自学教程：C++ DGifGetImageDesc函数代码示例

/* Originally based on, but in its current form merely inspired by Imlib2's * src/modules/loaders/loader_gif.c:load(), written by Carsten Haitzler. */bool img_load_gif(img_t *img, const fileinfo_t *file) {	GifFileType *gif;	GifRowType *rows = NULL;	GifRecordType rec;	ColorMapObject *cmap;	DATA32 bgpixel, *data, *ptr;	DATA32 *prev_frame = NULL;	Imlib_Image *im;	int i, j, bg, r, g, b;	int x, y, w, h, sw, sh;	int intoffset[] = { 0, 4, 2, 1 };	int intjump[] = { 8, 8, 4, 2 };	int transp = -1;	unsigned int delay = 0;	bool err = false;	if (img->multi.cap == 0) {		img->multi.cap = 8;		img->multi.frames = (img_frame_t*)		                    s_malloc(sizeof(img_frame_t) * img->multi.cap);	}	img->multi.cnt = 0;	img->multi.sel = 0;	gif = DGifOpenFileName(file->path);	if (gif == NULL) {		warn("could not open gif file: %s", file->name);		return false;	}	bg = gif->SBackGroundColor;	sw = gif->SWidth;	sh = gif->SHeight;	do {		if (DGifGetRecordType(gif, &rec) == GIF_ERROR) {			err = true;			break;		}		if (rec == EXTENSION_RECORD_TYPE) {			int ext_code;			GifByteType *ext = NULL;			DGifGetExtension(gif, &ext_code, &ext);			while (ext) {				if (ext_code == 0xf9) {					if (ext[1] & 1)						transp = (int) ext[4];					else						transp = -1;					delay = 10 * ((unsigned int) ext[3] << 8 | (unsigned int) ext[2]);					if (delay)						delay = MAX(delay, MIN_GIF_DELAY);					/* TODO: handle disposal method, section 23.c.iv of					         http://www.w3.org/Graphics/GIF/spec-gif89a.txt */				}				ext = NULL;				DGifGetExtensionNext(gif, &ext);			}		} else if (rec == IMAGE_DESC_RECORD_TYPE) {			if (DGifGetImageDesc(gif) == GIF_ERROR) {				err = true;				break;			}			x = gif->Image.Left;			y = gif->Image.Top;			w = gif->Image.Width;			h = gif->Image.Height;			rows = (GifRowType*) s_malloc(h * sizeof(GifRowType));			for (i = 0; i < h; i++)				rows[i] = (GifRowType) s_malloc(w * sizeof(GifPixelType));			if (gif->Image.Interlace) {				for (i = 0; i < 4; i++) {					for (j = intoffset[i]; j < h; j += intjump[i])						DGifGetLine(gif, rows[j], w);				}			} else {				for (i = 0; i < h; i++)					DGifGetLine(gif, rows[i], w);			}			ptr = data = (DATA32*) s_malloc(sizeof(DATA32) * sw * sh);			cmap = gif->Image.ColorMap ? gif->Image.ColorMap : gif->SColorMap;			r = cmap->Colors[bg].Red;			g = cmap->Colors[bg].Green;			b = cmap->Colors[bg].Blue;			bgpixel = 0x00ffffff & (r << 16 | g << 8 | b);			for (i = 0; i < sh; i++) {				for (j = 0; j < sw; j++) {					if (i < y || i >= y + h || j < x || j >= x + w ||					    rows[i-y][j-x] == transp)					{						if (prev_frame != NULL)							*ptr = prev_frame[i * sw + j];//.........这里部分代码省略.........

GDALDataset *GIFDataset::Open( GDALOpenInfo * poOpenInfo ){    if( !Identify( poOpenInfo ) )        return NULL;    if( poOpenInfo->eAccess == GA_Update )    {        CPLError( CE_Failure, CPLE_NotSupported,                   "The GIF driver does not support update access to existing"                  " files./n" );        return NULL;    }/* -------------------------------------------------------------------- *//*      Open the file and ingest.                                       *//* -------------------------------------------------------------------- */    GifFileType 	*hGifFile;    VSILFILE                *fp;    int                  nGifErr;    fp = VSIFOpenL( poOpenInfo->pszFilename, "r" );    if( fp == NULL )        return NULL;    hGifFile = GIFAbstractDataset::myDGifOpen( fp, VSIGIFReadFunc );    if( hGifFile == NULL )    {        VSIFCloseL( fp );        CPLError( CE_Failure, CPLE_OpenFailed,                   "DGifOpen() failed for %s./n"                  "Perhaps the gif file is corrupt?/n",                  poOpenInfo->pszFilename );        return NULL;    }    /* The following code enables us to detect GIF datasets eligible */    /* for BIGGIF driver even with an unpatched giflib  */    /* -------------------------------------------------------------------- */    /*      Find the first image record.                                    */    /* -------------------------------------------------------------------- */    GifRecordType RecordType = TERMINATE_RECORD_TYPE;    while( DGifGetRecordType(hGifFile, &RecordType) != GIF_ERROR        && RecordType != TERMINATE_RECORD_TYPE        && RecordType != IMAGE_DESC_RECORD_TYPE )    {        /* Skip extension records found before IMAGE_DESC_RECORD_TYPE */        if (RecordType == EXTENSION_RECORD_TYPE)        {            int nFunction;            GifByteType *pExtData;            if (DGifGetExtension(hGifFile, &nFunction, &pExtData) == GIF_ERROR)                break;            while (pExtData != NULL)            {                if (DGifGetExtensionNext(hGifFile, &pExtData) == GIF_ERROR)                    break;            }        }    }    if( RecordType == IMAGE_DESC_RECORD_TYPE  &&        DGifGetImageDesc(hGifFile) != GIF_ERROR)    {        int width = hGifFile->SavedImages[0].ImageDesc.Width;        int height = hGifFile->SavedImages[0].ImageDesc.Height;        if ((double) width * (double) height > 100000000.0 )        {            CPLDebug( "GIF",                      "Due to limitations of the GDAL GIF driver we deliberately avoid/n"                      "opening large GIF files (larger than 100 megapixels).");            GIFAbstractDataset::myDGifCloseFile( hGifFile );            VSIFCloseL( fp );            return NULL;        }    }    GIFAbstractDataset::myDGifCloseFile( hGifFile );    VSIFSeekL( fp, 0, SEEK_SET);    hGifFile = GIFAbstractDataset::myDGifOpen( fp, VSIGIFReadFunc );    if( hGifFile == NULL )    {        VSIFCloseL( fp );        CPLError( CE_Failure, CPLE_OpenFailed,                   "DGifOpen() failed for %s./n"                  "Perhaps the gif file is corrupt?/n",                  poOpenInfo->pszFilename );        return NULL;    }    nGifErr = DGifSlurp( hGifFile );    if( nGifErr != GIF_OK || hGifFile->SavedImages == NULL )    {//.........这里部分代码省略.........

