[PATCH 3/5] windowscodecs: Use IWICComponentFactory_CreateMetadataReader instead of create_instance.

[Rémi Bernon]

Signed-off-by: Rémi Bernon 
---
 dlls/windowscodecs/decoder.c           | 46 ++++++--------------------
 dlls/windowscodecs/libtiff.c           |  4 +--
 dlls/windowscodecs/wincodecs_private.h |  4 +--
 3 files changed, 15 insertions(+), 39 deletions(-)

diff --git a/dlls/windowscodecs/decoder.c b/dlls/windowscodecs/decoder.c
index 3e43fa91114..0af203febf6 100644
--- a/dlls/windowscodecs/decoder.c
+++ b/dlls/windowscodecs/decoder.c
@@ -634,48 +634,24 @@ static HRESULT WINAPI CommonDecoderFrame_Block_GetReaderByIndex(IWICMetadataBloc
                 offset, length);
         }

-        if (This->metadata_blocks[nIndex].options & DECODER_BLOCK_READER_CLSID)
-        {
-            IWICMetadataReader *reader;
-            IWICPersistStream *persist;
-            if (SUCCEEDED(hr))
-            {
-                hr = create_instance(&This->metadata_blocks[nIndex].reader_clsid,
-                    &IID_IWICMetadataReader, (void**)&reader);
-            }
-
-            if (SUCCEEDED(hr))
-            {
-                hr = IWICMetadataReader_QueryInterface(reader, &IID_IWICPersistStream, (void**)&persist);
-
-                if (SUCCEEDED(hr))
-                {
-                    hr = IWICPersistStream_LoadEx(persist, (IStream*)stream, NULL,
-                        This->metadata_blocks[nIndex].options & DECODER_BLOCK_OPTION_MASK);
-
-                    IWICPersistStream_Release(persist);
-                }
+        if (SUCCEEDED(hr))
+            hr = CoCreateInstance(&CLSID_WICImagingFactory, NULL, CLSCTX_INPROC_SERVER,
+                                  &IID_IWICComponentFactory, (void **)&factory);

-                if (SUCCEEDED(hr))
-                    *ppIMetadataReader = reader;
-                else
-                    IWICMetadataReader_Release(reader);
-            }
-        }
-        else
+        if (SUCCEEDED(hr))
         {
-            if (SUCCEEDED(hr))
-                hr = ImagingFactory_CreateInstance(&IID_IWICComponentFactory, (void**)&factory);
-
-            if (SUCCEEDED(hr))
-            {
+            if (This->metadata_blocks[nIndex].options & DECODER_BLOCK_FORMAT_GUID)
+                hr = IWICComponentFactory_CreateMetadataReader(factory,
+                    &This->metadata_blocks[nIndex].format_guid, NULL,
+                    This->metadata_blocks[nIndex].options & DECODER_BLOCK_OPTION_MASK,
+                    (IStream*)stream, ppIMetadataReader);
+            else
                 hr = IWICComponentFactory_CreateMetadataReaderFromContainer(factory,
                     &This->parent->decoder_info.block_format, NULL,
                     This->metadata_blocks[nIndex].options & DECODER_BLOCK_OPTION_MASK,
                     (IStream*)stream, ppIMetadataReader);

-                IWICComponentFactory_Release(factory);
-            }
+            IWICComponentFactory_Release(factory);
         }

IWICStream_Release(stream);
diff --git a/dlls/windowscodecs/libtiff.c b/dlls/windowscodecs/libtiff.c
index 6f5cfc53c62..d318ff80095 100644
--- a/dlls/windowscodecs/libtiff.c
+++ b/dlls/windowscodecs/libtiff.c
@@ -1129,8 +1129,8 @@ static HRESULT CDECL tiff_decoder_get_metadata_blocks(struct decoder *iface,
 #else
     result.options = byte_swapped ? WICPersistOptionBigEndian : WICPersistOptionLittleEndian;
 #endif
-    result.options |= WICPersistOptionNoCacheStream|DECODER_BLOCK_FULL_STREAM|DECODER_BLOCK_READER_CLSID;
-    result.reader_clsid = CLSID_WICIfdMetadataReader;
+    result.options |= WICPersistOptionNoCacheStream|DECODER_BLOCK_FULL_STREAM|DECODER_BLOCK_FORMAT_GUID;
+    result.format_guid = GUID_MetadataFormatIfd;

*blocks = RtlAllocateHeap(GetProcessHeap(), 0, sizeof(**blocks));
     **blocks = result;
diff --git a/dlls/windowscodecs/wincodecs_private.h b/dlls/windowscodecs/wincodecs_private.h
index 3b20f7d6c24..5085e4c057c 100644
--- a/dlls/windowscodecs/wincodecs_private.h
+++ b/dlls/windowscodecs/wincodecs_private.h
@@ -284,13 +284,13 @@ struct decoder_frame

#define DECODER_BLOCK_OPTION_MASK 0x0001000F
 #define DECODER_BLOCK_FULL_STREAM 0x80000000
-#define DECODER_BLOCK_READER_CLSID 0x40000000
+#define DECODER_BLOCK_FORMAT_GUID 0x40000000
 struct decoder_block
 {
     ULONGLONG offset;
     ULONGLONG length;
     DWORD options;
-    GUID reader_clsid;
+    GUID format_guid;
 };

struct decoder