C++ LibRaw::open_datastream方法代码示例

static BOOL DLL_CALLCONV
Validate(FreeImageIO *io, fi_handle handle) {
	LibRaw RawProcessor;
	BOOL bSuccess = TRUE;
	
	// wrap the input datastream
	LibRaw_freeimage_datastream datastream(io, handle);

	// open the datastream
	if(RawProcessor.open_datastream(&datastream) != LIBRAW_SUCCESS) {
		bSuccess = FALSE;	// LibRaw : failed to open input stream (unknown format)
	}

	// clean-up internal memory allocations
	RawProcessor.recycle();

	return bSuccess;
}

bool RawIOHandlerPrivate::load(QIODevice *device)
{
    if (device == 0) return false;

    if (raw != 0) return true;

    stream = new Datastream(device);
    raw = new LibRaw;
    if (raw->open_datastream(stream) != LIBRAW_SUCCESS) {
        delete raw;
        raw = 0;
        delete stream;
        stream = 0;
        return false;
    }

    defaultSize = QSize(raw->imgdata.sizes.width,
                        raw->imgdata.sizes.height);
    if (raw->imgdata.sizes.flip == 5 || raw->imgdata.sizes.flip == 6) {
        defaultSize.transpose();
    }
    return true;
}

static FIBITMAP * DLL_CALLCONV
Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
	FIBITMAP *dib = NULL;
	LibRaw RawProcessor;

	BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS;

	try {
		// wrap the input datastream
		LibRaw_freeimage_datastream datastream(io, handle);

		// set decoding parameters
		// the following parameters affect data reading
		// --------------------------------------------

		// (-w) Use camera white balance, if possible (otherwise, fallback to auto_wb)
		RawProcessor.imgdata.params.use_camera_wb = 1;
		// RAW data filtration mode during data unpacking and postprocessing
		RawProcessor.imgdata.params.filtering_mode = LIBRAW_FILTERING_AUTOMATIC;
		// (-h) outputs the image in 50% size
		RawProcessor.imgdata.params.half_size = ((flags & RAW_HALFSIZE) == RAW_HALFSIZE) ? 1 : 0;

		// open the datastream
		if(RawProcessor.open_datastream(&datastream) != LIBRAW_SUCCESS) {
			throw "LibRaw : failed to open input stream (unknown format)";
		}

		if(header_only) {
			// header only mode
			dib = FreeImage_AllocateHeaderT(header_only, FIT_RGB16, RawProcessor.imgdata.sizes.width, RawProcessor.imgdata.sizes.height);
			// try to get JPEG embedded Exif metadata
			if(dib) {
				FIBITMAP *metadata_dib = libraw_LoadEmbeddedPreview(RawProcessor, FIF_LOAD_NOPIXELS);
				if(metadata_dib) {
					FreeImage_CloneMetadata(dib, metadata_dib);
					FreeImage_Unload(metadata_dib);
				}
			}
		}
		else if((flags & RAW_PREVIEW) == RAW_PREVIEW) {
			// try to get the embedded JPEG
			dib = libraw_LoadEmbeddedPreview(RawProcessor, 0);
			if(!dib) {
				// no JPEG preview: try to load as 8-bit/sample (i.e. RGB 24-bit)
				dib = libraw_LoadRawData(RawProcessor, 8);
			}
		} 
		else if((flags & RAW_DISPLAY) == RAW_DISPLAY) {
			// load raw data as 8-bit/sample (i.e. RGB 24-bit)
			dib = libraw_LoadRawData(RawProcessor, 8);
		} 
		else {
			// default: load raw data as linear 16-bit/sample (i.e. RGB 48-bit)
			dib = libraw_LoadRawData(RawProcessor, 16);
		}

		// save ICC profile if present
		if(NULL != RawProcessor.imgdata.color.profile) {
			FreeImage_CreateICCProfile(dib, RawProcessor.imgdata.color.profile, RawProcessor.imgdata.color.profile_length);
		}

		// try to get JPEG embedded Exif metadata
		if(dib && !((flags & RAW_PREVIEW) == RAW_PREVIEW) ) {
			FIBITMAP *metadata_dib = libraw_LoadEmbeddedPreview(RawProcessor, FIF_LOAD_NOPIXELS);
			if(metadata_dib) {
				FreeImage_CloneMetadata(dib, metadata_dib);
				FreeImage_Unload(metadata_dib);
			}
		}

		// clean-up internal memory allocations
		RawProcessor.recycle();

		return dib;

	} catch(const char *text) {
		if(dib) {
			FreeImage_Unload(dib);
		}
		RawProcessor.recycle();
		FreeImage_OutputMessageProc(s_format_id, text);
	}

	return NULL;
}