//.........这里部分代码省略.........	XScale = XSize / ((double) GifFileIn->SWidth);	YScale = YSize / ((double) GifFileIn->SHeight);    }    else    {	XSize = (int) (GifFileIn->SWidth * XScale + 0.5);	YSize = (int) (GifFileIn->SHeight * YScale + 0.5);    }    /* As at this time we know the Screen size of the input gif file, and as */    /* all image(s) in file must be less/equal to it, we can allocate the    */    /* scan lines for the input file, and output file. The number of lines   */    /* to allocate for each is set by ScaleDown & XScale & YScale:	     */    LineOut = (GifRowType) malloc(XSize * sizeof(GifPixelType));    LineIn = (GifRowType) malloc(GifFileIn->SWidth * sizeof(GifPixelType));    /* Open stdout for the output file: */    if ((GifFileOut = EGifOpenFileHandle(1)) == NULL)	QuitGifError(GifFileIn, GifFileOut);    /* And dump out its new scaled screen information: */    if (EGifPutScreenDesc(GifFileOut, XSize, YSize,	GifFileIn->SColorResolution, GifFileIn->SBackGroundColor,	GifFileIn->SColorMap) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);    /* Scan the content of the GIF file and load the image(s) in: */    do {	if (DGifGetRecordType(GifFileIn, &RecordType) == GIF_ERROR)	    QuitGifError(GifFileIn, GifFileOut);	switch (RecordType) {	    case IMAGE_DESC_RECORD_TYPE:		if (DGifGetImageDesc(GifFileIn) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		/* Put the image descriptor to out file: */		l = (int) (GifFileIn->Image.Left * XScale + 0.5);		w = (int) (GifFileIn->Image.Width * XScale + 0.5);		t = (int) (GifFileIn->Image.Top * YScale + 0.5);		h = (int) (GifFileIn->Image.Height * YScale + 0.5);		if (l < 0) l = 0;		if (t < 0) t = 0;		if (l + w > XSize) w = XSize - l;		if (t + h > YSize) h = YSize - t;		if (EGifPutImageDesc(GifFileOut, l, t, w, h,		    GifFileIn->Image.Interlace,		    GifFileIn->Image.ColorMap) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		if (GifFileIn->Image.Interlace) {		    GIF_EXIT("Cannt resize interlaced images - use GifInter first.");		}		else {		    GifQprintf("/n%s: Image %d at (%d, %d) [%dx%d]:     ",			PROGRAM_NAME, ++ImageNum,			GifFileOut->Image.Left, GifFileOut->Image.Top,			GifFileOut->Image.Width, GifFileOut->Image.Height);		    for (i = GifFileIn->Image.Height, y = 0.0, last_iy = -1;			 i-- > 0;			 y += YScale) {			if (DGifGetLine(GifFileIn, LineIn,					GifFileIn->Image.Width) == GIF_ERROR)			    QuitGifError(GifFileIn, GifFileOut);

unsigned char      *loader_gif(FILE *f, int *w, int *h, int *t){  unsigned char      *data, *ptr;  GifFileType        *gif;  GifRowType         *rows;  GifRecordType       rec;  ColorMapObject     *cmap;  int                 i, j, done, bg, csize, r, g, b;  int                 intoffset[] = {0, 4, 2, 1};  int                 intjump[] = {8, 8, 4, 2};  int                 istransp, transp;  int                 fd;  done = 0;  istransp = 0;  fd = fileno(f);  /* Apparently rewind(f) isn't sufficient */  lseek(fd, (long) 0, 0);  gif = DGifOpenFileHandle(fd);  transp = -1;  data = NULL;  rows = NULL;  if (!gif)    return NULL;  do    {      if (DGifGetRecordType(gif, &rec) == GIF_ERROR)	{	  PrintGifError();	  rec = TERMINATE_RECORD_TYPE;	}      if ((rec == IMAGE_DESC_RECORD_TYPE) && (!done))	{	  if (DGifGetImageDesc(gif) == GIF_ERROR)	    {	      PrintGifError();	      rec = TERMINATE_RECORD_TYPE;	    }	  *w = gif->Image.Width;	  *h = gif->Image.Height;	  if(*h > 32767 || *w > 32767)	    {	      return NULL;	    }	  rows = malloc(*h * sizeof(GifRowType *));	  if (!rows)	    {	      DGifCloseFile(gif);	      return NULL;	    }	  data = _gdk_malloc_image(*w, *h);	  if (!data)	    {	      DGifCloseFile(gif);	      free(rows);	      return NULL;	    }	  for (i = 0; i < *h; i++)	    rows[i] = NULL;	  for (i = 0; i < *h; i++)	    {	      rows[i] = malloc(*w * sizeof(GifPixelType));	      if (!rows[i])		{		  DGifCloseFile(gif);		  for (i = 0; i < *h; i++)		    if (rows[i])		      free(rows[i]);		  free(rows);		  free(data);		  return NULL;		}	    }	  if (gif->Image.Interlace)	    {	      for (i = 0; i < 4; i++)		{		  for (j = intoffset[i]; j < *h; j += intjump[i])		    DGifGetLine(gif, rows[j], *w);		}	    }	  else	    {	      for (i = 0; i < *h; i++)		DGifGetLine(gif, rows[i], *w);	    }	  done = 1;	}      else if (rec == EXTENSION_RECORD_TYPE)	{	  int                 ext_code;	  GifByteType        *ext;	  ext = NULL;	  DGifGetExtension(gif, &ext_code, &ext);//.........这里部分代码省略.........

