blob: 6be0276bafdbcb88610fc0fc76b76db768c5fc81 [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 <array>
#include <limits>
#include <memory>
#include <numeric>
#include <utility>
#include "absl/algorithm/container.h"
#include "api/video/encoded_image.h"
#include "api/video/i420_buffer.h"
#include "api/video/video_bitrate_allocator_factory.h"
#include "api/video/video_codec_constants.h"
#include "api/video_codecs/video_encoder.h"
#include "modules/video_coding/codecs/vp9/svc_rate_allocator.h"
#include "modules/video_coding/include/video_codec_initializer.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/alr_experiment.h"
#include "rtc_base/experiments/quality_scaling_experiment.h"
#include "rtc_base/experiments/rate_control_settings.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"
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;
const size_t kDefaultPayloadSize = 1440;
const int64_t kParameterUpdateIntervalMs = 1000;
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;
}
bool RequiresEncoderReset(const VideoCodec& prev_send_codec,
const VideoCodec& new_send_codec,
bool was_encode_called_since_last_initialization) {
// Does not check max/minBitrate or maxFramerate.
if (new_send_codec.codecType != prev_send_codec.codecType ||
new_send_codec.width != prev_send_codec.width ||
new_send_codec.height != prev_send_codec.height ||
new_send_codec.qpMax != prev_send_codec.qpMax ||
new_send_codec.numberOfSimulcastStreams !=
prev_send_codec.numberOfSimulcastStreams ||
new_send_codec.mode != prev_send_codec.mode) {
return true;
}
if (!was_encode_called_since_last_initialization &&
(new_send_codec.startBitrate != prev_send_codec.startBitrate)) {
// If start bitrate has changed reconfigure encoder only if encoding had not
// yet started.
return true;
}
switch (new_send_codec.codecType) {
case kVideoCodecVP8:
if (new_send_codec.VP8() != prev_send_codec.VP8()) {
return true;
}
break;
case kVideoCodecVP9:
if (new_send_codec.VP9() != prev_send_codec.VP9()) {
return true;
}
break;
case kVideoCodecH264:
if (new_send_codec.H264() != prev_send_codec.H264()) {
return true;
}
break;
default:
break;
}
for (unsigned char i = 0; i < new_send_codec.numberOfSimulcastStreams; ++i) {
if (new_send_codec.simulcastStream[i].width !=
prev_send_codec.simulcastStream[i].width ||
new_send_codec.simulcastStream[i].height !=
prev_send_codec.simulcastStream[i].height ||
new_send_codec.simulcastStream[i].numberOfTemporalLayers !=
prev_send_codec.simulcastStream[i].numberOfTemporalLayers ||
new_send_codec.simulcastStream[i].qpMax !=
prev_send_codec.simulcastStream[i].qpMax ||
new_send_codec.simulcastStream[i].active !=
prev_send_codec.simulcastStream[i].active) {
return true;
}
}
return false;
}
std::array<uint8_t, 2> GetExperimentGroups() {
std::array<uint8_t, 2> experiment_groups;
absl::optional<AlrExperimentSettings> experiment_settings =
AlrExperimentSettings::CreateFromFieldTrial(
AlrExperimentSettings::kStrictPacingAndProbingExperimentName);
if (experiment_settings) {
experiment_groups[0] = experiment_settings->group_id + 1;
} else {
experiment_groups[0] = 0;
}
experiment_settings = AlrExperimentSettings::CreateFromFieldTrial(
AlrExperimentSettings::kScreenshareProbingBweExperimentName);
if (experiment_settings) {
experiment_groups[1] = experiment_settings->group_id + 1;
} else {
experiment_groups[1] = 0;
}
return experiment_groups;
}
// Limit allocation across TLs in bitrate allocation according to number of TLs
// in EncoderInfo.
VideoBitrateAllocation UpdateAllocationFromEncoderInfo(
const VideoBitrateAllocation& allocation,
const VideoEncoder::EncoderInfo& encoder_info) {
if (allocation.get_sum_bps() == 0) {
return allocation;
}
VideoBitrateAllocation new_allocation;
for (int si = 0; si < kMaxSpatialLayers; ++si) {
if (encoder_info.fps_allocation[si].size() == 1 &&
allocation.IsSpatialLayerUsed(si)) {
// One TL is signalled to be used by the encoder. Do not distribute
// bitrate allocation across TLs (use sum at ti:0).
new_allocation.SetBitrate(si, 0, allocation.GetSpatialLayerSum(si));
} else {
for (int ti = 0; ti < kMaxTemporalStreams; ++ti) {
if (allocation.HasBitrate(si, ti))
new_allocation.SetBitrate(si, ti, allocation.GetBitrate(si, ti));
}
}
}
return new_allocation;
}
} // 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_RUN_ON(&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;
}
int GetHigherResolutionThan(int pixel_count) const {
// 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.
