardware_accelerated),
this);
pending_encoder_creation_ = false;
}
int num_layers;
if (codec.codecType == kVideoCodecVP8) {
num_layers = codec.VP8()->numberOfTemporalLayers;
} else if (codec.codecType == kVideoCodecVP9) {
num_layers = codec.VP9()->numberOfTemporalLayers;
} else if (codec.codecType == kVideoCodecGeneric &&
codec.numberOfSimulcastStreams > 0) {
// This is mainly for unit testing, disabling frame dropping.
// TODO(sprang): Add a better way to disable frame dropping.
num_layers = codec.simulcastStream[0].numberOfTemporalLayers;
} else {
num_layers = 1;
}
frame_dropper_.Reset();
frame_dropper_.SetRates(codec.startBitrate, max_framerate_);
uint32_t framerate_fps = GetInputFramerateFps();
// Force-disable frame dropper if either:
// * We have screensharing with layers.
// * "WebRTC-FrameDropper" field trial is "Disabled".
force_disable_frame_dropper_ =
field_trial::IsDisabled(kFrameDropperFieldTrial) ||
(num_layers > 1 && codec.mode == VideoCodecMode::kScreensharing);
if (rate_allocator_ && last_observed_bitrate_bps_ > 0) {
// We have a new rate allocator instance and already configured target
// bitrate. Update the rate allocation and notify observsers.
VideoBitrateAllocation bitrate_allocation =
GetBitrateAllocationAndNotifyObserver(last_observed_bitrate_bps_,
framerate_fps);
video_sender_.SetChannelParameters(bitrate_allocation, framerate_fps);
}
encoder_stats_observer_->OnEncoderReconfigured(encoder_config_, streams);
pending_encoder_reconfiguration_ = false;
sink_->OnEncoderConfigurationChanged(
std::move(streams), encoder_config_.content_type,
encoder_config_.min_transmit_bitrate_bps);
// Get the current target framerate, ie the maximum framerate as specified by
// the current codec configuration, or any limit imposed by cpu adaption in
// maintain-resolution or balanced mode. This is used to make sure overuse
// detection doesn't needlessly trigger in low and/or variable framerate
// scenarios.
int target_framerate = std::min(
max_framerate_, source_proxy_->GetActiveSinkWants().max_framerate_fps);
overuse_detector_->OnTargetFramerateUpdated(target_framerate);
ConfigureQualityScaler();
}
void VideoStreamEncoder::ConfigureQualityScaler() {
RTC_DCHECK_RUN_ON(&encoder_queue_);
const auto scaling_settings = encoder_->GetEncoderInfo().scaling_settings;
const bool quality_scaling_allowed =
IsResolutionScalingEnabled(degradation_preference_) &&
scaling_settings.thresholds;
if (quality_scaling_allowed) {
if (quality_scaler_.get() == nullptr) {
// Quality scaler has not already been configured.
// Use experimental thresholds if available.
absl::optional<VideoEncoder::QpThresholds> experimental_thresholds;
if (quality_scaling_experiment_enabled_) {
experimental_thresholds = QualityScalingExperiment::GetQpThresholds(
encoder_config_.codec_type);
}
// Since the interface is non-public, absl::make_unique can't do this
// upcast.
AdaptationObserverInterface* observer = this;
quality_scaler_ = absl::make_unique<QualityScaler>(
observer, experimental_thresholds ? *experimental_thresholds
: *(scaling_settings.thresholds));
has_seen_first_significant_bwe_change_ = false;
initial_framedrop_ = 0;
}
} else {
quality_scaler_.reset(nullptr);
initial_framedrop_ = kMaxInitialFramedrop;
}
encoder_stats_observer_->OnAdaptationChanged(
VideoStreamEncoderObserver::AdaptationReason::kNone,
GetActiveCounts(kCpu), GetActiveCounts(kQuality));
}
void VideoStreamEncoder::OnFrame(const VideoFrame& video_frame) {
RTC_DCHECK_RUNS_SERIALIZED(&incoming_frame_race_checker_);
const VideoFrame::PartialFrameDescription* partial_desc =
video_frame.partial_frame_description();
VideoFrame incoming_frame = video_frame;
if (video_frame.cache_buffer_for_partial_updates()) {
VideoFrameBuffer* input_buffer = video_frame.video_frame_buffer();
if (!partial_frame_assembler_.ApplyPartialUpdate(
input_buffer, &incoming_frame, partial_desc)) {
// Can't apply new image to the cached buffer because of some error.
// Nothing sensible to encode.
