DirectX based screen capturer logic

webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc

+/*
+ *  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 "webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h"
+
+#include <string.h>
+
+#include <comdef.h>
+#include <wincodec.h>
+#include <DXGI.h>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
+#include "webrtc/system_wrappers/include/logging.h"
+#include "webrtc/system_wrappers/include/tick_util.h"
+
+namespace webrtc {
+
+using Microsoft::WRL::ComPtr;
+using rtc::CriticalSection;
+using rtc::CritScope;
+
+namespace {
+
+rtc::GlobalLock initialize_lock;

[Sergey Ulanov, 2016/04/08 21:22:26]

non-POD is not allowed as global.

What you can do instead is to move all these globals to a class which is lazily
created when necessary, e.g.:

class DuplicateApiContext {
 public:
  static DuplicateApiContext* GetInstance();
  ...
 private:
  static void EnsureCreated()
  ...
}

static CRITICAL_SECTION g_duplicate_api_context_init_lock = {(void
*)((size_t)-1), -1, 0, 0, 0, 0};
static DuplicateApiContext* g_duplicate_api_context;

DuplicateApiContext* DuplicateApiContext::GetInstance() {
  EnsureCreated();
  return g_duplicate_api_context;
}


void DuplicateApiContext::EnsureCreated() {
  EnterCriticalSection(&g_duplicate_api_context_init_lock);
  if (!g_duplicate_api_context)
    g_duplicate_api_context = new DuplicateApiContext();
  LeaveCriticalSection(&g_duplicate_api_context_init_lock);  
}


There is base::Singleton class in Chromium that implements this, but we cannot
use it in webrtc.

[Hzj_jie, 2016/04/11 22:19:16]

Changed into rtc::GlobalLockPod, which is a POD spinlock, and designed for
global initialization.

