Category : C Source Code
Archive   : GIF_LIB.ZIP
Filename : GIFINTER.C

/*****************************************************************************
* "Gif-Lib" - Yet another gif library. *
* *
* Written by: Gershon Elber IBM PC Ver 0.1, Jul. 1989 *
******************************************************************************
* Program to flip interlaced and non interlaced images in GIF files. *
* Options: *
* -i : Force all images to be intelaced. *
* -s : Force all images to be sequencial (non interlaced). This is default. *
* -h : on line help *
******************************************************************************
* History: *
* 5 Jul 89 - Version 1.0 by Gershon Elber. *
*****************************************************************************/

#include
#include
#include
#include
#include
#include "gif_lib.h"
#include "getarg.h"

#define PROGRAM_NAME "GifInter"
#define VERSION "á Version 1.0, "

extern unsigned int
_stklen = 16384; /* Increase default stack size */

static char
*VersionStr =
PROGRAM_NAME
" IBMPC "
VERSION
" Gershon Elber, "
__DATE__ ", " __TIME__ "\n"
"(C) Copyright 1989 Gershon Elber, Non commercial use only.\n";
static char
*CtrlStr =
PROGRAM_NAME
" i%- s%- h%- GifFile!*s";
static char
*ProgramName;

/* Make some variables global, so we could access them faster: */
static int
ImageNum = 0,
SequencialFlag = FALSE,
InterlacedFlag = FALSE,
HelpFlag = FALSE,
InterlacedOffset[] = { 0, 4, 2, 1 }, /* The way Interlaced image should */
InterlacedJumps[] = { 8, 8, 4, 2 }; /* be read - offsets and jumps... */

static int LoadImage(GifFileType *GifFile, RowType **ImageBuffer);
static int DumpImage(GifFileType *GifFile, RowType *ImageBuffer);
static void QuitGifError(GifFileType *GifFileIn, GifFileType *GifFileOut);

/******************************************************************************
* Interpret the command line and scan the given GIF file. *
******************************************************************************/
void main(int argc, char **argv)
{
int Error, NumFiles, ExtCode;
GifRecordType RecordType;
ByteType *Extension;
char **FileName = NULL;
RowType *ImageBuffer;
GifFileType *GifFileIn = NULL, *GifFileOut = NULL;

if (strlen(ProgramName = argv[0]) == 0) /* DOS 3.x only! */
ProgramName = PROGRAM_NAME; /* Do something reasonable for 2.x */

if ((Error = GAGetArgs(argc, argv, CtrlStr,
&SequencialFlag, &InterlacedFlag, &HelpFlag,
&NumFiles, &FileName)) != FALSE ||
(NumFiles > 1 && !HelpFlag)) {
if (Error) GAPrintErrMsg(Error);
else
if (NumFiles > 1)
MESSAGE("Error in command line parsing - one GIF file please\n");
GAPrintHowTo(CtrlStr);
exit(1);
}

if (HelpFlag) {
fprintf(stderr, VersionStr);
GAPrintHowTo(CtrlStr);
exit(0);
}
if (!InterlacedFlag && SequencialFlag)
InterlacedFlag = TRUE;

if (NumFiles == 1) {
if ((GifFileIn = DGifOpenFileName(*FileName)) == NULL)
QuitGifError(GifFileIn, GifFileOut);
}
else {
/* Use the stdin instead: */
if ((GifFileIn = DGifOpenFileHandle(0)) == NULL)
QuitGifError(GifFileIn, GifFileOut);
}

/* Open stdout for the output file: */
if ((GifFileOut = EGifOpenFileHandle(1)) == NULL)
QuitGifError(GifFileIn, GifFileOut);

/* And dump out exactly same screen information: */
if (EGifPutScreenDesc(GifFileOut,
GifFileIn -> SWidth, GifFileIn -> SHeight,
GifFileIn -> SColorResolution, GifFileIn -> SBackGroundColor,
GifFileIn -> SBitsPerPixel, GifFileIn -> SColorMap) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

/* Scan the content of the GIF file and load the image(s) in: */
do {
if (DGifGetRecordType(GifFileIn, &RecordType) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

switch (RecordType) {
case IMAGE_DESC_RECORD_TYPE:
if (DGifGetImageDesc(GifFileIn) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

/* Put the image descriptor to out file: */
if (EGifPutImageDesc(GifFileOut,
GifFileIn -> ILeft, GifFileIn -> ITop,
GifFileIn -> IWidth, GifFileIn -> IHeight,
InterlacedFlag, GifFileIn -> IBitsPerPixel,
GifFileIn -> IColorMap) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