// Detailed error message is already logged by |ApplyPartialUpdate()|.
return;
}
} else {
partial_frame_assembler_.Reset();
}
// Local time in webrtc time base.
int64_t current_time_us = clock_->TimeInMicroseconds();
int64_t current_time_ms = current_time_us / rtc::kNumMicrosecsPerMillisec;
// In some cases, e.g., when the frame from decoder is fed to encoder,
// the timestamp may be set to the future. As the encoding pipeline assumes
// capture time to be less than present time, we should reset the capture
// timestamps here. Otherwise there may be issues with RTP send stream.
if (incoming_frame.timestamp_us() > current_time_us)
incoming_frame.set_timestamp_us(current_time_us);
// Capture time may come from clock with an offset and drift from clock_.
int64_t capture_ntp_time_ms;
if (video_frame.ntp_time_ms() > 0) {
capture_ntp_time_ms = video_frame.ntp_time_ms();
} else if (video_frame.render_time_ms() != 0) {
capture_ntp_time_ms = video_frame.render_time_ms() + delta_ntp_internal_ms_;
} else {
capture_ntp_time_ms = current_time_ms + delta_ntp_internal_ms_;
}
incoming_frame.set_ntp_time_ms(capture_ntp_time_ms);
// Convert NTP time, in ms, to RTP timestamp.
const int kMsToRtpTimestamp = 90;
incoming_frame.set_timestamp(
kMsToRtpTimestamp * static_cast<uint32_t>(incoming_frame.ntp_time_ms()));
if (incoming_frame.ntp_time_ms() <= last_captured_timestamp_) {
// We don't allow the same capture time for two frames, drop this one.
RTC_LOG(LS_WARNING) << "Same/old NTP timestamp ("
<< incoming_frame.ntp_time_ms()
<< " <= " << last_captured_timestamp_
<< ") for incoming frame. Dropping.";
return;
}
bool log_stats = false;
if (current_time_ms - last_frame_log_ms_ > kFrameLogIntervalMs) {
last_frame_log_ms_ = current_time_ms;
log_stats = true;
}
last_captured_timestamp_ = incoming_frame.ntp_time_ms();
int64_t post_time_us = rtc::TimeMicros();
++posted_frames_waiting_for_encode_;
encoder_queue_.PostTask(
[this, incoming_frame, post_time_us, log_stats]() {
RTC_DCHECK_RUN_ON(&encoder_queue_);
encoder_stats_observer_->OnIncomingFrame(incoming_frame.width(),
incoming_frame.height());
++captured_frame_count_;
const int posted_frames_waiting_for_encode =
posted_frames_waiting_for_encode_.fetch_sub(1);
RTC_DCHECK_GT(posted_frames_waiting_for_encode, 0);
if (posted_frames_waiting_for_encode == 1) {
MaybeEncodeVideoFrame(incoming_frame, post_time_us);
} else {
// There is a newer frame in flight. Do not encode this frame.
RTC_LOG(LS_VERBOSE)
<< "Incoming frame dropped due to that the encoder is blocked.";
++dropped_frame_count_;
encoder_stats_observer_->OnFrameDropped(
VideoStreamEncoderObserver::DropReason::kEncoderQueue);
}
if (log_stats) {
RTC_LOG(LS_INFO) << "Number of frames: captured "
<< captured_frame_count_
<< ", dropped (due to encoder blocked) "
<< dropped_frame_count_ << ", interval_ms "
<< kFrameLogIntervalMs;
captured_frame_count_ = 0;
dropped_frame_count_ = 0;
}
});
}
void VideoStreamEncoder::OnDiscardedFrame() {
encoder_stats_observer_->OnFrameDropped(
VideoStreamEncoderObserver::DropReason::kSource);
}
bool VideoStreamEncoder::EncoderPaused() const {
RTC_DCHECK_RUN_ON(&encoder_queue_);
// Pause video if paused by caller or as long as the network is down or the
// pacer queue has grown too large in buffered mode.
// If the pacer queue has grown too large or the network is down,
// last_observed_bitrate_bps_ will be 0.
return last_observed_bitrate_bps_ == 0;
}
void VideoStreamEncoder::TraceFrameDropStart() {
RTC_DCHECK_RUN_ON(&encoder_queue_);
// Start trace event only on the first frame after encoder is paused.
if (!encoder_paused_and_dropped_frame_) {
TRACE_EVENT_ASYNC_BEGIN0("webrtc", "EncoderPaused", this);
}
encoder_paused_and_dropped_frame_ = true;
}
void VideoStreamEncoder::TraceFrameDropEnd() {
RTC_DCHECK_RUN_ON(&encoder_queue_);
// End trace event on first frame after encoder resumes, if frame was dropped.
if (encoder_paused_and_dropped_frame_) {
TRACE_EVENT_ASYNC_END0("webrtc", "EncoderPaused", this);
}
encoder_paused_and_dropped_frame_ = false;
}
VideoBitrateAllocation
VideoStreamEncoder::GetBitrateAllocationAndNotifyObserver(
const uint32_t target_bitrate_bps,
uint32_t framerate_fps) {
// Only call allocators if bitrate > 0 (ie, not suspended), otherwise they
// might cap the bitrate to the min bitrate configured.