int main(int argc, char **argv) {   //   // local vars   //   GifFileType *GIFfile;   GifRecordType GIFtype;   GifByteType *GIFextension;   GifPixelType *GIFline;   uint32_t w[8],**lower_array,**upper_array;   int x,y,z,i,j,k,n,p,imin,imax;   int image_width,image_height,image_count,color_resolution,GIFcode,ret;   float threshold,voxel_size;   char comment[256],rules[255][20];   struct fab_vars v;   init_vars(&v);   //   // command line args   //   if (!((argc == 3) || (argc == 4) || (argc == 5) || (argc == 6))) {      printf("command line: gif_stl in.gif out.stl [threshold [size [points [angle]]]]/n");      printf("   in.gif = input GIF section file/n");      printf("   out.stl = output STL file/n");      printf("   threshold: surface intensity threshold (0 = min, 1 = max, default 0.5))/n");      printf("   size = voxel size (mm, default from file))/n");      printf("   points = points to interpolate per point (default 0)/n");      printf("   to be implemented: angle = minimum relative face angle to decimate vertices (default 0)/n");      exit(-1);      }   p = 0;   threshold = 0.5;   voxel_size = -1;   image_width = -1;   image_height = -1;   image_count = -1;   if (argc >= 4)      sscanf(argv[3],"%f",&threshold);   if (argc >= 5)      sscanf(argv[4],"%f",&voxel_size);   if (argc >= 6)      sscanf(argv[5],"%d",&p);   //   // initialize the rule table   //   init_rules(rules);   //   // scan the file    //   printf("read %s/n",argv[1]);   color_resolution = -1;#if GIFLIB_MAJOR >= 5   GIFfile = DGifOpenFileName(argv[1], NULL);#else   GIFfile = DGifOpenFileName(argv[1]);#endif   if (GIFfile == NULL) {      printf("gif_stl: oops -- can not open %s/n",argv[1]);      exit(-1);      }   GIFline = malloc(MAX_LINE*sizeof(GifPixelType));   imin = 256;   imax = 0;   do {      DGifGetRecordType(GIFfile,&GIFtype);      switch (GIFtype) {         case IMAGE_DESC_RECORD_TYPE:            DGifGetImageDesc(GIFfile);            image_width = GIFfile->SWidth;            image_height = GIFfile->SHeight;            image_count = GIFfile->ImageCount;            color_resolution = GIFfile->SColorResolution;            for (y = 0; y < GIFfile->SHeight; ++y) {               ret = DGifGetLine(GIFfile,GIFline,GIFfile->SWidth);               if (ret != GIF_OK) {                  printf("gif_stl: oops -- error reading line/n");                  exit(-1);                  }               for (x = 0; x < GIFfile->SWidth; ++x) {                  if (GIFline[x] < imin) imin = GIFline[x];                  if (GIFline[x] > imax) imax = GIFline[x];                  }               }            break;         case EXTENSION_RECORD_TYPE:            DGifGetExtension(GIFfile,&GIFcode,&GIFextension);            if (GIFcode == COMMENT_EXT_FUNC_CODE) {               n = GIFextension[0];               for (i = 1; i <= n; ++i)                  comment[i-1] = GIFextension[i];               comment[n] = 0;               if (voxel_size == -1)                  sscanf(comment,"mm per pixel: %f;",&voxel_size);               }            while (GIFextension != NULL)               DGifGetExtensionNext(GIFfile,&GIFextension);            break;         case SCREEN_DESC_RECORD_TYPE:            DGifGetScreenDesc(GIFfile);            break;         case TERMINATE_RECORD_TYPE:            break;//.........这里部分代码省略.........

/* * Partially based on code in gif2rgb from giflib, by Gershon Elber. */RImage *RLoadGIF(const char *file, int index){	RImage *image = NULL;	unsigned char *cptr;	GifFileType *gif = NULL;	GifPixelType *buffer = NULL;	int i, j, k;	int width, height;	GifRecordType recType;	ColorMapObject *colormap;	unsigned char rmap[256];	unsigned char gmap[256];	unsigned char bmap[256];	if (index < 0)		index = 0;	/* default error message */	RErrorCode = RERR_BADINDEX;	gif = DGifOpenFileName(file);	if (!gif) {		switch (GifLastError()) {		case D_GIF_ERR_OPEN_FAILED:			RErrorCode = RERR_OPEN;			break;		case D_GIF_ERR_READ_FAILED:			RErrorCode = RERR_READ;			break;		default:			RErrorCode = RERR_BADIMAGEFILE;			break;		}		return NULL;	}	if (gif->SWidth < 1 || gif->SHeight < 1) {		DGifCloseFile(gif);		RErrorCode = RERR_BADIMAGEFILE;		return NULL;	}	colormap = gif->SColorMap;	i = 0;	do {		int extCode;		GifByteType *extension;		if (DGifGetRecordType(gif, &recType) == GIF_ERROR) {			goto giferr;		}		switch (recType) {		case IMAGE_DESC_RECORD_TYPE:			if (i++ != index)				break;			if (DGifGetImageDesc(gif) == GIF_ERROR) {				goto giferr;			}			width = gif->Image.Width;			height = gif->Image.Height;			if (gif->Image.ColorMap)				colormap = gif->Image.ColorMap;			/* the gif specs talk about a default colormap, but it			 * doesnt say what the heck is this default colormap */			if (!colormap) {				/*				 * Well, since the spec says the colormap can be anything,				 * lets just render it with whatever garbage the stack				 * has :)				 *				 goto bye;				 */			} else {				for (j = 0; j < colormap->ColorCount; j++) {					rmap[j] = colormap->Colors[j].Red;					gmap[j] = colormap->Colors[j].Green;					bmap[j] = colormap->Colors[j].Blue;				}			}			buffer = malloc(width * sizeof(GifColorType));			if (!buffer) {				RErrorCode = RERR_NOMEMORY;				goto bye;			}			image = RCreateImage(width, height, False);			if (!image) {				goto bye;//.........这里部分代码省略.........