return (pixel_count * 5) / 3;
}
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 {
sink_wants_.target_pixel_count = GetHigherResolutionThan(pixel_count);
}
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);
return wants;
}
rtc::CriticalSection crit_;
SequenceChecker 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::EncoderRateSettings::EncoderRateSettings()
: rate_control(),
encoder_target(DataRate::Zero()),
stable_encoder_target(DataRate::Zero()) {}
VideoStreamEncoder::EncoderRateSettings::EncoderRateSettings(
const VideoBitrateAllocation& bitrate,
double framerate_fps,
DataRate bandwidth_allocation,
DataRate encoder_target,
DataRate stable_encoder_target)
: rate_control(bitrate, framerate_fps, bandwidth_allocation),
encoder_target(encoder_target),
stable_encoder_target(stable_encoder_target) {}
bool VideoStreamEncoder::EncoderRateSettings::operator==(
const EncoderRateSettings& rhs) const {
return rate_control == rhs.rate_control &&
encoder_target == rhs.encoder_target &&
stable_encoder_target == rhs.stable_encoder_target;
}
bool VideoStreamEncoder::EncoderRateSettings::operator!=(
const EncoderRateSettings& rhs) const {
return !(*this == rhs);
}
VideoStreamEncoder::VideoStreamEncoder(
Clock* clock,
uint32_t number_of_cores,
VideoStreamEncoderObserver* encoder_stats_observer,
const VideoStreamEncoderSettings& settings,
std::unique_ptr<OveruseFrameDetector> overuse_detector,
TaskQueueFactory* task_queue_factory)
: 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),
rate_control_settings_(RateControlSettings::ParseFromFieldTrials()),
quality_scaler_settings_(QualityScalerSettings::ParseFromFieldTrials()),
overuse_detector_(std::move(overuse_detector)),
encoder_stats_observer_(encoder_stats_observer),
encoder_initialized_(false),
max_framerate_(-1),
pending_encoder_reconfiguration_(false),
pending_encoder_creation_(false),
crop_width_(0),
crop_height_(0),
encoder_start_bitrate_bps_(0),
set_start_bitrate_bps_(0),
set_start_bitrate_time_ms_(0),
has_seen_first_bwe_drop_(false),
max_data_payload_length_(0),
encoder_paused_and_dropped_frame_(false),
was_encode_called_since_last_initialization_(false),
encoder_failed_(false),
clock_(clock),
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),
accumulated_update_rect_{0, 0, 0, 0},
accumulated_update_rect_is_valid_(true),
bitrate_observer_(nullptr),
fec_controller_override_(nullptr),
force_disable_frame_dropper_(false),
input_framerate_(kFrameRateAvergingWindowSizeMs, 1000),
pending_frame_drops_(0),
next_frame_types_(1, VideoFrameType::kVideoFrameDelta),
frame_encode_metadata_writer_(this),
experiment_groups_(GetExperimentGroups()),
next_frame_id_(0),
encoder_switch_experiment_(ParseEncoderSwitchFieldTrial()),
encoder_switch_requested_(false),
encoder_queue_(task_queue_factory->CreateTaskQueue(
"EncoderQueue",
TaskQueueFactory::Priority::NORMAL)) {
RTC_DCHECK(encoder_stats_observer);
RTC_DCHECK(overuse_detector_);
RTC_DCHECK_GE(number_of_cores, 1);
for (auto& state : encoder_buffer_state_)
state.fill(std::numeric_limits<int64_t>::max());
}
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_ = nullptr;
bitrate_observer_ = nullptr;
ReleaseEncoder();
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::SetFecControllerOverride(
FecControllerOverride* fec_controller_override) {
encoder_queue_.PostTask([this, fec_controller_override] {
RTC_DCHECK_RUN_ON(&encoder_queue_);
RTC_DCHECK(!fec_controller_override_);
fec_controller_override_ = fec_controller_override;
if (encoder_) {
encoder_->SetFecControllerOverride(fec_controller_override_);
}
});
}
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(encoder_->GetEncoderInfo());
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;
set_start_bitrate_bps_ = start_bitrate_bps;
set_start_bitrate_time_ms_ = clock_->TimeInMilliseconds();
});
}
void VideoStreamEncoder::ConfigureEncoder(VideoEncoderConfig config,
size_t max_data_payload_length) {
encoder_queue_.PostTask(
[this, config = std::move(config), max_data_payload_length]() mutable {
RTC_DCHECK_RUN_ON(&encoder_queue_);
RTC_DCHECK(sink_);
RTC_LOG(LS_INFO) << "ConfigureEncoder requested.";
pending_encoder_creation_ =
(!encoder_ || encoder_config_.video_format != config.video_format ||
max_data_payload_length_ != max_data_payload_length);
encoder_config_ = std::move(config);
max_data_payload_length_ = max_data_payload_length;
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 {
codec_info_ = settings_.encoder_factory->QueryVideoEncoder(
encoder_config_.video_format);
if (HasInternalSource()) {
last_frame_info_ = VideoFrameInfo(176, 144, false);
ReconfigureEncoder();
}
}
});
}
static absl::optional<VideoEncoder::ResolutionBitrateLimits>
GetEncoderBitrateLimits(const VideoEncoder::EncoderInfo& encoder_info,
int frame_size_pixels) {
std::vector<VideoEncoder::ResolutionBitrateLimits> bitrate_limits =
encoder_info.resolution_bitrate_limits;
// Sort the list of bitrate limits by resolution.
sort(bitrate_limits.begin(), bitrate_limits.end(),
[](const VideoEncoder::ResolutionBitrateLimits& lhs,
const VideoEncoder::ResolutionBitrateLimits& rhs) {
return lhs.frame_size_pixels < rhs.frame_size_pixels;
});
for (size_t i = 0; i < bitrate_limits.size(); ++i) {
RTC_DCHECK_GT(bitrate_limits[i].min_bitrate_bps, 0);
RTC_DCHECK_GE(bitrate_limits[i].min_start_bitrate_bps,
bitrate_limits[i].min_bitrate_bps);
RTC_DCHECK_GT(bitrate_limits[i].max_bitrate_bps,
bitrate_limits[i].min_start_bitrate_bps);
if (i > 0) {
// The bitrate limits aren't expected to decrease with resolution.
RTC_DCHECK_GE(bitrate_limits[i].min_bitrate_bps,
bitrate_limits[i - 1].min_bitrate_bps);
RTC_DCHECK_GE(bitrate_limits[i].min_start_bitrate_bps,
bitrate_limits[i - 1].min_start_bitrate_bps);
RTC_DCHECK_GE(bitrate_limits[i].max_bitrate_bps,
bitrate_limits[i - 1].max_bitrate_bps);
}
if (bitrate_limits[i].frame_size_pixels >= frame_size_pixels) {
return absl::optional<VideoEncoder::ResolutionBitrateLimits>(
bitrate_limits[i]);
}
}
return absl::nullopt;
}
// 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_);
if (encoder_switch_experiment_.IsPixelCountBelowThreshold(
last_frame_info_->width * last_frame_info_->height) &&
!encoder_switch_requested_ && settings_.encoder_switch_request_callback) {
EncoderSwitchRequestCallback::Config conf;
conf.codec_name = encoder_switch_experiment_.to_codec;
conf.param = encoder_switch_experiment_.to_param;
conf.value = encoder_switch_experiment_.to_value;
settings_.encoder_switch_request_callback->RequestEncoderSwitch(conf);
encoder_switch_requested_ = true;
}
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 = absl::c_max_element(
streams, [](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;
bool encoder_reset_required = false;
if (pending_encoder_creation_) {
// Destroy existing encoder instance before creating a new one. Otherwise
// attempt to create another instance will fail if encoder factory
// supports only single instance of encoder of given type.
encoder_.reset();
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_);
encoder_->SetFecControllerOverride(fec_controller_override_);
codec_info_ = settings_.encoder_factory->QueryVideoEncoder(
encoder_config_.video_format);
encoder_reset_required = true;
}
encoder_bitrate_limits_ = GetEncoderBitrateLimits(
encoder_->GetEncoderInfo(),
last_frame_info_->width * last_frame_info_->height);
if (streams.size() == 1 && encoder_bitrate_limits_) {
// Use bitrate limits recommended by encoder only if app didn't set any of
// them.