+CriticalSection* duplication_lock;
+CriticalSection* acquire_lock;
+
+bool initialized GUARDED_BY(initialize_lock) = false;
+bool initialize_result GUARDED_BY(initialize_lock) = false;
+ID3D11Device* d3d11_device GUARDED_BY(initialize_lock) = nullptr;
+ID3D11DeviceContext* d3d11_context GUARDED_BY(initialize_lock) = nullptr;
+IDXGIOutput1* dxgi_output1 GUARDED_BY(initialize_lock) = nullptr;
+ComPtr<IDXGIOutputDuplication> dxgi_output_duplication
+    GUARDED_BY(duplication_lock);
+DesktopSize desktop_size GUARDED_BY(acquire_lock);
+std::vector<BYTE> metadata GUARDED_BY(acquire_lock);
+
+}  // namespace
+
+bool ScreenCapturerWinDirectX::Initialize() {
+  if (!initialized) {
+    rtc::GlobalLockScope lock(&initialize_lock);
+    if (!initialized) {
+      initialize_result = DoInitialize();
+      initialized = true;
+      if (initialize_result) {
+        return true;
+      }
+
+      // Clean up if DirectX cannot work on the system.
+      if (dxgi_output_duplication) {
+        dxgi_output_duplication.Reset();
+      }
+
+      if (dxgi_output1 != nullptr) {
+        dxgi_output1->Release();
+        dxgi_output1 = nullptr;
+      }
+
+      if (d3d11_context != nullptr) {
+        d3d11_context->Release();
+        d3d11_context = nullptr;
+      }
+
+      if (d3d11_device != nullptr) {
+        d3d11_device->Release();
+        d3d11_device = nullptr;
+      }
+
+      return false;
+    }
+  }
+
+  return initialize_result;
+}
+
+bool ScreenCapturerWinDirectX::DoInitialize() {
+  D3D_FEATURE_LEVEL feature_level;
+  _com_error err(D3D11CreateDevice(
+      nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr,
+      D3D11_CREATE_DEVICE_BGRA_SUPPORT | D3D11_CREATE_DEVICE_SINGLETHREADED,
+      nullptr, 0, D3D11_SDK_VERSION, &d3d11_device, &feature_level,
+      &d3d11_context));
+  if (err.Error() != S_OK || d3d11_device == nullptr ||
+      d3d11_context == nullptr) {
+    LOG(LS_WARNING) << "D3D11CreateDeivce returns error " << err.ErrorMessage()
+                    << " with code " << err.Error();
+    return false;
+  }
+
+  if (feature_level < D3D_FEATURE_LEVEL_11_0) {
+    LOG(LS_WARNING) << "D3D11CreateDevice returns an instance without DirectX "
+                       "11 support, level "
+                    << feature_level;
+    return false;
+  }
+
+  ComPtr<IDXGIDevice> device;
+  err = _com_error(d3d11_device->QueryInterface(
+      __uuidof(IDXGIDevice), reinterpret_cast<void**>(device.GetAddressOf())));
+  if (err.Error() != S_OK || !device) {
+    LOG(LS_WARNING) << "ID3D11Device is not an implementation of IDXGIDevice, "
+                       "this usually means the system does not support DirectX "
+                       "11";
+    return false;
+  }
+
+  ComPtr<IDXGIAdapter> adapter;
+  err = _com_error(device->GetAdapter(adapter.GetAddressOf()));
+  if (err.Error() != S_OK || !adapter) {
+    LOG(LS_WARNING) << "Failed to get an IDXGIAdapter implementation from "
+                       "IDXGIDevice.";
+    return false;
+  }
+
+  ComPtr<IDXGIOutput> output;
+  for (int i = 0;; i++) {
+    err = _com_error(adapter->EnumOutputs(i, output.GetAddressOf()));
+    if (err.Error() == DXGI_ERROR_NOT_FOUND) {
+      LOG(LS_WARNING) << "No output detected.";
+      return false;
+    }
+    if (err.Error() == S_OK && output) {
+      DXGI_OUTPUT_DESC desc;
+      err = _com_error(output->GetDesc(&desc));
+      if (err.Error() == S_OK) {
+        if (desc.AttachedToDesktop) {
+          // Current output instance is the device attached to desktop.
+          break;
+        }
+      } else {
+        LOG(LS_WARNING) << "Failed to get output description of device " << i
+                        << ", ignore.";
+      }
+    }
+  }
+
+  RTC_DCHECK(output);
+  err = _com_error(output.CopyTo(__uuidof(IDXGIOutput1),
+                                 reinterpret_cast<void**>(&dxgi_output1)));
+  if (err.Error() != S_OK || dxgi_output1 == nullptr) {
+    LOG(LS_WARNING) << "Failed to convert IDXGIOutput to IDXGIOutput1, this "
+                       "usually means the system does not support DirectX 11";
+    return false;
+  }
+
+  duplication_lock = new CriticalSection();
+  acquire_lock = new CriticalSection();
+  if (DuplicateOutput()) {
+    DesktopFrameWinDxgi::Initialize(d3d11_device, d3d11_context);
+    return true;
+  }
+
+  return false;
+}
+
+bool ScreenCapturerWinDirectX::DuplicateOutput() {
+  RTC_DCHECK(dxgi_output1 != nullptr);
+  // We are updating the instance.
+  CritScope lock(duplication_lock);
+  // Make sure nobody is using current instance.
+  CritScope lock2(acquire_lock);
+  if (dxgi_output_duplication) {