VideoBitrateAllocation bitrate_allocation;
if (rate_allocator_ && target_bitrate_bps > 0) {
bitrate_allocation =
rate_allocator_->GetAllocation(target_bitrate_bps, framerate_fps);
}
if (bitrate_observer_ && bitrate_allocation.get_sum_bps() > 0) {
bitrate_observer_->OnBitrateAllocationUpdated(bitrate_allocation);
}
return bitrate_allocation;
}
uint32_t VideoStreamEncoder::GetInputFramerateFps() {
const uint32_t default_fps = max_framerate_ != -1 ? max_framerate_ : 30;
return input_framerate_.Rate(clock_->TimeInMilliseconds())
.value_or(default_fps);
}
void VideoStreamEncoder::MaybeEncodeVideoFrame(const VideoFrame& video_frame,
int64_t time_when_posted_us) {
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (!last_frame_info_ || video_frame.width() != last_frame_info_->width ||
video_frame.height() != last_frame_info_->height ||
video_frame.is_texture() != last_frame_info_->is_texture) {
pending_encoder_reconfiguration_ = true;
last_frame_info_ = VideoFrameInfo(video_frame.width(), video_frame.height(),
video_frame.is_texture());
RTC_LOG(LS_INFO) << "Video frame parameters changed: dimensions="
<< last_frame_info_->width << "x"
<< last_frame_info_->height
<< ", texture=" << last_frame_info_->is_texture << ".";
}
// We have to create then encoder before the frame drop logic,
// because the latter depends on encoder_->GetScalingSettings.
// According to the testcase
// InitialFrameDropOffWhenEncoderDisabledScaling, the return value
// from GetScalingSettings should enable or disable the frame drop.
uint32_t framerate_fps = GetInputFramerateFps();
int64_t now_ms = clock_->TimeInMilliseconds();
if (pending_encoder_reconfiguration_) {
ReconfigureEncoder();
last_parameters_update_ms_.emplace(now_ms);
} else if (!last_parameters_update_ms_ ||
now_ms - *last_parameters_update_ms_ >=
vcm::VCMProcessTimer::kDefaultProcessIntervalMs) {
video_sender_.SetChannelParameters(
GetBitrateAllocationAndNotifyObserver(last_observed_bitrate_bps_,
framerate_fps),
framerate_fps);
last_parameters_update_ms_.emplace(now_ms);
}
if (DropDueToSize(video_frame.size())) {
RTC_LOG(LS_INFO) << "Dropping frame. Too large for target bitrate.";
int count = GetConstAdaptCounter().ResolutionCount(kQuality);
AdaptDown(kQuality);
if (GetConstAdaptCounter().ResolutionCount(kQuality) > count) {
encoder_stats_observer_->OnInitialQualityResolutionAdaptDown();
}
++initial_framedrop_;
// Storing references to a native buffer risks blocking frame capture.
if (video_frame.video_frame_buffer()->type() !=
VideoFrameBuffer::Type::kNative) {
pending_frame_ = video_frame;
pending_frame_post_time_us_ = time_when_posted_us;
} else {
// Ensure that any previously stored frame is dropped.
pending_frame_.reset();
}
return;
}
initial_framedrop_ = kMaxInitialFramedrop;
if (EncoderPaused()) {
// Storing references to a native buffer risks blocking frame capture.
if (video_frame.video_frame_buffer()->type() !=
VideoFrameBuffer::Type::kNative) {
if (pending_frame_)
TraceFrameDropStart();
pending_frame_ = video_frame;
pending_frame_post_time_us_ = time_when_posted_us;
} else {
// Ensure that any previously stored frame is dropped.
pending_frame_.reset();
TraceFrameDropStart();
}
return;
}
pending_frame_.reset();
frame_dropper_.Leak(framerate_fps);
// Frame dropping is enabled iff frame dropping is not force-disabled, and
// rate controller is not trusted.
