blob: 7b69165fc8646d07dd0f470be4138f0ce40fafbc [file] [log] [blame]
/*
* Copyright (c) 2021 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/frame_cadence_adapter.h"
#include <atomic>
#include <deque>
#include <memory>
#include <utility>
#include <vector>
#include "absl/algorithm/container.h"
#include "absl/base/attributes.h"
#include "api/sequence_checker.h"
#include "api/task_queue/task_queue_base.h"
#include "api/units/time_delta.h"
#include "api/video/video_frame.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/race_checker.h"
#include "rtc_base/rate_statistics.h"
#include "rtc_base/synchronization/mutex.h"
#include "rtc_base/system/no_unique_address.h"
#include "rtc_base/task_utils/pending_task_safety_flag.h"
#include "rtc_base/task_utils/to_queued_task.h"
#include "rtc_base/thread_annotations.h"
#include "rtc_base/time_utils.h"
#include "system_wrappers/include/clock.h"
#include "system_wrappers/include/field_trial.h"
#include "system_wrappers/include/metrics.h"
#include "system_wrappers/include/ntp_time.h"
namespace webrtc {
namespace {
// Abstracts concrete modes of the cadence adapter.
class AdapterMode {
public:
virtual ~AdapterMode() = default;
// Called on the worker thread for every frame that enters.
virtual void OnFrame(Timestamp post_time,
int frames_scheduled_for_processing,
const VideoFrame& frame) = 0;
// Returns the currently estimated input framerate.
virtual absl::optional<uint32_t> GetInputFrameRateFps() = 0;
// Updates the frame rate.
virtual void UpdateFrameRate() = 0;
};
// Implements a pass-through adapter. Single-threaded.
class PassthroughAdapterMode : public AdapterMode {
public:
PassthroughAdapterMode(Clock* clock,
FrameCadenceAdapterInterface::Callback* callback)
: clock_(clock), callback_(callback) {
sequence_checker_.Detach();
}
// Adapter overrides.
void OnFrame(Timestamp post_time,
int frames_scheduled_for_processing,
const VideoFrame& frame) override {
RTC_DCHECK_RUN_ON(&sequence_checker_);
callback_->OnFrame(post_time, frames_scheduled_for_processing, frame);
}
absl::optional<uint32_t> GetInputFrameRateFps() override {
RTC_DCHECK_RUN_ON(&sequence_checker_);
return input_framerate_.Rate(clock_->TimeInMilliseconds());
}
void UpdateFrameRate() override {
RTC_DCHECK_RUN_ON(&sequence_checker_);
input_framerate_.Update(1, clock_->TimeInMilliseconds());
}
private:
Clock* const clock_;
FrameCadenceAdapterInterface::Callback* const callback_;
RTC_NO_UNIQUE_ADDRESS SequenceChecker sequence_checker_;
// Input frame rate statistics for use when not in zero-hertz mode.
RateStatistics input_framerate_ RTC_GUARDED_BY(sequence_checker_){
FrameCadenceAdapterInterface::kFrameRateAveragingWindowSizeMs, 1000};
};
// Implements a frame cadence adapter supporting zero-hertz input.
class ZeroHertzAdapterMode : public AdapterMode {
public:
ZeroHertzAdapterMode(TaskQueueBase* queue,
Clock* clock,
FrameCadenceAdapterInterface::Callback* callback,
double max_fps);
// Reconfigures according to parameters.
// All spatial layer trackers are initialized as unconverged by this method.
void ReconfigureParameters(
const FrameCadenceAdapterInterface::ZeroHertzModeParams& params);
// Updates spatial layer quality convergence status.
void UpdateLayerQualityConvergence(int spatial_index, bool quality_converged);
// Updates spatial layer enabled status.
void UpdateLayerStatus(int spatial_index, bool enabled);
// Adapter overrides.
void OnFrame(Timestamp post_time,
int frames_scheduled_for_processing,
const VideoFrame& frame) override;
absl::optional<uint32_t> GetInputFrameRateFps() override;
void UpdateFrameRate() override {}
// Conditionally requests a refresh frame via
// Callback::RequestRefreshFrame.
void ProcessKeyFrameRequest();
private:
// The tracking state of each spatial layer. Used for determining when to
// stop repeating frames.
struct SpatialLayerTracker {
// If unset, the layer is disabled. Otherwise carries the quality
// convergence status of the layer.
absl::optional<bool> quality_converged;
};
// The state of a scheduled repeat.
struct ScheduledRepeat {
ScheduledRepeat(Timestamp origin,
int64_t origin_timestamp_us,
int64_t origin_ntp_time_ms)
: scheduled(origin),
idle(false),
origin(origin),
origin_timestamp_us(origin_timestamp_us),
origin_ntp_time_ms(origin_ntp_time_ms) {}
// The instant when the repeat was scheduled.