+    dxgi_output_duplication->ReleaseFrame();
+    dxgi_output_duplication.Reset();
+  }
+
+  for (int i = 0; i < kDuplicateOutputAttempts; i++) {
+    _com_error err(
+        dxgi_output1->DuplicateOutput(static_cast<IUnknown*>(d3d11_device),
+                                      dxgi_output_duplication.GetAddressOf()));
+    if (err.Error() == S_OK && dxgi_output_duplication) {
+      DXGI_OUTDUPL_DESC desc;
+      dxgi_output_duplication->GetDesc(&desc);
+      if (desc.ModeDesc.Format != DXGI_FORMAT_B8G8R8A8_UNORM) {
+        LOG(LS_ERROR) << "IDXGIDuplicateOutput does not use RGBA (8 bit) "
+                         "format, which is required by downstream components, "
+                         "format is "
+                      << desc.ModeDesc.Format;
+        return false;
+      }
+
+      desktop_size.set(desc.ModeDesc.Width, desc.ModeDesc.Height);
+      return true;
+    } else {
+      // Make sure we have correct signal and duplicate the output next time.
+      dxgi_output_duplication.Reset();
+      LOG(LS_WARNING) << "Failed to duplicate output from IDXGIOutput1, error "
+                      << err.ErrorMessage() << ", with code " << err.Error();
+      Sleep(kDuplicateOutputWait);
+    }
+  }
+
+  return false;
+}
+
+ScreenCapturerWinDirectX::ScreenCapturerWinDirectX(
+    const DesktopCaptureOptions& options)
+    : callback_(nullptr), set_thread_execution_state_failed_(false) {
+  RTC_DCHECK(initialized && initialize_result);
+}
+
+ScreenCapturerWinDirectX::~ScreenCapturerWinDirectX() {}
+
+void ScreenCapturerWinDirectX::Start(Callback* callback) {
+  RTC_DCHECK(callback_ == nullptr);
+  RTC_DCHECK(callback != nullptr);
+
+  callback_ = callback;
+}
+
+void ScreenCapturerWinDirectX::SetSharedMemoryFactory(
+    rtc::scoped_ptr<SharedMemoryFactory> shared_memory_factory) {
+  shared_memory_factory_ =
+      rtc::ScopedToUnique(std::move(shared_memory_factory));
+}
+
+bool ScreenCapturerWinDirectX::DetectUpdatedRegion(
+    const DXGI_OUTDUPL_FRAME_INFO& frame_info,
+    DesktopFrame* frame) {
+  RTC_DCHECK(dxgi_output_duplication);
+  RTC_DCHECK(frame != nullptr);
+  DesktopRegion& updated_region = *frame->mutable_updated_region();
+  updated_region.Clear();
+  if (frame_info.TotalMetadataBufferSize == 0) {
+    // This should not happen, since frame_info.AccumulatedFrames > 0.
+    LOG(LS_ERROR) << "frame_info.AccumulatedFrames > 0, "
+                     "but TotalMetadataBufferSize == 0";
+    return false;
+  }
+
+  if (metadata.size() < frame_info.TotalMetadataBufferSize) {
+    metadata.clear();  // Avoid data copy
+    metadata.reserve(frame_info.TotalMetadataBufferSize);
+  }
+
+  UINT buff_size = 0;
+  DXGI_OUTDUPL_MOVE_RECT* move_rects = nullptr;
+  size_t move_rects_count = 0;
+  RECT* dirty_rects = nullptr;
+  size_t dirty_rects_count = 0;
+  for (int i = 0; i < 2; i++) {
+    _com_error err(S_OK);
+    if (i == 0) {
+      move_rects = reinterpret_cast<DXGI_OUTDUPL_MOVE_RECT*>(metadata.data());
+      err = _com_error(dxgi_output_duplication->GetFrameMoveRects(
+          static_cast<UINT>(metadata.capacity()), move_rects, &buff_size));
+    } else {
+      dirty_rects = reinterpret_cast<RECT*>(metadata.data() + buff_size);
+      err = _com_error(dxgi_output_duplication->GetFrameDirtyRects(
+          static_cast<UINT>(metadata.capacity()) - buff_size, dirty_rects,
+          &buff_size));
+    }
+    if (err.Error() != S_OK) {
+      if (err.Error() == DXGI_ERROR_ACCESS_LOST) {
+        DuplicateOutput();
+      } else {
+        LOG(LS_ERROR) << "Failed to get " << (i == 0 ? "move" : "dirty")
+                      << " rectangles, error " << err.ErrorMessage()
+                      << ", code " << err.Error();
+      }
+      // Send entire desktop as we cannot get dirty or move rectangles.
+      return false;
+    }
+    if (i == 0) {
+      move_rects_count = buff_size / sizeof(DXGI_OUTDUPL_MOVE_RECT);
+    } else {
+      dirty_rects_count = buff_size / sizeof(RECT);
+    }
+  }
+
+  LOG(LS_INFO) << "Found " << move_rects_count << " moved rectangles and "
+               << dirty_rects_count << " dirty rectangles";
+  while (move_rects_count > 0) {
+    updated_region.AddRect(DesktopRect::MakeXYWH(
+        move_rects->SourcePoint.x, move_rects->SourcePoint.y,
+        move_rects->DestinationRect.right - move_rects->DestinationRect.left,
+        move_rects->DestinationRect.bottom - move_rects->DestinationRect.top));
+    updated_region.AddRect(DesktopRect::MakeLTRB(
+        move_rects->DestinationRect.left, move_rects->DestinationRect.top,
+        move_rects->DestinationRect.right, move_rects->DestinationRect.bottom));
