Support EXIF data in PNGs when using GDI+

src/JPEGView/ImageLoadThread.cpp

@@ -322,19 +322,14 @@ void CImageLoadThread::ProcessRequest(CRequestBase& request) {
 			DeleteCachedAvifDecoder();
 			ProcessReadWEBPRequest(&rq);
 			break;
-#ifndef WINXP
 		case IF_PNG:
 			DeleteCachedGDIBitmap();
 			DeleteCachedWebpDecoder();
 			DeleteCachedJxlDecoder();
 			DeleteCachedAvifDecoder();
-			if (CSettingsProvider::This().ForceGDIPlus()) {
-				DeleteCachedPngDecoder();
-				ProcessReadGDIPlusRequest(&rq);
-			} else {
-				ProcessReadPNGRequest(&rq);
-			}
+			ProcessReadPNGRequest(&rq);
 			break;
+#ifndef WINXP
 		case IF_JXL:
 			DeleteCachedGDIBitmap();
 			DeleteCachedWebpDecoder();
@@ -652,7 +647,6 @@ void CImageLoadThread::ProcessReadWEBPRequest(CRequest * request) {
 
 #ifndef WINXP
 void CImageLoadThread::ProcessReadPNGRequest(CRequest* request) {
-	bool bSuccess = false;
 	bool bUseCachedDecoder = false;
 	const wchar_t* sFileName;
 	sFileName = (const wchar_t*)request->FileName;
@@ -670,36 +664,42 @@ void CImageLoadThread::ProcessReadPNGRequest(CRequest* request) {
 			return;
 		}
 	}
-	char* pBuffer = NULL;
+	HGLOBAL hFileBuffer = NULL;
+	void* pBuffer = NULL;
 	try {
 		unsigned int nFileSize;
 		unsigned int nNumBytesRead;
 		if (!bUseCachedDecoder) {
 			// Don't read too huge files
 			nFileSize = ::GetFileSize(hFile, NULL);
 			if (nFileSize > MAX_PNG_FILE_SIZE) {
+				request->OutOfMemory = true;
 				::CloseHandle(hFile);
-				return ProcessReadGDIPlusRequest(request);
+				return;
 			}
-
-			pBuffer = new(std::nothrow) char[nFileSize];
+			hFileBuffer = ::GlobalAlloc(GMEM_MOVEABLE, nFileSize);
+			pBuffer = (hFileBuffer == NULL) ? NULL : ::GlobalLock(hFileBuffer);
 			if (pBuffer == NULL) {
+				if (hFileBuffer) ::GlobalFree(hFileBuffer);
+				request->OutOfMemory = true;
 				::CloseHandle(hFile);
-				return ProcessReadGDIPlusRequest(request);
+				return;
 			}
-		}
-		else {
+		} else {
 			nFileSize = 0; // to avoid compiler warnings, not used
 		}
 		if (bUseCachedDecoder || (::ReadFile(hFile, pBuffer, nFileSize, (LPDWORD)&nNumBytesRead, NULL) && nNumBytesRead == nFileSize)) {
 			int nWidth, nHeight, nBPP, nFrameCount, nFrameTimeMs;
 			bool bHasAnimation;
 			uint8* pPixelData = NULL;
-			void* pEXIFData;
+			void* pEXIFData = NULL;
 
+#ifndef WINXP
 			// If UseEmbeddedColorProfiles is true and the image isn't animated, we should use GDI+ for better color management
-			if (bUseCachedDecoder || !CSettingsProvider::This().UseEmbeddedColorProfiles() || PngReader::IsAnimated(pBuffer, nFileSize))
+			bool bUseGDIPlus = CSettingsProvider::This().ForceGDIPlus() || CSettingsProvider::This().UseEmbeddedColorProfiles();
+			if (bUseCachedDecoder || !bUseGDIPlus || PngReader::IsAnimated(pBuffer, nFileSize))
 				pPixelData = (uint8*)PngReader::ReadImage(nWidth, nHeight, nBPP, bHasAnimation, nFrameCount, nFrameTimeMs, pEXIFData, request->OutOfMemory, pBuffer, nFileSize);
+#endif
 