Timestamp scheduled;
// True if the repeat was scheduled as an idle repeat (long), false
// otherwise.
bool idle;
// The moment we decided to start repeating.
Timestamp origin;
// The timestamp_us of the frame when we started repeating.
int64_t origin_timestamp_us;
// The ntp_times_ms of the frame when we started repeating.
int64_t origin_ntp_time_ms;
};
// Returns true if all spatial layers can be considered to be converged in
// terms of quality.
// Convergence means QP has dropped to a low-enough level to warrant ceasing
// to send identical frames at high frequency.
bool HasQualityConverged() const RTC_RUN_ON(sequence_checker_);
// Resets quality convergence information. HasQualityConverged() returns false
// after this call.
void ResetQualityConvergenceInfo() RTC_RUN_ON(sequence_checker_);
// Processes incoming frames on a delayed cadence.
void ProcessOnDelayedCadence() RTC_RUN_ON(sequence_checker_);
// Schedules a later repeat with delay depending on state of layer trackers.
// If true is passed in `idle_repeat`, the repeat is going to be
// kZeroHertzIdleRepeatRatePeriod. Otherwise it'll be the value of
// `frame_delay`.
void ScheduleRepeat(int frame_id, bool idle_repeat)
RTC_RUN_ON(sequence_checker_);
// Repeats a frame in the abscence of incoming frames. Slows down when quality
// convergence is attained, and stops the cadence terminally when new frames
// have arrived.
void ProcessRepeatedFrameOnDelayedCadence(int frame_id)
RTC_RUN_ON(sequence_checker_);
// Sends a frame, updating the timestamp to the current time.
void SendFrameNow(const VideoFrame& frame) const
RTC_RUN_ON(sequence_checker_);
// Returns the repeat duration depending on if it's an idle repeat or not.
TimeDelta RepeatDuration(bool idle_repeat) const
RTC_RUN_ON(sequence_checker_);
TaskQueueBase* const queue_;
Clock* const clock_;
FrameCadenceAdapterInterface::Callback* const callback_;
// The configured max_fps.
// TODO(crbug.com/1255737): support max_fps updates.
const double max_fps_;
// How much the incoming frame sequence is delayed by.
const TimeDelta frame_delay_ = TimeDelta::Seconds(1) / max_fps_;
RTC_NO_UNIQUE_ADDRESS SequenceChecker sequence_checker_;
// A queue of incoming frames and repeated frames.
std::deque<VideoFrame> queued_frames_ RTC_GUARDED_BY(sequence_checker_);
// The current frame ID to use when starting to repeat frames. This is used
// for cancelling deferred repeated frame processing happening.
int current_frame_id_ RTC_GUARDED_BY(sequence_checker_) = 0;
// Has content when we are repeating frames.
absl::optional<ScheduledRepeat> scheduled_repeat_
RTC_GUARDED_BY(sequence_checker_);
// Convergent state of each of the configured simulcast layers.
std::vector<SpatialLayerTracker> layer_trackers_
RTC_GUARDED_BY(sequence_checker_);
ScopedTaskSafety safety_;
};
class FrameCadenceAdapterImpl : public FrameCadenceAdapterInterface {
public:
FrameCadenceAdapterImpl(Clock* clock, TaskQueueBase* queue);
~FrameCadenceAdapterImpl();
// FrameCadenceAdapterInterface overrides.
void Initialize(Callback* callback) override;
void SetZeroHertzModeEnabled(
absl::optional<ZeroHertzModeParams> params) override;
absl::optional<uint32_t> GetInputFrameRateFps() override;
void UpdateFrameRate() override;
void UpdateLayerQualityConvergence(int spatial_index,
bool quality_converged) override;
void UpdateLayerStatus(int spatial_index, bool enabled) override;
void ProcessKeyFrameRequest() override;
// VideoFrameSink overrides.
