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/*
* Copyright (c) 2016 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 "modules/desktop_capture/win/dxgi_duplicator_controller.h"
#include <windows.h>
#include <algorithm>
#include <string>
#include "modules/desktop_capture/desktop_capture_types.h"
#include "modules/desktop_capture/win/dxgi_frame.h"
#include "modules/desktop_capture/win/screen_capture_utils.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/time_utils.h"
#include "system_wrappers/include/sleep.h"
namespace webrtc {
namespace {
constexpr DWORD kInvalidSessionId = 0xFFFFFFFF;
DWORD GetCurrentSessionId() {
DWORD session_id = kInvalidSessionId;
if (!::ProcessIdToSessionId(::GetCurrentProcessId(), &session_id)) {
RTC_LOG(LS_WARNING)
<< "Failed to retrieve current session Id, current binary "
"may not have required priviledge.";
}
return session_id;
}
bool IsConsoleSession() {
return WTSGetActiveConsoleSessionId() == GetCurrentSessionId();
}
} // namespace
// static
std::string DxgiDuplicatorController::ResultName(
DxgiDuplicatorController::Result result) {
switch (result) {
case Result::SUCCEEDED:
return "Succeeded";
case Result::UNSUPPORTED_SESSION:
return "Unsupported session";
case Result::FRAME_PREPARE_FAILED:
return "Frame preparation failed";
case Result::INITIALIZATION_FAILED:
return "Initialization failed";
case Result::DUPLICATION_FAILED:
return "Duplication failed";
case Result::INVALID_MONITOR_ID:
return "Invalid monitor id";
default:
return "Unknown error";
}
}
// static
rtc::scoped_refptr<DxgiDuplicatorController>
DxgiDuplicatorController::Instance() {
// The static instance won't be deleted to ensure it can be used by other
// threads even during program exiting.
static DxgiDuplicatorController* instance = new DxgiDuplicatorController();
return rtc::scoped_refptr<DxgiDuplicatorController>(instance);
}
// static
bool DxgiDuplicatorController::IsCurrentSessionSupported() {
DWORD current_session_id = GetCurrentSessionId();
return current_session_id != kInvalidSessionId && current_session_id != 0;
}
DxgiDuplicatorController::DxgiDuplicatorController() : refcount_(0) {}
void DxgiDuplicatorController::AddRef() {
int refcount = (++refcount_);
RTC_DCHECK(refcount > 0);
}
void DxgiDuplicatorController::Release() {
int refcount = (--refcount_);
RTC_DCHECK(refcount >= 0);
if (refcount == 0) {
RTC_LOG(LS_WARNING) << "Count of references reaches zero, "
"DxgiDuplicatorController will be unloaded.";
Unload();
}
}
bool DxgiDuplicatorController::IsSupported() {
MutexLock lock(&mutex_);
return Initialize();
}
bool DxgiDuplicatorController::RetrieveD3dInfo(D3dInfo* info) {
bool result = false;
{
MutexLock lock(&mutex_);
result = Initialize();
*info = d3d_info_;
}
if (!result) {
RTC_LOG(LS_WARNING) << "Failed to initialize DXGI components, the D3dInfo "
"retrieved may not accurate or out of date.";
}
return result;
}
DxgiDuplicatorController::Result DxgiDuplicatorController::Duplicate(
DxgiFrame* frame) {
return DoDuplicate(frame, -1);
}
DxgiDuplicatorController::Result DxgiDuplicatorController::DuplicateMonitor(
DxgiFrame* frame,
int monitor_id) {
RTC_DCHECK_GE(monitor_id, 0);
return DoDuplicate(frame, monitor_id);
}
DesktopVector DxgiDuplicatorController::system_dpi() {
MutexLock lock(&mutex_);
if (Initialize()) {
return system_dpi_;
}
return DesktopVector();
}
int DxgiDuplicatorController::ScreenCount() {
MutexLock lock(&mutex_);
if (Initialize()) {
return ScreenCountUnlocked();
}
return 0;
}
bool DxgiDuplicatorController::GetDeviceNames(
std::vector<std::string>* output) {
MutexLock lock(&mutex_);
if (Initialize()) {
GetDeviceNamesUnlocked(output);
return true;
}
return false;
}
DxgiDuplicatorController::Result DxgiDuplicatorController::DoDuplicate(
DxgiFrame* frame,
int monitor_id) {
RTC_DCHECK(frame);
MutexLock lock(&mutex_);
// The dxgi components and APIs do not update the screen resolution without
// a reinitialization. So we use the GetDC() function to retrieve the screen
// resolution to decide whether dxgi components need to be reinitialized.