+    move_rects++;
+    move_rects_count--;
+  }
+
+  while (dirty_rects_count > 0) {
+    updated_region.AddRect(
+        DesktopRect::MakeLTRB(dirty_rects->left, dirty_rects->top,
+                              dirty_rects->right, dirty_rects->bottom));
+    dirty_rects++;
+    dirty_rects_count--;
+  }
+
+  return true;
+}
+
+bool ScreenCapturerWinDirectX::ProcessFrame(
+    const DXGI_OUTDUPL_FRAME_INFO& frame_info,
+    IDXGIResource* resource) {
+  RTC_DCHECK(resource != nullptr);
+  RTC_DCHECK(frame_info.AccumulatedFrames > 0);
+  // We have something to update, so move to next frame.
+  frames_.MoveToNextFrame();
+  DesktopFrameWinDxgi* frame = ReplaceCurrentFrameIfEmpty();
+
+  if (!frame->Capture(frame_info, resource)) {
+    return false;
+  }
+
+  if (!DetectUpdatedRegion(frame_info, frame)) {
+    frame->mutable_updated_region()->Clear();
+    frame->mutable_updated_region()->AddRect(
+        DesktopRect::MakeSize(desktop_size));
+  }
+
+  return true;
+}
+
+void ScreenCapturerWinDirectX::Capture(const DesktopRegion& region) {
+  RTC_DCHECK(callback_ != nullptr);
+
+  if (!dxgi_output_duplication && !DuplicateOutput()) {
+    // Receive a capture request when application is shutting down, or between
+    // mode change.
+    callback_->OnCaptureCompleted(nullptr);
+    return;
+  }
+
+  TickTime capture_start_time = TickTime::Now();
+
+  // Make sure even nothing captured, we still have a valid frame to emit.
+  ReplaceCurrentFrameIfEmpty();
+  // Before we move to next frame, current frame cannot be changed, it may be
+  // being used by encoder.
+  // TODO(zijiehe): Use differ to detect changed region.
+
+  if (!SetThreadExecutionState(ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED)) {
+    if (!set_thread_execution_state_failed_) {
+      set_thread_execution_state_failed_ = true;
+      LOG(LS_WARNING) << "Failed to make system & display power assertion: "
+                      << GetLastError();
+    }
+  }
+
+  DXGI_OUTDUPL_FRAME_INFO frame_info{};
+  ComPtr<IDXGIResource> resource;
+  CritScope lock(acquire_lock);
+  _com_error err(dxgi_output_duplication->AcquireNextFrame(
+      kAcquireTimeout, &frame_info, resource.GetAddressOf()));
+  if (err.Error() == DXGI_ERROR_ACCESS_LOST) {
+    LOG(LS_ERROR) << "Access lost " << err.ErrorMessage();
+    if (DuplicateOutput()) {
+      EmitCurrentFrame();
+    } else {
+      callback_->OnCaptureCompleted(nullptr);
+    }
+    return;
+  }
+
+  if (err.Error() == DXGI_ERROR_WAIT_TIMEOUT) {
+    LOG(LS_INFO) << "Acquire timeout " << err.ErrorMessage();
+    // Nothing changed.
+    EmitCurrentFrame();
+    return;
+  }
+
+  if (err.Error() != S_OK) {
+    LOG(LS_ERROR) << "Failed to capture frame, error " << err.ErrorMessage()
+                  << ", code " << err.Error();
+    callback_->OnCaptureCompleted(nullptr);
+    return;
+  }
+
+  if (frame_info.AccumulatedFrames == 0) {
+    LOG(LS_INFO) << "Nothing captured";
+    EmitCurrentFrame();
+    dxgi_output_duplication->ReleaseFrame();
+    return;
+  }
+
+  LOG(LS_INFO) << "Captured " << frame_info.AccumulatedFrames << " frames";
+  // Everything looks good so far, build next frame.
+  bool result = ProcessFrame(frame_info, resource.Get());
+  // DetectUpdatedRegion may release last dxgi_output_duplication. But
+  // DuplicateOutput function will always release last frame, so there is no
+  // potential leak.
+  if (dxgi_output_duplication) {
+    dxgi_output_duplication->ReleaseFrame();
+  }
+  if (result) {
+    frames_.current_frame()->set_capture_time_ms(
+        (TickTime::Now() - capture_start_time).Milliseconds());
+    EmitCurrentFrame();
+  } else {
+    callback_->OnCaptureCompleted(nullptr);
+  }
+}
+
+bool ScreenCapturerWinDirectX::GetScreenList(ScreenList* screens) {
+  RTC_DCHECK(screens != nullptr);
+  RTC_DCHECK(screens->size() == 0);
+  screens->push_back(Screen{});
+  return true;
+}
+
+bool ScreenCapturerWinDirectX::SelectScreen(ScreenId id) {
+  return id == 0 || id == kFullDesktopScreenId;
+}
+
+DesktopFrameWinDxgi* ScreenCapturerWinDirectX::ReplaceCurrentFrameIfEmpty() {
+  if (frames_.current_frame() == nullptr) {
+    std::unique_ptr<DesktopFrameWinDxgi> frame(DesktopFrameWinDxgi::Create(
+        desktop_size, shared_memory_factory_.get()));
+    frames_.ReplaceCurrentFrame(frame.get());
+    return frame.release();
+  }
+
+  return reinterpret_cast<DesktopFrameWinDxgi*>(
+      frames_.current_frame()->GetUnderlyingFrame());
+}
+
+void ScreenCapturerWinDirectX::EmitCurrentFrame() {
+  callback_->OnCaptureCompleted(frames_.current_frame()->Share());
+}
+
+}  // namespace webrtc