[svn-r3919]

Purpose:
    Adding new feature
Description:
    Added gif2h5 and h52gif conversion utilities
Solution:
    The utilites follow the framework built for the gif2hdf and hdf2gif
    utilities for hdf4. The main files modified were those that read the
    H5 file and those that write H5 file. In the future, if you wish to
    continue with the framework and extend it to .png or some other fileformat
    the main files to edit will be the gif reader and writer.
    One point to note with h52gif. You have to specify the exact location of
    the image and the palette that it links to. You can choose not to specify
    a palette (uniform grayscale chosen in this case) but you must specify
    image location. In the future, someone could edit the readhdf.c source
    to enable the reader to parse the hdf file and select all images with
    corresponding palettes.
Platforms tested:
    modi4 , eirene , hawkwind , arabica , Ren (NT 4.0) , Personal box (win2k)

1 files changed, 299 insertions, 0 deletions

diff --git a/tools/gifconv/decompress.c b/tools/gifconv/decompress.c
new file mode 100644
index 0000000..18dbb3e
--- /dev/null
+++ b/tools/gifconv/decompress.c
@@ -0,0 +1,299 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "gif.h"
+
+#define NEXTBYTE (*ptr++)
+#define IMAGESEP 0x2c
+#define INTERLACEMASK 0x40
+#define COLORMAPMASK 0x80
+#define False 0
+#define True 1
+
+WORD           iWIDE,iHIGH,eWIDE,eHIGH,expand,numcols,strip,nostrip;
+unsigned long  cols[256];
+char           *cmd;
+
+FILE *fp;
+
+static int BitOffset = 0,	/* Bit Offset of next code */
+XC = 0, YC = 0,				/* Output X and Y coords of current pixel */
+Pass = 0,					/* Used by output routine if WORDerlaced pic */
+OutCount = 0,				/* Decompressor output 'stack count' */
+RWidth, RHeight,			/* screen dimensions */
+IWidth, IHeight,			/* image dimensions */
+LeftOfs, TopOfs,			/* image offset */
+BitsPerPixel,				/* Bits per pixel, read from GIF header */
+BytesPerScanline,			/* Bytes per scanline in output raster */
+ColorMapSize,				/* number of colors */
+Background,					/* background color */
+CodeSize,					/* Code size, read from GIF header */
+InitCodeSize,				/* Starting code size, used during Clear */
+Code,						/* Value returned by ReadCode */
+MaxCode,					/* limiting value for current code size */
+ClearCode,					/* GIF clear code */
+EOFCode,					/* GIF end-of-information code */
+CurCode, OldCode, InCode,	/* Decompressor variables */
+FirstFree,					/* First free code, generated per GIF spec */
+FreeCode,					/* Decompressor, next free slot in hash table */
+FinChar,					/* Decompressor variable */
+DataMask,					/* AND mask for data size */
+ReadMask;                   /* Code AND mask for current code size */
+
+/*MODIFICATIONS*/
+BYTE tempbyte[10];
+BYTE * tempBYTEptr[10];
+WORD tempint[10];
+WORD ImageCount = 0;
+/*END MODIFICATION*/
+
+boolean Interlace, HasColormap;
+
+
+BYTE *Image;			/* The result array */
+BYTE *RawGIF;			/* The heap array to hold it, raw */
+BYTE *Raster;			/* The raster data stream, unblocked */
+
+/* The hash table used by the decompressor */
+
+int Prefix[4096];
+int Suffix[4096];
+
+/* An output array used by the decompressor */
+
+int OutCode[1025];
+
+/* The color map, read from the GIF header */
+
+int  numused;
+
+/* Fetch the next code from the raster data stream.  The codes can be
+* any length from 3 to 12 bits, packed WORDo 8-bit BYTEs, so we have to
+* maWORDain our location in the Raster array as a BIT Offset.  We compute
+* the BYTE Offset WORDo the raster array by dividing this by 8, pick up
+* three BYTEs, compute the bit Offset WORDo our 24-bit chunk, shift to
+* bring the desired code to the bottom, then mask it off and return it. 
+*/
+ReadCode()
+{
+	int RawCode, ByteOffset;
+	
+    ByteOffset = BitOffset / 8;
+    RawCode = Raster[ByteOffset] + (0x100 * Raster[ByteOffset + 1]);
+    if (CodeSize >= 8)
+		RawCode += (0x10000 * Raster[ByteOffset + 2]);
+    RawCode >>= (BitOffset % 8);
+    BitOffset += CodeSize;
+    return(RawCode & ReadMask);
+}
+
+
+AddToPixel(Index)
+BYTE Index;
+{
+    if (YC<IHeight)
+        *(Image + YC * BytesPerScanline + XC) = Index;
+	
+
+    
+    /* Update the X-coordinate, and if it overflows, update the Y-coordinate */
+    if (++XC == IWidth) {
+		
+	/* If a non-WORDerlaced picture, just increment YC to the next scan line. 
+	* If it's WORDerlaced, deal with the WORDerlace as described in the GIF
+	* spec.  Put the decoded scan line out to the screen if we haven't gone
+	* past the bottom of it.
+		*/
+		
+		XC = 0;
+		if (!Interlace) YC++;
+		else {
+			switch (Pass) {
