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content / browser / media / capture / desktop_capture_device.cc [blame]
// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/media/capture/desktop_capture_device.h"
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <algorithm>
#include <memory>
#include <utility>
#include "base/check_op.h"
#include "base/command_line.h"
#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/location.h"
#include "base/memory/raw_ptr.h"
#include "base/message_loop/message_pump_type.h"
#include "base/metrics/histogram_macros.h"
#include "base/notreached.h"
#include "base/strings/string_number_conversions.h"
#include "base/synchronization/lock.h"
#include "base/task/single_thread_task_runner.h"
#include "base/threading/thread.h"
#include "base/threading/thread_restrictions.h"
#include "base/time/tick_clock.h"
#include "base/timer/timer.h"
#include "base/trace_event/trace_event.h"
#include "build/build_config.h"
#include "build/chromeos_buildflags.h"
#include "content/browser/media/capture/desktop_capture_device_uma_types.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/desktop_capture.h"
#include "content/public/browser/desktop_media_id.h"
#include "content/public/browser/device_service.h"
#include "content/public/common/content_switches.h"
#include "media/base/video_util.h"
#include "media/capture/content/capture_resolution_chooser.h"
#include "media/webrtc/webrtc_features.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "services/device/public/mojom/wake_lock.mojom.h"
#include "services/device/public/mojom/wake_lock_provider.mojom.h"
#include "third_party/libyuv/include/libyuv/scale_argb.h"
#include "third_party/webrtc/modules/desktop_capture/cropped_desktop_frame.h"
#include "third_party/webrtc/modules/desktop_capture/cropping_window_capturer.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_and_cursor_composer.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_capture_options.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_capture_types.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
#include "third_party/webrtc/modules/desktop_capture/fake_desktop_capturer.h"
#include "third_party/webrtc/modules/desktop_capture/mouse_cursor_monitor.h"
#include "ui/gfx/icc_profile.h"
namespace content {
namespace {
// Maximum CPU time percentage of a single core that can be consumed for desktop
// capturing. This means that on systems where screen scraping is slow we may
// need to capture at frame rate lower than requested. This is necessary to keep
// UI responsive.
const int kDefaultMaximumCpuConsumptionPercentage = 50;
// Constant which sets the cutoff frequency in an an exponential moving average
// (EMA) filter used to calculate the current frame rate (in frames per second).
constexpr float kAlpha = 0.1;
const char* DesktopMediaTypeToString(DesktopMediaID::Type type) {
switch (type) {
case DesktopMediaID::TYPE_NONE:
return "NONE";
case DesktopMediaID::TYPE_SCREEN:
return "SCREEN";
case DesktopMediaID::TYPE_WINDOW:
return "WINDOW";
case DesktopMediaID::TYPE_WEB_CONTENTS:
return "WEB_CONTENTS";
default:
return "UNKNOWN";
}
}
webrtc::DesktopRect ComputeLetterboxRect(
const webrtc::DesktopSize& max_size,
const webrtc::DesktopSize& source_size) {
gfx::Rect result = media::ComputeLetterboxRegion(
gfx::Rect(0, 0, max_size.width(), max_size.height()),
gfx::Size(source_size.width(), source_size.height()));
return webrtc::DesktopRect::MakeLTRB(
result.x(), result.y(), result.right(), result.bottom());
}
bool IsFrameUnpackedOrInverted(webrtc::DesktopFrame* frame) {
return frame->stride() !=
frame->size().width() * webrtc::DesktopFrame::kBytesPerPixel;
}
void BindWakeLockProvider(
mojo::PendingReceiver<device::mojom::WakeLockProvider> receiver) {
DCHECK_CURRENTLY_ON(BrowserThread::UI);
GetDeviceService().BindWakeLockProvider(std::move(receiver));
}
void LogDesktopCaptureZeroHzIsActive(DesktopMediaID::Type capturer_type,
bool zero_hz_is_active) {
if (capturer_type == DesktopMediaID::TYPE_SCREEN) {
UMA_HISTOGRAM_BOOLEAN("WebRTC.DesktopCapture.IsZeroHzActive.Screen",
zero_hz_is_active);
} else {
UMA_HISTOGRAM_BOOLEAN("WebRTC.DesktopCapture.IsZeroHzActive.Window",
zero_hz_is_active);
}
}
void LogDesktopCaptureFrameIsRefresh(DesktopMediaID::Type capturer_type,
bool is_refresh_frame) {
if (capturer_type == DesktopMediaID::TYPE_SCREEN) {
UMA_HISTOGRAM_BOOLEAN("WebRTC.DesktopCapture.FrameIsRefresh.Screen",
is_refresh_frame);
} else {
UMA_HISTOGRAM_BOOLEAN("WebRTC.DesktopCapture.FrameIsRefresh.Window",
is_refresh_frame);
}
}
void LogDesktopCaptureFrameRate(DesktopMediaID::Type capturer_type,
int frame_rate_fps) {
if (capturer_type == DesktopMediaID::TYPE_SCREEN) {
UMA_HISTOGRAM_COUNTS_100("WebRTC.DesktopCapture.FrameRate.Screen",
frame_rate_fps);
} else {
UMA_HISTOGRAM_COUNTS_100("WebRTC.DesktopCapture.FrameRate.Window",
frame_rate_fps);
}
}
void LogDesktopCaptureRequestRefreshRate(DesktopMediaID::Type capturer_type,
int rrf_rate_fps) {
if (capturer_type == DesktopMediaID::TYPE_SCREEN) {
UMA_HISTOGRAM_COUNTS_100("WebRTC.DesktopCapture.RefreshRate.Screen",
rrf_rate_fps);
} else {
UMA_HISTOGRAM_COUNTS_100("WebRTC.DesktopCapture.RefreshRate.Window",
rrf_rate_fps);
}
}
// Helper class which request that the system-global Windows timer interrupt
// frequency be raised at construction. The corresponding deactivation is done
// at destruction. How high the frequency is raised depends on the system's
// power state and possibly other options. Only supported on Windows.