// If the screen resolution changed, it's very likely the next Duplicate()
// function call will fail because of a missing monitor or the frame size is
// not enough to store the output. So we reinitialize dxgi components in-place
// to avoid a capture failure.
// But there is no guarantee GetDC() function returns the same resolution as
// dxgi APIs, we still rely on dxgi components to return the output frame
// size.
// TODO(zijiehe): Confirm whether IDXGIOutput::GetDesc() and
// IDXGIOutputDuplication::GetDesc() can detect the resolution change without
// reinitialization.
if (display_configuration_monitor_.IsChanged(frame->source_id_)) {
Deinitialize();
}
if (!Initialize()) {
if (succeeded_duplications_ == 0 && !IsCurrentSessionSupported()) {
RTC_LOG(LS_WARNING) << "Current binary is running in session 0. DXGI "
"components cannot be initialized.";
return Result::UNSUPPORTED_SESSION;
}
// Cannot initialize COM components now, display mode may be changing.
return Result::INITIALIZATION_FAILED;
}
if (!frame->Prepare(SelectedDesktopSize(monitor_id), monitor_id)) {
return Result::FRAME_PREPARE_FAILED;
}
frame->frame()->mutable_updated_region()->Clear();
if (DoDuplicateUnlocked(frame->context(), monitor_id, frame->frame())) {
succeeded_duplications_++;
return Result::SUCCEEDED;
}
if (monitor_id >= ScreenCountUnlocked()) {
// It's a user error to provide a `monitor_id` larger than screen count. We
// do not need to deinitialize.
return Result::INVALID_MONITOR_ID;
}
// If the `monitor_id` is valid, but DoDuplicateUnlocked() failed, something
// must be wrong from capturer APIs. We should Deinitialize().
Deinitialize();
return Result::DUPLICATION_FAILED;
}
void DxgiDuplicatorController::Unload() {
MutexLock lock(&mutex_);
Deinitialize();
}
void DxgiDuplicatorController::Unregister(const Context* const context) {
MutexLock lock(&mutex_);
if (ContextExpired(context)) {
// The Context has not been setup after a recent initialization, so it
// should not been registered in duplicators.
return;
}
for (size_t i = 0; i < duplicators_.size(); i++) {
duplicators_[i].Unregister(&context->contexts[i]);
}
}
bool DxgiDuplicatorController::Initialize() {
if (!duplicators_.empty()) {
return true;
}
if (DoInitialize()) {
return true;
}
Deinitialize();
return false;
}
bool DxgiDuplicatorController::DoInitialize() {
RTC_DCHECK(desktop_rect_.is_empty());
RTC_DCHECK(duplicators_.empty());
d3d_info_.min_feature_level = static_cast<D3D_FEATURE_LEVEL>(0);
d3d_info_.max_feature_level = static_cast<D3D_FEATURE_LEVEL>(0);
std::vector<D3dDevice> devices = D3dDevice::EnumDevices();
if (devices.empty()) {
RTC_LOG(LS_WARNING) << "No D3dDevice found.";
return false;
}
for (size_t i = 0; i < devices.size(); i++) {
D3D_FEATURE_LEVEL feature_level =
devices[i].d3d_device()->GetFeatureLevel();
if (d3d_info_.max_feature_level == 0 ||
feature_level > d3d_info_.max_feature_level) {
d3d_info_.max_feature_level = feature_level;
}
if (d3d_info_.min_feature_level == 0 ||
feature_level < d3d_info_.min_feature_level) {
d3d_info_.min_feature_level = feature_level;
}
DxgiAdapterDuplicator duplicator(devices[i]);
// There may be several video cards on the system, some of them may not
// support IDXGOutputDuplication. But they should not impact others from
// taking effect, so we should continually try other adapters. This usually
// happens when a non-official virtual adapter is installed on the system.