if (encoder_config_.max_bitrate_bps <= 0 &&
(encoder_config_.simulcast_layers.empty() ||
encoder_config_.simulcast_layers[0].min_bitrate_bps <= 0)) {
streams.back().min_bitrate_bps = encoder_bitrate_limits_->min_bitrate_bps;
streams.back().max_bitrate_bps = encoder_bitrate_limits_->max_bitrate_bps;
streams.back().target_bitrate_bps =
std::min(streams.back().target_bitrate_bps,
encoder_bitrate_limits_->max_bitrate_bps);
}
}
VideoCodec codec;
if (!VideoCodecInitializer::SetupCodec(encoder_config_, streams, &codec)) {
RTC_LOG(LS_ERROR) << "Failed to create encoder configuration.";
}
// 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(streams[0].max_bitrate_bps,
SvcRateAllocator::GetMaxBitrate(codec).bps<int>());
streams[0].min_bitrate_bps = codec.spatialLayers[0].minBitrate * 1000;
// target_bitrate_bps specifies the maximum padding bitrate.
streams[0].target_bitrate_bps =
SvcRateAllocator::GetPaddingBitrate(codec).bps<int>();
}
char log_stream_buf[4 * 1024];
rtc::SimpleStringBuilder log_stream(log_stream_buf);
log_stream << "ReconfigureEncoder:\n";
log_stream << "Simulcast streams:\n";
for (size_t i = 0; i < codec.numberOfSimulcastStreams; ++i) {
log_stream << i << ": " << codec.simulcastStream[i].width << "x"
<< codec.simulcastStream[i].height
<< " fps: " << codec.simulcastStream[i].maxFramerate
<< " min_bps: " << codec.simulcastStream[i].minBitrate
<< " target_bps: " << codec.simulcastStream[i].targetBitrate
<< " max_bps: " << codec.simulcastStream[i].maxBitrate
<< " max_qp: " << codec.simulcastStream[i].qpMax
<< " num_tl: " << codec.simulcastStream[i].numberOfTemporalLayers
<< " active: "
<< (codec.simulcastStream[i].active ? "true" : "false") << "\n";
}
if (encoder_config_.codec_type == kVideoCodecVP9) {
size_t num_spatial_layers = codec.VP9()->numberOfSpatialLayers;
log_stream << "Spatial layers:\n";
for (size_t i = 0; i < num_spatial_layers; ++i) {
log_stream << i << ": " << codec.spatialLayers[i].width << "x"
<< codec.spatialLayers[i].height
<< " fps: " << codec.spatialLayers[i].maxFramerate
<< " min_bps: " << codec.spatialLayers[i].minBitrate
<< " target_bps: " << codec.spatialLayers[i].targetBitrate
<< " max_bps: " << codec.spatialLayers[i].maxBitrate
<< " max_qp: " << codec.spatialLayers[i].qpMax
<< " num_tl: " << codec.spatialLayers[i].numberOfTemporalLayers
<< " active: "
<< (codec.spatialLayers[i].active ? "true" : "false") << "\n";
}
}
RTC_LOG(LS_INFO) << log_stream.str();
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;
// Make sure the start bit rate is sane...
RTC_DCHECK_LE(codec.startBitrate, 1000000);
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);
if (codec.maxBitrate == 0) {
// max is one bit per pixel
codec.maxBitrate =
(static_cast<int>(codec.height) * static_cast<int>(codec.width) *
static_cast<int>(codec.maxFramerate)) /
1000;
if (codec.startBitrate > codec.maxBitrate) {
// But if the user tries to set a higher start bit rate we will
// increase the max accordingly.
codec.maxBitrate = codec.startBitrate;
}
}
if (codec.startBitrate > codec.maxBitrate) {
codec.startBitrate = codec.maxBitrate;
}
rate_allocator_ =
settings_.bitrate_allocator_factory->CreateVideoBitrateAllocator(codec);
// Reset (release existing encoder) if one exists and anything except
// start bitrate or max framerate has changed.
if (!encoder_reset_required) {
encoder_reset_required = RequiresEncoderReset(
codec, send_codec_, was_encode_called_since_last_initialization_);
}
send_codec_ = codec;
encoder_switch_experiment_.SetCodec(send_codec_.codecType);
// 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().
bool success = true;
if (encoder_reset_required) {
ReleaseEncoder();
const size_t max_data_payload_length = max_data_payload_length_ > 0
? max_data_payload_length_
: kDefaultPayloadSize;
if (encoder_->InitEncode(
&send_codec_,
VideoEncoder::Settings(settings_.capabilities, number_of_cores_,
max_data_payload_length)) != 0) {
RTC_LOG(LS_ERROR) << "Failed to initialize the encoder associated with "
"codec type: "
<< CodecTypeToPayloadString(send_codec_.codecType)
<< " (" << send_codec_.codecType << ")";
ReleaseEncoder();
success = false;
} else {
encoder_initialized_ = true;
encoder_->RegisterEncodeCompleteCallback(this);
frame_encode_metadata_writer_.OnEncoderInit(send_codec_,
HasInternalSource());
}
frame_encode_metadata_writer_.Reset();
last_encode_info_ms_ = absl::nullopt;
was_encode_called_since_last_initialization_ = false;
}
if (success) {
next_frame_types_.clear();
next_frame_types_.resize(
std::max(static_cast<int>(codec.numberOfSimulcastStreams), 1),
VideoFrameType::kVideoFrameKey);
RTC_LOG(LS_VERBOSE) << " max bitrate " << codec.maxBitrate
<< " start bitrate " << codec.startBitrate
<< " max frame rate " << codec.maxFramerate
<< " max payload size " << max_data_payload_length_;
} else {
RTC_LOG(LS_ERROR) << "Failed to configure encoder.";
rate_allocator_ = nullptr;
}
if (pending_encoder_creation_) {
overuse_detector_->StopCheckForOveruse();
overuse_detector_->StartCheckForOveruse(
&encoder_queue_,
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 == kVideoCodecH264) {
num_layers = codec.H264()->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_);
// 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);
VideoEncoder::EncoderInfo info = encoder_->GetEncoderInfo();
if (rate_control_settings_.UseEncoderBitrateAdjuster()) {
bitrate_adjuster_ = std::make_unique<EncoderBitrateAdjuster>(codec);
bitrate_adjuster_->OnEncoderInfo(info);
}
if (rate_allocator_ && last_encoder_rate_settings_) {
// We have a new rate allocator instance and already configured target
// bitrate. Update the rate allocation and notify observers.
// We must invalidate the last_encoder_rate_settings_ to ensure
// the changes get propagated to all listeners.
