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src/Source/FreeImage/MNGHelper.cpp  view on Meta::CPAN

			if(key.size() == 0) {
				key = (char*)buffer;
				pos = 0;
				memset(buffer, 0, mLength * sizeof(BYTE));
			} else {
				break;
			}
		}
	}
	value = (char*)buffer;
	free(buffer);

	key_value_pair[key] = value;

	return TRUE;
}

// --------------------------------------------------------------------------

/**
Load a FIBITMAP from a MNG or a JNG stream
@param format_id ID of the caller
@param io Stream i/o functions
@param handle Stream handle
@param Offset Start of the first chunk
@param flags Loading flags
@return Returns a dib if successful, returns NULL otherwise
*/
FIBITMAP* 
mng_ReadChunks(int format_id, FreeImageIO *io, fi_handle handle, long Offset, int flags = 0) {
	DWORD mLength = 0;
	BYTE mChunkName[5];
	BYTE *mChunk = NULL;
	DWORD crc_file;
	long LastOffset;
	long mOrigPos;
	BYTE *PLTE_file_chunk = NULL;	// whole PLTE chunk (lentgh, name, array, crc)
	DWORD PLTE_file_size = 0;		// size of PLTE chunk

	BOOL m_HasGlobalPalette = FALSE; // may turn to TRUE in PLTE chunk
	unsigned m_TotalBytesOfChunks = 0;
	FIBITMAP *dib = NULL;
	FIBITMAP *dib_alpha = NULL;

	FIMEMORY *hJpegMemory = NULL;
	FIMEMORY *hPngMemory = NULL;
	FIMEMORY *hIDATMemory = NULL;

	// ---
	DWORD jng_width = 0;
	DWORD jng_height = 0;
	BYTE jng_color_type = 0;
	BYTE jng_image_sample_depth = 0;
	BYTE jng_image_compression_method = 0;

	BYTE jng_alpha_sample_depth = 0;
	BYTE jng_alpha_compression_method = 0;
	BYTE jng_alpha_filter_method = 0;
	BYTE jng_alpha_interlace_method = 0;

	DWORD mng_frame_width = 0;
	DWORD mng_frame_height = 0;
	DWORD mng_ticks_per_second = 0;
	DWORD mng_nominal_layer_count = 0;
	DWORD mng_nominal_frame_count = 0;
	DWORD mng_nominal_play_time = 0;
	DWORD mng_simplicity_profile = 0;


	DWORD res_x = 2835;	// 72 dpi
	DWORD res_y = 2835;	// 72 dpi
	RGBQUAD rgbBkColor = {0, 0, 0, 0};
	WORD bk_red, bk_green, bk_blue;
	BOOL hasBkColor = FALSE;
	BOOL mHasIDAT = FALSE;

	tEXtMAP key_value_pair;

	// ---

	BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS;
	
	// get the file size
	const long mLOF = mng_LOF(io, handle);
	// go to the first chunk
	io->seek_proc(handle, Offset, SEEK_SET);

	try {
		BOOL mEnd = FALSE;

		while(mEnd == FALSE) {
			// start of the chunk
			LastOffset = io->tell_proc(handle);
			// read length
			mLength = 0;			
			io->read_proc(&mLength, 1, sizeof(mLength), handle);
			mng_SwapLong(&mLength);
			// read name			
			io->read_proc(&mChunkName[0], 1, 4, handle);
			mChunkName[4] = '\0';