class ScopedHighResolutionTimer {
public:
#if !BUILDFLAG(IS_WIN)
ScopedHighResolutionTimer() {}
#else
ScopedHighResolutionTimer() {
if (!base::Time::IsHighResolutionTimerInUse()) {
enabled_ = base::Time::ActivateHighResolutionTimer(true);
}
}
~ScopedHighResolutionTimer() {
if (enabled_) {
base::Time::ActivateHighResolutionTimer(false);
}
}
private:
bool enabled_ = false;
#endif
};
} // namespace
class DesktopCaptureDevice::Core : public webrtc::DesktopCapturer::Callback {
public:
Core(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
std::unique_ptr<webrtc::DesktopCapturer> capturer,
DesktopMediaID::Type type,
bool zero_hertz_is_supported);
Core(const Core&) = delete;
Core& operator=(const Core&) = delete;
~Core() override;
// Implementation of VideoCaptureDevice methods.
void AllocateAndStart(const media::VideoCaptureParams& params,
std::unique_ptr<Client> client);
// Executes a refresh capture, if conditions permit. Otherwise, schedules a
// later retry. If a refresh was already pending, a new request is ignored.
void RequestRefreshFrame();
base::TimeDelta GetDelayBeforeNextRefreshAttempt() const;
void SetNotificationWindowId(gfx::NativeViewId window_id);
void SetMockTimeForTesting(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
const base::TickClock* tick_clock);
base::WeakPtr<Core> GetWeakPtr() { return weak_factory_.GetWeakPtr(); }
private:
// webrtc::DesktopCapturer::Callback interface.
// A side-effect of this method is to schedule the next frame.
void OnCaptureResult(
webrtc::DesktopCapturer::Result result,
std::unique_ptr<webrtc::DesktopFrame> frame) override;
// Method that is scheduled on |task_runner_| to be called on regular interval
// to capture a frame.
void OnCaptureTimer();
// Captures a frame. Upon completion, schedules the next frame. The frame type
// is a refresh frame if `is_refresh_frame` is true and a default frame
// otherwise. Sending refresh frames is expected to be a rare event since a
// refresh request will be canceled by default capture events and they are
// periodic.
void CaptureFrame(bool is_refresh_frame);
// Schedules a timer for the next call to |CaptureFrame|. This method assumes
// that |CaptureFrame| has already been called at least once before.
void ScheduleNextCaptureFrame();
void RequestWakeLock();
base::TimeTicks NowTicks() const;
bool zero_hertz_is_supported() const { return zero_hertz_is_supported_; }
// Requests high-resolution timers on Windows if not already active.
// Created in AllocateAndStart() and destroyed in ~Core().
std::unique_ptr<ScopedHighResolutionTimer> scoped_high_res_timer_;
// Task runner used for capturing operations.
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
// The underlying DesktopCapturer instance used to capture frames.
std::unique_ptr<webrtc::DesktopCapturer> desktop_capturer_;
// The device client which proxies device events to the controller. Accessed
// on the task_runner_ thread.
std::unique_ptr<Client> client_;
// Requested video capture frame rate.
float requested_frame_rate_;
// Inverse of the requested frame rate.
base::TimeDelta requested_frame_duration_;
// Contains the actual (measured) frame rate using an exponential moving
// average (EMA) filter. Uses a simple filter with 0.1 weight of the current
// sample. Unit is in frames per second (fps).
float frame_rate_;
// Contains the measured request-refresh rate using an exponential moving
// average (EMA) filter. Uses a simple filter with 0.1 weight of the current
// sample. Unit is in frames per second (fps).
float rrf_rate_;
// Records time of last call to CaptureFrame.
base::TimeTicks capture_start_time_;
// Size of frame most recently captured from the source.
webrtc::DesktopSize last_frame_size_;
// DesktopFrame into which captured frames are down-scaled and/or letterboxed,
// depending upon the caller's requested capture capabilities. If frames can
// be returned to the caller directly then this is NULL.
