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

/*****************************************************************************
* "Gif-Lib" - Yet another gif library. *
* *
* Written by: Gershon Elber IBM PC Ver 0.1, Jul. 1989 *
******************************************************************************
* Program to clip an image and dump out only portion of it. *
* Options: *
* -i left top width bottom : clipping information for first image. *
* -n n left top width bottom : clipping information for nth image. *
* -h : on line help *
******************************************************************************
* History: *
* 8 Jul 89 - Version 1.0 by Gershon Elber. *
*****************************************************************************/

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

#define PROGRAM_NAME "GifClip"
#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%-Xmin|Ymin|Xmax|Ymax!d!d!d!d n%-n|Xmin|Ymin|Xmax|Ymax!d!d!d!d!d h%- GifFile!*s";
static char
*ProgramName;

static void QuitGifError(GifFileType *GifFileIn, GifFileType *GifFileOut);

/******************************************************************************
* Interpret the command line and scan the given GIF file. *
******************************************************************************/
void main(int argc, char **argv)
{
int i, Error, NumFiles, ExtCode, CodeSize, ImageNum = 0,
ImageFlag = FALSE, ImageNFlag = FALSE, ImageN, ImageX1, ImageY1,
ImageX2, ImageY2, ImageWidth, HelpFlag = FALSE;
GifRecordType RecordType;
ByteType *Extension, *CodeBlock;
char **FileName = NULL;
RowType Line;
GifFileType *GifFileIn = NULL, *GifFileOut = NULL;

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

/* Same image dimension vars for both Image & ImageN as only one allowed */
if ((Error = GAGetArgs(argc, argv, CtrlStr,
&ImageFlag, &ImageX1, &ImageY1, &ImageX2, &ImageY2,
&ImageNFlag, &ImageN, &ImageX1, &ImageY1, &ImageX2, &ImageY2,
&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);
}

/* Test to make sure exactly one of ImageFlag & ImageNFlag is set: */
if ((ImageFlag && ImageNFlag) || (!ImageFlag && !ImageNFlag)) {
MESSAGE("Exactly one of [-i ...] && [-n ...] please\n");
GAPrintHowTo(CtrlStr);
exit(1);
}
if (ImageFlag) ImageN = 1; /* Its first image we are after */

/* Make sure the first coordinates of clipping box are smaller: */
if (ImageX1 > ImageX2) {
i = ImageX1;
ImageX1 = ImageX2;
ImageX2 = i;
}
if (ImageY1 > ImageY2) {
i = ImageX1;
ImageY1 = ImageY2;
ImageY2 = i;
}
ImageWidth = ImageX2 - ImageX1 + 1; /* Width of clipped image */

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);
if (++ImageNum == ImageN) {
/* We can handle only non interlaced images here: */
if (GifFileIn -> IInterlace)
EXIT("Image to clip is interlaced - use GifInter first\n");

/* This is the image we should clip - test sizes and */
/* dump out new clipped screen descriptor if o.k. */
if (GifFileIn -> IWidth <= ImageX2 ||
GifFileIn -> IHeight <= ImageY2)
EXIT("Image is smaller than given clip dimensions\n");

/* Put the image descriptor to out file: */
if (EGifPutImageDesc(GifFileOut,
GifFileIn -> ILeft, GifFileIn -> ITop,
ImageWidth, ImageY2 - ImageY1 + 1,
FALSE, GifFileIn -> IBitsPerPixel,
GifFileIn -> IColorMap) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

/* o.k. - read the image and clip it: */
Line = (RowType) malloc(GifFileIn -> IWidth *
sizeof(PixelType));
fprintf(stderr, "\n%s: Image %d at (%d, %d) [%dx%d]: ",
ProgramName, ImageNum,
GifFileIn -> ILeft, GifFileIn -> ITop,
GifFileIn -> IWidth, GifFileIn -> IHeight);

/* Skip lines below ImageY1: */
for (i=0; i if (DGifGetLine(GifFileIn, Line, GifFileIn -> IWidth)
== ERROR)
QuitGifError(GifFileIn, GifFileOut);
fprintf(stderr, "\b\b\b\b%-4d", i);
}

/* Clip the lines from ImageY1 to ImageY2 (to X1 - X2): */
for (i=ImageY1; i<=ImageY2; i++) {
if (DGifGetLine(GifFileIn, Line, GifFileIn -> IWidth)
== ERROR)
QuitGifError(GifFileIn, GifFileOut);
if (EGifPutLine(GifFileOut, &Line[ImageX1],
ImageWidth) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
fprintf(stderr, "\b\b\b\b%-4d", i);
}

/* Skip lines above ImageY2: */
for (i=ImageY2+1; i IHeight; i++) {
if (DGifGetLine(GifFileIn, Line, GifFileIn -> IWidth)
== ERROR)
QuitGifError(GifFileIn, GifFileOut);
fprintf(stderr, "\b\b\b\b%-4d", i);
}

free((char *) Line);
}
else {
/* Copy the image as is (we dont modify this one): */
if (EGifPutImageDesc(GifFileOut,
GifFileIn -> ILeft, GifFileIn -> ITop,
GifFileIn -> IWidth, GifFileIn -> IHeight,
GifFileIn -> IInterlace, GifFileIn -> IBitsPerPixel,
GifFileIn -> IColorMap) == ERROR)
QuitGifError(GifFileIn, GifFileOut);

/* Now read image itself in decoded form as we dont */
/* really care what is there, and this is much faster. */
if (DGifGetCode(GifFileIn, &CodeSize, &CodeBlock) == ERROR
|| EGifPutCode(GifFileOut, CodeSize, CodeBlock) == ERROR)
QuitGifError(GifFileIn, GifFileOut);
while (CodeBlock != NULL)
if (DGifGetCodeNext(GifFileIn, &CodeBlock) == ERROR ||
EGifPutCodeNext(GifFileOut, CodeBlock) == 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);
}

/******************************************************************************
* 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);
}