const bool frame_dropping_enabled =
!force_disable_frame_dropper_ &&
!encoder_info_.has_trusted_rate_controller;
frame_dropper_.Enable(frame_dropping_enabled);
if (frame_dropping_enabled && frame_dropper_.DropFrame()) {
RTC_LOG(LS_VERBOSE) << "Drop Frame: "
<< "target bitrate " << last_observed_bitrate_bps_
<< ", input frame rate " << framerate_fps;
OnDroppedFrame(
EncodedImageCallback::DropReason::kDroppedByMediaOptimizations);
return;
}
EncodeVideoFrame(video_frame, time_when_posted_us);
}
void VideoStreamEncoder::EncodeVideoFrame(const VideoFrame& video_frame,
int64_t time_when_posted_us) {
RTC_DCHECK_RUN_ON(&encoder_queue_);
TraceFrameDropEnd();
VideoFrame out_frame(video_frame);
// Crop frame if needed.
if (crop_width_ > 0 || crop_height_ > 0) {
int cropped_width = video_frame.width() - crop_width_;
int cropped_height = video_frame.height() - crop_height_;
rtc::scoped_refptr<I420Buffer> cropped_buffer =
I420Buffer::Create(cropped_width, cropped_height);
// TODO(ilnik): Remove scaling if cropping is too big, as it should never
// happen after SinkWants signaled correctly from ReconfigureEncoder.
if (crop_width_ < 4 && crop_height_ < 4) {
cropped_buffer->CropAndScaleFrom(
*video_frame.video_frame_buffer()->ToI420(), crop_width_ / 2,
crop_height_ / 2, cropped_width, cropped_height);
} else {
cropped_buffer->ScaleFrom(
*video_frame.video_frame_buffer()->ToI420().get());
}
out_frame = VideoFrame::Builder()
.set_video_frame_buffer(cropped_buffer)
.set_timestamp_rtp(video_frame.timestamp())
.set_timestamp_ms(video_frame.render_time_ms())
.set_rotation(video_frame.rotation())
.set_id(video_frame.id())
.build();
out_frame.set_ntp_time_ms(video_frame.ntp_time_ms());
}
TRACE_EVENT_ASYNC_STEP0("webrtc", "Video", video_frame.render_time_ms(),
"Encode");
overuse_detector_->FrameCaptured(out_frame, time_when_posted_us);
// Encoder metadata needs to be updated before encode complete callback.
VideoEncoder::EncoderInfo info = encoder_->GetEncoderInfo();
if (info.implementation_name != encoder_info_.implementation_name) {
encoder_stats_observer_->OnEncoderImplementationChanged(
info.implementation_name);
}
encoder_info_ = info;
input_framerate_.Update(1u, clock_->TimeInMilliseconds());
video_sender_.AddVideoFrame(out_frame, nullptr, encoder_info_);
}
void VideoStreamEncoder::SendKeyFrame() {
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask([this] { SendKeyFrame(); });
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
TRACE_EVENT0("webrtc", "OnKeyFrameRequest");
video_sender_.IntraFrameRequest(0);
}
EncodedImageCallback::Result VideoStreamEncoder::OnEncodedImage(
const EncodedImage& encoded_image,
const CodecSpecificInfo* codec_specific_info,
const RTPFragmentationHeader* fragmentation) {
// Encoded is called on whatever thread the real encoder implementation run
// on. In the case of hardware encoders, there might be several encoders
// running in parallel on different threads.
encoder_stats_observer_->OnSendEncodedImage(encoded_image,
codec_specific_info);
EncodedImageCallback::Result result =
sink_->OnEncodedImage(encoded_image, codec_specific_info, fragmentation);
int64_t time_sent_us = rtc::TimeMicros();
uint32_t timestamp = encoded_image.Timestamp();
const int qp = encoded_image.qp_;
int64_t capture_time_us =
encoded_image.capture_time_ms_ * rtc::kNumMicrosecsPerMillisec;
absl::optional<int> encode_duration_us;
if (encoded_image.timing_.flags != VideoSendTiming::kInvalid) {
encode_duration_us.emplace(
// TODO(nisse): Maybe use capture_time_ms_ rather than encode_start_ms_?
rtc::kNumMicrosecsPerMillisec *
(encoded_image.timing_.encode_finish_ms -
encoded_image.timing_.encode_start_ms));
}
// Run post encode tasks, such as overuse detection and frame rate/drop
// stats for internal encoders.
const size_t frame_size = encoded_image.size();
const bool keyframe = encoded_image._frameType == FrameType::kVideoFrameKey;
RunPostEncode(timestamp, time_sent_us, capture_time_us, encode_duration_us,
qp, frame_size, keyframe);
if (result.error == Result::OK) {
// In case of an internal encoder running on a separate thread, the
// decision to drop a frame might be a frame late and signaled via
// atomic flag. This is because we can't easily wait for the worker thread
// without risking deadlocks, eg during shutdown when the worker thread
// might be waiting for the internal encoder threads to stop.
