Tag Archives: image

Utility Clearance: Automatic Snapshots

Posted by on May 13, 2011 No comments

Automatic Snapshots runs as a background application monitors clipboard. Should a new image be copied there, the utility automatically writes the image into a file. The process does not require any user interaction and is completely automatic so that – per Mike Westen‘s request – user could quickly and easily create snapshots of a multitude of windows (Alt+Print Screen) or full screen images (Print Screen) using standard hotkeys.

Features:

  • Automatic PNG compression (can be disabled via registry and enable BMP mode)
  • Reduction of color depth to create smaller PNG files
  • Asynchronous processing, the compression and file writes are on background thread to not slow foreground application
  • Application window flashes on application bar while busy and indicates the status via window caption
  • Application appends current foreground window caption to the image file name

A binary [Win32, x64] and Visual C++ .NET 2010 source code are available from SVN.

How To: Save image to BMP file from IBasicVideo or VMR windowless interface

Posted by on August 24, 2008 No comments

A simple question being asked all over again. Given IBasicVideo, IBasicVideo2, IVMRWindowlessControl or IVMRWindowlessControl9, how to save image to file? It is easy. It is a bit easier with IBasicVideo because it is possible to query this interface directly from graph’s interface, such as IGraphBuilder, and the call will be forwarded to video renderer. This code assumes internal bitmap format is non-paletted, which I believe is always the case.

LONG nBufferSize = 0;
ATLENSURE_SUCCEEDED(pBasicVideo->GetCurrentImage(&nBufferSize, NULL));
CHeapPtr<BITMAPINFO> pBitmapInfo;
ATLENSURE_THROW(pBitmapInfo.AllocateBytes(nBufferSize), E_OUTOFMEMORY);
ATLENSURE_SUCCEEDED(pBasicVideo->GetCurrentImage(&nBufferSize, (LONG*) (BITMAPINFO*) pBitmapInfo));
const BYTE* pnData = (const BYTE*) (&pBitmapInfo->bmiHeader + 1);
// NOTE: You might wish to handle <=8 bpp bitmaps here
ATLASSERT(pBitmapInfo->bmiHeader.biBitCount > 8);
ATLASSERT(pBitmapInfo->bmiHeader.biCompression == BI_RGB);
ATLASSERT(pBitmapInfo->bmiHeader.biSizeImage);
BITMAPFILEHEADER BitmapFileHeader;
ZeroMemory(&BitmapFileHeader, sizeof BitmapFileHeader);
BitmapFileHeader.bfType = 'MB';
BitmapFileHeader.bfSize = (DWORD) (sizeof (BITMAPFILEHEADER) + pBitmapInfo->bmiHeader.biSize + pBitmapInfo->bmiHeader.biSizeImage);
BitmapFileHeader.bfOffBits = (DWORD) (sizeof (BITMAPFILEHEADER) + pBitmapInfo->bmiHeader.biSize);
ATLENSURE_SUCCEEDED(File.Write(&BitmapFileHeader, sizeof BitmapFileHeader));
ATLENSURE_SUCCEEDED(File.Write(&pBitmapInfo->bmiHeader, pBitmapInfo->bmiHeader.biSize));
ATLENSURE_SUCCEEDED(File.Write(pnData, (DWORD) pBitmapInfo->bmiHeader.biSizeImage));