void OnFrame(const VideoFrame& frame) override;
void OnDiscardedFrame() override { callback_->OnDiscardedFrame(); }
void OnConstraintsChanged(
const VideoTrackSourceConstraints& constraints) override;
private:
// Called from OnFrame in zero-hertz mode.
void OnFrameOnMainQueue(Timestamp post_time,
int frames_scheduled_for_processing,
const VideoFrame& frame) RTC_RUN_ON(queue_);
// Returns true under all of the following conditions:
// - constraints min fps set to 0
// - constraints max fps set and greater than 0,
// - field trial enabled
// - zero-hertz mode enabled
bool IsZeroHertzScreenshareEnabled() const RTC_RUN_ON(queue_);
// Handles adapter creation on configuration changes.
void MaybeReconfigureAdapters(bool was_zero_hertz_enabled) RTC_RUN_ON(queue_);
// Called to report on constraint UMAs.
void MaybeReportFrameRateConstraintUmas() RTC_RUN_ON(queue_);
Clock* const clock_;
TaskQueueBase* const queue_;
// True if we support frame entry for screenshare with a minimum frequency of
// 0 Hz.
const bool zero_hertz_screenshare_enabled_;
// The two possible modes we're under.
absl::optional<PassthroughAdapterMode> passthrough_adapter_;
absl::optional<ZeroHertzAdapterMode> zero_hertz_adapter_;
// If set, zero-hertz mode has been enabled.
absl::optional<ZeroHertzModeParams> zero_hertz_params_;
// Cache for the current adapter mode.
AdapterMode* current_adapter_mode_ = nullptr;
// Set up during Initialize.
Callback* callback_ = nullptr;
// The source's constraints.
absl::optional<VideoTrackSourceConstraints> source_constraints_
RTC_GUARDED_BY(queue_);
// Race checker for incoming frames. This is the network thread in chromium,
// but may vary from test contexts.
rtc::RaceChecker incoming_frame_race_checker_;
bool has_reported_screenshare_frame_rate_umas_ RTC_GUARDED_BY(queue_) = false;
// Number of frames that are currently scheduled for processing on the
// `queue_`.
std::atomic<int> frames_scheduled_for_processing_{0};
// Whether to ask for a refresh frame on activation of zero-hertz mode.
bool should_request_refresh_frame_ RTC_GUARDED_BY(queue_) = false;
ScopedTaskSafetyDetached safety_;
};
ZeroHertzAdapterMode::ZeroHertzAdapterMode(
TaskQueueBase* queue,
Clock* clock,
FrameCadenceAdapterInterface::Callback* callback,
double max_fps)
: queue_(queue), clock_(clock), callback_(callback), max_fps_(max_fps) {
sequence_checker_.Detach();
}
void ZeroHertzAdapterMode::ReconfigureParameters(
const FrameCadenceAdapterInterface::ZeroHertzModeParams& params) {
RTC_DCHECK_RUN_ON(&sequence_checker_);
RTC_LOG(LS_INFO) << __func__ << " this " << this << " num_simulcast_layers "
<< params.num_simulcast_layers;
// Start as unconverged.
layer_trackers_.clear();
layer_trackers_.resize(params.num_simulcast_layers,
SpatialLayerTracker{false});
}
void ZeroHertzAdapterMode::UpdateLayerQualityConvergence(
int spatial_index,
bool quality_converged) {
RTC_DCHECK_RUN_ON(&sequence_checker_);
RTC_DCHECK_LT(spatial_index, layer_trackers_.size());
RTC_LOG(LS_INFO) << __func__ << " this " << this << " layer " << spatial_index
<< " quality has converged: " << quality_converged;
if (layer_trackers_[spatial_index].quality_converged.has_value())
layer_trackers_[spatial_index].quality_converged = quality_converged;
}
void ZeroHertzAdapterMode::UpdateLayerStatus(int spatial_index, bool enabled) {
RTC_DCHECK_RUN_ON(&sequence_checker_);
RTC_DCHECK_LT(spatial_index, layer_trackers_.size());
if (enabled) {
if (!layer_trackers_[spatial_index].quality_converged.has_value()) {
// Assume quality has not converged until hearing otherwise.
layer_trackers_[spatial_index].quality_converged = false;
}
} else {
layer_trackers_[spatial_index].quality_converged = absl::nullopt;
}
RTC_LOG(LS_INFO)
<< __func__ << " this " << this << " layer " << spatial_index
<< (enabled
? (layer_trackers_[spatial_index].quality_converged.has_value()
? " enabled."