EncoderRateSettings rate_settings = *last_encoder_rate_settings_;
last_encoder_rate_settings_.reset();
rate_settings.rate_control.framerate_fps = GetInputFramerateFps();
SetEncoderRates(UpdateBitrateAllocationAndNotifyObserver(rate_settings));
}
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(info);
}
void VideoStreamEncoder::ConfigureQualityScaler(
const VideoEncoder::EncoderInfo& encoder_info) {
RTC_DCHECK_RUN_ON(&encoder_queue_);
const auto scaling_settings = encoder_info.scaling_settings;
const bool quality_scaling_allowed =
IsResolutionScalingEnabled(degradation_preference_) &&
scaling_settings.thresholds;
if (quality_scaling_allowed) {
if (quality_scaler_ == 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, std::make_unique can't do this
// upcast.
AdaptationObserverInterface* observer = this;
quality_scaler_ = std::make_unique<QualityScaler>(
&encoder_queue_, 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;
}
if (degradation_preference_ == DegradationPreference::BALANCED &&
quality_scaler_ && last_frame_info_) {
absl::optional<VideoEncoder::QpThresholds> thresholds =
balanced_settings_.GetQpThresholds(encoder_config_.codec_type,
last_frame_info_->pixel_count());
if (thresholds) {
quality_scaler_->SetQpThresholds(*thresholds);
}
}
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_);
VideoFrame incoming_frame = video_frame;
// 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.";
encoder_queue_.PostTask([this, incoming_frame]() {
RTC_DCHECK_RUN_ON(&encoder_queue_);
accumulated_update_rect_.Union(incoming_frame.update_rect());
accumulated_update_rect_is_valid_ &= incoming_frame.has_update_rect();
});
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);
accumulated_update_rect_.Union(incoming_frame.update_rect());
accumulated_update_rect_is_valid_ &= incoming_frame.has_update_rect();
}
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_encoder_rate_settings_->encoder_target| will be 0.
return !last_encoder_rate_settings_ ||
last_encoder_rate_settings_->encoder_target == DataRate::Zero();
}
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;
}
VideoStreamEncoder::EncoderRateSettings
VideoStreamEncoder::UpdateBitrateAllocationAndNotifyObserver(
const EncoderRateSettings& rate_settings) {
VideoBitrateAllocation new_allocation;
// Only call allocators if bitrate > 0 (ie, not suspended), otherwise they
// might cap the bitrate to the min bitrate configured.
if (rate_allocator_ && rate_settings.encoder_target > DataRate::Zero()) {
new_allocation = rate_allocator_->Allocate(VideoBitrateAllocationParameters(
rate_settings.encoder_target, rate_settings.stable_encoder_target,
rate_settings.rate_control.framerate_fps));
}
if (bitrate_observer_ && new_allocation.get_sum_bps() > 0) {
if (encoder_ && encoder_initialized_) {
// Avoid too old encoder_info_.
const int64_t kMaxDiffMs = 100;
const bool updated_recently =
(last_encode_info_ms_ && ((clock_->TimeInMilliseconds() -
*last_encode_info_ms_) < kMaxDiffMs));
// Update allocation according to info from encoder.
bitrate_observer_->OnBitrateAllocationUpdated(
UpdateAllocationFromEncoderInfo(
new_allocation,
updated_recently ? encoder_info_ : encoder_->GetEncoderInfo()));
} else {
bitrate_observer_->OnBitrateAllocationUpdated(new_allocation);
}
}
EncoderRateSettings new_rate_settings = rate_settings;
new_rate_settings.rate_control.bitrate = new_allocation;
// VideoBitrateAllocator subclasses may allocate a bitrate higher than the
// target in order to sustain the min bitrate of the video codec. In this
// case, make sure the bandwidth allocation is at least equal the allocation
// as that is part of the document contract for that field.
new_rate_settings.rate_control.bandwidth_allocation = std::max(
new_rate_settings.rate_control.bandwidth_allocation,
DataRate::bps(new_rate_settings.rate_control.bitrate.get_sum_bps()));
if (bitrate_adjuster_) {
VideoBitrateAllocation adjusted_allocation =
bitrate_adjuster_->AdjustRateAllocation(new_rate_settings.rate_control);
RTC_LOG(LS_VERBOSE) << "Adjusting allocation, fps = "
<< rate_settings.rate_control.framerate_fps << ", from "
<< new_allocation.ToString() << ", to "
<< adjusted_allocation.ToString();
new_rate_settings.rate_control.bitrate = adjusted_allocation;
}
encoder_stats_observer_->OnBitrateAllocationUpdated(
send_codec_, new_rate_settings.rate_control.bitrate);
return new_rate_settings;
}
uint32_t VideoStreamEncoder::GetInputFramerateFps() {
const uint32_t default_fps = max_framerate_ != -1 ? max_framerate_ : 30;
absl::optional<uint32_t> input_fps =
input_framerate_.Rate(clock_->TimeInMilliseconds());
if (!input_fps || *input_fps == 0) {
return default_fps;
}
return *input_fps;
}
void VideoStreamEncoder::SetEncoderRates(
const EncoderRateSettings& rate_settings) {
RTC_DCHECK_GT(rate_settings.rate_control.framerate_fps, 0.0);
bool rate_control_changed =
(!last_encoder_rate_settings_.has_value() ||
last_encoder_rate_settings_->rate_control != rate_settings.rate_control);
if (last_encoder_rate_settings_ != rate_settings) {
last_encoder_rate_settings_ = rate_settings;
}
if (!encoder_) {
return;
}
// |bitrate_allocation| is 0 it means that the network is down or the send
// pacer is full. We currently only report this if the encoder has an internal
// source. If the encoder does not have an internal source, higher levels
// are expected to not call AddVideoFrame. We do this since its unclear
// how current encoder implementations behave when given a zero target
// bitrate.
// TODO(perkj): Make sure all known encoder implementations handle zero
// target bitrate and remove this check.
if (!HasInternalSource() &&
rate_settings.rate_control.bitrate.get_sum_bps() == 0) {
return;
}
if (rate_control_changed) {
encoder_->SetRates(rate_settings.rate_control);
frame_encode_metadata_writer_.OnSetRates(
rate_settings.rate_control.bitrate,
static_cast<uint32_t>(rate_settings.rate_control.framerate_fps + 0.5));
}
}
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 << ".";
// Force full frame update, since resolution has changed.
accumulated_update_rect_ =
VideoFrame::UpdateRect{0, 0, video_frame.width(), video_frame.height()};
}
// 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.
// Update input frame rate before we start using it. If we update it after
// any potential frame drop we are going to artificially increase frame sizes.
// Poll the rate before updating, otherwise we risk the rate being estimated
// a little too high at the start of the call when then window is small.
uint32_t framerate_fps = GetInputFramerateFps();
input_framerate_.Update(1u, clock_->TimeInMilliseconds());
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_ >=
kParameterUpdateIntervalMs) {
if (last_encoder_rate_settings_) {
// Clone rate settings before update, so that SetEncoderRates() will
// actually detect the change between the input and
// |last_encoder_rate_setings_|, triggering the call to SetRate() on the
// encoder.