// TODO(https://crbug.com/1444340): should NOT be used to store frames
// received from the underlying capturer since it can cause cursor flickering
// if the frame is a DesktopFrameWithCursor. The output frame is black when
// |output_frame_is_black_| is set. This can happen when a minimized window
// is shared.
std::unique_ptr<webrtc::DesktopFrame> output_frame_;
// True when the |output_frame_->data()| contains only zeros. Tracking this is
// an optimization to avoid re-clearing |output_frame_| during stretches where
// we are only sending black frames.
bool output_frame_is_black_ = false;
// Determines the size of frames to deliver to the |client_|.
media::CaptureResolutionChooser resolution_chooser_;
raw_ptr<const base::TickClock> tick_clock_ = nullptr;
// Timer used to capture the frame.
std::unique_ptr<base::OneShotTimer> capture_timer_;
// See above description of kDefaultMaximumCpuConsumptionPercentage.
int max_cpu_consumption_percentage_;
// True when waiting for |desktop_capturer_| to capture current frame.
bool capture_in_progress_ = false;
// True when waiting for |desktop_capturer_| to capture current frame as a
// response to refresh frame request.
bool refresh_in_progress_ = false;
// True if the first capture call has returned. Used to log the first capture
// result.
bool first_capture_returned_ = false;
// True if the first capture permanent error has been logged. Used to log the
// first capture permanent error.
bool first_permanent_error_logged = false;
// The type of the capturer.
DesktopMediaID::Type capturer_type_;
// True if we support dropping captured frames where the updated region
// contains no change since last captured frame. To support this 0Hz mode,
// the utilized capturer implementation must updates the
// |DesktopFrame::updated_region()| desktop region for each captured frame.
const bool zero_hertz_is_supported_;
// The system time when we receive the first frame.
base::TimeTicks first_ref_time_;
// The time when Core::CaptureFrame() is called. Used to derive the delta
// time since last call. The delta time then drives the frame-rate filter
// which results in an average capture frame rate in `frame_rate_`.
base::TimeTicks last_capture_time_;
// The time when Core::RequestRefreshFrame() is called. Used to derive the
// delta time since last call. The delta time then drives the refresh-rate
// filter which results in an average refresh rate in `rrf_rate_`.
base::TimeTicks last_rrf_time_;
std::unique_ptr<webrtc::BasicDesktopFrame> black_frame_;
// TODO(jiayl): Remove wake_lock_ when there is an API to keep the
// screen from sleeping for the drive-by web.
mojo::Remote<device::mojom::WakeLock> wake_lock_;
base::WeakPtrFactory<Core> weak_factory_{this};
};
DesktopCaptureDevice::Core::Core(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
std::unique_ptr<webrtc::DesktopCapturer> capturer,
DesktopMediaID::Type type,
bool zero_hertz_is_supported)
: task_runner_(task_runner),
desktop_capturer_(std::move(capturer)),
capture_timer_(new base::OneShotTimer()),
max_cpu_consumption_percentage_(kDefaultMaximumCpuConsumptionPercentage),
capture_in_progress_(false),
first_capture_returned_(false),
first_permanent_error_logged(false),
capturer_type_(type),
zero_hertz_is_supported_(zero_hertz_is_supported) {}
DesktopCaptureDevice::Core::~Core() {
DCHECK(task_runner_->BelongsToCurrentThread());
client_.reset();
output_frame_.reset();
last_frame_size_.set(0, 0);
desktop_capturer_.reset();
}
void DesktopCaptureDevice::Core::AllocateAndStart(
const media::VideoCaptureParams& params,
std::unique_ptr<Client> client) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK_GT(params.requested_format.frame_size.GetArea(), 0);
DCHECK_GT(params.requested_format.frame_rate, 0);
DCHECK(desktop_capturer_);
DCHECK(client);
DCHECK(!client_);
scoped_high_res_timer_ = std::make_unique<ScopedHighResolutionTimer>();
client_ = std::move(client);
requested_frame_rate_ = params.requested_format.frame_rate;
frame_rate_ = requested_frame_rate_;
rrf_rate_ = 0;
requested_frame_duration_ = base::Microseconds(static_cast<int64_t>(
static_cast<double>(base::Time::kMicrosecondsPerSecond) /
requested_frame_rate_ +
0.5 /* round to nearest int */));
// Pass the min/max resolution and fixed aspect ratio settings from |params|
// to the CaptureResolutionChooser.