if (!duplicator.Initialize()) {
RTC_LOG(LS_WARNING) << "Failed to initialize DxgiAdapterDuplicator on "
"adapter "
<< i;
continue;
}
RTC_DCHECK(!duplicator.desktop_rect().is_empty());
duplicators_.push_back(std::move(duplicator));
desktop_rect_.UnionWith(duplicators_.back().desktop_rect());
}
TranslateRect();
HDC hdc = GetDC(nullptr);
// Use old DPI value if failed.
if (hdc) {
system_dpi_.set(GetDeviceCaps(hdc, LOGPIXELSX),
GetDeviceCaps(hdc, LOGPIXELSY));
ReleaseDC(nullptr, hdc);
}
identity_++;
if (duplicators_.empty()) {
RTC_LOG(LS_WARNING)
<< "Cannot initialize any DxgiAdapterDuplicator instance.";
}
return !duplicators_.empty();
}
void DxgiDuplicatorController::Deinitialize() {
desktop_rect_ = DesktopRect();
duplicators_.clear();
display_configuration_monitor_.Reset();
}
bool DxgiDuplicatorController::ContextExpired(
const Context* const context) const {
RTC_DCHECK(context);
return context->controller_id != identity_ ||
context->contexts.size() != duplicators_.size();
}
void DxgiDuplicatorController::Setup(Context* context) {
if (ContextExpired(context)) {
RTC_DCHECK(context);
context->contexts.clear();
context->contexts.resize(duplicators_.size());
for (size_t i = 0; i < duplicators_.size(); i++) {
duplicators_[i].Setup(&context->contexts[i]);
}
context->controller_id = identity_;
}
}
bool DxgiDuplicatorController::DoDuplicateUnlocked(Context* context,
int monitor_id,
SharedDesktopFrame* target) {
Setup(context);
if (!EnsureFrameCaptured(context, target)) {
return false;
}
bool result = false;
if (monitor_id < 0) {
// Capture entire screen.
result = DoDuplicateAll(context, target);
} else {
result = DoDuplicateOne(context, monitor_id, target);
}
if (result) {
target->set_dpi(system_dpi_);
return true;
}
return false;
}
bool DxgiDuplicatorController::DoDuplicateAll(Context* context,
SharedDesktopFrame* target) {
for (size_t i = 0; i < duplicators_.size(); i++) {
if (!duplicators_[i].Duplicate(&context->contexts[i], target)) {
return false;
}
}
return true;
}
bool DxgiDuplicatorController::DoDuplicateOne(Context* context,
int monitor_id,
SharedDesktopFrame* target) {
RTC_DCHECK(monitor_id >= 0);
for (size_t i = 0; i < duplicators_.size() && i < context->contexts.size();
i++) {
if (monitor_id >= duplicators_[i].screen_count()) {
monitor_id -= duplicators_[i].screen_count();
} else {
if (duplicators_[i].DuplicateMonitor(&context->contexts[i], monitor_id,
target)) {
target->set_top_left(duplicators_[i].ScreenRect(monitor_id).top_left());
return true;
}
return false;
}
}
return false;
}
int64_t DxgiDuplicatorController::GetNumFramesCaptured() const {
int64_t min = INT64_MAX;
for (const auto& duplicator : duplicators_) {
min = std::min(min, duplicator.GetNumFramesCaptured());
}
return min;
}
DesktopSize DxgiDuplicatorController::desktop_size() const {
return desktop_rect_.size();
}
DesktopRect DxgiDuplicatorController::ScreenRect(int id) const {
RTC_DCHECK(id >= 0);
for (size_t i = 0; i < duplicators_.size(); i++) {
if (id >= duplicators_[i].screen_count()) {
id -= duplicators_[i].screen_count();
} else {
return duplicators_[i].ScreenRect(id);
}
}
return DesktopRect();
}
int DxgiDuplicatorController::ScreenCountUnlocked() const {
int result = 0;
for (auto& duplicator : duplicators_) {
result += duplicator.screen_count();
}
return result;
}
void DxgiDuplicatorController::GetDeviceNamesUnlocked(
std::vector<std::string>* output) const {
RTC_DCHECK(output);
for (auto& duplicator : duplicators_) {
for (int i = 0; i < duplicator.screen_count(); i++) {
output->push_back(duplicator.GetDeviceName(i));
}
}
}
DesktopSize DxgiDuplicatorController::SelectedDesktopSize(
int monitor_id) const {
if (monitor_id < 0) {
return desktop_size();
}
return ScreenRect(monitor_id).size();
}
bool DxgiDuplicatorController::EnsureFrameCaptured(Context* context,
SharedDesktopFrame* target) {
// On a modern system, the FPS / monitor refresh rate is usually larger than
// or equal to 60. So 17 milliseconds is enough to capture at least one frame.