EncoderRateSettings new_rate_settings = *last_encoder_rate_settings_;
new_rate_settings.rate_control.framerate_fps =
static_cast<double>(framerate_fps);
SetEncoderRates(
UpdateBitrateAllocationAndNotifyObserver(new_rate_settings));
}
last_parameters_update_ms_.emplace(now_ms);
}
// Because pending frame will be dropped in any case, we need to
// remember its updated region.
if (pending_frame_) {
encoder_stats_observer_->OnFrameDropped(
VideoStreamEncoderObserver::DropReason::kEncoderQueue);
accumulated_update_rect_.Union(pending_frame_->update_rect());
accumulated_update_rect_is_valid_ &= pending_frame_->has_update_rect();
}
if (DropDueToSize(video_frame.size())) {
RTC_LOG(LS_INFO) << "Dropping frame. Too large for target bitrate.";
int fps_count = GetConstAdaptCounter().FramerateCount(kQuality);
int res_count = GetConstAdaptCounter().ResolutionCount(kQuality);
AdaptDown(kQuality);
if (degradation_preference_ == DegradationPreference::BALANCED &&
GetConstAdaptCounter().FramerateCount(kQuality) > fps_count) {
// Adapt framerate in same step as resolution.
AdaptDown(kQuality);
}
if (GetConstAdaptCounter().ResolutionCount(kQuality) > res_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();
accumulated_update_rect_.Union(video_frame.update_rect());
accumulated_update_rect_is_valid_ &= video_frame.has_update_rect();
}
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();
accumulated_update_rect_.Union(video_frame.update_rect());
accumulated_update_rect_is_valid_ &= video_frame.has_update_rect();
}
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_encoder_rate_settings_
? last_encoder_rate_settings_->encoder_target.bps()
: 0)
<< ", input frame rate " << framerate_fps;
OnDroppedFrame(
EncodedImageCallback::DropReason::kDroppedByMediaOptimizations);
accumulated_update_rect_.Union(video_frame.update_rect());
accumulated_update_rect_is_valid_ &= video_frame.has_update_rect();
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_);
// If the encoder fail we can't continue to encode frames. When this happens
// the WebrtcVideoSender is notified and the whole VideoSendStream is
// recreated.
if (encoder_failed_)
return;
TraceFrameDropEnd();
// 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);
if (bitrate_adjuster_) {
// Encoder implementation changed, reset overshoot detector states.
bitrate_adjuster_->Reset();
}
}
if (bitrate_adjuster_) {
for (size_t si = 0; si < kMaxSpatialLayers; ++si) {
if (info.fps_allocation[si] != encoder_info_.fps_allocation[si]) {
bitrate_adjuster_->OnEncoderInfo(info);
break;
}
}
}
encoder_info_ = info;
last_encode_info_ms_ = clock_->TimeInMilliseconds();
VideoFrame out_frame(video_frame);
const VideoFrameBuffer::Type buffer_type =
out_frame.video_frame_buffer()->type();
const bool is_buffer_type_supported =
buffer_type == VideoFrameBuffer::Type::kI420 ||
(buffer_type == VideoFrameBuffer::Type::kNative &&
info.supports_native_handle);
if (!is_buffer_type_supported) {
// This module only supports software encoding.
rtc::scoped_refptr<I420BufferInterface> converted_buffer(
out_frame.video_frame_buffer()->ToI420());
if (!converted_buffer) {
RTC_LOG(LS_ERROR) << "Frame conversion failed, dropping frame.";
return;
}
VideoFrame::UpdateRect update_rect = out_frame.update_rect();
if (!update_rect.IsEmpty() &&
out_frame.video_frame_buffer()->GetI420() == nullptr) {
// UpdatedRect is reset to full update if it's not empty, and buffer was
// converted, therefore we can't guarantee that pixels outside of
// UpdateRect didn't change comparing to the previous frame.
update_rect =
VideoFrame::UpdateRect{0, 0, out_frame.width(), out_frame.height()};
}
out_frame.set_video_frame_buffer(converted_buffer);
out_frame.set_update_rect(update_rect);
}
// Crop frame if needed.
if ((crop_width_ > 0 || crop_height_ > 0) &&
out_frame.video_frame_buffer()->type() !=
VideoFrameBuffer::Type::kNative) {
// If the frame can't be converted to I420, drop it.
auto i420_buffer = video_frame.video_frame_buffer()->ToI420();
if (!i420_buffer) {
RTC_LOG(LS_ERROR) << "Frame conversion for crop failed, dropping frame.";
return;
}
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.
VideoFrame::UpdateRect update_rect = video_frame.update_rect();
if (crop_width_ < 4 && crop_height_ < 4) {
cropped_buffer->CropAndScaleFrom(*i420_buffer, crop_width_ / 2,
crop_height_ / 2, cropped_width,
cropped_height);
update_rect.offset_x -= crop_width_ / 2;
update_rect.offset_y -= crop_height_ / 2;
update_rect.Intersect(
VideoFrame::UpdateRect{0, 0, cropped_width, cropped_height});
} else {
cropped_buffer->ScaleFrom(*i420_buffer);
if (!update_rect.IsEmpty()) {
// Since we can't reason about pixels after scaling, we invalidate whole
// picture, if anything changed.
update_rect =
VideoFrame::UpdateRect{0, 0, cropped_width, cropped_height};
}
}
out_frame.set_video_frame_buffer(cropped_buffer);
out_frame.set_update_rect(update_rect);
out_frame.set_ntp_time_ms(video_frame.ntp_time_ms());
// Since accumulated_update_rect_ is constructed before cropping,
// we can't trust it. If any changes were pending, we invalidate whole
// frame here.
if (!accumulated_update_rect_.IsEmpty()) {
accumulated_update_rect_ =
VideoFrame::UpdateRect{0, 0, out_frame.width(), out_frame.height()};
accumulated_update_rect_is_valid_ = false;
}
}
if (!accumulated_update_rect_is_valid_) {
out_frame.clear_update_rect();
} else if (!accumulated_update_rect_.IsEmpty() &&
out_frame.has_update_rect()) {
accumulated_update_rect_.Union(out_frame.update_rect());
accumulated_update_rect_.Intersect(
VideoFrame::UpdateRect{0, 0, out_frame.width(), out_frame.height()});
out_frame.set_update_rect(accumulated_update_rect_);
accumulated_update_rect_.MakeEmptyUpdate();
}
accumulated_update_rect_is_valid_ = true;
TRACE_EVENT_ASYNC_STEP0("webrtc", "Video", video_frame.render_time_ms(),
"Encode");
overuse_detector_->FrameCaptured(out_frame, time_when_posted_us);
RTC_DCHECK_LE(send_codec_.width, out_frame.width());
RTC_DCHECK_LE(send_codec_.height, out_frame.height());
// Native frames should be scaled by the client.