const auto constraints = params.SuggestConstraints();
resolution_chooser_.SetConstraints(constraints.min_frame_size,
constraints.max_frame_size,
constraints.fixed_aspect_ratio);
VLOG(1) << __func__ << " (requested_frame_rate=" << requested_frame_rate_
<< ", max_frame_size=" << constraints.max_frame_size.ToString()
<< ", requested_frame_duration="
<< requested_frame_duration_.InMilliseconds()
<< ", max_cpu_consumption_percentage="
<< max_cpu_consumption_percentage_ << ")";
DCHECK(!wake_lock_);
RequestWakeLock();
desktop_capturer_->Start(this);
// Assume it will be always started successfully for now.
client_->OnStarted();
CaptureFrame(/*is_refresh_frame=*/false);
}
void DesktopCaptureDevice::Core::RequestRefreshFrame() {
DCHECK(task_runner_->BelongsToCurrentThread());
TRACE_EVENT0("webrtc", __func__);
VLOG(2) << __func__;
if (!client_) {
return;
}
const base::TimeTicks now = NowTicks();
if (last_rrf_time_.is_null()) {
last_rrf_time_ = now;
} else {
const base::TimeDelta delta_ms = now - last_rrf_time_;
// We use an exponential moving average (EMA) filter to calculate the
// current RRF frame rate (in frames per second).
const float input_frame_rate_fps = (1000.0 / delta_ms.InMillisecondsF());
rrf_rate_ = kAlpha * input_frame_rate_fps + (1.0 - kAlpha) * rrf_rate_;
last_rrf_time_ = now;
VLOG(2) << " rrf_delta_ms=" << delta_ms.InMillisecondsF()
<< ", rrf_rate=" << frame_rate_ << " [fps]";
const int rrf_rate_fps = base::saturated_cast<int>(frame_rate_ + 0.5);
LogDesktopCaptureRequestRefreshRate(capturer_type_, rrf_rate_fps);
}
if (!capture_in_progress_) {
CaptureFrame(/*is_refresh_frame=*/true);
}
}
void DesktopCaptureDevice::Core::SetNotificationWindowId(
gfx::NativeViewId window_id) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(window_id);
desktop_capturer_->SetExcludedWindow(window_id);
}
void DesktopCaptureDevice::Core::SetMockTimeForTesting(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
const base::TickClock* tick_clock) {
tick_clock_ = tick_clock;
capture_timer_ = std::make_unique<base::OneShotTimer>(tick_clock_);
capture_timer_->SetTaskRunner(task_runner);
}
void DesktopCaptureDevice::Core::OnCaptureResult(
webrtc::DesktopCapturer::Result result,
std::unique_ptr<webrtc::DesktopFrame> frame) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(client_);
DCHECK(capture_in_progress_ || refresh_in_progress_);
capture_in_progress_ = false;
const bool frame_is_refresh = refresh_in_progress_;
refresh_in_progress_ = false;
TRACE_EVENT1("webrtc", __func__, "frame_is_refresh", frame_is_refresh);
bool success = result == webrtc::DesktopCapturer::Result::SUCCESS;
if (!first_capture_returned_) {
first_capture_returned_ = true;
if (capturer_type_ == DesktopMediaID::TYPE_SCREEN) {
IncrementDesktopCaptureCounter(success ? FIRST_SCREEN_CAPTURE_SUCCEEDED
: FIRST_SCREEN_CAPTURE_FAILED);
} else {
IncrementDesktopCaptureCounter(success ? FIRST_WINDOW_CAPTURE_SUCCEEDED
: FIRST_WINDOW_CAPTURE_FAILED);
}
}
if (!success) {
VLOG(2) << __func__ << " [ERROR]";
if (result == webrtc::DesktopCapturer::Result::ERROR_PERMANENT) {
if (!first_permanent_error_logged) {
first_permanent_error_logged = true;
if (capturer_type_ == DesktopMediaID::TYPE_SCREEN) {
IncrementDesktopCaptureCounter(SCREEN_CAPTURER_PERMANENT_ERROR);
} else {
IncrementDesktopCaptureCounter(WINDOW_CAPTURER_PERMANENT_ERROR);
}
}
client_->OnError(media::VideoCaptureError::
kDesktopCaptureDeviceWebrtcDesktopCapturerHasFailed,
FROM_HERE, "The desktop capturer has failed.");
return;
}
// Continue capturing frames in the temporary error case.
ScheduleNextCaptureFrame();
return;
}
DCHECK(frame);
// Continue capturing frames when there are no changes in updated regions
// since the last captured frame but don't send the same frame again to the
// client. Checking `first_ref_time_` ensures that at least one frame has been
// captured before 0Hz can be activated. The zero-hertz mode is disabled if
// the captured frame is a refresh frame to guarantee that the client actually
// receives a new frame when explicitly asking for it.
