增加windows端屏幕捕获编码demo

demo/windows_sender/ScreenCapture.cpp

@@ -0,0 +1,120 @@
+#include "ScreenCapture.h"
+#include <iostream>
+
+ScreenCapture::ScreenCapture() = default;
+
+ScreenCapture::~ScreenCapture() {
+    if (frame_acquired_) {
+        ReleaseFrame();
+    }
+}
+
+bool ScreenCapture::Initialize() {
+    HRESULT hr = S_OK;
+
+    // Create D3D11 Device and Context
+    D3D_FEATURE_LEVEL featureLevels[] = {
+        D3D_FEATURE_LEVEL_11_1,
+        D3D_FEATURE_LEVEL_11_0,
+    };
+    D3D_FEATURE_LEVEL featureLevel;
+
+    hr = D3D11CreateDevice(
+        nullptr,
+        D3D_DRIVER_TYPE_HARDWARE,
+        nullptr,
+        D3D11_CREATE_DEVICE_BGRA_SUPPORT, // Needed for GDI compatibility if used, but generally good for D2D
+        featureLevels,
+        ARRAYSIZE(featureLevels),
+        D3D11_SDK_VERSION,
+        &device_,
+        &featureLevel,
+        &context_
+    );
+
+    if (FAILED(hr)) {
+        std::cerr << "Failed to create D3D11 device: " << std::hex << hr << std::endl;
+        return false;
+    }
+
+    // Get DXGI Device
+    ComPtr<IDXGIDevice> dxgiDevice;
+    hr = device_.As(&dxgiDevice);
+    if (FAILED(hr)) return false;
+
+    // Get DXGI Adapter
+    ComPtr<IDXGIAdapter> dxgiAdapter;
+    hr = dxgiDevice->GetAdapter(&dxgiAdapter);
+    if (FAILED(hr)) return false;
+
+    // Get DXGI Output (Monitor 0)
+    ComPtr<IDXGIOutput> dxgiOutput;
+    hr = dxgiAdapter->EnumOutputs(0, &dxgiOutput);
+    if (FAILED(hr)) {
+        std::cerr << "Failed to get DXGI output (monitor connected?)" << std::endl;
+        return false;
+    }
+
+    // QI for Output1 to support Duplication
+    ComPtr<IDXGIOutput1> dxgiOutput1;
+    hr = dxgiOutput.As(&dxgiOutput1);
+    if (FAILED(hr)) return false;
+
+    // Create Desktop Duplication
+    hr = dxgiOutput1->DuplicateOutput(device_.Get(), &duplication_);
+    if (FAILED(hr)) {
+        std::cerr << "Failed to duplicate output. Error: " << std::hex << hr << std::endl;
+        // Common errors: E_ACCESSDENIED (already duplicated), DXGI_ERROR_UNSUPPORTED (switchable graphics)
+        return false;
+    }
+
+    return true;
+}
+
+bool ScreenCapture::CaptureFrame(ComPtr<ID3D11Texture2D>& texture) {
+    if (frame_acquired_) {
+        ReleaseFrame();
+    }
+
+    DXGI_OUTDUPL_FRAME_INFO frameInfo;
+    ComPtr<IDXGIResource> resource;
+    
+    // Timeout 100ms
+    HRESULT hr = duplication_->AcquireNextFrame(100, &frameInfo, &resource);
+    
+    if (hr == DXGI_ERROR_WAIT_TIMEOUT) {
+        return false; // No new frame
+    }
+    
+    if (FAILED(hr)) {
+        // Maybe device lost or resolution changed
+        std::cerr << "AcquireNextFrame failed: " << std::hex << hr << std::endl;
+        return false;
+    }
+
+    frame_acquired_ = true;
+
+    // Only process if we have a desktop image update
+    if (frameInfo.LastPresentTime.QuadPart == 0) {
+        return false; // Only cursor moved or something else, no image update? 
+        // Actually AcquireNextFrame returns even if only cursor updated.
+        // But for video stream we might want to send anyway or skip. 
+        // If resource is null, it means no desktop image update.
+    }
+    
+    if (!resource) {
+        return false;
+    }
+
+    hr = resource.As(&texture);
+    if (FAILED(hr)) return false;
+
+    return true;
+}
+
+void ScreenCapture::ReleaseFrame() {
+    if (frame_acquired_ && duplication_) {
+        duplication_->ReleaseFrame();
+        frame_acquired_ = false;
+    }
+}