if (pending_frame_drops_.load() > 0) {
int pending_drops = pending_frame_drops_.fetch_sub(1);
RTC_DCHECK_GT(pending_drops, 0);
result.drop_next_frame = true;
}
}
return result;
}
void VideoStreamEncoder::OnDroppedFrame(DropReason reason) {
switch (reason) {
case DropReason::kDroppedByMediaOptimizations:
encoder_stats_observer_->OnFrameDropped(
VideoStreamEncoderObserver::DropReason::kMediaOptimization);
encoder_queue_.PostTask([this] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (quality_scaler_)
quality_scaler_->ReportDroppedFrameByMediaOpt();
});
break;
case DropReason::kDroppedByEncoder:
encoder_stats_observer_->OnFrameDropped(
VideoStreamEncoderObserver::DropReason::kEncoder);
encoder_queue_.PostTask([this] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (quality_scaler_)
quality_scaler_->ReportDroppedFrameByEncoder();
});
break;
}
}
void VideoStreamEncoder::OnBitrateUpdated(uint32_t bitrate_bps,
uint8_t fraction_lost,
int64_t round_trip_time_ms) {
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask(
[this, bitrate_bps, fraction_lost, round_trip_time_ms] {
OnBitrateUpdated(bitrate_bps, fraction_lost, round_trip_time_ms);
});
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
RTC_DCHECK(sink_) << "sink_ must be set before the encoder is active.";
RTC_LOG(LS_VERBOSE) << "OnBitrateUpdated, bitrate " << bitrate_bps
<< " packet loss " << static_cast<int>(fraction_lost)
<< " rtt " << round_trip_time_ms;
// On significant changes to BWE at the start of the call,
// enable frame drops to quickly react to jumps in available bandwidth.
if (encoder_start_bitrate_bps_ != 0 &&
!has_seen_first_significant_bwe_change_ && quality_scaler_ &&
initial_framedrop_on_bwe_enabled_ &&
abs_diff(bitrate_bps, encoder_start_bitrate_bps_) >=
kFramedropThreshold * encoder_start_bitrate_bps_) {
// Reset initial framedrop feature when first real BW estimate arrives.
// TODO(kthelgason): Update BitrateAllocator to not call OnBitrateUpdated
// without an actual BW estimate.
initial_framedrop_ = 0;
has_seen_first_significant_bwe_change_ = true;
}
uint32_t framerate_fps = GetInputFramerateFps();
frame_dropper_.SetRates((bitrate_bps + 500) / 1000, framerate_fps);
VideoBitrateAllocation bitrate_allocation =
GetBitrateAllocationAndNotifyObserver(bitrate_bps, framerate_fps);
video_sender_.SetChannelParameters(bitrate_allocation, framerate_fps);
encoder_start_bitrate_bps_ =
bitrate_bps != 0 ? bitrate_bps : encoder_start_bitrate_bps_;
bool video_is_suspended = bitrate_bps == 0;
bool video_suspension_changed = video_is_suspended != EncoderPaused();
last_observed_bitrate_bps_ = bitrate_bps;
if (video_suspension_changed) {
RTC_LOG(LS_INFO) << "Video suspend state changed to: "
<< (video_is_suspended ? "suspended" : "not suspended");
encoder_stats_observer_->OnSuspendChange(video_is_suspended);
}
if (video_suspension_changed && !video_is_suspended && pending_frame_ &&
!DropDueToSize(pending_frame_->size())) {
int64_t pending_time_us = rtc::TimeMicros() - pending_frame_post_time_us_;
if (pending_time_us < kPendingFrameTimeoutMs * 1000)
EncodeVideoFrame(*pending_frame_, pending_frame_post_time_us_);
pending_frame_.reset();
}
}
bool VideoStreamEncoder::DropDueToSize(uint32_t pixel_count) const {
if (initial_framedrop_ < kMaxInitialFramedrop &&
encoder_start_bitrate_bps_ > 0) {
if (encoder_start_bitrate_bps_ < 300000 /* qvga */) {
return pixel_count > 320 * 240;
} else if (encoder_start_bitrate_bps_ < 500000 /* vga */) {
return pixel_count > 640 * 480;
}
}
return false;
}
void VideoStreamEncoder::AdaptDown(AdaptReason reason) {
RTC_DCHECK_RUN_ON(&encoder_queue_);
AdaptationRequest adaptation_request = {
last_frame_info_->pixel_count(),
encoder_stats_observer_->GetInputFrameRate(),
AdaptationRequest::Mode::kAdaptDown};
bool downgrade_requested =
last_adaptation_request_ &&
last_adaptation_request_->mode_ == AdaptationRequest::Mode::kAdaptDown;
switch (degradation_preference_) {
case DegradationPreference::BALANCED:
break;
case DegradationPreference::MAINTAIN_FRAMERATE:
if (downgrade_requested &&
adaptation_request.input_pixel_count_ >=
last_adaptation_request_->input_pixel_count_) {
// Don't request lower resolution if the current resolution is not
// lower than the last time we asked for the resolution to be lowered.