 			if (pPixelData != NULL) {
 				if (bHasAnimation)
@@ -710,25 +710,35 @@ void CImageLoadThread::ProcessReadPNGRequest(CRequest* request) {
 					*pImage32++ = Helpers::AlphaBlendBackground(*pImage32, CSettingsProvider::This().ColorTransparency());
 
 				request->Image = new CJPEGImage(nWidth, nHeight, pPixelData, pEXIFData, 4, 0, IF_PNG, bHasAnimation, request->FrameIndex, nFrameCount, nFrameTimeMs);
-				free(pEXIFData);
-				bSuccess = true;
-			}
-			else {
+			} else {
 				DeleteCachedPngDecoder();
+
+				IStream* pStream = NULL;
+				if (::CreateStreamOnHGlobal(hFileBuffer, FALSE, &pStream) == S_OK) {
+					Gdiplus::Bitmap* pBitmap = Gdiplus::Bitmap::FromStream(pStream, CSettingsProvider::This().UseEmbeddedColorProfiles());
+					bool isOutOfMemory, isAnimatedGIF;
+					pEXIFData = PngReader::GetEXIFBlock(pBuffer, nFileSize);
+					request->Image = ConvertGDIPlusBitmapToJPEGImage(pBitmap, 0, pEXIFData, 0, isOutOfMemory, isAnimatedGIF);
+					request->OutOfMemory = request->Image == NULL && isOutOfMemory;
+					pStream->Release();
+					delete pBitmap;
+				} else {
+					request->OutOfMemory = true;
+				}
 			}
+			free(pEXIFData);
 		}
 	}
 	catch (...) {
-		// delete request->Image;
-		// request->Image = NULL;
+		delete request->Image;
+		request->Image = NULL;
 		request->ExceptionError = true;
 	}
 	if (!bUseCachedDecoder) {
 		::CloseHandle(hFile);
-		delete[] pBuffer;
+		if (pBuffer) ::GlobalUnlock(hFileBuffer);
+		if (hFileBuffer) ::GlobalFree(hFileBuffer);
 	}
-	if (!bSuccess)
-		return ProcessReadGDIPlusRequest(request);
 }
 #endif
 

src/JPEGView/PNGWrapper.cpp

@@ -400,3 +400,31 @@ bool PngReader::IsAnimated(void* buffer, size_t sizebytes) {
 	}
 	return false;
 }
+
+void* PngReader::GetEXIFBlock(void* buffer, size_t sizebytes) {
+	size_t offset = 8; // skip PNG signature
+	while (offset + 7 < sizebytes) {
+		unsigned int chunksize = *(unsigned int*)((char*)buffer + offset);
+		// PNG chunk sizes are big-endian and must be converted to little-endian
+		chunksize = _byteswap_ulong(chunksize);
+
+		if (memcmp((char*)buffer + offset + 4, "eXIf", 4) == 0 && chunksize < 65528 && offset + chunksize + 7 < sizebytes) {
+			void* exif_chunk = malloc(chunksize + 10);
+			if (exif_chunk != NULL) {
+				memcpy(exif_chunk, "\xFF\xE1\0\0Exif\0\0", 10);
+				*((unsigned short*)exif_chunk + 1) = _byteswap_ushort(chunksize + 8);
+				memcpy((char*)exif_chunk + 10, (char*)buffer + offset + 8, chunksize);
+			}
+			return exif_chunk;
+		}
+
+
+
+		// Prevent infinite loop
+		if (chunksize > PNG_UINT_31_MAX) return NULL;
+
+		// 12 comes from 4 bytes for chunk size, 4 for chunk name, and 4 for CRC32
+		offset += chunksize + 12;
+	}
+	return NULL;
+}

src/JPEGView/PNGWrapper.h

@@ -21,6 +21,9 @@ class PngReader
 	// Returns true if PNG is animated, false otherwise
 	static bool IsAnimated(void* buffer, size_t sizebytes);
 
+	// Get EXIF Block
+	static void* GetEXIFBlock(void* buffer, size_t sizebytes);
+
 private:
 	struct png_cache;
 	static png_cache cache;