/******************************************************************************* Main sequence******************************************************************************/int main(int argc, char **argv){    GifFileType *GifFileIn = NULL, *GifFileOut = NULL;    GifRecordType RecordType;    int CodeSize, ExtCode;    GifByteType *CodeBlock, *Extension;    /*     * Command-line processing goes here.     */    /* Use the stdin as input (note this also read screen descriptor in: */    if ((GifFileIn = DGifOpenFileHandle(0)) == NULL)	QuitGifError(GifFileIn, GifFileOut);    /* Use the stdout as output: */    if ((GifFileOut = EGifOpenFileHandle(1)) == NULL)	QuitGifError(GifFileIn, GifFileOut);    /* And dump out its screen information: */    if (EGifPutScreenDesc(GifFileOut,	GifFileIn->SWidth, GifFileIn->SHeight,	GifFileIn->SColorResolution, GifFileIn->SBackGroundColor,	GifFileIn->SColorMap) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);    /* Scan the content of the input GIF file and load the image(s) in: */    do {	if (DGifGetRecordType(GifFileIn, &RecordType) == GIF_ERROR)	    QuitGifError(GifFileIn, GifFileOut);	switch (RecordType) {	    case IMAGE_DESC_RECORD_TYPE:		if (DGifGetImageDesc(GifFileIn) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		/* Put image descriptor to out file: */		if (EGifPutImageDesc(GifFileOut,		    GifFileIn->Image.Left, GifFileIn->Image.Top,		    GifFileIn->Image.Width, GifFileIn->Image.Height,		    GifFileIn->Image.Interlace,		    GifFileIn->Image.ColorMap) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		/* Now read image itself in decoded form as we dont really   */		/* care what we have there, and this is much faster.	     */		if (DGifGetCode(GifFileIn, &CodeSize, &CodeBlock) == GIF_ERROR ||		    EGifPutCode(GifFileOut, CodeSize, CodeBlock) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		while (CodeBlock != NULL) {		    if (DGifGetCodeNext(GifFileIn, &CodeBlock) == GIF_ERROR ||			EGifPutCodeNext(GifFileOut, CodeBlock) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		}		break;	    case EXTENSION_RECORD_TYPE:		/* Skip any extension blocks in file: */		if (DGifGetExtension(GifFileIn, &ExtCode, &Extension) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		if (EGifPutExtension(GifFileOut, ExtCode, Extension[0],							Extension + 1) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		/* No support to more than one extension blocks, so discard: */		while (Extension != NULL) {		    if (DGifGetExtensionNext(GifFileIn, &Extension) == GIF_ERROR)			QuitGifError(GifFileIn, GifFileOut);		}		break;	    case TERMINATE_RECORD_TYPE:		break;	    default:	     /* Should be trapped by DGifGetRecordType */		break;	}    }    while (RecordType != TERMINATE_RECORD_TYPE);    if (DGifCloseFile(GifFileIn) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);    if (EGifCloseFile(GifFileOut) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);    return 0;}

static Image*readGif ( GifFileType *gf ){  Image*          firstImg = 0;  Image*	  img = 0;  int             i, extCode, width, height, row, cmapSize;  int             trans = -1, nFrames = 0, delay = 0;  GifRecordType   rec;  GifByteType     *ext;  ColorMapObject  *cmap;  GifColorType    *clrs;  GifPixelType    *rowBuf = (GifPixelType*) AWT_MALLOC( gf->SWidth * sizeof( GifPixelType) );  do {	CHECK( DGifGetRecordType( gf, &rec));	switch ( rec ) {	case IMAGE_DESC_RECORD_TYPE:	  CHECK( DGifGetImageDesc( gf));	  width    = gf->Image.Width;	  height   = gf->Image.Height;      cmap     = (gf->Image.ColorMap) ? gf->Image.ColorMap : gf->SColorMap;	  clrs     = cmap->Colors;      cmapSize = cmap->ColorCount;	  /*	   * create our image objects and keep track of frames 	   */	  if ( !firstImg ) {     /* this is the first (maybe only) frame */		firstImg = img = createImage( width, height);	  }	  else {                 /* this is a subsequent gif-movie frame, link it in */		img->next = createImage( width, height);		img = img->next;	  }	  /*	   * The trans index might have been cached by a preceeding extension record. Now	   * that we have the Image object, it's time to store it in img and to create the	   * mask	   */	  if ( trans != -1 ) {		img->trans = trans;		createXMaskImage( X, img);		trans = -1;	  }	  /*	   * Some browsers seem to assume minimal values, and some animations	   * seem to rely on this. But there's no safe guess, so we	   * skip it completely	   *//*	  if ( delay == 0 )		delay = 1000;	  else if ( delay < 100 )		delay = 100;*/	  img->latency = delay;	  img->left = gf->Image.Left;	  img->top = gf->Image.Top;	  img->frame = nFrames;	  nFrames++;	  createXImage( X, img);	  /*	   * start reading in the image data	   */	  if ( gf->Image.Interlace ) {		/* Need to perform 4 passes on the images: */		for ( i = 0; i < 4; i++ ) {		  for (row = iOffset[i]; row < height; row += iJumps[i]) {			memset( rowBuf, gf->SBackGroundColor, width);			CHECK( DGifGetLine( gf, rowBuf, width));			writeRow( img, rowBuf, clrs, row);		  }		}	  }	  else {		for ( row = 0; row < height; row++) {		  memset( rowBuf, gf->SBackGroundColor, width);		  CHECK( DGifGetLine(gf, rowBuf, width));		  writeRow( img, rowBuf, clrs, row);		}	  }	  break;	case EXTENSION_RECORD_TYPE:	  CHECK( DGifGetExtension( gf, &extCode, &ext));	  if ( extCode == 0xf9 ) {   /* graphics extension */		/*		 * extension record with transparency spec are preceeding description records		 * (which create new Images), so just cache the transp index, here//.........这里部分代码省略.........

