使用DirectX捕获屏幕 [英] Capture screen using DirectX
问题描述
我知道如何使用GDI捕获屏幕，但是它很慢（它几乎不捕获10 fps）
I know how to use GDI to capture screen, however it is very slow (it barely captures 10 fps)
我读过DirectX提供最好的速度。但在我开始学习DirectX之前，我想测试一个示例，看看它是否真的那么快。
I have read that DirectX offers the best speed. But before I start learning DirectX I wanted to test a sample to see if it is really that fast.
I have found this question that offers a sample code to do that:
void dump_buffer()
{
IDirect3DSurface9* pRenderTarget=NULL;
IDirect3DSurface9* pDestTarget=NULL;
const char file[] = "Pickture.bmp";
// sanity checks.
if (Device == NULL)
return;
// get the render target surface.
HRESULT hr = Device->GetRenderTarget(0, &pRenderTarget);
// get the current adapter display mode.
//hr = pDirect3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT,&d3ddisplaymode);
// create a destination surface.
hr = Device->CreateOffscreenPlainSurface(DisplayMde.Width,
DisplayMde.Height,
DisplayMde.Format,
D3DPOOL_SYSTEMMEM,
&pDestTarget,
NULL);
//copy the render target to the destination surface.
hr = Device->GetRenderTargetData(pRenderTarget, pDestTarget);
//save its contents to a bitmap file.
hr = D3DXSaveSurfaceToFile(file,
D3DXIFF_BMP,
pDestTarget,
NULL,
NULL);
// clean up.
pRenderTarget->Release();
pDestTarget->Release();
}
我试图包含所需的文件。但不是所有的都可以包括（例如 #include< D3dx9tex.h> ）。
I have tried to include the required files. However not all of them can be included (for example #include <D3dx9tex.h>).
我在Windows 7旗舰版上使用Visual C ++ 2010 Express（x64） ）。
I am using Visual C++ 2010 Express on Windows 7 Ultimate (x64).
编辑：
另外，此代码不完整，例如 Device 标识符是什么？
Also, this code is not complete, for example what is the Device identifier?!
推荐答案
下面是使用DirectX 9捕获屏幕的一些示例代码。
您不应该安装任何SDK（除了Visual Studio附带的标准文件，虽然我没有测试VS 2010）。
Here is some sample code to capture the screen with DirectX 9. You shouldn't have to install any SDK (except the standard files that come with Visual Studio, although I didn't tested VS 2010).
只需创建一个简单的Win32控制台应用程序，在stdafx.h文件中添加以下内容：
Just create a simple Win32 console application, add the following in the stdafx.h file:
#include <Wincodec.h> // we use WIC for saving images
#include <d3d9.h> // DirectX 9 header
#pragma comment(lib, "d3d9.lib") // link to DirectX 9 library
下面是主要实现示例
int _tmain(int argc, _TCHAR* argv[])
{
HRESULT hr = Direct3D9TakeScreenshots(D3DADAPTER_DEFAULT, 10);
return 0;
}
这将会捕获10倍的屏幕， i.png图像。它还将显示此时间（保存图像不计入在该时间，只有屏幕捕获）。
在我的桌面windows 8 - 戴尔Precision M2800 / i7-4810MQ-2.80GHz /英特尔HD 4600这是一个非常糟糕的机器）机器，需要100 1920x1080捕获在〜4秒，所以约20 / 25 fps。
What this will do is capture 10 times the screen, and save "cap%i.png" images on the disk. It will also display the time taken for this (saving images is not counted in that time, only screen captures). On my (desktop windows 8 - Dell Precision M2800/i7-4810MQ-2.80GHz/Intel HD 4600 which is a pretty crappy machine...) machine, it takes 100 1920x1080 captures in ~4sec, so around 20/25 fps.
