VC dxgi 截屏保存bmp文件

介绍

    win8 dxgi截屏保存为bmp文件。

代码

    其中用到的d3d,dxgi头文件和库都是win8或者win10sdk中所包含的。

#include <stdio.h>
#include <assert.h>
#include <process.h>
#include "D3D11.h"
#include "DXGI1_2.h"
#include "DXGICaptor.h"
#pragma comment(lib, "D3D11.lib")
#pragma comment(lib, "DXGI.lib")
#define RESET_OBJECT(obj) { if(obj) obj->Release(); obj = NULL; }
ID3D11Device
*m_hDevice = nullptr;
ID3D11DeviceContext
*m_hContext = nullptr;
IDXGIOutputDuplication *m_hDeskDupl = nullptr;
int iWidth
= 0;
int iHeight = 0;
BOOL Init()
{
HRESULT hr = S_OK;
// Driver types supported
D3D_DRIVER_TYPE DriverTypes[] =
{
D3D_DRIVER_TYPE_HARDWARE,
D3D_DRIVER_TYPE_WARP,
D3D_DRIVER_TYPE_REFERENCE,
};
UINT NumDriverTypes = ARRAYSIZE(DriverTypes);
// Feature levels supported
D3D_FEATURE_LEVEL FeatureLevels[] =
{
D3D_FEATURE_LEVEL_11_0,
D3D_FEATURE_LEVEL_10_1,
D3D_FEATURE_LEVEL_10_0,
D3D_FEATURE_LEVEL_9_1
};
UINT NumFeatureLevels = ARRAYSIZE(FeatureLevels);
D3D_FEATURE_LEVEL FeatureLevel;
//
// Create D3D device
//
for (UINT DriverTypeIndex = 0; DriverTypeIndex < NumDriverTypes; ++DriverTypeIndex)
{
hr = D3D11CreateDevice(NULL, DriverTypes[DriverTypeIndex], NULL, 0, FeatureLevels, NumFeatureLevels, D3D11_SDK_VERSION, &m_hDevice, &FeatureLevel, &m_hContext);
if (SUCCEEDED(hr))
{
break;
}
}
if (FAILED(hr))
{
return FALSE;
}
//
// Get DXGI device
//
IDXGIDevice *hDxgiDevice = NULL;
hr = m_hDevice->QueryInterface(__uuidof(IDXGIDevice), reinterpret_cast<void**>(&hDxgiDevice));
if (FAILED(hr))
{
return FALSE;
}
//
// Get DXGI adapter
//
IDXGIAdapter *hDxgiAdapter = NULL;
hr = hDxgiDevice->GetParent(__uuidof(IDXGIAdapter), reinterpret_cast<void**>(&hDxgiAdapter));
RESET_OBJECT(hDxgiDevice);
if (FAILED(hr))
{
return FALSE;
}
//
// Get output
//
INT nOutput = 0;
IDXGIOutput *hDxgiOutput = NULL;
hr = hDxgiAdapter->EnumOutputs(nOutput, &hDxgiOutput);
RESET_OBJECT(hDxgiAdapter);
if (FAILED(hr))
{
return FALSE;
}
//
// get output description struct
//
DXGI_OUTPUT_DESC
m_dxgiOutDesc;
hDxgiOutput->GetDesc(&m_dxgiOutDesc);
iWidth = m_dxgiOutDesc.DesktopCoordinates.right - m_dxgiOutDesc.DesktopCoordinates.left;
iHeight = m_dxgiOutDesc.DesktopCoordinates.bottom - m_dxgiOutDesc.DesktopCoordinates.top;
//
// QI for Output 1
//
IDXGIOutput1 *hDxgiOutput1 = NULL;
hr = hDxgiOutput->QueryInterface(__uuidof(hDxgiOutput1), reinterpret_cast<void**>(&hDxgiOutput1));
RESET_OBJECT(hDxgiOutput);
if (FAILED(hr))
{
return FALSE;
}
//
// Create desktop duplication
//
hr = hDxgiOutput1->DuplicateOutput(m_hDevice, &m_hDeskDupl);
RESET_OBJECT(hDxgiOutput1);
if (FAILED(hr))
{
return FALSE;
}
return TRUE;