return;
}
break;
case DegradationPreference::MAINTAIN_RESOLUTION:
if (adaptation_request.framerate_fps_ <= 0 ||
(downgrade_requested &&
adaptation_request.framerate_fps_ < kMinFramerateFps)) {
// If no input fps estimate available, can't determine how to scale down
// framerate. Otherwise, don't request lower framerate if we don't have
// a valid frame rate. Since framerate, unlike resolution, is a measure
// we have to estimate, and can fluctuate naturally over time, don't
// make the same kind of limitations as for resolution, but trust the
// overuse detector to not trigger too often.
return;
}
break;
case DegradationPreference::DISABLED:
return;
}
switch (degradation_preference_) {
case DegradationPreference::BALANCED: {
// Try scale down framerate, if lower.
int fps = MinFps(last_frame_info_->pixel_count());
if (source_proxy_->RestrictFramerate(fps)) {
GetAdaptCounter().IncrementFramerate(reason);
break;
}
// Scale down resolution.
RTC_FALLTHROUGH();
}
case DegradationPreference::MAINTAIN_FRAMERATE: {
// Scale down resolution.
bool min_pixels_reached = false;
if (!source_proxy_->RequestResolutionLowerThan(
adaptation_request.input_pixel_count_,
encoder_->GetEncoderInfo().scaling_settings.min_pixels_per_frame,
&min_pixels_reached)) {
if (min_pixels_reached)
encoder_stats_observer_->OnMinPixelLimitReached();
return;
}
GetAdaptCounter().IncrementResolution(reason);
break;
}
case DegradationPreference::MAINTAIN_RESOLUTION: {
// Scale down framerate.
const int requested_framerate = source_proxy_->RequestFramerateLowerThan(
adaptation_request.framerate_fps_);
if (requested_framerate == -1)
return;
RTC_DCHECK_NE(max_framerate_, -1);
overuse_detector_->OnTargetFramerateUpdated(
std::min(max_framerate_, requested_framerate));
GetAdaptCounter().IncrementFramerate(reason);
break;
}
case DegradationPreference::DISABLED:
RTC_NOTREACHED();
}
last_adaptation_request_.emplace(adaptation_request);
UpdateAdaptationStats(reason);
RTC_LOG(LS_INFO) << GetConstAdaptCounter().ToString();
}
void VideoStreamEncoder::AdaptUp(AdaptReason reason) {
RTC_DCHECK_RUN_ON(&encoder_queue_);
const AdaptCounter& adapt_counter = GetConstAdaptCounter();
int num_downgrades = adapt_counter.TotalCount(reason);
if (num_downgrades == 0)
return;
RTC_DCHECK_GT(num_downgrades, 0);
AdaptationRequest adaptation_request = {
last_frame_info_->pixel_count(),
encoder_stats_observer_->GetInputFrameRate(),
AdaptationRequest::Mode::kAdaptUp};
bool adapt_up_requested =
last_adaptation_request_ &&
last_adaptation_request_->mode_ == AdaptationRequest::Mode::kAdaptUp;
if (degradation_preference_ == DegradationPreference::MAINTAIN_FRAMERATE) {
if (adapt_up_requested &&
adaptation_request.input_pixel_count_ <=
last_adaptation_request_->input_pixel_count_) {
// Don't request higher resolution if the current resolution is not
// higher than the last time we asked for the resolution to be higher.
return;
}
}
switch (degradation_preference_) {
case DegradationPreference::BALANCED: {
// Try scale up framerate, if higher.
int fps = MaxFps(last_frame_info_->pixel_count());
if (source_proxy_->IncreaseFramerate(fps)) {
GetAdaptCounter().DecrementFramerate(reason, fps);
// Reset framerate in case of fewer fps steps down than up.
if (adapt_counter.FramerateCount() == 0 &&
fps != std::numeric_limits<int>::max()) {
RTC_LOG(LS_INFO) << "Removing framerate down-scaling setting.";
source_proxy_->IncreaseFramerate(std::numeric_limits<int>::max());
}
break;
}
// Scale up resolution.