: " enabled and it's assumed quality has not converged.")
: " disabled.");
}
void ZeroHertzAdapterMode::OnFrame(Timestamp post_time,
int frames_scheduled_for_processing,
const VideoFrame& frame) {
RTC_DCHECK_RUN_ON(&sequence_checker_);
RTC_DLOG(LS_VERBOSE) << "ZeroHertzAdapterMode::" << __func__ << " this "
<< this;
// Assume all enabled layers are unconverged after frame entry.
ResetQualityConvergenceInfo();
// Remove stored repeating frame if needed.
if (scheduled_repeat_.has_value()) {
RTC_DCHECK(queued_frames_.size() == 1);
RTC_DLOG(LS_VERBOSE) << __func__ << " this " << this
<< " cancel repeat and restart with original";
queued_frames_.pop_front();
}
// Store the frame in the queue and schedule deferred processing.
queued_frames_.push_back(frame);
current_frame_id_++;
scheduled_repeat_ = absl::nullopt;
queue_->PostDelayedTask(ToQueuedTask(safety_,
[this] {
RTC_DCHECK_RUN_ON(&sequence_checker_);
ProcessOnDelayedCadence();
}),
frame_delay_.ms());
}
absl::optional<uint32_t> ZeroHertzAdapterMode::GetInputFrameRateFps() {
RTC_DCHECK_RUN_ON(&sequence_checker_);
return max_fps_;
}
void ZeroHertzAdapterMode::ProcessKeyFrameRequest() {
RTC_DCHECK_RUN_ON(&sequence_checker_);
// If no frame was ever passed to us, request a refresh frame from the source.
if (current_frame_id_ == 0) {
RTC_LOG(LS_INFO)
<< __func__ << " this " << this
<< " requesting refresh frame due to no frames received yet.";
callback_->RequestRefreshFrame();
return;
}
// The next frame encoded will be a key frame. Reset quality convergence so we
// don't get idle repeats shortly after, because key frames need a lot of
// refinement frames.
ResetQualityConvergenceInfo();
// If we're not repeating, or we're repeating with short duration, we will
// very soon send out a frame and don't need a refresh frame.
if (!scheduled_repeat_.has_value() || !scheduled_repeat_->idle) {
RTC_LOG(LS_INFO) << __func__ << " this " << this
<< " not requesting refresh frame because of recently "
"incoming frame or short repeating.";
return;
}
// If the repeat is scheduled within a short (i.e. frame_delay_) interval, we
// will very soon send out a frame and don't need a refresh frame.
Timestamp now = clock_->CurrentTime();
if (scheduled_repeat_->scheduled + RepeatDuration(/*idle_repeat=*/true) -
now <=
frame_delay_) {
RTC_LOG(LS_INFO) << __func__ << " this " << this
<< " not requesting refresh frame because of soon "
"happening idle repeat";
return;
}
// Cancel the current repeat and reschedule a short repeat now. No need for a
// new refresh frame.
RTC_LOG(LS_INFO) << __func__ << " this " << this
<< " not requesting refresh frame and scheduling a short "
"repeat due to key frame request";
ScheduleRepeat(++current_frame_id_, /*idle_repeat=*/false);
return;
}
// RTC_RUN_ON(&sequence_checker_)
bool ZeroHertzAdapterMode::HasQualityConverged() const {
// 1. Define ourselves as unconverged with no spatial layers configured. This
// is to keep short repeating until the layer configuration comes.
// 2. Unset layers implicitly imply that they're converged to support
// disabling layers when they're not needed.
const bool quality_converged =
!layer_trackers_.empty() &&
absl::c_all_of(layer_trackers_, [](const SpatialLayerTracker& tracker) {
return tracker.quality_converged.value_or(true);
});
return quality_converged;
}
// RTC_RUN_ON(&sequence_checker_)
void ZeroHertzAdapterMode::ResetQualityConvergenceInfo() {
RTC_DLOG(LS_INFO) << __func__ << " this " << this;
for (auto& layer_tracker : layer_trackers_) {
if (layer_tracker.quality_converged.has_value())
layer_tracker.quality_converged = false;
}
}
// RTC_RUN_ON(&sequence_checker_)
void ZeroHertzAdapterMode::ProcessOnDelayedCadence() {
RTC_DCHECK(!queued_frames_.empty());
RTC_DLOG(LS_VERBOSE) << __func__ << " this " << this;
SendFrameNow(queued_frames_.front());
// If there were two or more frames stored, we do not have to schedule repeats
// of the front frame.
if (queued_frames_.size() > 1) {
queued_frames_.pop_front();
return;
}
// There's only one frame to send. Schedule a repeat sequence, which is
// cancelled by `current_frame_id_` getting incremented should new frames
// arrive.