/* Load the image (either Interlaced or not), and dump it as */
/* defined in GifFileOut -> IInterlaced. */
if (LoadImage(GifFileIn, &ImageBuffer) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
if (DumpImage(GifFileOut, ImageBuffer) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
break;
case EXTENSION_RECORD_TYPE:
/* Skip any extension blocks in file: */
if (DGifGetExtension(GifFileIn, &ExtCode, &Extension) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
if (EGifPutExtension(GifFileOut, ExtCode, Extension[0],
Extension) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

/* No support to more than one extension blocks, so discard: */
while (Extension != NULL) {
if (DGifGetExtensionNext(GifFileIn, &Extension) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
}
break;
case TERMINATE_RECORD_TYPE:
break;
default: /* Should be traps by DGifGetRecordType */
break;
}
}
while (RecordType != TERMINATE_RECORD_TYPE);

if (DGifCloseFile(GifFileIn) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
if (EGifCloseFile(GifFileOut) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
}

/******************************************************************************
* Routine to read Image out. The image can be Interlaced or None interlaced. *
* The memory required to hold the image is allocate by the routine itself. *
* The image is always loaded sequencially into the buffer. *
* Return OK if succesful, ERROR otherwise. *
******************************************************************************/
static int LoadImage(GifFileType *GifFile, RowType **ImageBufferPtr)
{
int Size, i, j, Count;
RowType *ImageBuffer;

/* Allocate the image as vector of column of rows. We cannt allocate */
/* the all screen at once, as this broken minded CPU can allocate up to */
/* 64k at a time and our image can be bigger than that: */
if ((ImageBuffer = (RowType *)
malloc(GifFile -> IHeight * sizeof(RowType *))) == NULL)
EXIT("Failed to allocate memory required, aborted");

Size = GifFile -> IWidth * sizeof(PixelType); /* One row size in bytes */
for (i=0; i IHeight; i++) {
/* Allocate the rows: */
if ((ImageBuffer[i] = (RowType) malloc(Size)) == NULL)
EXIT("Failed to allocate memory required, aborted\n");
}

*ImageBufferPtr = ImageBuffer;

fprintf(stderr, "\n%s: Image %d at (%d, %d) [%dx%d]: ",
ProgramName, ++ImageNum, GifFile -> ILeft, GifFile -> ITop,
GifFile -> IWidth, GifFile -> IHeight);
if (GifFile -> IInterlace) {
/* Need to perform 4 passes on the images: */
for (Count=i=0; i<4; i++)
for (j=InterlacedOffset[i]; j IHeight;
j += InterlacedJumps[i]) {
fprintf(stderr, "\b\b\b\b%-4d", Count++);
if (DGifGetLine(GifFile, ImageBuffer[j], GifFile -> IWidth)
== ERROR) return ERROR;
}
}
else {
for (i=0; i IHeight; i++) {
fprintf(stderr, "\b\b\b\b%-4d", i);
if (DGifGetLine(GifFile, ImageBuffer[i], GifFile -> IWidth)
== ERROR) return ERROR;
}
}

return OK;
}

/******************************************************************************
* Routine to dump image out. The given Image buffer should always hold the *
* image sequencially. Image will be dumped according to IInterlaced flag in *
* GifFile structure. Once dumped, the memory holding the image is freed. *
* Return OK if succesful, ERROR otherwise. *
******************************************************************************/
static int DumpImage(GifFileType *GifFile, RowType *ImageBuffer)
{
int i, j, Count;

if (GifFile -> IInterlace) {
/* Need to perform 4 passes on the images: */
for (Count=GifFile -> IHeight, i=0; i<4; i++)
for (j=InterlacedOffset[i]; j IHeight;
j += InterlacedJumps[i]) {
fprintf(stderr, "\b\b\b\b%-4d", Count--);
if (EGifPutLine(GifFile, ImageBuffer[j], GifFile -> IWidth)
== ERROR) return ERROR;
}
}
else {
for (Count=GifFile -> IHeight, i=0; i IHeight; i++) {
fprintf(stderr, "\b\b\b\b%-4d", Count--);
if (EGifPutLine(GifFile, ImageBuffer[i], GifFile -> IWidth)
== ERROR) return ERROR;
}
}

/* Free the memory used for this image: */
for (i=0; i IHeight; i++) free((char *) ImageBuffer[i]);
free((char *) ImageBuffer);

return OK;
}

/******************************************************************************
* Close both input and output file (if open), and exit. *
******************************************************************************/
static void QuitGifError(GifFileType *GifFileIn, GifFileType *GifFileOut)
{
PrintGifError();
if (GifFileIn != NULL) DGifCloseFile(GifFileIn);
if (GifFileOut != NULL) EGifCloseFile(GifFileOut);
exit(1);
}