Add helper functions for safe unicode transformations.

2 files changed, 47 insertions, 0 deletions

diff --git a/common/DSUtilLite/DShowUtil.cpp b/common/DSUtilLite/DShowUtil.cpp
index 01cac86d..b69f70a2 100644
--- a/common/DSUtilLite/DShowUtil.cpp
+++ b/common/DSUtilLite/DShowUtil.cpp
@@ -185,6 +185,48 @@ std::wstring WStringFromGUID(const GUID& guid)
   return std::wstring(StringFromGUID2(guid, buff, 127) > 0 ? buff : null);
 }
 
+int SafeMultiByteToWideChar(UINT CodePage, DWORD dwFlags, LPCSTR lpMultiByteStr, int cbMultiByte, LPWSTR lpWideCharStr, int cchWideChar)
+{
+  int len = MultiByteToWideChar(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, lpWideCharStr, cchWideChar);
+  if (len == cchWideChar) {
+    lpWideCharStr[len - 1] = 0;
+  }
+  return len;
+}
+
+int SafeWideCharToMultiByte(UINT CodePage, DWORD dwFlags, LPCWSTR lpWideCharStr, int cchWideChar, LPSTR lpMultiByteStr, int cbMultiByte, LPCSTR lpDefaultChar, LPBOOL lpUsedDefaultChar)
+{
+  int len = WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar);
+  if (len == cbMultiByte) {
+    lpMultiByteStr[len - 1] = 0;
+  }
+  return len;
+}
+
+LPWSTR CoTaskGetWideCharFromMultiByte(UINT CodePage, DWORD dwFlags, LPCSTR lpMultiByteStr, int cbMultiByte)
+{
+  int len = MultiByteToWideChar(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, nullptr, 0);
+  if (len) {
+    LPWSTR pszWideString = (LPWSTR)CoTaskMemAlloc(len * sizeof(WCHAR));
+    MultiByteToWideChar(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, pszWideString, len);
+
+    return pszWideString;
+  }
+  return NULL;
+}
+
+LPSTR CoTaskGetMultiByteFromWideChar(UINT CodePage, DWORD dwFlags, LPCWSTR lpMultiByteStr, int cbMultiByte)
+{
+  int len = WideCharToMultiByte(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, nullptr, 0, nullptr, nullptr);
+  if (len) {
+    LPSTR pszMBString = (LPSTR)CoTaskMemAlloc(len * sizeof(char));
+    WideCharToMultiByte(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, pszMBString, len, nullptr, nullptr);
+
+    return pszMBString;
+  }
+  return NULL;
+}
+
 BSTR ConvertCharToBSTR(const char *sz)
 {
   bool acp = false;
diff --git a/common/DSUtilLite/DShowUtil.h b/common/DSUtilLite/DShowUtil.h
index 14063d77..fca55d20 100644
--- a/common/DSUtilLite/DShowUtil.h
+++ b/common/DSUtilLite/DShowUtil.h
@@ -117,6 +117,11 @@ extern BOOL HasSourceWithType(IPin *pPin, const GUID &mediaType);
 std::wstring WStringFromGUID(const GUID& guid);
 BSTR ConvertCharToBSTR(const char *sz);
 
+int SafeMultiByteToWideChar(UINT CodePage, DWORD dwFlags, LPCSTR lpMultiByteStr, int cbMultiByte, LPWSTR lpWideCharStr, int cchWideChar);
+int SafeWideCharToMultiByte(UINT CodePage, DWORD dwFlags, LPCWSTR lpWideCharStr, int cchWideChar, LPSTR lpMultiByteStr, int cbMultiByte, LPCSTR lpDefaultChar, LPBOOL lpUsedDefaultChar);
+LPWSTR CoTaskGetWideCharFromMultiByte(UINT CodePage, DWORD dwFlags, LPCSTR lpMultiByteStr, int cbMultiByte);
+LPSTR CoTaskGetMultiByteFromWideChar(UINT CodePage, DWORD dwFlags, LPCWSTR lpMultiByteStr, int cbMultiByte);
+
 unsigned int lav_xiphlacing(unsigned char *s, unsigned int v);
 
 void videoFormatTypeHandler(const AM_MEDIA_TYPE &mt, BITMAPINFOHEADER **pBMI = nullptr, REFERENCE_TIME *prtAvgTime = nullptr, DWORD *pDwAspectX = nullptr, DWORD *pDwAspectY = nullptr);