// For internal encoders we scale everything in one place here.
RTC_DCHECK((out_frame.video_frame_buffer()->type() ==
VideoFrameBuffer::Type::kNative) ||
(send_codec_.width == out_frame.width() &&
send_codec_.height == out_frame.height()));
TRACE_EVENT1("webrtc", "VCMGenericEncoder::Encode", "timestamp",
out_frame.timestamp());
frame_encode_metadata_writer_.OnEncodeStarted(out_frame);
const int32_t encode_status = encoder_->Encode(out_frame, &next_frame_types_);
was_encode_called_since_last_initialization_ = true;
if (encode_status < 0) {
if (encode_status == WEBRTC_VIDEO_CODEC_ENCODER_FAILURE) {
RTC_LOG(LS_ERROR) << "Encoder failed, failing encoder format: "
<< encoder_config_.video_format.ToString();
if (settings_.encoder_switch_request_callback) {
encoder_failed_ = true;
settings_.encoder_switch_request_callback->RequestEncoderFallback();
} else {
RTC_LOG(LS_ERROR)
<< "Encoder failed but no encoder fallback callback is registered";
}
} else {
RTC_LOG(LS_ERROR) << "Failed to encode frame. Error code: "
<< encode_status;
}
return;
}
for (auto& it : next_frame_types_) {
it = VideoFrameType::kVideoFrameDelta;
}
}
void VideoStreamEncoder::SendKeyFrame() {
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask([this] { SendKeyFrame(); });
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
TRACE_EVENT0("webrtc", "OnKeyFrameRequest");
RTC_DCHECK(!next_frame_types_.empty());
// TODO(webrtc:10615): Map keyframe request to spatial layer.
std::fill(next_frame_types_.begin(), next_frame_types_.end(),
VideoFrameType::kVideoFrameKey);
if (HasInternalSource()) {
// Try to request the frame if we have an external encoder with
// internal source since AddVideoFrame never will be called.
// TODO(nisse): Used only with internal source. Delete as soon as
// that feature is removed. The only implementation I've been able
// to find ignores what's in the frame. With one exception: It seems
// a few test cases, e.g.,
// VideoSendStreamTest.VideoSendStreamStopSetEncoderRateToZero, set
// internal_source to true and use FakeEncoder. And the latter will
// happily encode this 1x1 frame and pass it on down the pipeline.
if (encoder_->Encode(VideoFrame::Builder()
.set_video_frame_buffer(I420Buffer::Create(1, 1))
.set_rotation(kVideoRotation_0)
.set_timestamp_us(0)
.build(),
&next_frame_types_) == WEBRTC_VIDEO_CODEC_OK) {
// Try to remove just-performed keyframe request, if stream still exists.
std::fill(next_frame_types_.begin(), next_frame_types_.end(),
VideoFrameType::kVideoFrameDelta);
}
}
}
void VideoStreamEncoder::OnLossNotification(
const VideoEncoder::LossNotification& loss_notification) {
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask(
[this, loss_notification] { OnLossNotification(loss_notification); });
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (encoder_) {
encoder_->OnLossNotification(loss_notification);
}
}
EncodedImageCallback::Result VideoStreamEncoder::OnEncodedImage(
const EncodedImage& encoded_image,
const CodecSpecificInfo* codec_specific_info,
const RTPFragmentationHeader* fragmentation) {
TRACE_EVENT_INSTANT1("webrtc", "VCMEncodedFrameCallback::Encoded",
"timestamp", encoded_image.Timestamp());
const size_t spatial_idx = encoded_image.SpatialIndex().value_or(0);
EncodedImage image_copy(encoded_image);
frame_encode_metadata_writer_.FillTimingInfo(spatial_idx, &image_copy);
std::unique_ptr<RTPFragmentationHeader> fragmentation_copy =
frame_encode_metadata_writer_.UpdateBitstream(codec_specific_info,
fragmentation, &image_copy);
// Piggyback ALR experiment group id and simulcast id into the content type.
const uint8_t experiment_id =
experiment_groups_[videocontenttypehelpers::IsScreenshare(
image_copy.content_type_)];
// TODO(ilnik): This will force content type extension to be present even
// for realtime video. At the expense of miniscule overhead we will get
// sliced receive statistics.
RTC_CHECK(videocontenttypehelpers::SetExperimentId(&image_copy.content_type_,
experiment_id));
// We count simulcast streams from 1 on the wire. That's why we set simulcast
// id in content type to +1 of that is actual simulcast index. This is because
// value 0 on the wire is reserved for 'no simulcast stream specified'.
RTC_CHECK(videocontenttypehelpers::SetSimulcastId(
&image_copy.content_type_, static_cast<uint8_t>(spatial_idx + 1)));
// 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(image_copy, codec_specific_info);
// The simulcast id is signaled in the SpatialIndex. This makes it impossible
// to do simulcast for codecs that actually support spatial layers since we
// can't distinguish between an actual spatial layer and a simulcast stream.
// TODO(bugs.webrtc.org/10520): Signal the simulcast id explicitly.
int simulcast_id = 0;
if (codec_specific_info &&
(codec_specific_info->codecType == kVideoCodecVP8 ||
codec_specific_info->codecType == kVideoCodecH264 ||
codec_specific_info->codecType == kVideoCodecGeneric)) {
simulcast_id = encoded_image.SpatialIndex().value_or(0);
}
std::unique_ptr<CodecSpecificInfo> codec_info_copy;
{
rtc::CritScope cs(&encoded_image_lock_);
if (codec_specific_info && codec_specific_info->generic_frame_info) {
codec_info_copy =
std::make_unique<CodecSpecificInfo>(*codec_specific_info);
GenericFrameInfo& generic_info = *codec_info_copy->generic_frame_info;
generic_info.frame_id = next_frame_id_++;
if (encoder_buffer_state_.size() <= static_cast<size_t>(simulcast_id)) {
RTC_LOG(LS_ERROR) << "At most " << encoder_buffer_state_.size()
<< " simulcast streams supported.";
} else {
std::array<int64_t, kMaxEncoderBuffers>& state =
encoder_buffer_state_[simulcast_id];
for (const CodecBufferUsage& buffer : generic_info.encoder_buffers) {
if (state.size() <= static_cast<size_t>(buffer.id)) {
RTC_LOG(LS_ERROR)
<< "At most " << state.size() << " encoder buffers supported.";
break;
}
if (buffer.referenced) {
int64_t diff = generic_info.frame_id - state[buffer.id];
if (diff <= 0) {
RTC_LOG(LS_ERROR) << "Invalid frame diff: " << diff << ".";
} else if (absl::c_find(generic_info.frame_diffs, diff) ==
generic_info.frame_diffs.end()) {
generic_info.frame_diffs.push_back(diff);
}
}
if (buffer.updated)
state[buffer.id] = generic_info.frame_id;
}
}
}
}
EncodedImageCallback::Result result = sink_->OnEncodedImage(
image_copy, codec_info_copy ? codec_info_copy.get() : codec_specific_info,
fragmentation_copy ? fragmentation_copy.get() : fragmentation);
// We are only interested in propagating the meta-data about the image, not
// encoded data itself, to the post encode function. Since we cannot be sure
// the pointer will still be valid when run on the task queue, set it to null.