HRESULT Direct3D9TakeScreenshots(UINT adapter, UINT count)
{
HRESULT hr = S_OK;
IDirect3D9 *d3d = nullptr;
IDirect3DDevice9 *device = nullptr;
IDirect3DSurface9 *surface = nullptr;
D3DPRESENT_PARAMETERS parameters = { 0 };
D3DDISPLAYMODE mode;
D3DLOCKED_RECT rc;
UINT pitch;
SYSTEMTIME st;
LPBYTE *shots = nullptr;
// init D3D and get screen size
d3d = Direct3DCreate9(D3D_SDK_VERSION);
HRCHECK(d3d->GetAdapterDisplayMode(adapter, &mode));
parameters.Windowed = TRUE;
parameters.BackBufferCount = 1;
parameters.BackBufferHeight = mode.Height;
parameters.BackBufferWidth = mode.Width;
parameters.SwapEffect = D3DSWAPEFFECT_DISCARD;
parameters.hDeviceWindow = NULL;
// create device & capture surface
HRCHECK(d3d->CreateDevice(adapter, D3DDEVTYPE_HAL, NULL, D3DCREATE_SOFTWARE_VERTEXPROCESSING, ¶meters, &device));
HRCHECK(device->CreateOffscreenPlainSurface(mode.Width, mode.Height, D3DFMT_A8R8G8B8, D3DPOOL_SYSTEMMEM, &surface, nullptr));
// compute the required buffer size
HRCHECK(surface->LockRect(&rc, NULL, 0));
pitch = rc.Pitch;
HRCHECK(surface->UnlockRect());
// allocate screenshots buffers
shots = new LPBYTE[count];
for (UINT i = 0; i < count; i++)
{
shots[i] = new BYTE[pitch * mode.Height];
}
GetSystemTime(&st); // measure the time we spend doing <count> captures
wprintf(L"%i:%i:%i.%i\n", st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
for (UINT i = 0; i < count; i++)
{
// get the data
HRCHECK(device->GetFrontBufferData(0, surface));
// copy it into our buffers
HRCHECK(surface->LockRect(&rc, NULL, 0));
CopyMemory(shots[i], rc.pBits, rc.Pitch * mode.Height);
HRCHECK(surface->UnlockRect());
}
GetSystemTime(&st);
wprintf(L"%i:%i:%i.%i\n", st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
// save all screenshots
for (UINT i = 0; i < count; i++)
{
WCHAR file[100];
wsprintf(file, L"cap%i.png", i);
HRCHECK(SavePixelsToFile32bppPBGRA(mode.Width, mode.Height, pitch, shots[i], file, GUID_ContainerFormatPng));
}
cleanup:
if (shots != nullptr)
{
for (UINT i = 0; i < count; i++)
{
delete shots[i];
}
delete[] shots;
}
RELEASE(surface);
RELEASE(device);
RELEASE(d3d);
return hr;
}
要编译这个，你还需要 WIC （Windows中包含的成像库已有很长时间了）保存图像（因此，需要安装需要安装旧DirectX SDK的着名的D3DXSaveSurfaceToFile）：
To compile this, you will also need WIC (an imaging library included with Windows for quite a time now) to save an image (so you don't need the famous D3DXSaveSurfaceToFile that require old DirectX SDKs to be installed):
HRESULT SavePixelsToFile32bppPBGRA(UINT width, UINT height, UINT stride, LPBYTE pixels, LPWSTR filePath, const GUID &format)
{
if (!filePath || !pixels)
return E_INVALIDARG;
HRESULT hr = S_OK;
IWICImagingFactory *factory = nullptr;
IWICBitmapEncoder *encoder = nullptr;
IWICBitmapFrameEncode *frame = nullptr;
IWICStream *stream = nullptr;
GUID pf = GUID_WICPixelFormat32bppPBGRA;
BOOL coInit = CoInitialize(nullptr);
HRCHECK(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&factory)));
HRCHECK(factory->CreateStream(&stream));
HRCHECK(stream->InitializeFromFilename(filePath, GENERIC_WRITE));
HRCHECK(factory->CreateEncoder(format, nullptr, &encoder));
HRCHECK(encoder->Initialize(stream, WICBitmapEncoderNoCache));
HRCHECK(encoder->CreateNewFrame(&frame, nullptr)); // we don't use options here
HRCHECK(frame->Initialize(nullptr)); // we dont' use any options here
HRCHECK(frame->SetSize(width, height));
HRCHECK(frame->SetPixelFormat(&pf));
HRCHECK(frame->WritePixels(height, stride, stride * height, pixels));
HRCHECK(frame->Commit());
HRCHECK(encoder->Commit());
cleanup:
RELEASE(stream);
RELEASE(frame);
RELEASE(encoder);
RELEASE(factory);
if (coInit) CoUninitialize();
return hr;
}
我使用的一些宏：
#define WIDEN2(x) L ## x
#define WIDEN(x) WIDEN2(x)
#define __WFILE__ WIDEN(__FILE__)
#define HRCHECK(__expr) {hr=(__expr);if(FAILED(hr)){wprintf(L"FAILURE 0x%08X (%i)\n\tline: %u file: '%s'\n\texpr: '" WIDEN(#__expr) L"'\n",hr, hr, __LINE__,__WFILE__);goto cleanup;}}
#define RELEASE(__p) {if(__p!=nullptr){__p->Release();__p=nullptr;}}
：对于Windows 8+客户端，应该删除所有这些（WIC除外）以支持桌面复制API 。
这篇关于使用DirectX捕获屏幕的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