// |zero_hertz_is_supported()| can be false in combination with capturers that
// do not support the 0Hz mode, e.g. Windows capturers using the WGC API.
const bool zero_hertz_is_active =
zero_hertz_is_supported() && !first_ref_time_.is_null() &&
!frame_is_refresh && frame->updated_region().is_empty();
VLOG(2) << __func__ << " [SUCCESS]" << (frame_is_refresh ? "[RRF]" : "")
<< (zero_hertz_is_active ? "[0Hz]" : "");
if (zero_hertz_is_supported()) {
LogDesktopCaptureZeroHzIsActive(capturer_type_, zero_hertz_is_active);
}
if (zero_hertz_is_active) {
ScheduleNextCaptureFrame();
return;
}
// If the frame size has changed, drop the output frame (if any), and
// determine the new output size.
if (!last_frame_size_.equals(frame->size())) {
output_frame_.reset();
resolution_chooser_.SetSourceSize(
gfx::Size(frame->size().width(), frame->size().height()));
last_frame_size_ = frame->size();
}
// Align to 2x2 pixel boundaries, as required by OnIncomingCapturedData() so
// it can convert the frame to I420 format.
webrtc::DesktopSize output_size(
resolution_chooser_.capture_size().width() & ~1,
resolution_chooser_.capture_size().height() & ~1);
if (output_size.is_empty()) {
// Even RESOLUTION_POLICY_ANY_WITHIN_LIMIT is used, a non-empty size should
// be guaranteed.
output_size.set(2, 2);
}
VLOG(2) << __func__ << " [output_size=(" << output_size.width() << "x"
<< output_size.height() << ")]";
size_t output_bytes = output_size.width() * output_size.height() *
webrtc::DesktopFrame::kBytesPerPixel;
const uint8_t* output_data = nullptr;
if (frame->size().width() <= 1 || frame->size().height() <= 1) {
// On OSX We receive a 1x1 frame when the shared window is minimized. It
// cannot be subsampled to I420 and will be dropped downstream. So we
// replace it with a black frame to avoid the video appearing frozen at the
// last frame.
if (!output_frame_ || !output_frame_->size().equals(output_size)) {
// The new frame will be black by default.
output_frame_ = std::make_unique<webrtc::BasicDesktopFrame>(output_size);
output_frame_is_black_ = true;
}
if (!output_frame_is_black_) {
output_frame_->SetFrameDataToBlack();
output_frame_is_black_ = true;
}
} else {
// Scaling frame with odd dimensions to even dimensions will cause
// blurring. See https://crbug.com/737278.
// Since chromium always requests frames to be with even dimensions,
// i.e. for I420 format and video codec, always cropping captured frame
// to even dimensions.
const int32_t frame_width = frame->size().width();
const int32_t frame_height = frame->size().height();
// TODO(braveyao): remove the check once |CreateCroppedDesktopFrame| can
// do this check internally.
if (frame_width & 1 || frame_height & 1) {
frame = webrtc::CreateCroppedDesktopFrame(
std::move(frame),
webrtc::DesktopRect::MakeWH(frame_width & ~1, frame_height & ~1));
}
DCHECK(frame);
DCHECK(!frame->size().is_empty());
if (!frame->size().equals(output_size)) {
VLOG(2) << " Downscaling: frame->size=(" << frame->size().width() << "x"
<< frame->size().height() << ")";
// Down-scale and/or letterbox to the target format if the frame does
// not match the output size.
// Allocate a buffer of the correct size to scale the frame into.
// |output_frame_| is cleared whenever the output size changes, so we
// don't need to worry about clearing out stale pixel data in
// letterboxed areas.
if (!output_frame_) {
output_frame_ =
std::make_unique<webrtc::BasicDesktopFrame>(output_size);
}
DCHECK(output_frame_->size().equals(output_size));
// TODO(wez): Optimize this to scale only changed portions of the
// output, using ARGBScaleClip().
const webrtc::DesktopRect output_rect =
ComputeLetterboxRect(output_size, frame->size());
uint8_t* output_rect_data =
output_frame_->GetFrameDataAtPos(output_rect.top_left());
libyuv::ARGBScale(frame->data(), frame->stride(), frame->size().width(),
frame->size().height(), output_rect_data,
output_frame_->stride(), output_rect.width(),
output_rect.height(), libyuv::kFilterBilinear);
output_data = output_frame_->data();
output_frame_is_black_ = false;
} else if (IsFrameUnpackedOrInverted(frame.get())) {
// If |frame| is not packed top-to-bottom then create a packed
// top-to-bottom copy. This is required if the frame is inverted (see
// crbug.com/306876), or if |frame| is cropped form a larger frame (see
// crbug.com/437740).
if (!output_frame_) {
output_frame_ =
std::make_unique<webrtc::BasicDesktopFrame>(output_size);
}
output_frame_->CopyPixelsFrom(
*frame, webrtc::DesktopVector(),
webrtc::DesktopRect::MakeSize(frame->size()));
output_data = output_frame_->data();
output_frame_is_black_ = false;
} else {
// If the captured frame matches the output size, we can return the pixel
// data directly.
