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wicdec: add alpha support for paletted formats

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Fixes issue #141.

Change-Id: I5d8163329a9e363da9db9d70d25edeb29da32e9e
This commit is contained in:
James Zern 2013-02-05 16:25:47 -08:00
parent e7ea61eb75
commit c9f1649012
1 changed files with 65 additions and 21 deletions
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86
examples/wicdec.c
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@ -40,7 +40,8 @@
// modified version of DEFINE_GUID from guiddef.h.
#define WEBP_DEFINE_GUID(name, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
const GUID name = { l, w1, w2, { b1, b2, b3, b4, b5, b6, b7, b8 } }
static const GUID name = \
{ l, w1, w2, { b1, b2, b3, b4, b5, b6, b7, b8 } }
#ifdef __cplusplus
#define MAKE_REFGUID(x) (x)
@ -54,6 +55,22 @@ typedef struct WICFormatImporter {
int (*import)(WebPPicture* const, const uint8_t* const, int);
} WICFormatImporter;
// From Microsoft SDK 7.0a -- wincodec.h
// Create local copies for compatibility when building against earlier
// versions of the SDK.
WEBP_DEFINE_GUID(GUID_WICPixelFormat24bppBGR_,
0x6fddc324, 0x4e03, 0x4bfe,
0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0c);
WEBP_DEFINE_GUID(GUID_WICPixelFormat24bppRGB_,
0x6fddc324, 0x4e03, 0x4bfe,
0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0d);
WEBP_DEFINE_GUID(GUID_WICPixelFormat32bppBGRA_,
0x6fddc324, 0x4e03, 0x4bfe,
0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0f);
WEBP_DEFINE_GUID(GUID_WICPixelFormat32bppRGBA_,
0xf5c7ad2d, 0x6a8d, 0x43dd,
0xa7, 0xa8, 0xa2, 0x99, 0x35, 0x26, 0x1a, 0xe9);
static HRESULT OpenInputStream(const char* filename, IStream** ppStream) {
HRESULT hr = S_OK;
IFS(SHCreateStreamOnFileA(filename, STGM_READ, ppStream));
@ -135,27 +152,58 @@ static HRESULT ExtractMetadata(IWICImagingFactory* const pFactory,
// -----------------------------------------------------------------------------
static int HasPalette(GUID pixel_format) {
return (IsEqualGUID(MAKE_REFGUID(pixel_format),
MAKE_REFGUID(GUID_WICPixelFormat1bppIndexed)) ||
IsEqualGUID(MAKE_REFGUID(pixel_format),
MAKE_REFGUID(GUID_WICPixelFormat2bppIndexed)) ||
IsEqualGUID(MAKE_REFGUID(pixel_format),
MAKE_REFGUID(GUID_WICPixelFormat4bppIndexed)) ||
IsEqualGUID(MAKE_REFGUID(pixel_format),
MAKE_REFGUID(GUID_WICPixelFormat8bppIndexed)));
}
static int HasAlpha(IWICImagingFactory* const pFactory,
IWICBitmapDecoder* const pDecoder,
IWICBitmapFrameDecode* const pFrame,
GUID srcPixelFormat) {
int has_alpha;
if (HasPalette(srcPixelFormat)) {
IWICPalette* pFramePalette = NULL;
IWICPalette* pGlobalPalette = NULL;
BOOL frame_palette_has_alpha = FALSE;
BOOL global_palette_has_alpha = FALSE;
// A palette may exist at the frame or container level,
// check IWICPalette::HasAlpha() for both if present.
if (SUCCEEDED(IWICImagingFactory_CreatePalette(pFactory, &pFramePalette)) &&
SUCCEEDED(IWICBitmapFrameDecode_CopyPalette(pFrame, pFramePalette))) {
IWICPalette_HasAlpha(pFramePalette, &frame_palette_has_alpha);
}
if (SUCCEEDED(IWICImagingFactory_CreatePalette(pFactory,
&pGlobalPalette)) &&
SUCCEEDED(IWICBitmapDecoder_CopyPalette(pDecoder, pGlobalPalette))) {
IWICPalette_HasAlpha(pGlobalPalette, &global_palette_has_alpha);
}
has_alpha = frame_palette_has_alpha || global_palette_has_alpha;
if (pFramePalette != NULL) IUnknown_Release(pFramePalette);
if (pGlobalPalette != NULL) IUnknown_Release(pGlobalPalette);
} else {
has_alpha = IsEqualGUID(MAKE_REFGUID(srcPixelFormat),
MAKE_REFGUID(GUID_WICPixelFormat32bppRGBA_)) ||
IsEqualGUID(MAKE_REFGUID(srcPixelFormat),
MAKE_REFGUID(GUID_WICPixelFormat32bppBGRA_));
}
return has_alpha;
}
int ReadPictureWithWIC(const char* const filename,
WebPPicture* const pic, int keep_alpha,
Metadata* const metadata) {
// From Microsoft SDK 6.0a -- ks.h
// Define a local copy to avoid link errors under mingw.
WEBP_DEFINE_GUID(GUID_NULL_, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
// From Microsoft SDK 7.0a -- wincodec.h
// Create local copies for compatibility when building against earlier
// versions of the SDK.
WEBP_DEFINE_GUID(GUID_WICPixelFormat24bppBGR_,
0x6fddc324, 0x4e03, 0x4bfe,
0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0c);
WEBP_DEFINE_GUID(GUID_WICPixelFormat24bppRGB_,
0x6fddc324, 0x4e03, 0x4bfe,
0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0d);
WEBP_DEFINE_GUID(GUID_WICPixelFormat32bppBGRA_,
0x6fddc324, 0x4e03, 0x4bfe,
0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0f);
WEBP_DEFINE_GUID(GUID_WICPixelFormat32bppRGBA_,
0xf5c7ad2d, 0x6a8d, 0x43dd,
0xa7, 0xa8, 0xa2, 0x99, 0x35, 0x26, 0x1a, 0xe9);
const WICFormatImporter alphaFormatImporters[] = {
{ &GUID_WICPixelFormat32bppBGRA_, 4, WebPPictureImportBGRA },
{ &GUID_WICPixelFormat32bppRGBA_, 4, WebPPictureImportRGBA },
@ -214,11 +262,7 @@ int ReadPictureWithWIC(const char* const filename,
const GUID** guid;
for (guid = alphaContainers; *guid != NULL; ++guid) {
if (IsEqualGUID(MAKE_REFGUID(srcContainerFormat), MAKE_REFGUID(**guid))) {
has_alpha =
IsEqualGUID(MAKE_REFGUID(srcPixelFormat),
MAKE_REFGUID(GUID_WICPixelFormat32bppRGBA_)) ||
IsEqualGUID(MAKE_REFGUID(srcPixelFormat),
MAKE_REFGUID(GUID_WICPixelFormat32bppBGRA_));
has_alpha = HasAlpha(pFactory, pDecoder, pFrame, srcPixelFormat);
break;
}
}