int ReadPNG(const uint8_t* const data, size_t data_size,
struct WebPPicture* const pic,
int keep_alpha, struct Metadata* const metadata) {
volatile png_structp png = NULL;
volatile png_infop info = NULL;
volatile png_infop end_info = NULL;
PNGReadContext context = { NULL, 0, 0 };
int color_type, bit_depth, interlaced;
int has_alpha;
int num_passes;
int p;
volatile int ok = 0;
png_uint_32 width, height, y;
int64_t stride;
uint8_t* volatile rgb = NULL;
if (data == NULL || data_size == 0 || pic == NULL) return 0;
context.data = data;
context.data_size = data_size;
png = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL,
NULL, MallocFunc, FreeFunc);
if (png == NULL) goto End;
png_set_error_fn(png, 0, error_function, NULL);
if (setjmp(png_jmpbuf(png))) {
Error:
MetadataFree(metadata);
goto End;
}
info = png_create_info_struct(png);
if (info == NULL) goto Error;
end_info = png_create_info_struct(png);
if (end_info == NULL) goto Error;
png_set_read_fn(png, &context, ReadFunc);
png_read_info(png, info);
if (!png_get_IHDR(png, info,
&width, &height, &bit_depth, &color_type, &interlaced,
NULL, NULL)) goto Error;
png_set_strip_16(png);
png_set_packing(png);
if (color_type == PNG_COLOR_TYPE_PALETTE) {
png_set_palette_to_rgb(png);
}
if (color_type == PNG_COLOR_TYPE_GRAY ||
color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
if (bit_depth < 8) {
png_set_expand_gray_1_2_4_to_8(png);
}
png_set_gray_to_rgb(png);
}
if (png_get_valid(png, info, PNG_INFO_tRNS)) {
png_set_tRNS_to_alpha(png);
has_alpha = 1;
} else {
has_alpha = !!(color_type & PNG_COLOR_MASK_ALPHA);
}
// Apply gamma correction if needed.
{
double image_gamma = 1 / 2.2, screen_gamma = 2.2;
int srgb_intent;
if (png_get_sRGB(png, info, &srgb_intent) ||
png_get_gAMA(png, info, &image_gamma)) {
png_set_gamma(png, screen_gamma, image_gamma);
}
}
if (!keep_alpha) {
png_set_strip_alpha(png);
has_alpha = 0;
}
num_passes = png_set_interlace_handling(png);
png_read_update_info(png, info);
stride = (int64_t)(has_alpha ? 4 : 3) * width * sizeof(*rgb);
if (stride != (int)stride ||
!ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
goto Error;
}
rgb = (uint8_t*)malloc((size_t)stride * height);
if (rgb == NULL) goto Error;
for (p = 0; p < num_passes; ++p) {
png_bytep row = rgb;
for (y = 0; y < height; ++y) {
png_read_rows(png, &row, NULL, 1);
row += stride;
}
}
png_read_end(png, end_info);
if (metadata != NULL &&
!ExtractMetadataFromPNG(png, info, end_info, metadata)) {
fprintf(stderr, "Error extracting PNG metadata!\n");
goto Error;
}
pic->width = (int)width;
pic->height = (int)height;
ok = has_alpha ? WebPPictureImportRGBA(pic, rgb, (int)stride)
: WebPPictureImportRGB(pic, rgb, (int)stride);
if (!ok) {
goto Error;
}
End:
if (png != NULL) {
png_destroy_read_struct((png_structpp)&png,
(png_infopp)&info, (png_infopp)&end_info);
}
free(rgb);
return ok;
}
static png_voidp MallocFunc(png_structp png_ptr, LocalPngAllocSize size) {
(void)png_ptr;
if (size != (size_t)size) return NULL;
if (!ImgIoUtilCheckSizeArgumentsOverflow(size, 1)) return NULL;
return (png_voidp)malloc((size_t)size);
}
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);
static const WICFormatImporter kAlphaFormatImporters[] = {
{ &GUID_WICPixelFormat32bppBGRA_, 4, WebPPictureImportBGRA },
{ &GUID_WICPixelFormat32bppRGBA_, 4, WebPPictureImportRGBA },
{ NULL, 0, NULL },
};
static const WICFormatImporter kNonAlphaFormatImporters[] = {
{ &GUID_WICPixelFormat24bppBGR_, 3, WebPPictureImportBGR },
{ &GUID_WICPixelFormat24bppRGB_, 3, WebPPictureImportRGB },
{ NULL, 0, NULL },
};
HRESULT hr = S_OK;
IWICBitmapFrameDecode* frame = NULL;
IWICFormatConverter* converter = NULL;
IWICImagingFactory* factory = NULL;
IWICBitmapDecoder* decoder = NULL;
IStream* stream = NULL;
UINT frame_count = 0;
UINT width = 0, height = 0;
BYTE* rgb = NULL;
WICPixelFormatGUID src_pixel_format = GUID_WICPixelFormatUndefined;
const WICFormatImporter* importer = NULL;
GUID src_container_format = GUID_NULL_;
static const GUID* kAlphaContainers[] = {
&GUID_ContainerFormatBmp,
&GUID_ContainerFormatPng,
&GUID_ContainerFormatTiff,
NULL
};
int has_alpha = 0;
int64_t stride;
IFS(CoInitialize(NULL));
IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
CLSCTX_INPROC_SERVER,
MAKE_REFGUID(IID_IWICImagingFactory),
(LPVOID*)&factory));
if (hr == REGDB_E_CLASSNOTREG) {
fprintf(stderr,
"Couldn't access Windows Imaging Component (are you running "
"Windows XP SP3 or newer?). Most formats not available. "
"Use -s for the available YUV input.\n");
}
// Prepare for image decoding.
