windows-nt/Source/XPSP1/NT/shell/ext/shimgvw/recompress.cpp
2020-09-26 16:20:57 +08:00

313 lines
9.7 KiB
C++

#include "precomp.h"
#include "prevwnd.h"
#pragma hdrstop
// class which implements IRecompress
class CImgRecompress : public IImageRecompress, public NonATLObject
{
public:
CImgRecompress();
~CImgRecompress();
// IUnknown
STDMETHOD(QueryInterface)(REFIID riid, void **ppv);
STDMETHOD_(ULONG, AddRef)();
STDMETHOD_(ULONG, Release)();
// IImageRecompress
STDMETHODIMP RecompressImage(IShellItem *psi, int cx, int cy, int iQuality, IStorage *pstg, IStream **ppstrmOut);
protected:
LONG _cRef; // object lifetime
IShellItem *_psi; // current shell item
IShellImageDataFactory *_psidf;
HRESULT _FindEncoder(IShellItem *psi, IShellImageData *psid, IStorage *pstg, IStream **ppstrmOut, BOOL *pfChangeFmt, GUID *pDataFormat);
HRESULT _InitRecompress(IShellItem *psi, IStream **ppstrm, STATSTG *pstatIn);
HRESULT _SaveImage(IShellImageData *psid, int cx, int cy, int iQuality, GUID *pRawDataFmt, IStream *pstrm);
};
// Recompress interface
CImgRecompress::CImgRecompress() :
_cRef(1), _psidf(NULL)
{
_Module.Lock();
}
CImgRecompress::~CImgRecompress()
{
ATOMICRELEASE(_psidf);
_Module.Unlock();
}
STDMETHODIMP CImgRecompress::QueryInterface(REFIID riid, void **ppv)
{
static const QITAB qit[] =
{
QITABENT(CImgRecompress, IImageRecompress),
{ 0 },
};
return QISearch(this, qit, riid, ppv);
}
STDMETHODIMP_(ULONG) CImgRecompress::AddRef()
{
return InterlockedIncrement(&_cRef);
}
STDMETHODIMP_(ULONG) CImgRecompress::Release()
{
if (InterlockedDecrement(&_cRef))
return _cRef;
delete this;
return 0;
}
HRESULT CImgRecompress::_InitRecompress(IShellItem *psi, IStream **ppstrm, STATSTG *pstatIn)
{
HRESULT hr = S_OK;
if (!_psidf)
hr = CoCreateInstance(CLSID_ShellImageDataFactory, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARG(IShellImageDataFactory, &_psidf));
if (SUCCEEDED(hr))
{
IBindCtx *pbc;
hr = BindCtx_CreateWithMode(STGM_READ | STGM_SHARE_DENY_NONE, &pbc);
if (SUCCEEDED(hr))
{
IStream *pstrm;
hr = psi->BindToHandler(pbc, BHID_Stream, IID_PPV_ARG(IStream, &pstrm));
if (SUCCEEDED(hr))
{
hr = pstrm->Stat(pstatIn, STATFLAG_NONAME);
if (SUCCEEDED(hr))
{
hr = pstrm->QueryInterface(IID_PPV_ARG(IStream, ppstrm));
}
pstrm->Release();
}
pbc->Release();
}
}
return hr;
}
HRESULT CImgRecompress::RecompressImage(IShellItem *psi, int cx, int cy, int iQuality, IStorage *pstg, IStream **ppstrmOut)
{
STATSTG statIn;
IStream *pstrm;
HRESULT hr = S_FALSE;
if (SUCCEEDED(_InitRecompress(psi, &pstrm, &statIn)))
{
IShellImageData * psid;
if (SUCCEEDED(_psidf->CreateImageFromStream(pstrm, &psid)))
{
// we need to decode the image before we can read its header - unfortunately
if (SUCCEEDED(psid->Decode(SHIMGDEC_DEFAULT, 0, 0)))
{
BOOL fRecompress = FALSE;
GUID guidDataFormat;
if (S_OK == _FindEncoder(psi, psid, pstg, ppstrmOut, &fRecompress, &guidDataFormat))
{
int cxOut = 0, cyOut = 0;
// lets compute to see if we need to recompress the image, we do this by
// looking at its size compared ot the size the caller has given us,
// we also compare based on the larger axis to ensure we keep aspect ratio.
SIZE szImage;
if (SUCCEEDED(psid->GetSize(&szImage)))
{
// If the image is too big scale it down to screen size (use large axis for threshold check)
if (szImage.cx > szImage.cy)
{
cxOut = min(szImage.cx, cx);
fRecompress |= szImage.cx > cx;
}
else
{
cyOut = min(szImage.cy, cy);
fRecompress |= szImage.cy > cy;
}
}
// if fRecompress then we generate the new stream, if the new stream is not
// smaller than the current image that we started with then lets
// ignore it (always better to send the smaller of the two).
//
if (fRecompress)
{
hr = _SaveImage(psid, cxOut, cyOut, iQuality, &guidDataFormat, *ppstrmOut);
// If its not worth keeping then lets discard it (eg.
