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examples: (windows/WIC) add alpha support

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Portions based on a patch by Ismail Keskin (iskeskin at gmail dot com)
Fixes issue #83.

Change-Id: Ib54188910354240a2731b0a3a3d0915d17af2233
This commit is contained in:
James Zern 2011-06-21 18:29:30 -07:00
parent 5a18eb1a31
commit 3cfe0888ae
2 changed files with 54 additions and 16 deletions
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52
examples/cwebp.c
View File

@ -44,6 +44,10 @@
DEFINE_GUID(GUID_WICPixelFormat24bppRGB,
0x6fddc324, 0x4e03, 0x4bfe, 0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0d);
#endif
#ifndef GUID_WICPixelFormat32bppRGBA
DEFINE_GUID(GUID_WICPixelFormat32bppRGBA,
0xf5c7ad2d, 0x6a8d, 0x43dd, 0xa7, 0xa8, 0xa2, 0x99, 0x35, 0x26, 0x1a, 0xe9);
#endif
#endif /* HAVE_WINCODEC_H */
@ -109,7 +113,7 @@ static HRESULT OpenInputStream(const char* filename, IStream** ppStream) {
}
static HRESULT ReadPictureWithWIC(const char* filename,
WebPPicture* const pic) {
WebPPicture* const pic, int keep_alpha) {
HRESULT hr = S_OK;
IWICBitmapFrameDecode* pFrame = NULL;
IWICFormatConverter* pConverter = NULL;
@ -119,6 +123,15 @@ static HRESULT ReadPictureWithWIC(const char* filename,
UINT frameCount = 0;
UINT width, height = 0;
BYTE* rgb = NULL;
WICPixelFormatGUID srcPixelFormat = { 0 };
GUID srcContainerFormat = { 0 };
const GUID* alphaContainers[] = {
&GUID_ContainerFormatBmp,
&GUID_ContainerFormatPng,
&GUID_ContainerFormatTiff
};
int has_alpha = 0;
int i, stride;
IFS(CoInitialize(NULL));
IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
@ -139,28 +152,53 @@ static HRESULT ReadPictureWithWIC(const char* filename,
hr = E_FAIL;
}
IFS(IWICBitmapDecoder_GetFrame(pDecoder, 0, &pFrame));
IFS(IWICBitmapFrameDecode_GetPixelFormat(pFrame, &srcPixelFormat));
IFS(IWICBitmapDecoder_GetContainerFormat(pDecoder, &srcContainerFormat));
has_alpha = keep_alpha;
for (i = 0;
has_alpha && i < sizeof(alphaContainers)/sizeof(alphaContainers[0]);
++i) {
if (IsEqualGUID(&srcContainerFormat, alphaContainers[i])) {
has_alpha =
IsEqualGUID(&srcPixelFormat, &GUID_WICPixelFormat32bppRGBA) ||
IsEqualGUID(&srcPixelFormat, &GUID_WICPixelFormat32bppBGRA);
break;
}
}
// Prepare for pixel format conversion (if necessary).
IFS(IWICImagingFactory_CreateFormatConverter(pFactory, &pConverter));
IFS(IWICFormatConverter_Initialize(pConverter, (IWICBitmapSource*)pFrame,
MAKE_REFGUID(GUID_WICPixelFormat24bppRGB), WICBitmapDitherTypeNone,
has_alpha ? MAKE_REFGUID(GUID_WICPixelFormat32bppRGBA)
: MAKE_REFGUID(GUID_WICPixelFormat24bppRGB),
WICBitmapDitherTypeNone,
NULL, 0.0, WICBitmapPaletteTypeCustom));
// Decode.
IFS(IWICFormatConverter_GetSize(pConverter, &width, &height));
stride = (has_alpha ? 4 : 3) * width * sizeof(*rgb);
if (SUCCEEDED(hr)) {
rgb = (BYTE*)malloc(3 * width * height);
rgb = (BYTE*)malloc(stride * height);
if (rgb == NULL)
hr = E_OUTOFMEMORY;
}
IFS(IWICFormatConverter_CopyPixels(pConverter, NULL, 3 * width,
3 * width * height, rgb));
IFS(IWICFormatConverter_CopyPixels(pConverter, NULL, stride,
stride * height, rgb));
// WebP conversion.
if (SUCCEEDED(hr)) {
int ok;
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (has_alpha) {
pic->colorspace |= WEBP_CSP_ALPHA_BIT;
}
#endif
pic->width = width;
pic->height = height;
if (!WebPPictureImportRGB(pic, rgb, 3 * width))
ok = has_alpha ? WebPPictureImportRGBA(pic, rgb, stride)
: WebPPictureImportRGB(pic, rgb, stride);
if (!ok)
hr = E_FAIL;
}
@ -188,7 +226,7 @@ static int ReadPicture(const char* const filename, WebPPicture* const pic,
fclose(in_file);
} else {
// If no size specified, try to decode it using WIC.
ok = SUCCEEDED(ReadPictureWithWIC(filename, pic));
ok = SUCCEEDED(ReadPictureWithWIC(filename, pic, keep_alpha));
}
if (!ok) {
fprintf(stderr, "Error! Could not process file %s\n", filename);

18
examples/dwebp.c
View File

@ -86,13 +86,14 @@ static HRESULT CreateOutputStream(const char* out_file_name,
static HRESULT WriteUsingWIC(const char* out_file_name, REFGUID container_guid,
unsigned char* rgb, int stride,
uint32_t width, uint32_t height) {
uint32_t width, uint32_t height, int has_alpha) {
HRESULT hr = S_OK;
IWICImagingFactory* pFactory = NULL;
IWICBitmapFrameEncode* pFrame = NULL;
IWICBitmapEncoder* pEncoder = NULL;
IStream* pStream = NULL;
GUID pixel_format = GUID_WICPixelFormat24bppBGR;
WICPixelFormatGUID pixel_format = has_alpha ? GUID_WICPixelFormat32bppBGRA
: GUID_WICPixelFormat24bppBGR;
IFS(CoInitialize(NULL));
IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
@ -130,11 +131,11 @@ static int WritePNG(const char* out_file_name,
const uint32_t height = buffer->height;
unsigned char* const rgb = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const int has_alpha = (buffer->colorspace == MODE_RGBA);
assert(!has_alpha); // TODO(mikolaj)
const int has_alpha = (buffer->colorspace == MODE_BGRA);
return SUCCEEDED(WriteUsingWIC(out_file_name,
MAKE_REFGUID(GUID_ContainerFormatPng), rgb, stride, width,
height));
height, has_alpha));
}
#elif defined(WEBP_HAVE_PNG) // !HAVE_WINCODEC_H
@ -264,7 +265,7 @@ static void SaveOutput(const WebPDecBuffer* const buffer,
if (verbose)
StopwatchReadAndReset(&stop_watch);
#ifdef _WIN32
#ifdef HAVE_WINCODEC_H
needs_open_file = (format != PNG);
#endif
if (needs_open_file) {
@ -429,9 +430,8 @@ int main(int argc, const char *argv[]) {
switch (format) {
case PNG:
#ifdef _WIN32
// TODO(mikolaj): no alpha for now
output_buffer->colorspace = MODE_BGR;
#ifdef HAVE_WINCODEC_H
output_buffer->colorspace = bitstream->has_alpha ? MODE_BGRA : MODE_BGR;
#else
output_buffer->colorspace = bitstream->has_alpha ? MODE_RGBA : MODE_RGB;
#endif