IFS(OpenInputStream(filename, &stream));
IFS(IWICImagingFactory_CreateDecoderFromStream(
factory, stream, NULL,
WICDecodeMetadataCacheOnDemand, &decoder));
IFS(IWICBitmapDecoder_GetFrameCount(decoder, &frame_count));
if (SUCCEEDED(hr) && frame_count == 0) {
fprintf(stderr, "No frame found in input file.\n");
hr = E_FAIL;
}
IFS(IWICBitmapDecoder_GetFrame(decoder, 0, &frame));
IFS(IWICBitmapFrameDecode_GetPixelFormat(frame, &src_pixel_format));
IFS(IWICBitmapDecoder_GetContainerFormat(decoder, &src_container_format));
if (SUCCEEDED(hr) && keep_alpha) {
const GUID** guid;
for (guid = kAlphaContainers; *guid != NULL; ++guid) {
if (IsEqualGUID(MAKE_REFGUID(src_container_format),
MAKE_REFGUID(**guid))) {
has_alpha = HasAlpha(factory, decoder, frame, src_pixel_format);
break;
}
}
}
// Prepare for pixel format conversion (if necessary).
IFS(IWICImagingFactory_CreateFormatConverter(factory, &converter));
for (importer = has_alpha ? kAlphaFormatImporters : kNonAlphaFormatImporters;
hr == S_OK && importer->import != NULL; ++importer) {
BOOL can_convert;
const HRESULT cchr = IWICFormatConverter_CanConvert(
converter,
MAKE_REFGUID(src_pixel_format),
MAKE_REFGUID(*importer->pixel_format),
&can_convert);
if (SUCCEEDED(cchr) && can_convert) break;
}
if (importer->import == NULL) hr = E_FAIL;
IFS(IWICFormatConverter_Initialize(converter, (IWICBitmapSource*)frame,
importer->pixel_format,
WICBitmapDitherTypeNone,
NULL, 0.0, WICBitmapPaletteTypeCustom));
// Decode.
IFS(IWICFormatConverter_GetSize(converter, &width, &height));
stride = (int64_t)importer->bytes_per_pixel * width * sizeof(*rgb);
if (stride != (int)stride ||
!ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
hr = E_FAIL;
}
if (SUCCEEDED(hr)) {
rgb = (BYTE*)malloc((size_t)stride * height);
if (rgb == NULL)
hr = E_OUTOFMEMORY;
}
IFS(IWICFormatConverter_CopyPixels(converter, NULL,
(UINT)stride, (UINT)stride * height, rgb));
// WebP conversion.
if (SUCCEEDED(hr)) {
int ok;
pic->width = width;
pic->height = height;
pic->use_argb = 1; // For WIC, we always force to argb
ok = importer->import(pic, rgb, (int)stride);
if (!ok) hr = E_FAIL;
}
if (SUCCEEDED(hr)) {
if (metadata != NULL) {
hr = ExtractMetadata(factory, frame, metadata);
if (FAILED(hr)) {
fprintf(stderr, "Error extracting image metadata using WIC!\n");
}
}
}
// Cleanup.
if (converter != NULL) IUnknown_Release(converter);
if (frame != NULL) IUnknown_Release(frame);
if (decoder != NULL) IUnknown_Release(decoder);
if (factory != NULL) IUnknown_Release(factory);
if (stream != NULL) IUnknown_Release(stream);
free(rgb);
return SUCCEEDED(hr);
}