RTC_FALLTHROUGH();
}
case DegradationPreference::MAINTAIN_FRAMERATE: {
// Scale up resolution.
int pixel_count = adaptation_request.input_pixel_count_;
if (adapt_counter.ResolutionCount() == 1) {
RTC_LOG(LS_INFO) << "Removing resolution down-scaling setting.";
pixel_count = std::numeric_limits<int>::max();
}
if (!source_proxy_->RequestHigherResolutionThan(pixel_count))
return;
GetAdaptCounter().DecrementResolution(reason);
break;
}
case DegradationPreference::MAINTAIN_RESOLUTION: {
// Scale up framerate.
int fps = adaptation_request.framerate_fps_;
if (adapt_counter.FramerateCount() == 1) {
RTC_LOG(LS_INFO) << "Removing framerate down-scaling setting.";
fps = std::numeric_limits<int>::max();
}
const int requested_framerate =
source_proxy_->RequestHigherFramerateThan(fps);
if (requested_framerate == -1) {
overuse_detector_->OnTargetFramerateUpdated(max_framerate_);
return;
}
overuse_detector_->OnTargetFramerateUpdated(
std::min(max_framerate_, requested_framerate));
GetAdaptCounter().DecrementFramerate(reason);
break;
}
case DegradationPreference::DISABLED:
return;
}
last_adaptation_request_.emplace(adaptation_request);
UpdateAdaptationStats(reason);
RTC_LOG(LS_INFO) << adapt_counter.ToString();
}
// TODO(nisse): Delete, once AdaptReason and AdaptationReason are merged.
void VideoStreamEncoder::UpdateAdaptationStats(AdaptReason reason) {
switch (reason) {
case kCpu:
encoder_stats_observer_->OnAdaptationChanged(
VideoStreamEncoderObserver::AdaptationReason::kCpu,
GetActiveCounts(kCpu), GetActiveCounts(kQuality));
break;
case kQuality:
encoder_stats_observer_->OnAdaptationChanged(
VideoStreamEncoderObserver::AdaptationReason::kQuality,
GetActiveCounts(kCpu), GetActiveCounts(kQuality));
break;
}
}
VideoStreamEncoderObserver::AdaptationSteps VideoStreamEncoder::GetActiveCounts(
AdaptReason reason) {
VideoStreamEncoderObserver::AdaptationSteps counts =
GetConstAdaptCounter().Counts(reason);
switch (reason) {
case kCpu:
if (!IsFramerateScalingEnabled(degradation_preference_))
counts.num_framerate_reductions = absl::nullopt;
if (!IsResolutionScalingEnabled(degradation_preference_))
counts.num_resolution_reductions = absl::nullopt;
break;
case kQuality:
if (!IsFramerateScalingEnabled(degradation_preference_) ||
!quality_scaler_) {
counts.num_framerate_reductions = absl::nullopt;
}
if (!IsResolutionScalingEnabled(degradation_preference_) ||
!quality_scaler_) {
counts.num_resolution_reductions = absl::nullopt;
}
break;
}
return counts;
}
VideoStreamEncoder::AdaptCounter& VideoStreamEncoder::GetAdaptCounter() {
return adapt_counters_[degradation_preference_];
}
const VideoStreamEncoder::AdaptCounter&
VideoStreamEncoder::GetConstAdaptCounter() {
return adapt_counters_[degradation_preference_];
}
void VideoStreamEncoder::RunPostEncode(uint32_t frame_timestamp,
int64_t time_sent_us,
int64_t capture_time_us,
absl::optional<int> encode_durations_us,
int qp,
size_t frame_size_bytes,
bool keyframe) {
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask([this, frame_timestamp, time_sent_us, qp,
capture_time_us, encode_durations_us,
frame_size_bytes, keyframe] {
RunPostEncode(frame_timestamp, time_sent_us, capture_time_us,
encode_durations_us, qp, frame_size_bytes, keyframe);
});
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (frame_size_bytes > 0) {
frame_dropper_.Fill(frame_size_bytes, !keyframe);
}
if (encoder_info_.has_internal_source) {
// Update frame dropper after the fact for internal sources.
input_framerate_.Update(1u, clock_->TimeInMilliseconds());
frame_dropper_.Leak(GetInputFramerateFps());
// Signal to encoder to drop next frame.
if (frame_dropper_.DropFrame()) {
pending_frame_drops_.fetch_add(1);
}
}
overuse_detector_->FrameSent(frame_timestamp, time_sent_us, capture_time_us,
encode_durations_us);
if (quality_scaler_ && qp >= 0)
quality_scaler_->ReportQp(qp);
}
// Class holding adaptation information.