image_copy.set_buffer(nullptr, 0);
int temporal_index = 0;
if (codec_specific_info) {
if (codec_specific_info->codecType == kVideoCodecVP9) {
temporal_index = codec_specific_info->codecSpecific.VP9.temporal_idx;
} else if (codec_specific_info->codecType == kVideoCodecVP8) {
temporal_index = codec_specific_info->codecSpecific.VP8.temporalIdx;
}
}
if (temporal_index == kNoTemporalIdx) {
temporal_index = 0;
}
RunPostEncode(image_copy, rtc::TimeMicros(), temporal_index);
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;
}
sink_->OnDroppedFrame(reason);
}
void VideoStreamEncoder::OnBitrateUpdated(DataRate target_bitrate,
DataRate stable_target_bitrate,
DataRate link_allocation,
uint8_t fraction_lost,
int64_t round_trip_time_ms) {
RTC_DCHECK_GE(link_allocation, target_bitrate);
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask([this, target_bitrate, stable_target_bitrate,
link_allocation, fraction_lost,
round_trip_time_ms] {
OnBitrateUpdated(target_bitrate, stable_target_bitrate, link_allocation,
fraction_lost, round_trip_time_ms);
});
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
if (encoder_switch_experiment_.IsBitrateBelowThreshold(target_bitrate) &&
settings_.encoder_switch_request_callback && !encoder_switch_requested_) {
EncoderSwitchRequestCallback::Config conf;
conf.codec_name = encoder_switch_experiment_.to_codec;
conf.param = encoder_switch_experiment_.to_param;
conf.value = encoder_switch_experiment_.to_value;
settings_.encoder_switch_request_callback->RequestEncoderSwitch(conf);
encoder_switch_requested_ = true;
}
RTC_DCHECK(sink_) << "sink_ must be set before the encoder is active.";
RTC_LOG(LS_VERBOSE) << "OnBitrateUpdated, bitrate " << target_bitrate.bps()
<< " stable bitrate = " << stable_target_bitrate.bps()
<< " link allocation bitrate = " << link_allocation.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(target_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;
}
if (set_start_bitrate_bps_ > 0 && !has_seen_first_bwe_drop_ &&
quality_scaler_ && quality_scaler_settings_.InitialBitrateIntervalMs() &&
quality_scaler_settings_.InitialBitrateFactor()) {
int64_t diff_ms = clock_->TimeInMilliseconds() - set_start_bitrate_time_ms_;
if (diff_ms < quality_scaler_settings_.InitialBitrateIntervalMs().value() &&
(target_bitrate.bps() <
(set_start_bitrate_bps_ *
quality_scaler_settings_.InitialBitrateFactor().value()))) {
RTC_LOG(LS_INFO) << "Reset initial_framedrop_. Start bitrate: "
<< set_start_bitrate_bps_
<< ", target bitrate: " << target_bitrate.bps();
initial_framedrop_ = 0;
has_seen_first_bwe_drop_ = true;
}
}
if (encoder_) {
encoder_->OnPacketLossRateUpdate(static_cast<float>(fraction_lost) / 256.f);
encoder_->OnRttUpdate(round_trip_time_ms);
}
uint32_t framerate_fps = GetInputFramerateFps();
frame_dropper_.SetRates((target_bitrate.bps() + 500) / 1000, framerate_fps);
const bool video_is_suspended = target_bitrate == DataRate::Zero();
const bool video_suspension_changed = video_is_suspended != EncoderPaused();
EncoderRateSettings new_rate_settings{
VideoBitrateAllocation(), static_cast<double>(framerate_fps),
link_allocation, target_bitrate, stable_target_bitrate};
SetEncoderRates(UpdateBitrateAllocationAndNotifyObserver(new_rate_settings));
encoder_start_bitrate_bps_ = target_bitrate.bps() != 0
? target_bitrate.bps()
: encoder_start_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) {
return false;
}
absl::optional<VideoEncoder::ResolutionBitrateLimits> encoder_bitrate_limits =
GetEncoderBitrateLimits(encoder_->GetEncoderInfo(), pixel_count);
if (encoder_bitrate_limits.has_value()) {
// Use bitrate limits provided by encoder.
return encoder_start_bitrate_bps_ <
static_cast<uint32_t>(encoder_bitrate_limits->min_start_bitrate_bps);
}
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;
}
bool 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;
bool did_adapt = true;
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 true;
}
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 true;
}
break;
case DegradationPreference::DISABLED:
return true;
}
switch (degradation_preference_) {
case DegradationPreference::BALANCED: {
// Try scale down framerate, if lower.
int fps = balanced_settings_.MinFps(encoder_config_.codec_type,
last_frame_info_->pixel_count());
if (source_proxy_->RestrictFramerate(fps)) {
GetAdaptCounter().IncrementFramerate(reason);
// Check if requested fps is higher (or close to) input fps.
absl::optional<int> min_diff =
balanced_settings_.MinFpsDiff(last_frame_info_->pixel_count());
if (min_diff && adaptation_request.framerate_fps_ > 0) {
int fps_diff = adaptation_request.framerate_fps_ - fps;
if (fps_diff < min_diff.value()) {
did_adapt = false;
}
}
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 true;
}
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 true;
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();
return did_adapt;
}
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: {
// Check if quality should be increased based on bitrate.
if (reason == kQuality &&
!balanced_settings_.CanAdaptUp(last_frame_info_->pixel_count(),
encoder_start_bitrate_bps_)) {
return;
}
// Try scale up framerate, if higher.
int fps = balanced_settings_.MaxFps(encoder_config_.codec_type,
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;
}
// Check if resolution should be increased based on bitrate.
if (reason == kQuality &&
!balanced_settings_.CanAdaptUpResolution(
last_frame_info_->pixel_count(), encoder_start_bitrate_bps_)) {
return;
}
// Scale up resolution.
