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/*
* Copyright (c) 2020 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.
*/
#ifndef MODULES_DESKTOP_CAPTURE_WIN_WGC_CAPTURE_SESSION_H_
#define MODULES_DESKTOP_CAPTURE_WIN_WGC_CAPTURE_SESSION_H_
#include <d3d11.h>
#include <windows.graphics.capture.h>
#include <windows.graphics.h>
#include <wrl/client.h>
#include <memory>
#include "api/sequence_checker.h"
#include "modules/desktop_capture/desktop_capture_options.h"
#include "modules/desktop_capture/screen_capture_frame_queue.h"
#include "modules/desktop_capture/shared_desktop_frame.h"
#include "modules/desktop_capture/win/wgc_capture_source.h"
#include "rtc_base/event.h"
namespace webrtc {
class WgcCaptureSession final {
public:
WgcCaptureSession(
Microsoft::WRL::ComPtr<ID3D11Device> d3d11_device,
Microsoft::WRL::ComPtr<
ABI::Windows::Graphics::Capture::IGraphicsCaptureItem> item,
ABI::Windows::Graphics::SizeInt32 size);
// Disallow copy and assign.
WgcCaptureSession(const WgcCaptureSession&) = delete;
WgcCaptureSession& operator=(const WgcCaptureSession&) = delete;
~WgcCaptureSession();
HRESULT StartCapture(const DesktopCaptureOptions& options);
// Returns a frame from the local frame queue, if any are present.
bool GetFrame(std::unique_ptr<DesktopFrame>* output_frame);
bool IsCaptureStarted() const {
RTC_DCHECK_RUN_ON(&sequence_checker_);
return is_capture_started_;
}
// We only keep 1 buffer in the internal frame pool to reduce the latency as
// much as possible.
// We make this public for tests.
static constexpr int kNumBuffers = 1;
private:
// Initializes `mapped_texture_` with the properties of the `src_texture`,
// overrides the values of some necessary properties like the
// D3D11_CPU_ACCESS_READ flag. Also has optional parameters for what size
// `mapped_texture_` should be, if they aren't provided we will use the size
// of `src_texture`.
HRESULT CreateMappedTexture(
Microsoft::WRL::ComPtr<ID3D11Texture2D> src_texture,
UINT width = 0,
UINT height = 0);
// Event handler for `item_`'s Closed event.
HRESULT OnItemClosed(
ABI::Windows::Graphics::Capture::IGraphicsCaptureItem* sender,
IInspectable* event_args);
// Wraps calls to ProcessFrame and deals with the uniqe start-up phase
// ensuring that we always have one captured frame available.
void EnsureFrame();
// Process the captured frame and copy it to the `queue_`.
HRESULT ProcessFrame();
void RemoveEventHandler();
bool FrameContentCanBeCompared();
bool allow_zero_hertz() const { return allow_zero_hertz_; }
std::unique_ptr<EventRegistrationToken> item_closed_token_;
// A Direct3D11 Device provided by the caller. We use this to create an
// IDirect3DDevice, and also to create textures that will hold the image data.
Microsoft::WRL::ComPtr<ID3D11Device> d3d11_device_;
// This item represents what we are capturing, we use it to create the
// capture session, and also to listen for the Closed event.
Microsoft::WRL::ComPtr<ABI::Windows::Graphics::Capture::IGraphicsCaptureItem>
item_;
// The IDirect3DDevice is necessary to instantiate the frame pool.
Microsoft::WRL::ComPtr<
ABI::Windows::Graphics::DirectX::Direct3D11::IDirect3DDevice>
direct3d_device_;
// The frame pool is where frames are deposited during capture, we retrieve
// them from here with TryGetNextFrame().
Microsoft::WRL::ComPtr<
ABI::Windows::Graphics::Capture::IDirect3D11CaptureFramePool>
frame_pool_;
// This texture holds the final image data. We made it a member so we can
// reuse it, instead of having to create a new texture every time we grab a
// frame.
Microsoft::WRL::ComPtr<ID3D11Texture2D> mapped_texture_;
// This is the size of `mapped_texture_` and the buffers in `frame_pool_`. We
// store this as a member so we can compare it to the size of incoming frames
// and resize if necessary.
ABI::Windows::Graphics::SizeInt32 size_;
// The capture session lets us set properties about the capture before it
// starts such as whether to capture the mouse cursor, and it lets us tell WGC
// to start capturing frames.
Microsoft::WRL::ComPtr<
ABI::Windows::Graphics::Capture::IGraphicsCaptureSession>
session_;
// Queue of captured video frames. The queue holds 2 frames and it avoids
// alloc/dealloc per captured frame. Incoming frames from the internal frame
// pool are copied to this queue after required processing in ProcessFrame().
ScreenCaptureFrameQueue<SharedDesktopFrame> queue_;
bool item_closed_ = false;
bool is_capture_started_ = false;
// Caches the value of DesktopCaptureOptions.allow_wgc_zero_hertz() in
// StartCapture(). Adds 0Hz detection in ProcessFrame() when enabled which
// adds complexity since memcmp() is performed on two successive frames.
bool allow_zero_hertz_ = false;
// Tracks damage region updates that were reported since the last time a frame
// was captured. Currently only supports either the complete rect being
// captured or an empty region. Will always be empty if `allow_zero_hertz_` is
// false.
DesktopRegion damage_region_;
SequenceChecker sequence_checker_;
};
} // namespace webrtc
#endif // MODULES_DESKTOP_CAPTURE_WIN_WGC_CAPTURE_SESSION_H_