output_data = frame->data();
output_frame_is_black_ = false;
}
}
gfx::ColorSpace frame_color_space;
if (!frame->icc_profile().empty()) {
gfx::ICCProfile icc_profile = gfx::ICCProfile::FromData(
frame->icc_profile().data(), frame->icc_profile().size());
frame_color_space = icc_profile.GetColorSpace();
}
base::TimeTicks now = NowTicks();
if (first_ref_time_.is_null())
first_ref_time_ = now;
client_->OnIncomingCapturedData(
output_data, output_bytes,
media::VideoCaptureFormat(
gfx::Size(output_size.width(), output_size.height()),
requested_frame_rate_, media::PIXEL_FORMAT_ARGB),
frame_color_space, 0 /* clockwise_rotation */, false /* flip_y */, now,
now - first_ref_time_, std::nullopt);
ScheduleNextCaptureFrame();
}
void DesktopCaptureDevice::Core::OnCaptureTimer() {
DCHECK(task_runner_->BelongsToCurrentThread());
if (!client_)
return;
CaptureFrame(/*is_refresh_frame=*/false);
}
void DesktopCaptureDevice::Core::CaptureFrame(bool is_refresh_frame) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(!capture_in_progress_);
TRACE_EVENT1("webrtc", __func__, "is_refresh_frame", is_refresh_frame);
VLOG(2) << __func__ << "(is_refresh_frame=" << is_refresh_frame << ")";
LogDesktopCaptureFrameIsRefresh(capturer_type_, is_refresh_frame);
capture_start_time_ = NowTicks();
if (!is_refresh_frame) {
capture_in_progress_ = true;
} else {
refresh_in_progress_ = true;
}
// Track the average frame rate for the default capture path. Frame rate for
// request refresh frames is tracked separately by calls to
// RequestRefreshFrame (see `rrf_rate_`);
if (!is_refresh_frame) {
if (last_capture_time_.is_null()) {
last_capture_time_ = capture_start_time_;
} else {
const base::TimeDelta delta_ms = capture_start_time_ - last_capture_time_;
// We use an exponential moving average (EMA) filter to calculate the
// current frame rate (in frames per second). The filter has the following
// difference (time-domain) equation:
// y[i]=α⋅x[i]+(1-α)⋅y[i−1]
// where
// y is the output, [i] denotes the sample number, x is the input, and α
// is a constant which sets the cutoff frequency (a value between 0 and
// 1 where 1 corresponds to "no filtering").
// A value of α=0.1 results in a suitable amount of smoothing.
const float input_frame_rate_fps = (1000.0 / delta_ms.InMillisecondsF());
frame_rate_ =
kAlpha * input_frame_rate_fps + (1.0 - kAlpha) * frame_rate_;
last_capture_time_ = capture_start_time_;
VLOG(2) << " delta_ms=" << delta_ms.InMillisecondsF()
<< ", frame_rate=" << frame_rate_ << " [fps]";
const int frame_rate_fps = base::saturated_cast<int>(frame_rate_ + 0.5);
LogDesktopCaptureFrameRate(capturer_type_, frame_rate_fps);
}
}
desktop_capturer_->CaptureFrame();
}
void DesktopCaptureDevice::Core::ScheduleNextCaptureFrame() {
// Make sure CaptureFrame() was called at least once before.
DCHECK(!capture_start_time_.is_null());
base::TimeDelta last_capture_duration = NowTicks() - capture_start_time_;
VLOG(2) << __func__ << " [last_capture_duration="
<< last_capture_duration.InMilliseconds() << "]";
// Limit frame-rate to reduce CPU consumption.
base::TimeDelta capture_period =
std::max((last_capture_duration * 100) / max_cpu_consumption_percentage_,
requested_frame_duration_);
VLOG(2) << " capture_period=" << capture_period.InMilliseconds();
VLOG(2) << " timer(dT="
<< (capture_period - last_capture_duration).InMilliseconds() << ")";
// Schedule a task for the next frame.
capture_timer_->Start(FROM_HERE, capture_period - last_capture_duration, this,
&Core::OnCaptureTimer);
}
void DesktopCaptureDevice::Core::RequestWakeLock() {
mojo::Remote<device::mojom::WakeLockProvider> wake_lock_provider;
auto receiver = wake_lock_provider.BindNewPipeAndPassReceiver();
// TODO(crbug.com/41377723): Fix DesktopCaptureDeviceTest and remove
// this conditional.