intDGifSlurp(GifFileType *GifFile){    size_t ImageSize;    GifRecordType RecordType;    SavedImage *sp;    GifByteType *ExtData;    int ExtFunction;    GifFile->ExtensionBlocks = NULL;    GifFile->ExtensionBlockCount = 0;    //主循环    do {        //判断当前读取的块类型        if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR)            return (GIF_ERROR);        switch (RecordType) {            //每一帧图片的图片头 Descriptor 也就是0x2c            //包含当前帧的上下左右位置(为了节省空间，GIF的单个帧可以不是完整的GIF的大小，如果小于GIF的分辨率 就需要上下左右来定位)            //局部的颜色空间(每一帧可以有自己的颜色空间，是可选的)          case IMAGE_DESC_RECORD_TYPE:              if (DGifGetImageDesc(GifFile) == GIF_ERROR)                  return (GIF_ERROR);              sp = &GifFile->SavedImages[GifFile->ImageCount - 1];              /* Allocate memory for the image */              if (sp->ImageDesc.Width < 0 && sp->ImageDesc.Height < 0 &&                      sp->ImageDesc.Width > (INT_MAX / sp->ImageDesc.Height)) {                  return GIF_ERROR;              }              ImageSize = sp->ImageDesc.Width * sp->ImageDesc.Height;              if (ImageSize > (SIZE_MAX / sizeof(GifPixelType))) {                  return GIF_ERROR;              }              //分配空间给解码后的图像像素              sp->RasterBits = (unsigned char *)malloc(ImageSize *                      sizeof(GifPixelType));              if (sp->RasterBits == NULL) {                  return GIF_ERROR;              }	      if (sp->ImageDesc.Interlace) {		  int i, j;		   /* 		    * The way an interlaced image should be read - 		    * offsets and jumps...		    */		  int InterlacedOffset[] = { 0, 4, 2, 1 };		  int InterlacedJumps[] = { 8, 8, 4, 2 };		  /* Need to perform 4 passes on the image */		  for (i = 0; i < 4; i++)		      for (j = InterlacedOffset[i]; 			   j < sp->ImageDesc.Height;			   j += InterlacedJumps[i]) {			  if (DGifGetLine(GifFile, 					  sp->RasterBits+j*sp->ImageDesc.Width, 					  sp->ImageDesc.Width) == GIF_ERROR)			      return GIF_ERROR;		      }	      }	      else {		  if (DGifGetLine(GifFile,sp->RasterBits,ImageSize)==GIF_ERROR)		      return (GIF_ERROR);	      }              if (GifFile->ExtensionBlocks) {                  sp->ExtensionBlocks = GifFile->ExtensionBlocks;                  sp->ExtensionBlockCount = GifFile->ExtensionBlockCount;                  GifFile->ExtensionBlocks = NULL;                  GifFile->ExtensionBlockCount = 0;              }              break;          case EXTENSION_RECORD_TYPE:              if (DGifGetExtension(GifFile,&ExtFunction,&ExtData) == GIF_ERROR)                  return (GIF_ERROR);	      /* Create an extension block with our data */              if (ExtData != NULL) {		  if (GifAddExtensionBlock(&GifFile->ExtensionBlockCount,					   &GifFile->ExtensionBlocks, 					   ExtFunction, ExtData[0], &ExtData[1])		      == GIF_ERROR)		      return (GIF_ERROR);	      }              while (ExtData != NULL) {                  if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR)                      return (GIF_ERROR);                  /* Continue the extension block */		  if (ExtData != NULL)		      if (GifAddExtensionBlock(&GifFile->ExtensionBlockCount,					       &GifFile->ExtensionBlocks,					       CONTINUE_EXT_FUNC_CODE, //.........这里部分代码省略.........

//int fh_gif_load(char *name,unsigned char *buffer, unsigned char ** alpha, int x,int y)int fh_gif_load(aml_dec_para_t* para , aml_image_info_t* image){  int in_nextrow[4]={8,8,4,2};   //interlaced jump to the row current+in_nextrow  int in_beginrow[4]={0,4,2,1};  //begin pass j from that row number  int transparency=-1;  //-1 means not transparency present    int px,py,i,ibxs;    int j;    char *fbptr;    char *lb;    char *slb;    GifFileType *gft;    GifByteType *extension;    int extcode;    GifRecordType rt;    ColorMapObject *cmap;    int cmaps;    char *p,*q;    int buf_len;    char* name;    char* buffer;    char* alpha = NULL;    int x,y;        name = para->fn;    buffer = (unsigned char*) malloc(para->iwidth * para->iheight * 4);    buf_len = para->iwidth * para->iheight;    x = para->iwidth;    y = para->iheight;    gft=DGifOpenFileName(name);    if(gft==NULL){printf("err5/n"); gflush;} //////////    do    {	if(DGifGetRecordType(gft,&rt) == GIF_ERROR) grflush;	switch(rt)	{	    case IMAGE_DESC_RECORD_TYPE:		if(DGifGetImageDesc(gft)==GIF_ERROR) grflush;		px=gft->Image.Width;		py=gft->Image.Height;		lb=(char*)malloc(px*3);		slb=(char*) malloc(px);//  printf("reading.../n");		if(lb!=NULL && slb!=NULL)		{			unsigned char *alphaptr = NULL;					    cmap=(gft->Image.ColorMap ? gft->Image.ColorMap : gft->SColorMap);		    cmaps=cmap->ColorCount;		    ibxs=ibxs*3;		    fbptr=(char*)buffer;						if(transparency != -1)			{				alphaptr = malloc(px * py);				alpha = alphaptr;			}					    if(!(gft->Image.Interlace))		    {			for(i=0;i<py;i++,fbptr+=px*3)			{				int j;			    if(DGifGetLine(gft,(GifPixelType*)slb,px)==GIF_ERROR) mgrflush;			    m_rend_gif_decodecolormap((unsigned char*)slb,(unsigned char*)lb,cmap,cmaps,px,transparency);			    memcpy(fbptr,lb,px*3);				if(alphaptr)					for(j = 0; j<px; j++) *(alphaptr++) = (((unsigned char*) slb)[j] == transparency) ? 0x00 : 0xff;        		}                    }                    else		    {				unsigned char * aptr = NULL;					               for(j=0;j<4;j++)	               {						int k;				        if(alphaptr)							aptr = alphaptr + (in_beginrow[j] * px);												    fbptr=(char*)buffer + (in_beginrow[j] * px * 3);					    for(i = in_beginrow[j]; i<py; i += in_nextrow[j], fbptr += px * 3 * in_nextrow[j], aptr += px * in_nextrow[j])			    {				if(DGifGetLine(gft,(GifPixelType*)slb,px)==GIF_ERROR) mgrflush; /////////////				m_rend_gif_decodecolormap((unsigned char*)slb,(unsigned char*)lb,cmap,cmaps,px,transparency);				memcpy(fbptr,lb,px*3);				if(alphaptr)					for(k = 0; k<px; k++) aptr[k] = (((unsigned char*) slb)[k] == transparency) ? 0x00 : 0xff;          		    }			}		    }		}		if(lb) free(lb);		if(slb) free(slb);                break;	    case EXTENSION_RECORD_TYPE:		if(DGifGetExtension(gft,&extcode,&extension)==GIF_ERROR) grflush; //////////		if(extcode==0xf9) //look image transparency in graph ctr extension		{//.........这里部分代码省略.........

