I am doing desktop screen capture and wanted the output to be a video file. Currently I have codes getting from here to output png images. I modified the code a bit to change the output to JPEG file and then convert it to avi video output using openCV 3.0.0. Reason I need the JPEG file as output is because I am running on Windows 8.1 and OpenCV VideoWriter::fourcc('M', 'J', 'P', 'G') are the only options that work for me.
Output of PNG image works perfectly but not JPEG. There are vertical lines on the image and the time to generate the JPEG outputs is relatively far longer than PNG.
I have 2 options here:
Improve the output of JPEG file to work faster and have a clear image.
Get rid of the OpenCV 3.0.0 issue to accept PNG file input and able to output a video file.(preferably AVI/MP4 file format)
Either solution will do for me. PLease help. Thank you.
My code:
#include "stdafx.h"
#include <Wincodec.h> // we use WIC for saving images
#include <d3d9.h> // DirectX 9 header
#include <opencvcv.h>
#include <opencvcxcore.hpp>
#include <opencv2highguihighgui.hpp>
#pragma comment(lib, "d3d9.lib") // link to DirectX 9 library
using namespace cv;
#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)
line: %u file: '%s'
expr: '" WIDEN(#__expr) L"'
",hr, hr, __LINE__,__WFILE__);goto cleanup;}}
#define RELEASE(__p) {if(__p!=nullptr){__p->Release();__p=nullptr;}}
HRESULT Direct3D9TakeScreenshots(UINT adapter, UINT count);
HRESULT SavePixelsToFile32bppPBGRA(UINT width, UINT height, UINT stride, LPBYTE pixels, LPWSTR filePath, const GUID &format);
int _tmain(int argc, _TCHAR* argv[])
{
HRESULT hr = Direct3D9TakeScreenshots(D3DADAPTER_DEFAULT, 10);
return 0;
}
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"START Capture--> %i:%i:%i.%i
", 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"END Capture--> %i:%i:%i.%i
", 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.jpg", i);
HRCHECK(SavePixelsToFile32bppPBGRA(mode.Width, mode.Height, pitch, shots[i], file, GUID_ContainerFormatJpeg));
}
cleanup:
if (shots != nullptr)
{
for (UINT i = 0; i < count; i++)
{
delete shots[i];
}
delete[] shots;
}
RELEASE(surface);
RELEASE(device);
RELEASE(d3d);
return hr;
}
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();
//This part do encode JPEG file to video file
VideoCapture in_capture("cap%d.jpg");
Mat img;
VideoWriter out_capture("video.avi", CV_FOURCC('M','J','P','G'), 1, Size(1920,1080));
while (true)
{
in_capture >> img;
if(img.empty())
break;
out_capture.write(img);
}
return hr;
}