ScheduleRepeat(current_frame_id_, HasQualityConverged());
}
// RTC_RUN_ON(&sequence_checker_)
void ZeroHertzAdapterMode::ScheduleRepeat(int frame_id, bool idle_repeat) {
RTC_DLOG(LS_VERBOSE) << __func__ << " this " << this << " frame_id "
<< frame_id;
Timestamp now = clock_->CurrentTime();
if (!scheduled_repeat_.has_value()) {
scheduled_repeat_.emplace(now, queued_frames_.front().timestamp_us(),
queued_frames_.front().ntp_time_ms());
}
scheduled_repeat_->scheduled = now;
scheduled_repeat_->idle = idle_repeat;
TimeDelta repeat_delay = RepeatDuration(idle_repeat);
queue_->PostDelayedTask(
ToQueuedTask(safety_,
[this, frame_id] {
RTC_DCHECK_RUN_ON(&sequence_checker_);
ProcessRepeatedFrameOnDelayedCadence(frame_id);
}),
repeat_delay.ms());
}
// RTC_RUN_ON(&sequence_checker_)
void ZeroHertzAdapterMode::ProcessRepeatedFrameOnDelayedCadence(int frame_id) {
RTC_DLOG(LS_VERBOSE) << __func__ << " this " << this << " frame_id "
<< frame_id;
RTC_DCHECK(!queued_frames_.empty());
// Cancel this invocation if new frames turned up.
if (frame_id != current_frame_id_)
return;
RTC_DCHECK(scheduled_repeat_.has_value());
VideoFrame& frame = queued_frames_.front();
// Since this is a repeated frame, nothing changed compared to before.
VideoFrame::UpdateRect empty_update_rect;
empty_update_rect.MakeEmptyUpdate();
frame.set_update_rect(empty_update_rect);
// Adjust timestamps of the frame of the repeat, accounting for the actual
// delay since we started repeating.
//
// NOTE: No need to update the RTP timestamp as the VideoStreamEncoder
// overwrites it based on its chosen NTP timestamp source.
TimeDelta total_delay = clock_->CurrentTime() - scheduled_repeat_->origin;
if (frame.timestamp_us() > 0) {
frame.set_timestamp_us(scheduled_repeat_->origin_timestamp_us +
total_delay.us());
}
if (frame.ntp_time_ms()) {
frame.set_ntp_time_ms(scheduled_repeat_->origin_ntp_time_ms +
total_delay.ms());
}
SendFrameNow(frame);
// Schedule another repeat.
ScheduleRepeat(frame_id, HasQualityConverged());
}
// RTC_RUN_ON(&sequence_checker_)
void ZeroHertzAdapterMode::SendFrameNow(const VideoFrame& frame) const {
RTC_DLOG(LS_VERBOSE) << __func__ << " this " << this << " timestamp "
<< frame.timestamp() << " timestamp_us "
<< frame.timestamp_us() << " ntp_time_ms "
<< frame.ntp_time_ms();
// TODO(crbug.com/1255737): figure out if frames_scheduled_for_processing
// makes sense to compute in this implementation.