+			case 0:
+				YC += 8;
+				if (YC >= IHeight) {
+					Pass++;
+					YC = 4;
+				}
+				break;
+			case 1:
+				YC += 8;
+				if (YC >= IHeight) {
+					Pass++;
+					YC = 2;
+				}
+				break;
+				
+			case 2:
+				YC += 4;
+				if (YC >= IHeight) {
+					Pass++;
+					YC = 1;
+				}
+				break;
+			case 3:
+				YC += 2;
+				break;
+			default:
+				break;
+			}
+		}
+    }
+}
+
+/* Main routine.  Convert a GIF image to an HDF image */
+
+BYTE* Decompress(GifImageDesc , GifHead)
+GIFIMAGEDESC *GifImageDesc;
+GIFHEAD      *GifHead;
+{
+	int i;
+
+	XC = 0; 
+	YC = 0;
+	Pass = 0;
+	OutCount = 0;
+	BitOffset = 0;
+	
+	DataMask = (WORD)((1L << ((GifHead->PackedField & 0x07) +1)) -1);
+	Raster = GifImageDesc->GIFImage;
+	
+	
+	/* Check for image seperator */
+	
+	/* Now read in values from the image descriptor */
+	IWidth = GifImageDesc->ImageWidth;
+	IHeight = GifImageDesc->ImageHeight;
+	Interlace = GifImageDesc->PackedField & 0x40;
+	
+	/* Note that I ignore the possible existence of a local color map.
+	* I'm told there aren't many files around that use them, and the spec
+	* says it's defined for future use.  This could lead to an error
+	* reading some files. 
+	*/
+	
+	/* Start reading the raster data. First we get the WORDial code size
+	* and compute decompressor constant values, based on this code size.
+	*/
+	
+	CodeSize = GifImageDesc->CodeSize;
+	ClearCode = (1 << CodeSize);
+	EOFCode = ClearCode + 1;
+	FreeCode = FirstFree = ClearCode + 2;
+	
+	/* The GIF spec has it that the code size is the code size used to
+	* compute the above values is the code size given in the file, but the
+	* code size used in compression/decompression is the code size given in
+	* the file plus one. (thus the ++).
+	*/
+	
+	CodeSize++;
+	InitCodeSize = CodeSize;
+	MaxCode = (1 << CodeSize);
+	ReadMask = MaxCode - 1;
+	
+	/* Read the raster data.  Here we just transpose it from the GIF array
+	* to the Raster array, turning it from a series of blocks WORDo one long
+	* data stream, which makes life much easier for ReadCode().
+	*/
+	
+	
+	
+	/*    free(RawGIF);		 We're not done just yet - change made */
+	
+	/* Allocate the Image */
+	
+	if (!(Image = (BYTE *)malloc(IWidth*IHeight))) {
+		printf("Out of memory");
+		exit(-1);
+	}
+	
+	BytesPerScanline = IWidth;
+	
+	/* Decompress the file, continuing until you see the GIF EOF code.
+	* One obvious enhancement is to add checking for corrupt files here.
+	*/
+	
+	Code = ReadCode();
+	while (Code != EOFCode) {
+		
+	/* Clear code sets everything back to its initial value, then reads the
+	* immediately subsequent code as uncompressed data.
+		*/
+		
+		if (Code == ClearCode) {
+			CodeSize = InitCodeSize;
+			MaxCode = (1 << CodeSize);
+			ReadMask = MaxCode - 1;
+			FreeCode = FirstFree;
+			CurCode = OldCode = Code = ReadCode();
+			FinChar = CurCode & DataMask;
+			AddToPixel(FinChar);
+		}
+		else {
+			
+			/* If not a clear code, then must be data: save same as CurCode and InCode */
+			
+			CurCode = InCode = Code;
+			
+			/* If greater or equal to FreeCode, not in the hash table yet;
+			* repeat the last character decoded
+			*/
+			
+			if (CurCode >= FreeCode) {
+				CurCode = OldCode;
+				OutCode[OutCount++] = FinChar;
+			}
+			
+			/* Unless this code is raw data, pursue the chain poWORDed to by CurCode
+			* through the hash table to its end; each code in the chain puts its
+			* associated output code on the output queue.
+			*/
+			
+			while (CurCode > DataMask) {
+				if (OutCount > 1024) {
+					/*return error message*/	
+				}
+				OutCode[OutCount++] = Suffix[CurCode];
+				CurCode = Prefix[CurCode];
+			}
+			
+			/* The last code in the chain is treated as raw data. */
+			
+			FinChar = CurCode & DataMask;
+			OutCode[OutCount++] = FinChar;
+			
+			/* Now we put the data out to the Output routine.
+			* It's been stacked LIFO, so deal with it that way...
+			*/
+			
+			for (i = OutCount - 1; i >= 0; i--)
+				AddToPixel(OutCode[i]);
+			OutCount = 0;
+			
+			/* Build the hash table on-the-fly. No table is stored in the file. */
+			
+			Prefix[FreeCode] = OldCode;
+			Suffix[FreeCode] = FinChar;
+			OldCode = InCode;
+			
+			/* PoWORD to the next slot in the table.  If we exceed the current
+			* MaxCode value, increment the code size unless it's already 12.  If it
+			* is, do nothing: the next code decompressed better be CLEAR
+			*/
+			
+			FreeCode++;
+			if (FreeCode >= MaxCode) {
+				if (CodeSize < 12) {
+					CodeSize++;
+					MaxCode *= 2;
+					ReadMask = (1 << CodeSize) - 1;
+				}
+			}
+		}
+		Code = ReadCode();
+	}
+
+	return Image;	
+}
+
+