if (BrowserThread::IsThreadInitialized(BrowserThread::UI)) {
GetUIThreadTaskRunner({})->PostTask(
FROM_HERE, base::BindOnce(&BindWakeLockProvider, std::move(receiver)));
}
wake_lock_provider->GetWakeLockWithoutContext(
device::mojom::WakeLockType::kPreventDisplaySleep,
device::mojom::WakeLockReason::kOther, "Native desktop capture",
wake_lock_.BindNewPipeAndPassReceiver());
wake_lock_->RequestWakeLock();
}
base::TimeTicks DesktopCaptureDevice::Core::NowTicks() const {
return tick_clock_ ? tick_clock_->NowTicks() : base::TimeTicks::Now();
}
// static
std::unique_ptr<media::VideoCaptureDevice> DesktopCaptureDevice::Create(
const DesktopMediaID& source) {
VLOG(1) << __func__ << "(source=" << source.ToString() << ")";
auto options = desktop_capture::CreateDesktopCaptureOptions();
std::unique_ptr<webrtc::DesktopCapturer> capturer;
std::unique_ptr<media::VideoCaptureDevice> result;
#if BUILDFLAG(IS_WIN)
options.set_allow_cropping_window_capturer(true);
// We prefer to allow the WGC and DXGI capturers to embed the cursor when
// possible. The DXGI implementation uses this switch in combination with
// internal checks for support of if it is possible to embed the cursor.
// Note that, very few graphical adapters support embedding the cursor into
// the captured frame in combination with DXGI; hence most cursors will be
// added separately by a desktop and cursor composer even if this option is
// set to true. GDI does not use this option.
// TODO(crbug.com/40259358): Possibly remove this flag. Keeping for now to
// force non embedded cursor for all capture APIs on Windows.
static BASE_FEATURE(kAllowWinCursorEmbedded, "AllowWinCursorEmbedded",
base::FEATURE_ENABLED_BY_DEFAULT);
if (base::FeatureList::IsEnabled(kAllowWinCursorEmbedded)) {
options.set_prefer_cursor_embedded(true);
}
if (base::FeatureList::IsEnabled(features::kWebRtcAllowWgcScreenCapturer)) {
options.set_allow_wgc_screen_capturer(true);
// 0Hz support is by default disabled for WGC but it can be enabled using
// the `kWebRtcAllowWgcZeroHz` feature flag. When enabled, the WGC capturer
// will compare the pixel values of the new frame and the previous frame and
// update the DesktopRegion part of the frame to reflect if the content has
// changed or not. DesktopFrame::updated_region() will be empty if nothing
// has changed and contain one (damage) region corresponding to the complete
// screen or window being captured if any change is detected.
if (source.type == DesktopMediaID::TYPE_SCREEN) {
options.set_allow_wgc_zero_hertz(
base::FeatureList::IsEnabled(features::kWebRtcAllowWgcScreenZeroHz));
}
}
if (base::FeatureList::IsEnabled(features::kWebRtcAllowWgcWindowCapturer)) {
options.set_allow_wgc_window_capturer(true);
if (source.type == DesktopMediaID::TYPE_WINDOW) {
options.set_allow_wgc_zero_hertz(
base::FeatureList::IsEnabled(features::kWebRtcAllowWgcWindowZeroHz));
}
}
VLOG(1) << "DesktopCaptureOptions: options={prefer_cursor_embedded: "
<< options.prefer_cursor_embedded() << ", allow_wgc_screen_capturer: "
<< options.allow_wgc_screen_capturer()
<< ", allow_wgc_window_capturer: "
<< options.allow_wgc_window_capturer()
<< ", allow_wgc_zero_hertz: " << options.allow_wgc_zero_hertz()
<< "}";
#endif
// For browser tests, to create a fake desktop capturer.
if (source.id == DesktopMediaID::kFakeId) {
capturer = std::make_unique<webrtc::FakeDesktopCapturer>();
result.reset(new DesktopCaptureDevice(std::move(capturer), source.type));
return result;
}
switch (source.type) {
case DesktopMediaID::TYPE_SCREEN: {
std::unique_ptr<webrtc::DesktopCapturer> screen_capturer(
webrtc::DesktopCapturer::CreateScreenCapturer(options));
if (screen_capturer && screen_capturer->SelectSource(source.id)) {
capturer = std::make_unique<webrtc::DesktopAndCursorComposer>(
std::move(screen_capturer), options);
IncrementDesktopCaptureCounter(SCREEN_CAPTURER_CREATED);
IncrementDesktopCaptureCounter(
source.audio_share ? SCREEN_CAPTURER_CREATED_WITH_AUDIO
: SCREEN_CAPTURER_CREATED_WITHOUT_AUDIO);
}
break;
}
case DesktopMediaID::TYPE_WINDOW: {
std::unique_ptr<webrtc::DesktopCapturer> window_capturer =
webrtc::DesktopCapturer::CreateWindowCapturer(options);
if (window_capturer && window_capturer->SelectSource(source.id)) {
capturer = std::make_unique<webrtc::DesktopAndCursorComposer>(
std::move(window_capturer), options);
IncrementDesktopCaptureCounter(WINDOW_CAPTURER_CREATED);
}
break;
}
default: {
NOTREACHED_IN_MIGRATION();
}
}
if (capturer)
result.reset(new DesktopCaptureDevice(std::move(capturer), source.type));
return result;
}
DesktopCaptureDevice::~DesktopCaptureDevice() {
DCHECK(!core_);
}
void DesktopCaptureDevice::AllocateAndStart(
const media::VideoCaptureParams& params,
std::unique_ptr<Client> client) {
thread_.task_runner()->PostTask(
FROM_HERE, base::BindOnce(&Core::AllocateAndStart, core_->GetWeakPtr(),
params, std::move(client)));
}
void DesktopCaptureDevice::StopAndDeAllocate() {
if (core_) {
// This thread should mostly be an idle observer. Stopping it should be
// fast.