callback_->OnFrame(/*post_time=*/clock_->CurrentTime(),
/*frames_scheduled_for_processing=*/1, frame);
}
// RTC_RUN_ON(&sequence_checker_)
TimeDelta ZeroHertzAdapterMode::RepeatDuration(bool idle_repeat) const {
return idle_repeat
? FrameCadenceAdapterInterface::kZeroHertzIdleRepeatRatePeriod
: frame_delay_;
}
FrameCadenceAdapterImpl::FrameCadenceAdapterImpl(Clock* clock,
TaskQueueBase* queue)
: clock_(clock),
queue_(queue),
zero_hertz_screenshare_enabled_(
!field_trial::IsDisabled("WebRTC-ZeroHertzScreenshare")) {}
FrameCadenceAdapterImpl::~FrameCadenceAdapterImpl() {
RTC_DLOG(LS_VERBOSE) << __func__ << " this " << this;
}
void FrameCadenceAdapterImpl::Initialize(Callback* callback) {
callback_ = callback;
passthrough_adapter_.emplace(clock_, callback);
current_adapter_mode_ = &passthrough_adapter_.value();
}
void FrameCadenceAdapterImpl::SetZeroHertzModeEnabled(
absl::optional<ZeroHertzModeParams> params) {
RTC_DCHECK_RUN_ON(queue_);
bool was_zero_hertz_enabled = zero_hertz_params_.has_value();
if (params.has_value() && !was_zero_hertz_enabled)
has_reported_screenshare_frame_rate_umas_ = false;
zero_hertz_params_ = params;
MaybeReconfigureAdapters(was_zero_hertz_enabled);
}
absl::optional<uint32_t> FrameCadenceAdapterImpl::GetInputFrameRateFps() {
RTC_DCHECK_RUN_ON(queue_);
return current_adapter_mode_->GetInputFrameRateFps();
}
void FrameCadenceAdapterImpl::UpdateFrameRate() {
RTC_DCHECK_RUN_ON(queue_);
// The frame rate need not be updated for the zero-hertz adapter. The
// passthrough adapter however uses it. Always pass frames into the
// passthrough to keep the estimation alive should there be an adapter switch.
passthrough_adapter_->UpdateFrameRate();
}
void FrameCadenceAdapterImpl::UpdateLayerQualityConvergence(
int spatial_index,
bool quality_converged) {
if (zero_hertz_adapter_.has_value())
zero_hertz_adapter_->UpdateLayerQualityConvergence(spatial_index,
quality_converged);
}
void FrameCadenceAdapterImpl::UpdateLayerStatus(int spatial_index,
bool enabled) {
if (zero_hertz_adapter_.has_value())
zero_hertz_adapter_->UpdateLayerStatus(spatial_index, enabled);
}
void FrameCadenceAdapterImpl::ProcessKeyFrameRequest() {
RTC_DCHECK_RUN_ON(queue_);
if (zero_hertz_adapter_)
zero_hertz_adapter_->ProcessKeyFrameRequest();
else
should_request_refresh_frame_ = true;
}
void FrameCadenceAdapterImpl::OnFrame(const VideoFrame& frame) {
// This method is called on the network thread under Chromium, or other
// various contexts in test.
RTC_DCHECK_RUNS_SERIALIZED(&incoming_frame_race_checker_);
RTC_DLOG(LS_VERBOSE) << "FrameCadenceAdapterImpl::" << __func__ << " this "
<< this;
// Local time in webrtc time base.
Timestamp post_time = clock_->CurrentTime();
frames_scheduled_for_processing_.fetch_add(1, std::memory_order_relaxed);
queue_->PostTask(ToQueuedTask(safety_.flag(), [this, post_time, frame] {
RTC_DCHECK_RUN_ON(queue_);
const int frames_scheduled_for_processing =
frames_scheduled_for_processing_.fetch_sub(1,
std::memory_order_relaxed);
OnFrameOnMainQueue(post_time, frames_scheduled_for_processing,
std::move(frame));
MaybeReportFrameRateConstraintUmas();
}));
}
void FrameCadenceAdapterImpl::OnConstraintsChanged(
const VideoTrackSourceConstraints& constraints) {
RTC_LOG(LS_INFO) << __func__ << " this " << this << " min_fps "
<< constraints.min_fps.value_or(-1) << " max_fps "
<< constraints.max_fps.value_or(-1);
queue_->PostTask(ToQueuedTask(safety_.flag(), [this, constraints] {
RTC_DCHECK_RUN_ON(queue_);
bool was_zero_hertz_enabled = IsZeroHertzScreenshareEnabled();
source_constraints_ = constraints;
MaybeReconfigureAdapters(was_zero_hertz_enabled);
}));
}
// RTC_RUN_ON(queue_)
void FrameCadenceAdapterImpl::OnFrameOnMainQueue(
Timestamp post_time,
int frames_scheduled_for_processing,
const VideoFrame& frame) {
current_adapter_mode_->OnFrame(post_time, frames_scheduled_for_processing,
frame);
}
// RTC_RUN_ON(queue_)
bool FrameCadenceAdapterImpl::IsZeroHertzScreenshareEnabled() const {
return zero_hertz_screenshare_enabled_ && source_constraints_.has_value() &&
source_constraints_->max_fps.value_or(-1) > 0 &&
source_constraints_->min_fps.value_or(-1) == 0 &&
zero_hertz_params_.has_value();
}
// RTC_RUN_ON(queue_)
void FrameCadenceAdapterImpl::MaybeReconfigureAdapters(
bool was_zero_hertz_enabled) {
bool is_zero_hertz_enabled = IsZeroHertzScreenshareEnabled();
if (is_zero_hertz_enabled) {
if (!was_zero_hertz_enabled) {
zero_hertz_adapter_.emplace(queue_, clock_, callback_,
source_constraints_->max_fps.value());
RTC_LOG(LS_INFO) << "Zero hertz mode activated.";
if (should_request_refresh_frame_) {
// Ensure we get a first frame to work with.