}
void Finit()
{
RESET_OBJECT(m_hDeskDupl);
RESET_OBJECT(m_hContext);
RESET_OBJECT(m_hDevice);
}
BOOL AttatchToThread(VOID)
{
HDESK hold = GetThreadDesktop(GetCurrentThreadId());
HDESK hCurrentDesktop = OpenInputDesktop(0, FALSE, GENERIC_ALL);
if (!hCurrentDesktop)
{
return FALSE;
}
// Attach desktop to this thread
BOOL bDesktopAttached = SetThreadDesktop(hCurrentDesktop) ? true : false;
int err = GetLastError();
CloseDesktop(hold);
CloseDesktop(hCurrentDesktop);
//hCurrentDesktop = NULL;
return bDesktopAttached;
}
BOOL QueryFrame(const char *fileName, void *pImgData, INT &nImgSize)
{
if (!AttatchToThread())
{
return FALSE;
}
nImgSize = 0;
IDXGIResource *hDesktopResource = NULL;
DXGI_OUTDUPL_FRAME_INFO FrameInfo;
m_hDeskDupl->ReleaseFrame();
HRESULT hr = m_hDeskDupl->AcquireNextFrame(500, &FrameInfo, &hDesktopResource);
if (FAILED(hr))
{
//
// 在一些win10的系统上,如果桌面没有变化的情况下，
// 这里会发生超时现象，但是这并不是发生了错误，而是系统优化了刷新动作导致的。
// 所以，这里没必要返回FALSE，返回不带任何数据的TRUE即可
//
return TRUE;
}
//
// query next frame staging buffer
//
ID3D11Texture2D *hAcquiredDesktopImage = NULL;
hr = hDesktopResource->QueryInterface(__uuidof(ID3D11Texture2D), reinterpret_cast<void **>(&hAcquiredDesktopImage));
RESET_OBJECT(hDesktopResource);
if (FAILED(hr))
{
return FALSE;
}
//
// copy old description
//
D3D11_TEXTURE2D_DESC frameDescriptor;
hAcquiredDesktopImage->GetDesc(&frameDescriptor);
//
// create a new staging buffer for fill frame image
//
ID3D11Texture2D *hNewDesktopImage = NULL;
frameDescriptor.Usage = D3D11_USAGE_STAGING;
frameDescriptor.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
frameDescriptor.BindFlags = 0;
frameDescriptor.MiscFlags = 0;
frameDescriptor.MipLevels = 1;
frameDescriptor.ArraySize = 1;
frameDescriptor.SampleDesc.Count = 1;
hr = m_hDevice->CreateTexture2D(&frameDescriptor, NULL, &hNewDesktopImage);
if (FAILED(hr))
{
RESET_OBJECT(hAcquiredDesktopImage);
m_hDeskDupl->ReleaseFrame();
return FALSE;
}
//
// copy next staging buffer to new staging buffer
//
m_hContext->CopyResource(hNewDesktopImage, hAcquiredDesktopImage);
RESET_OBJECT(hAcquiredDesktopImage);
m_hDeskDupl->ReleaseFrame();
//
// create staging buffer for map bits
//
IDXGISurface *hStagingSurf = NULL;
hr = hNewDesktopImage->QueryInterface(__uuidof(IDXGISurface), (void **)(&hStagingSurf));
RESET_OBJECT(hNewDesktopImage);
if (FAILED(hr))
{
return FALSE;
}
DXGI_SURFACE_DESC hStagingSurfDesc;
// BGRA8
hStagingSurf->GetDesc(&hStagingSurfDesc);
//
// copy bits to user space
//
DXGI_MAPPED_RECT mappedRect;
hr = hStagingSurf->Map(&mappedRect, DXGI_MAP_READ);
int imgSize = iWidth * iHeight *4;