base::ScopedAllowBaseSyncPrimitivesOutsideBlockingScope allow_thread_join;
thread_.task_runner()->DeleteSoon(FROM_HERE, core_.release());
thread_.Stop();
}
}
void DesktopCaptureDevice::RequestRefreshFrame() {
// Refresh request shall have no effect after the capturer has been stopped.
if (!core_) {
return;
}
thread_.task_runner()->PostTask(
FROM_HERE,
base::BindOnce(&Core::RequestRefreshFrame, core_->GetWeakPtr()));
}
void DesktopCaptureDevice::SetNotificationWindowId(
gfx::NativeViewId window_id) {
// This may be called after the capturer has been stopped.
if (!core_)
return;
thread_.task_runner()->PostTask(
FROM_HERE, base::BindOnce(&Core::SetNotificationWindowId,
core_->GetWeakPtr(), window_id));
}
DesktopCaptureDevice::DesktopCaptureDevice(
std::unique_ptr<webrtc::DesktopCapturer> capturer,
DesktopMediaID::Type type)
: thread_("desktopCaptureThread") {
DVLOG(1) << __func__ << "(type=" << DesktopMediaTypeToString(type) << ")";
#if BUILDFLAG(IS_WIN) || BUILDFLAG(IS_MAC)
// On Windows/OSX the thread must be a UI thread.
base::MessagePumpType thread_type = base::MessagePumpType::UI;
#else
base::MessagePumpType thread_type = base::MessagePumpType::DEFAULT;
#endif
bool zero_hertz_is_supported = true;
#if BUILDFLAG(IS_WIN)
const bool wgc_screen_zero_hertz =
base::FeatureList::IsEnabled(features::kWebRtcAllowWgcScreenZeroHz);
const bool wgc_window_zero_hertz =
base::FeatureList::IsEnabled(features::kWebRtcAllowWgcWindowZeroHz);
// TODO(crbug.com/40259358): 0Hz mode seems to cause a flickering
// cursor in some setups. This flag allows us to disable 0Hz when needed.
const bool dxgi_gdi_zero_hertz =
base::FeatureList::IsEnabled(features::kWebRtcAllowDxgiGdiZeroHz);
const bool wgc_screen_capturer =
base::FeatureList::IsEnabled(features::kWebRtcAllowWgcScreenCapturer);
const bool wgc_window_capturer =
base::FeatureList::IsEnabled(features::kWebRtcAllowWgcWindowCapturer);
if (!wgc_window_capturer && !wgc_screen_capturer) {
zero_hertz_is_supported = dxgi_gdi_zero_hertz;
} else if (!wgc_window_capturer && wgc_screen_capturer) {
zero_hertz_is_supported = (type == DesktopMediaID::TYPE_SCREEN)
? wgc_screen_zero_hertz
: dxgi_gdi_zero_hertz;
} else if (wgc_window_capturer && !wgc_screen_capturer) {
zero_hertz_is_supported = (type == DesktopMediaID::TYPE_WINDOW)
? wgc_window_zero_hertz
: dxgi_gdi_zero_hertz;
} else {
if (type == DesktopMediaID::TYPE_SCREEN) {
zero_hertz_is_supported = wgc_screen_zero_hertz;
} else if (type == DesktopMediaID::TYPE_WINDOW) {
zero_hertz_is_supported = wgc_window_zero_hertz;
} else {
zero_hertz_is_supported = false;
}
}
VLOG(1) << __func__ << " [zero_hertz_is_supported=" << zero_hertz_is_supported
<< "]";
#endif
thread_.StartWithOptions(base::Thread::Options(thread_type, 0));
core_ = std::make_unique<Core>(thread_.task_runner(), std::move(capturer),
type, zero_hertz_is_supported);
}
void DesktopCaptureDevice::SetMockTimeForTesting(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
const base::TickClock* tick_clock) {
core_->SetMockTimeForTesting(task_runner, tick_clock); // IN-TEST
}
} // namespace content