should_request_refresh_frame_ = false;
callback_->RequestRefreshFrame();
}
}
zero_hertz_adapter_->ReconfigureParameters(zero_hertz_params_.value());
current_adapter_mode_ = &zero_hertz_adapter_.value();
} else {
if (was_zero_hertz_enabled)
zero_hertz_adapter_ = absl::nullopt;
current_adapter_mode_ = &passthrough_adapter_.value();
}
}
// RTC_RUN_ON(queue_)
void FrameCadenceAdapterImpl::MaybeReportFrameRateConstraintUmas() {
if (has_reported_screenshare_frame_rate_umas_)
return;
has_reported_screenshare_frame_rate_umas_ = true;
if (!zero_hertz_params_.has_value())
return;
RTC_HISTOGRAM_BOOLEAN("WebRTC.Screenshare.FrameRateConstraints.Exists",
source_constraints_.has_value());
if (!source_constraints_.has_value())
return;
RTC_HISTOGRAM_BOOLEAN("WebRTC.Screenshare.FrameRateConstraints.Min.Exists",
source_constraints_->min_fps.has_value());
if (source_constraints_->min_fps.has_value()) {
RTC_HISTOGRAM_COUNTS_100(
"WebRTC.Screenshare.FrameRateConstraints.Min.Value",
source_constraints_->min_fps.value());
}
RTC_HISTOGRAM_BOOLEAN("WebRTC.Screenshare.FrameRateConstraints.Max.Exists",
source_constraints_->max_fps.has_value());
if (source_constraints_->max_fps.has_value()) {
RTC_HISTOGRAM_COUNTS_100(
"WebRTC.Screenshare.FrameRateConstraints.Max.Value",
source_constraints_->max_fps.value());
}
if (!source_constraints_->min_fps.has_value()) {
if (source_constraints_->max_fps.has_value()) {
RTC_HISTOGRAM_COUNTS_100(
"WebRTC.Screenshare.FrameRateConstraints.MinUnset.Max",
source_constraints_->max_fps.value());
}
} else if (source_constraints_->max_fps.has_value()) {
if (source_constraints_->min_fps.value() <
source_constraints_->max_fps.value()) {
RTC_HISTOGRAM_COUNTS_100(
"WebRTC.Screenshare.FrameRateConstraints.MinLessThanMax.Min",
source_constraints_->min_fps.value());
RTC_HISTOGRAM_COUNTS_100(
"WebRTC.Screenshare.FrameRateConstraints.MinLessThanMax.Max",
source_constraints_->max_fps.value());
}
// Multi-dimensional histogram for min and max FPS making it possible to
// uncover min and max combinations. See
// https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md#multidimensional-histograms
constexpr int kMaxBucketCount =
60 * /*max min_fps=*/60 + /*max max_fps=*/60 - 1;
RTC_HISTOGRAM_ENUMERATION_SPARSE(
"WebRTC.Screenshare.FrameRateConstraints.60MinPlusMaxMinusOne",
source_constraints_->min_fps.value() * 60 +
source_constraints_->max_fps.value() - 1,
/*boundary=*/kMaxBucketCount);
}
}
} // namespace
std::unique_ptr<FrameCadenceAdapterInterface>
FrameCadenceAdapterInterface::Create(Clock* clock, TaskQueueBase* queue) {
return std::make_unique<FrameCadenceAdapterImpl>(clock, queue);
}
} // namespace webrtc