VideoStreamEncoder::AdaptCounter::AdaptCounter() {
fps_counters_.resize(kScaleReasonSize);
resolution_counters_.resize(kScaleReasonSize);
static_assert(kScaleReasonSize == 2, "Update MoveCount.");
}
VideoStreamEncoder::AdaptCounter::~AdaptCounter() {}
std::string VideoStreamEncoder::AdaptCounter::ToString() const {
rtc::StringBuilder ss;
ss << "Downgrade counts: fps: {" << ToString(fps_counters_);
ss << "}, resolution: {" << ToString(resolution_counters_) << "}";
return ss.Release();
}
VideoStreamEncoderObserver::AdaptationSteps
VideoStreamEncoder::AdaptCounter::Counts(int reason) const {
VideoStreamEncoderObserver::AdaptationSteps counts;
counts.num_framerate_reductions = fps_counters_[reason];
counts.num_resolution_reductions = resolution_counters_[reason];
return counts;
}
void VideoStreamEncoder::AdaptCounter::IncrementFramerate(int reason) {
++(fps_counters_[reason]);
}
void VideoStreamEncoder::AdaptCounter::IncrementResolution(int reason) {
++(resolution_counters_[reason]);
}
void VideoStreamEncoder::AdaptCounter::DecrementFramerate(int reason) {
if (fps_counters_[reason] == 0) {
// Balanced mode: Adapt up is in a different order, switch reason.
// E.g. framerate adapt down: quality (2), framerate adapt up: cpu (3).
// 1. Down resolution (cpu): res={quality:0,cpu:1}, fps={quality:0,cpu:0}
// 2. Down fps (quality): res={quality:0,cpu:1}, fps={quality:1,cpu:0}
// 3. Up fps (cpu): res={quality:1,cpu:0}, fps={quality:0,cpu:0}
// 4. Up resolution (quality): res={quality:0,cpu:0}, fps={quality:0,cpu:0}
RTC_DCHECK_GT(TotalCount(reason), 0) << "No downgrade for reason.";
RTC_DCHECK_GT(FramerateCount(), 0) << "Framerate not downgraded.";
MoveCount(&resolution_counters_, reason);
MoveCount(&fps_counters_, (reason + 1) % kScaleReasonSize);
}
--(fps_counters_[reason]);
RTC_DCHECK_GE(fps_counters_[reason], 0);
}
void VideoStreamEncoder::AdaptCounter::DecrementResolution(int reason) {
if (resolution_counters_[reason] == 0) {
// Balanced mode: Adapt up is in a different order, switch reason.
RTC_DCHECK_GT(TotalCount(reason), 0) << "No downgrade for reason.";
RTC_DCHECK_GT(ResolutionCount(), 0) << "Resolution not downgraded.";
MoveCount(&fps_counters_, reason);
MoveCount(&resolution_counters_, (reason + 1) % kScaleReasonSize);
}
--(resolution_counters_[reason]);
RTC_DCHECK_GE(resolution_counters_[reason], 0);
}
void VideoStreamEncoder::AdaptCounter::DecrementFramerate(int reason,
int cur_fps) {
DecrementFramerate(reason);
// Reset if at max fps (i.e. in case of fewer steps up than down).
if (cur_fps == std::numeric_limits<int>::max())
std::fill(fps_counters_.begin(), fps_counters_.end(), 0);
}
int VideoStreamEncoder::AdaptCounter::FramerateCount() const {
return Count(fps_counters_);
}
int VideoStreamEncoder::AdaptCounter::ResolutionCount() const {
return Count(resolution_counters_);
}
int VideoStreamEncoder::AdaptCounter::FramerateCount(int reason) const {
return fps_counters_[reason];
}
int VideoStreamEncoder::AdaptCounter::ResolutionCount(int reason) const {
return resolution_counters_[reason];
}
int VideoStreamEncoder::AdaptCounter::TotalCount(int reason) const {
return FramerateCount(reason) + ResolutionCount(reason);
}
int VideoStreamEncoder::AdaptCounter::Count(
const std::vector<int>& counters) const {
return std::accumulate(counters.begin(), counters.end(), 0);
}
void VideoStreamEncoder::AdaptCounter::MoveCount(std::vector<int>* counters,
int from_reason) {
int to_reason = (from_reason + 1) % kScaleReasonSize;
++((*counters)[to_reason]);
--((*counters)[from_reason]);
}
std::string VideoStreamEncoder::AdaptCounter::ToString(
const std::vector<int>& counters) const {
rtc::StringBuilder ss;
for (size_t reason = 0; reason < kScaleReasonSize; ++reason) {
ss << (reason ? " cpu" : "quality") << ":" << counters[reason];
}
return ss.Release();
}
} // namespace webrtc