void*open_gif_file (const char *filename, int *width, int *height){    int interlace_offset[] = { 0, 4, 2, 1 };    int interlace_jump[] = { 8, 8, 4, 2 };        GifColorType *colormap;    GifRecordType record_type;    GifRowType *buffer = NULL;        int i, j;    int color_index;    unsigned char *ptr = NULL;                    gif_data_t *data = (gif_data_t*)malloc(sizeof(gif_data_t));        assert(data != 0);        int error;    data->file = DGifOpenFileName(filename, &error);        assert(data->file !=0);            do    {        assert(DGifGetRecordType(data->file, &record_type) != GIF_ERROR) ;        switch (record_type)        {        case IMAGE_DESC_RECORD_TYPE:            assert(DGifGetImageDesc(data->file) != GIF_ERROR);                        *width = data->file->Image.Width;            *height = data->file->Image.Height;            data->width = *width;            data->height = *height;                        buffer = malloc(*height * sizeof(GifRowType *));            assert(buffer != NULL);                        for (i = 0; i < *height; i++)             {                buffer[i] = malloc(*width * sizeof(GifPixelType));                assert(buffer[i] != NULL);            }                        if (data->file->Image.Interlace)            {                for (i = 0; i < 4; i++)                    for (j = interlace_offset[i]; j < *height;                          j += interlace_jump[i])                        DGifGetLine(data->file, buffer[j], *width);            }            else            {                for (i = 0; i < *height; i++)                    DGifGetLine(data->file, buffer[i], *width);            }            break;        case EXTENSION_RECORD_TYPE:        {            /* Skip extension blocks */            int ext_code;            GifByteType *ext;            assert(DGifGetExtension(data->file, &ext_code, &ext) != GIF_ERROR);                         while (ext != NULL)             {                assert(DGifGetExtensionNext(data->file, &ext) != GIF_ERROR);             }        }        break;        case TERMINATE_RECORD_TYPE:            break;        default:            fprintf(stderr, "unknown record type in GIF file/n");            break;        }    } while (record_type != TERMINATE_RECORD_TYPE);            colormap = (data->file->Image.ColorMap ? data->file->Image.ColorMap->Colors                : data->file->SColorMap->Colors);    data->rgb = (unsigned char*)malloc( (data->width* data->height * 3) );    assert(data->rgb != NULL);        ptr = data->rgb;        for (j = 0; j < *height; j++)    {        for (i = 0; i < *width; i++)        {            color_index = (int) buffer[j][i];            *ptr++ = (unsigned char) colormap[color_index].Red;            *ptr++ = (unsigned char) colormap[color_index].Green;            *ptr++ = (unsigned char) colormap[color_index].Blue;        }        free(buffer[j]);    }    free(buffer);//.........这里部分代码省略.........

static void GIF2RGB(int NumFiles, char *FileName,             bool OneFileFlag,             char *OutFileName){    int	i, j, Size, Row, Col, Width, Height, ExtCode, Count;    GifRecordType RecordType;    GifByteType *Extension;    GifRowType *ScreenBuffer;    GifFileType *GifFile;    int    InterlacedOffset[] = { 0, 4, 2, 1 }, /* The way Interlaced image should. */    InterlacedJumps[] = { 8, 8, 4, 2 };    /* be read - offsets and jumps... */    int ImageNum = 0;    ColorMapObject *ColorMap;    int Error;    if (NumFiles == 1) {    int Error;    if ((GifFile = DGifOpenFileName(FileName, &Error)) == NULL) {        PrintGifError(Error);        exit(EXIT_FAILURE);    }    }    else {    int Error;    /* Use stdin instead: */    if ((GifFile = DGifOpenFileHandle(0, &Error)) == NULL) {        PrintGifError(Error);        exit(EXIT_FAILURE);    }    }    /*      * Allocate the screen as vector of column of rows. Note this     * screen is device independent - it's the screen defined by the     * GIF file parameters.     */    if ((ScreenBuffer = (GifRowType *)    malloc(GifFile->SHeight * sizeof(GifRowType))) == NULL)        GIF_EXIT("Failed to allocate memory required, aborted.");    Size = GifFile->SWidth * sizeof(GifPixelType);/* Size in bytes one row.*/    if ((ScreenBuffer[0] = (GifRowType) malloc(Size)) == NULL) /* First row. */    GIF_EXIT("Failed to allocate memory required, aborted.");    for (i = 0; i < GifFile->SWidth; i++)  /* Set its color to BackGround. */    ScreenBuffer[0][i] = GifFile->SBackGroundColor;    for (i = 1; i < GifFile->SHeight; i++) {        /* Allocate the other rows, and set their color to background too: */        if ((ScreenBuffer[i] = (GifRowType) malloc(Size)) == NULL)            GIF_EXIT("Failed to allocate memory required, aborted.");        memcpy(ScreenBuffer[i], ScreenBuffer[0], Size);    }    /* Scan the content of the GIF file and load the image(s) in: */    do {        if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR) {            PrintGifError(GifFile->Error);            exit(EXIT_FAILURE);        }        switch (RecordType) {            case IMAGE_DESC_RECORD_TYPE:                {                    if (DGifGetImageDesc(GifFile) == GIF_ERROR) {                        PrintGifError(GifFile->Error);                        exit(EXIT_FAILURE);                    }                    Row = GifFile->Image.Top; /* Image Position relative to Screen. */                    Col = GifFile->Image.Left;                    Width = GifFile->Image.Width;                    Height = GifFile->Image.Height;                    GifQprintf("/n%s: Image %d at (%d, %d) [%dx%d]:     ",                        PROGRAM_NAME, ++ImageNum, Col, Row, Width, Height);                    if (GifFile->Image.Left + GifFile->Image.Width > GifFile->SWidth ||                        GifFile->Image.Top + GifFile->Image.Height > GifFile->SHeight) {                            fprintf(stderr, "Image %d is not confined to screen dimension, aborted./n",ImageNum);                            exit(EXIT_FAILURE);                    }                    if (GifFile->Image.Interlace) {                        /* Need to perform 4 passes on the images: */                        for (Count = i = 0; i < 4; i++)                            for (j = Row + InterlacedOffset[i]; j < Row + Height;                                j += InterlacedJumps[i]) {                                    GifQprintf("/b/b/b/b%-4d", Count++);                                    if (DGifGetLine(GifFile, &ScreenBuffer[j][Col],                                        Width) == GIF_ERROR) {                                            PrintGifError(GifFile->Error);                                            exit(EXIT_FAILURE);                                    }                            }                    }                    else {                        for (i = 0; i < Height; i++) {                            GifQprintf("/b/b/b/b%-4d", i);                            if (DGifGetLine(GifFile, &ScreenBuffer[Row++][Col],                                Width) == GIF_ERROR) {                                    PrintGifError(GifFile->Error);                                    exit(EXIT_FAILURE);                            }                        }//.........这里部分代码省略.........