// there was a failure, or new image is bigger than the original.
// tests have shown that this never gets hit, so I'm removing it b/c it will break
// the web publishing wizard's request to resize to this specific size. a client
// of recompress can perform this check itself if it needs to.
#if 0
STATSTG statOut;
hr = (*ppstrmOut)->Stat(&statOut, STATFLAG_NONAME);
if (FAILED(hr) || (statOut.cbSize.QuadPart > statIn.cbSize.QuadPart))
{
hr = S_FALSE;
}
#endif
}
if (hr == S_OK)
{
(*ppstrmOut)->Commit(0); // commit our changes to the stream
LARGE_INTEGER li0 = {0}; // seek to the head of the file so reading gives us bits
(*ppstrmOut)->Seek(li0, 0, NULL);
}
else if (*ppstrmOut)
{
(*ppstrmOut)->Release();
*ppstrmOut = NULL;
}
}
}
psid->Release();
}
pstrm->Release();
}
return hr;
}
HRESULT CImgRecompress::_SaveImage(IShellImageData *psid, int cx, int cy, int iQuality, GUID *pRawDataFmt, IStream *pstrm)
{
HRESULT hr = S_OK;
// Scale the image
if (cx || cy)
{
hr = psid->Scale(cx, cy, InterpolationModeHighQuality);
}
// Make a property bag containing the encoder parameters and set it (if we are changing format)
if (SUCCEEDED(hr) && pRawDataFmt)
{
IPropertyBag *pbagEnc;
hr = SHCreatePropertyBagOnMemory(STGM_READWRITE, IID_PPV_ARG(IPropertyBag, &pbagEnc));
if (SUCCEEDED(hr))
{
// write the encoder CLSID into the property bag
VARIANT var;
hr = InitVariantFromGUID(&var, *pRawDataFmt);
if (SUCCEEDED(hr))
{
hr = pbagEnc->Write(SHIMGKEY_RAWFORMAT, &var);
VariantClear(&var);
}
// write the quality value for the recompression into the property bag
if (SUCCEEDED(hr))
hr = SHPropertyBag_WriteInt(pbagEnc, SHIMGKEY_QUALITY, iQuality);
// pass the parameters over to the encoder
if (SUCCEEDED(hr))
hr = psid->SetEncoderParams(pbagEnc);
pbagEnc->Release();
}
}
// Now persist the file away
if (SUCCEEDED(hr))
{
IPersistStream *ppsImg;
hr = psid->QueryInterface(IID_PPV_ARG(IPersistStream, &ppsImg));
if (SUCCEEDED(hr))
{
hr = ppsImg->Save(pstrm, TRUE);
ppsImg->Release();
}
}
return hr;
}
HRESULT CImgRecompress::_FindEncoder(IShellItem *psi, IShellImageData *psid, IStorage *pstg, IStream **ppstrmOut, BOOL *pfChangeFmt, GUID *pDataFormat)
{
GUID guidDataFormat;
BOOL fChangeExt = FALSE;
// read the relative name from the stream so that we can create a temporary one which maps
LPWSTR pwszName;
HRESULT hr = psi->GetDisplayName(SIGDN_PARENTRELATIVEPARSING, &pwszName);
if (SUCCEEDED(hr))
{
// get the data format from the image we are decompressing
hr = psid->GetRawDataFormat(&guidDataFormat);
if (SUCCEEDED(hr))
{
if (!IsEqualGUID(guidDataFormat, ImageFormatJPEG))
{
// ask the image about it's properties
if ((S_FALSE == psid->IsMultipage()) &&
(S_FALSE == psid->IsVector()) &&
(S_FALSE == psid->IsTransparent()) &&
(S_FALSE == psid->IsAnimated()))
{
guidDataFormat = ImageFormatJPEG;
fChangeExt = TRUE;
}
else
{
hr = S_FALSE; // can't be translated
}
}
// update the name accordingly before making a stream
TCHAR szOutName[MAX_PATH];
StrCpyNW(szOutName, pwszName, ARRAYSIZE(szOutName));
if (fChangeExt)
{
PathRenameExtension(szOutName, TEXT(".jpg"));
}
// TODO: need to get FILE_FLAG_DELETE_ON_CLOSE to happen on CreateFile
hr = StgMakeUniqueName(pstg, szOutName, IID_PPV_ARG(IStream, ppstrmOut));
}
CoTaskMemFree(pwszName);
}
if (pfChangeFmt)
*pfChangeFmt = fChangeExt;
*pDataFormat = guidDataFormat;
return hr;
}
STDAPI CImgRecompress_CreateInstance(IUnknown* pUnkOuter, IUnknown** ppunk, LPCOBJECTINFO poi)
{
CImgRecompress *pr = new CImgRecompress();
if (!pr)
{
*ppunk = NULL; // incase of failure
return E_OUTOFMEMORY;
}
HRESULT hr = pr->QueryInterface(IID_PPV_ARG(IUnknown, ppunk));
pr->Release();
return hr;
}