ERR PKCodecFactory_CreateDecoderFromFile(const char* szFilename, PKImageDecode** ppDecoder)
{
ERR err = WMP_errSuccess;
char *pExt = NULL;
const PKIID* pIID = NULL;
struct WMPStream* pStream = NULL;
PKImageDecode* pDecoder = NULL;
// get file extension
pExt = strrchr(szFilename, '.');
FailIf(NULL == pExt, WMP_errUnsupportedFormat);
// get decode PKIID
Call(GetImageDecodeIID(pExt, &pIID));
// create stream
Call(CreateWS_File(&pStream, szFilename, "rb"));
// Create decoder
#if 0
Call(PKCodecFactory_CreateCodec(pIID, (void **) ppDecoder));
#else
// We know we are creating a decoder here
Call(PKImageDecode_Create_WMP(ppDecoder));
#endif
pDecoder = *ppDecoder;
// attach stream to decoder
Call(pDecoder->Initialize(pDecoder, pStream));
pDecoder->fStreamOwner = !0;
Cleanup:
return err;
}
static FIBITMAP * DLL_CALLCONV
Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
PKImageDecode *pDecoder = NULL; // decoder interface
ERR error_code = 0; // error code as returned by the interface
PKPixelFormatGUID guid_format; // loaded pixel format (== input file pixel format if no conversion needed)
FREE_IMAGE_TYPE image_type = FIT_UNKNOWN; // input image type
unsigned bpp = 0; // input image bit depth
FIBITMAP *dib = NULL;
// get the I/O stream wrapper
WMPStream *pDecodeStream = (WMPStream*)data;
if(!handle || !pDecodeStream) {
return NULL;
}
BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS;
try {
int width, height; // image dimensions (in pixels)
// create a JXR decoder interface and initialize function pointers with *_WMP functions
error_code = PKImageDecode_Create_WMP(&pDecoder);
JXR_CHECK(error_code);
// attach the stream to the decoder ...
// ... then read the image container and the metadata
error_code = pDecoder->Initialize(pDecoder, pDecodeStream);
JXR_CHECK(error_code);
// set decoder parameters
SetDecoderParameters(pDecoder, flags);
// get dst image format specifications
unsigned red_mask = 0, green_mask = 0, blue_mask = 0;
error_code = GetInputPixelFormat(pDecoder, &guid_format, &image_type, &bpp, &red_mask, &green_mask, &blue_mask);
JXR_CHECK(error_code);
// get image dimensions
pDecoder->GetSize(pDecoder, &width, &height);
// allocate dst image
{
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, bpp, red_mask, green_mask, blue_mask);
if(!dib) {
throw FI_MSG_ERROR_DIB_MEMORY;
}
if(FreeImage_GetBPP(dib) == 1) {
// BD_1 - build a FIC_MINISBLACK palette
RGBQUAD *pal = FreeImage_GetPalette(dib);
pal[0].rgbRed = pal[0].rgbGreen = pal[0].rgbBlue = 0;
pal[1].rgbRed = pal[1].rgbGreen = pal[1].rgbBlue = 255;
}
}
// get image resolution
{
float resX, resY; // image resolution (in dots per inch)
// convert from English units, i.e. dots per inch to universal units, i.e. dots per meter
pDecoder->GetResolution(pDecoder, &resX, &resY);
FreeImage_SetDotsPerMeterX(dib, (unsigned)(resX / 0.0254F + 0.5F));
FreeImage_SetDotsPerMeterY(dib, (unsigned)(resY / 0.0254F + 0.5F));
}
// get metadata & ICC profile
error_code = ReadMetadata(pDecoder, dib);
JXR_CHECK(error_code);
if(header_only) {
// header only mode ...
// free the decoder
pDecoder->Release(&pDecoder);
assert(pDecoder == NULL);
return dib;
}
// copy pixels into the dib, perform pixel conversion if needed
error_code = CopyPixels(pDecoder, guid_format, dib, width, height);
JXR_CHECK(error_code);
// free the decoder
pDecoder->Release(&pDecoder);
assert(pDecoder == NULL);
return dib;
} catch (const char *message) {
// unload the dib
FreeImage_Unload(dib);
// free the decoder
pDecoder->Release(&pDecoder);
if(NULL != message) {
FreeImage_OutputMessageProc(s_format_id, message);
}
}
return NULL;
}