//.........这里部分代码省略.........  rowsize = gifp->SWidth * sizeof(GifPixelType);  buffer[0] = (GifRowType)malloc(rowsize);  if(buffer[0] == NULL) {    free(buffer);    free(picture);    DGifCloseFile(gifp);    return NULL;  }  for(i = 0 ; i < gifp->SWidth ; i++)    buffer[0][i] = gifp->SBackGroundColor;  for(i = 0 ; i < gifp->SHeight ; i++) {    buffer[i] = (GifRowType)malloc(rowsize);    if(buffer[i] == NULL) {      while(--i >= 0)	free(buffer[i]);      free(buffer);      free(picture);      DGifCloseFile(gifp);      return NULL;    }    memcpy(buffer[i], buffer[0], rowsize);  }  /* We only read the first GIF image right now, since we are not   * supporting animated GIF images. Perhaps the last image would   * actually be a better choice. Oh well.   */  images_read = 0;  do {    DGifGetRecordType(gifp, &record);    ret = GIF_OK;    switch(record) {    case IMAGE_DESC_RECORD_TYPE:      ret = DGifGetImageDesc(gifp);      if(ret == GIF_ERROR)	break;#if 0      fprintf(stderr, "image width=%d, height=%d, interlace=%d/n",	      gifp->Image.Width, gifp->Image.Height, gifp->Image.Interlace);#endif      row = gifp->Image.Top;      col = gifp->Image.Left;      image_width = gifp->Image.Width;      image_height = gifp->Image.Height;      if(gifp->Image.Interlace) {	for(i = 0 ; i < 4 ; i++) {	  for(j = row + interlaceoffset[i] ; 	      j < row + image_height ;	      j += interlacejump[i]) {	    DGifGetLine(gifp, &buffer[j][col], image_width);	  }	}      } else {	for(i = 0 ; i < image_height ; i++) {	  DGifGetLine(gifp, &buffer[row++][col], image_width);	}      }      images_read++;            break;      /* Read and skip any extension. */

void DDGifSlurp(GifInfo *info, bool shouldDecode) {    GifRecordType RecordType;    GifByteType *ExtData;    int codeSize;    int ExtFunction;    do {        if (DGifGetRecordType(info->gifFilePtr, &RecordType) == GIF_ERROR)            return;        switch (RecordType) {            case IMAGE_DESC_RECORD_TYPE:                if (DGifGetImageDesc(info->gifFilePtr, !shouldDecode) == GIF_ERROR)                    return;                const uint_fast16_t requiredScreenWidth = info->gifFilePtr->Image.Left + info->gifFilePtr->Image.Width;                const uint_fast16_t requiredScreenHeight = info->gifFilePtr->Image.Top + info->gifFilePtr->Image.Height;                if (requiredScreenWidth > info->gifFilePtr->SWidth || requiredScreenHeight > info->gifFilePtr->SHeight) {                    if (shouldDecode) {                        void *tmpRasterBits = realloc(info->rasterBits,                                                      requiredScreenWidth * requiredScreenHeight * sizeof(GifPixelType));                        if (tmpRasterBits == NULL) {                            info->gifFilePtr->Error = D_GIF_ERR_NOT_ENOUGH_MEM;                            return;                        }                        info->rasterBits = tmpRasterBits;                    }                    else {                        info->gifFilePtr->SWidth = requiredScreenWidth;                        info->gifFilePtr->SHeight = requiredScreenHeight;                    }                }                if (shouldDecode) {                    if (info->gifFilePtr->Image.Interlace) {                        uint_fast16_t i, j;                        /*                         * The way an interlaced image should be read -                         * offsets and jumps...                         */                        uint_fast8_t InterlacedOffset[] = {0, 4, 2, 1};                        uint_fast8_t InterlacedJumps[] = {8, 8, 4, 2};                        /* Need to perform 4 passes on the image */                        for (i = 0; i < 4; i++)                            for (j = InterlacedOffset[i]; j < info->gifFilePtr->Image.Height; j += InterlacedJumps[i]) {                                if (DGifGetLine(info->gifFilePtr, info->rasterBits + j * info->gifFilePtr->Image.Width,                                                info->gifFilePtr->Image.Width) == GIF_ERROR)                                    return;                            }                    }                    else {                        if (DGifGetLine(                                info->gifFilePtr, info->rasterBits,                                info->gifFilePtr->Image.Width * info->gifFilePtr->Image.Height) == GIF_ERROR)                            return;                    }                    return;                }                else {                    if (DGifGetCode(info->gifFilePtr, &codeSize, &ExtData) == GIF_ERROR)                        return;                    while (ExtData != NULL) {                        if (DGifGetCodeNext(info->gifFilePtr, &ExtData) == GIF_ERROR)                            return;                    }                }                break;            case EXTENSION_RECORD_TYPE:                if (DGifGetExtension(info->gifFilePtr, &ExtFunction, &ExtData) == GIF_ERROR)                    return;                if (!shouldDecode) {                    GraphicsControlBlock *tmpInfos = realloc(info->controlBlock,                                                             (info->gifFilePtr->ImageCount + 1) *                                                             sizeof(GraphicsControlBlock));                    if (tmpInfos == NULL) {                        info->gifFilePtr->Error = D_GIF_ERR_NOT_ENOUGH_MEM;                        return;                    }                    info->controlBlock = tmpInfos;                    info->controlBlock[info->gifFilePtr->ImageCount].DelayTime = DEFAULT_FRAME_DURATION_MS;                    if (readExtensions(ExtFunction, ExtData, info) == GIF_ERROR)                        return;                }                while (ExtData != NULL) {                    if (DGifGetExtensionNext(info->gifFilePtr, &ExtData,                                             &ExtFunction) == GIF_ERROR)                        return;                    if (!shouldDecode) {                        if (readExtensions(ExtFunction, ExtData, info) == GIF_ERROR)                            return;                    }                }                break;            case TERMINATE_RECORD_TYPE:                break;            default: /* Should be trapped by DGifGetRecordType */                break;//.........这里部分代码省略.........