			if(mLength > 0) {
				mChunk = (BYTE*)realloc(mChunk, mLength);
				if(!mChunk) {
					FreeImage_OutputMessageProc(format_id, "Error while parsing %s chunk: out of memory", mChunkName);
					throw (const char*)NULL;
				}				
				Offset = io->tell_proc(handle);
				if(Offset + (long)mLength > mLOF) {
					FreeImage_OutputMessageProc(format_id, "Error while parsing %s chunk: unexpected end of file", mChunkName);
					throw (const char*)NULL;
				}
				// read chunk
				io->read_proc(mChunk, 1, mLength, handle);
			}
			// read crc
			io->read_proc(&crc_file, 1, sizeof(crc_file), handle);
			mng_SwapLong(&crc_file);
			// check crc
			DWORD crc_check = FreeImage_ZLibCRC32(0, &mChunkName[0], 4);
			crc_check = FreeImage_ZLibCRC32(crc_check, mChunk, mLength);
			if(crc_check != crc_file) {
				FreeImage_OutputMessageProc(format_id, "Error while parsing %s chunk: bad CRC", mChunkName);
				throw (const char*)NULL;
			}		

			switch( mng_GetChunckType(mChunkName) ) {
				case MHDR:
					// The MHDR chunk is always first in all MNG datastreams except for those 
					// that consist of a single PNG or JNG datastream with a PNG or JNG signature. 
					if(mLength == 28) {
						memcpy(&mng_frame_width, &mChunk[0], 4);
						memcpy(&mng_frame_height, &mChunk[4], 4);
						memcpy(&mng_ticks_per_second, &mChunk[8], 4);
						memcpy(&mng_nominal_layer_count, &mChunk[12], 4);
						memcpy(&mng_nominal_frame_count, &mChunk[16], 4);
						memcpy(&mng_nominal_play_time, &mChunk[20], 4);
						memcpy(&mng_simplicity_profile, &mChunk[24], 4);

						mng_SwapLong(&mng_frame_width);
						mng_SwapLong(&mng_frame_height);
						mng_SwapLong(&mng_ticks_per_second);
						mng_SwapLong(&mng_nominal_layer_count);
						mng_SwapLong(&mng_nominal_frame_count);
						mng_SwapLong(&mng_nominal_play_time);
						mng_SwapLong(&mng_simplicity_profile);

					} else {
						FreeImage_OutputMessageProc(format_id, "Error while parsing %s chunk: size is %d instead of 28", mChunkName, mLength);
					}
					break;

				case MEND:
					mEnd = TRUE;
					break;

				case LOOP:
				case ENDL:
					break;
				case DEFI:
					break;
				case SAVE:
				case SEEK:
				case TERM:
					break;
				case BACK:
					break;

					// Global "PLTE" and "tRNS" (if any).  PNG "PLTE" will be of 0 byte, as it uses global data.
				case PLTE:	// Global
					m_HasGlobalPalette = TRUE;
					PLTE_file_size = mLength + 12; // (lentgh, name, array, crc) = (4, 4, mLength, 4)
					PLTE_file_chunk = (BYTE*)realloc(PLTE_file_chunk, PLTE_file_size);
					if(!PLTE_file_chunk) {
						FreeImage_OutputMessageProc(format_id, "Error while parsing %s chunk: out of memory", mChunkName);
						throw (const char*)NULL;
					} else {
						mOrigPos = io->tell_proc(handle);
						// seek to the start of the chunk
						io->seek_proc(handle, LastOffset, SEEK_SET);
						// load the whole chunk
						io->read_proc(PLTE_file_chunk, 1, PLTE_file_size, handle);
						// go to the start of the next chunk
						io->seek_proc(handle, mOrigPos, SEEK_SET);
					}
					break;

				case tRNS:	// Global
					break;
					
				case IHDR:
					Offset = LastOffset;
					// parse the PNG file and get its file size
					if(mng_CountPNGChunks(io, handle, Offset, &m_TotalBytesOfChunks) == FALSE) {
						// reach an unexpected end of file
						mEnd = TRUE;
						FreeImage_OutputMessageProc(format_id, "Error while parsing %s chunk: unexpected end of PNG file", mChunkName);
						break;
					}
					
					// wrap the { IHDR, ..., IEND } chunks as a PNG stream
					if(hPngMemory == NULL) {
						hPngMemory = FreeImage_OpenMemory();
					}