if (SUCCEEDED(hr))
{
nImgSize = imgSize;
memcpy(pImgData, mappedRect.pBits, imgSize);
hStagingSurf->Unmap();
}else {
printf("failed.n");
}
printf("finish.n");
RESET_OBJECT(hStagingSurf);
return SUCCEEDED(hr);
}
void rotateImg(unsigned char *pImgData)
{
unsigned int* pImg32 = (unsigned int*)pImgData;
int iCount = iWidth * iHeight;
unsigned int* pRotateImg32 = new unsigned int[iCount];
for (int i = 0; i < iCount; ++ i) {
pRotateImg32[i] = pImg32[iCount - i - 1];
}
unsigned int* pRotateImg32_r = (unsigned int*)pImgData;
for (int i = 0; i < iHeight; ++ i) {
for (int j = 0; j < iWidth; ++ j) {
pRotateImg32_r[j + i * iWidth] = pRotateImg32[iWidth - j - 1 + i * iWidth];
}
}
delete [] pRotateImg32;
}
void saveBmpFile(const char *fileName, unsigned char *pImgData, int imgLength)
{
BITMAPFILEHEADER bmheader;
memset(&bmheader, 0, sizeof(bmheader));
bmheader.bfType = 0x4d42;
//图像格式。必须为'BM'格式。
bmheader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER); //从文件开头到数据的偏移量
bmheader.bfSize = imgLength + bmheader.bfOffBits;//文件大小
BITMAPINFOHEADER bmInfo;
memset(&bmInfo, 0, sizeof(bmInfo));
bmInfo.biSize = sizeof(bmInfo);
bmInfo.biWidth = iWidth;
bmInfo.biHeight = iHeight;
bmInfo.biPlanes = 1;
bmInfo.biBitCount = 32;
bmInfo.biCompression = BI_RGB;
HANDLE hFile = CreateFileA(fileName, GENERIC_WRITE, 0, 0, CREATE_ALWAYS, 0, 0);
if (hFile != INVALID_HANDLE_VALUE) {
DWORD dwWritten;
BOOL bRet = WriteFile(hFile, &bmheader, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
assert(TRUE == bRet);
bRet = WriteFile(hFile, &bmInfo, sizeof(BITMAPINFOHEADER), &dwWritten, NULL);
assert(TRUE == bRet);
bRet =WriteFile(hFile, pImgData, imgLength, &dwWritten, NULL);
assert(TRUE == bRet);
CloseHandle(hFile);
}
}
unsigned __stdcall capture(void *arg)
{
unsigned char *pImgData = new unsigned char[iWidth * iHeight * 4];
int imgLength = iWidth * iHeight * 4;
int i = 1;
while (true) {
char buf[10] = {0};
sprintf(buf, "%d.bmp", i);
QueryFrame(buf, pImgData, imgLength);
rotateImg(pImgData);
saveBmpFile(buf, pImgData, imgLength);
++ i;
Sleep(500);
}
return 0;
}
int main(int argc, TCHAR *argv[])
{
if (!Init()) {
Finit();
printf("not support dxgi.");
return -1;
}
HANDLE handle = (HANDLE)_beginthreadex(NULL, 0, capture, NULL, 0, NULL);
CloseHandle(handle);
getchar();
Finit();
return 0;
}

总结

    以上代码，在测试中发现几个问题：

• 第一张图片截屏的总是黑屏，暂时不知道原因。
• 最初的时候在截屏完成并写入到bmp文件时图片全是倒置的，并没有找到原因或者是在哪里有设置可以使图片显示正常，所以只好自己就写了一个函数rotateImg直接把整个数组和左右一并给倒置了，这样图片保存到bmp文件时才显示正常。
• 当程序运行在双显卡机器时可能出现问题，因为当时测试时使用的是笔记本双显卡机器，在高性能处理器处于激活状态时，在调用函数DuplicateOutput时出错，错误提示不支持，不知道是因为是这款显卡不支持又或者是其它原因，而如果把显卡激活到集成显卡时，程序就能正常运行。