const int64_t ms_per_frame = 17;
// Skip frames to ensure a full frame refresh has occurred and the DXGI
// machinery is producing frames before this function returns.
int64_t frames_to_skip = 1;
// The total time out milliseconds for this function. If we cannot get enough
// frames during this time interval, this function returns false, and cause
// the DXGI components to be reinitialized. This usually should not happen
// unless the system is switching display mode when this function is being
// called. 500 milliseconds should be enough for ~30 frames.
const int64_t timeout_ms = 500;
if (GetNumFramesCaptured() == 0 && !IsConsoleSession()) {
// When capturing a console session, waiting for a single frame is
// sufficient to ensure that DXGI output duplication is working. When the
// session is not attached to the console, it has been observed that DXGI
// may produce up to 4 frames (typically 1-2 though) before stopping. When
// this condition occurs, no errors are returned from the output duplication
// API, it simply appears that nothing is changing on the screen. Thus for
// detached sessions, we need to capture a few extra frames before we can be
// confident that output duplication was initialized properly.
frames_to_skip = 5;
}
if (GetNumFramesCaptured() >= frames_to_skip) {
return true;
}
std::unique_ptr<SharedDesktopFrame> fallback_frame;
SharedDesktopFrame* shared_frame = nullptr;
if (target->size().width() >= desktop_size().width() &&
target->size().height() >= desktop_size().height()) {
// `target` is large enough to cover entire screen, we do not need to use
// `fallback_frame`.
shared_frame = target;
} else {
fallback_frame = SharedDesktopFrame::Wrap(
std::unique_ptr<DesktopFrame>(new BasicDesktopFrame(desktop_size())));
shared_frame = fallback_frame.get();
}
const int64_t start_ms = rtc::TimeMillis();
while (GetNumFramesCaptured() < frames_to_skip) {
if (!DoDuplicateAll(context, shared_frame)) {
return false;
}
// Calling DoDuplicateAll() may change the number of frames captured.
if (GetNumFramesCaptured() >= frames_to_skip) {
break;
}
if (rtc::TimeMillis() - start_ms > timeout_ms) {
RTC_LOG(LS_ERROR) << "Failed to capture " << frames_to_skip
<< " frames "
"within "
<< timeout_ms << " milliseconds.";
return false;
}
// Sleep `ms_per_frame` before attempting to capture the next frame to
// ensure the video adapter has time to update the screen.
webrtc::SleepMs(ms_per_frame);
}
// When capturing multiple monitors, we need to update the captured region to
// prevent flickering by re-setting context. See
if (shared_frame != target) {
context->Reset();
Setup(context);
}
return true;
}
void DxgiDuplicatorController::TranslateRect() {
const DesktopVector position =
DesktopVector().subtract(desktop_rect_.top_left());
desktop_rect_.Translate(position);
for (auto& duplicator : duplicators_) {
duplicator.TranslateRect(position);
}
}
} // namespace webrtc