RTC_FALLTHROUGH();
}
case DegradationPreference::MAINTAIN_FRAMERATE: {
// Check if resolution should be increased based on bitrate and
// limits specified by encoder capabilities.
if (reason == kQuality &&
!CanAdaptUpResolution(last_frame_info_->pixel_count(),
encoder_start_bitrate_bps_)) {
return;
}
// 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();
}
bool VideoStreamEncoder::CanAdaptUpResolution(int pixels,
uint32_t bitrate_bps) const {
absl::optional<VideoEncoder::ResolutionBitrateLimits> bitrate_limits =
GetEncoderBitrateLimits(encoder_info_,
source_proxy_->GetHigherResolutionThan(pixels));
if (!bitrate_limits.has_value() || bitrate_bps == 0) {
return true; // No limit configured or bitrate provided.
}
RTC_DCHECK_GE(bitrate_limits->frame_size_pixels, pixels);
return bitrate_bps >=
static_cast<uint32_t>(bitrate_limits->min_start_bitrate_bps);
}
// 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(EncodedImage encoded_image,
int64_t time_sent_us,
int temporal_index) {
if (!encoder_queue_.IsCurrent()) {
encoder_queue_.PostTask(
[this, encoded_image, time_sent_us, temporal_index] {
RunPostEncode(encoded_image, time_sent_us, temporal_index);
});
return;
}
RTC_DCHECK_RUN_ON(&encoder_queue_);
absl::optional<int> encode_duration_us;
if (encoded_image.timing_.flags != VideoSendTiming::kInvalid) {
encode_duration_us =
// 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 == VideoFrameType::kVideoFrameKey;
if (frame_size > 0) {
frame_dropper_.Fill(frame_size, !keyframe);
}
if (HasInternalSource()) {
// 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(
encoded_image.Timestamp(), time_sent_us,
encoded_image.capture_time_ms_ * rtc::kNumMicrosecsPerMillisec,
encode_duration_us);
if (quality_scaler_ && encoded_image.qp_ >= 0)
quality_scaler_->ReportQp(encoded_image.qp_, time_sent_us);
if (bitrate_adjuster_) {
bitrate_adjuster_->OnEncodedFrame(encoded_image, temporal_index);
}
}
bool VideoStreamEncoder::HasInternalSource() const {
// TODO(sprang): Checking both info from encoder and from encoder factory
// until we have deprecated and removed the encoder factory info.
return codec_info_.has_internal_source || encoder_info_.has_internal_source;
}
void VideoStreamEncoder::ReleaseEncoder() {
if (!encoder_ || !encoder_initialized_) {
return;
}
encoder_->Release();
encoder_initialized_ = false;
TRACE_EVENT0("webrtc", "VCMGenericEncoder::Release");
}
// 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())
absl::c_fill(fps_counters_, 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 absl::c_accumulate(counters, 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();
}
bool VideoStreamEncoder::EncoderSwitchExperiment::IsBitrateBelowThreshold(
const DataRate& target_bitrate) {
DataRate rate =
DataRate::kbps(bitrate_filter.Apply(1.0, target_bitrate.kbps()));
return current_thresholds.bitrate && rate < *current_thresholds.bitrate;
}
bool VideoStreamEncoder::EncoderSwitchExperiment::IsPixelCountBelowThreshold(
int pixel_count) const {
return current_thresholds.pixel_count &&
pixel_count < *current_thresholds.pixel_count;
}
void VideoStreamEncoder::EncoderSwitchExperiment::SetCodec(
VideoCodecType codec) {
auto it = codec_thresholds.find(codec);
if (it == codec_thresholds.end()) {
current_thresholds = {};
} else {
current_thresholds = it->second;
}
}
VideoStreamEncoder::EncoderSwitchExperiment
VideoStreamEncoder::ParseEncoderSwitchFieldTrial() const {
EncoderSwitchExperiment result;
// Each "codec threshold" have the format
// "<codec name>;<bitrate kbps>;<pixel count>", and are separated by the "|"
// character.
webrtc::FieldTrialOptional<std::string> codec_thresholds_string{
"codec_thresholds"};
webrtc::FieldTrialOptional<std::string> to_codec{"to_codec"};
webrtc::FieldTrialOptional<std::string> to_param{"to_param"};
webrtc::FieldTrialOptional<std::string> to_value{"to_value"};
webrtc::FieldTrialOptional<double> window{"window"};
webrtc::ParseFieldTrial(
{&codec_thresholds_string, &to_codec, &to_param, &to_value, &window},
webrtc::field_trial::FindFullName(
"WebRTC-NetworkCondition-EncoderSwitch"));
if (!codec_thresholds_string || !to_codec || !window) {
return {};
}
result.bitrate_filter.Reset(1.0 - 1.0 / *window);
result.to_codec = *to_codec;
result.to_param = to_param.GetOptional();
result.to_value = to_value.GetOptional();
std::vector<std::string> codecs_thresholds;
if (rtc::split(*codec_thresholds_string, '|', &codecs_thresholds) == 0) {
return {};
}
for (const std::string& codec_threshold : codecs_thresholds) {
std::vector<std::string> thresholds_split;
if (rtc::split(codec_threshold, ';', &thresholds_split) != 3) {
return {};
}
VideoCodecType codec = PayloadStringToCodecType(thresholds_split[0]);
int bitrate_kbps;
rtc::FromString(thresholds_split[1], &bitrate_kbps);
int pixel_count;
rtc::FromString(thresholds_split[2], &pixel_count);
if (bitrate_kbps > 0) {
result.codec_thresholds[codec].bitrate = DataRate::kbps(bitrate_kbps);
}
if (pixel_count > 0) {
result.codec_thresholds[codec].pixel_count = pixel_count;
}
if (!result.codec_thresholds[codec].bitrate &&
!result.codec_thresholds[codec].pixel_count) {
return {};
}
}
rtc::StringBuilder ss;
ss << "Successfully parsed WebRTC-NetworkCondition-EncoderSwitch field "
"trial."
<< " to_codec:" << result.to_codec
<< " to_param:" << result.to_param.value_or("<none>")
<< " to_value:" << result.to_value.value_or("<none>")
<< " codec_thresholds:";
for (auto kv : result.codec_thresholds) {
std::string codec_name = CodecTypeToPayloadString(kv.first);
std::string bitrate = kv.second.bitrate
? std::to_string(kv.second.bitrate->kbps())
: "<none>";
std::string pixels = kv.second.pixel_count
? std::to_string(*kv.second.pixel_count)
: "<none>";
ss << " (" << codec_name << ":" << bitrate << ":" << pixels << ")";
}
RTC_LOG(LS_INFO) << ss.str();
return result;
}
} // namespace webrtc