/****************************************************************************** * This routine reads an entire GIF into core, hanging all its state info off * the GifFileType pointer.  Call DGifOpenFileName() or DGifOpenFileHandle() * first to initialize I/O.  Its inverse is EGifSpew(). ******************************************************************************/intDGifSlurp(GifFileType * GifFile) {    int ImageSize;    GifRecordType RecordType;    SavedImage *sp;    GifByteType *ExtData;    Extensions temp_save;    temp_save.ExtensionBlocks = NULL;    temp_save.ExtensionBlockCount = 0;    do {        if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR)            return (GIF_ERROR);        switch (RecordType) {          case IMAGE_DESC_RECORD_TYPE:              if (DGifGetImageDesc(GifFile) == GIF_ERROR)                  return (GIF_ERROR);              sp = &GifFile->SavedImages[GifFile->ImageCount - 1];              ImageSize = sp->ImageDesc.Width * sp->ImageDesc.Height;              sp->RasterBits = ungif_alloc(ImageSize * sizeof(GifPixelType));              if (sp->RasterBits == NULL) {                  return GIF_ERROR;              }              if (DGifGetLine(GifFile, sp->RasterBits, ImageSize) ==                  GIF_ERROR)                  return (GIF_ERROR);              if (temp_save.ExtensionBlocks) {                  sp->Extensions.ExtensionBlocks = temp_save.ExtensionBlocks;                  sp->Extensions.ExtensionBlockCount = temp_save.ExtensionBlockCount;                  temp_save.ExtensionBlocks = NULL;                  temp_save.ExtensionBlockCount = 0;                  /* FIXME: The following is wrong.  It is left in only for                   * backwards compatibility.  Someday it should go away. Use                   * the sp->ExtensionBlocks->Function variable instead. */                  sp->Extensions.Function = sp->Extensions.ExtensionBlocks[0].Function;              }              break;          case EXTENSION_RECORD_TYPE:          {              int Function;              Extensions *Extensions;              if (DGifGetExtension(GifFile, &Function, &ExtData) == GIF_ERROR)                  return (GIF_ERROR);              if (GifFile->ImageCount || Function == GRAPHICS_EXT_FUNC_CODE)                  Extensions = &temp_save;              else                  Extensions = &GifFile->Extensions;              Extensions->Function = Function;              /* Create an extension block with our data */              if (AddExtensionBlock(Extensions, ExtData[0], &ExtData[1]) == GIF_ERROR)                  return (GIF_ERROR);              while (ExtData != NULL) {                  int Len;                  GifByteType *Data;                  if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR)                      return (GIF_ERROR);                  if (ExtData)                  {                      Len = ExtData[0];                      Data = &ExtData[1];                  }                  else                  {                      Len = 0;                      Data = NULL;                  }                  if (AppendExtensionBlock(Extensions, Len, Data) == GIF_ERROR)                      return (GIF_ERROR);              }              break;          }          case TERMINATE_RECORD_TYPE:              break;          default:    /* Should be trapped by DGifGetRecordType */              break;        }    } while (RecordType != TERMINATE_RECORD_TYPE);//.........这里部分代码省略.........

CPLErr BIGGIFDataset::ReOpen(){/* -------------------------------------------------------------------- *//*      If the file is already open, close it so we can restart.        *//* -------------------------------------------------------------------- */    if( hGifFile != NULL )        DGifCloseFile( hGifFile );/* -------------------------------------------------------------------- *//*      If we are actually reopening, then we assume that access to     *//*      the image data is not strictly once through sequential, and     *//*      we will try to create a working database in a temporary         *//*      directory to hold the image as we read through it the second    *//*      time.                                                           *//* -------------------------------------------------------------------- */    if( hGifFile != NULL )    {        GDALDriver *poGTiffDriver = (GDALDriver*) GDALGetDriverByName("GTiff");                if( poGTiffDriver != NULL )        {            /* Create as a sparse file to avoid filling up the whole file */            /* while closing and then destroying this temporary dataset */            const char* apszOptions[] = { "COMPRESS=LZW", "SPARSE_OK=YES", NULL };            CPLString osTempFilename = CPLGenerateTempFilename("biggif");            osTempFilename += ".tif";            poWorkDS = poGTiffDriver->Create( osTempFilename,                                               nRasterXSize, nRasterYSize, 1,                                               GDT_Byte, const_cast<char**>(apszOptions));        }    }/* -------------------------------------------------------------------- *//*      Open                                                            *//* -------------------------------------------------------------------- */    VSIFSeekL( fp, 0, SEEK_SET );    nLastLineRead = -1;#if defined(GIFLIB_MAJOR) && GIFLIB_MAJOR >= 5    int nError;    hGifFile = DGifOpen( fp, VSIGIFReadFunc, &nError );#else    hGifFile = DGifOpen( fp, VSIGIFReadFunc );#endif    if( hGifFile == NULL )    {        CPLError( CE_Failure, CPLE_OpenFailed,                   "DGifOpen() failed.  Perhaps the gif file is corrupt?/n" );        return CE_Failure;    }/* -------------------------------------------------------------------- *//*      Find the first image record.                                    *//* -------------------------------------------------------------------- */    GifRecordType RecordType = TERMINATE_RECORD_TYPE;    while( DGifGetRecordType(hGifFile, &RecordType) != GIF_ERROR           && RecordType != TERMINATE_RECORD_TYPE           && RecordType != IMAGE_DESC_RECORD_TYPE )    {        /* Skip extension records found before IMAGE_DESC_RECORD_TYPE */        if (RecordType == EXTENSION_RECORD_TYPE)        {            int nFunction;            GifByteType *pExtData;            if (DGifGetExtension(hGifFile, &nFunction, &pExtData) == GIF_ERROR)                break;            while (pExtData != NULL)            {                if (DGifGetExtensionNext(hGifFile, &pExtData) == GIF_ERROR)                    break;            }        }    }    if( RecordType != IMAGE_DESC_RECORD_TYPE )    {        DGifCloseFile( hGifFile );        hGifFile = NULL;        CPLError( CE_Failure, CPLE_OpenFailed,                   "Failed to find image description record in GIF file." );        return CE_Failure;    }        if (DGifGetImageDesc(hGifFile) == GIF_ERROR)    {        DGifCloseFile( hGifFile );        hGifFile = NULL;        CPLError( CE_Failure, CPLE_OpenFailed,                   "Image description reading failed in GIF file." );        return CE_Failure;    }        return CE_None;//.........这里部分代码省略.........

intimage_gif_load(image *im){  int x, y, ofs;  GifRecordType RecordType;  GifPixelType *line = NULL;  int ExtFunction = 0;  GifByteType *ExtData;  SavedImage *sp;  SavedImage temp_save;  int BackGround = 0;  int trans_index = 0; // transparent index if any  ColorMapObject *ColorMap;  GifColorType *ColorMapEntry;  temp_save.ExtensionBlocks = NULL;  temp_save.ExtensionBlockCount = 0;  // If reusing the object a second time, start over  if (im->used) {    DEBUG_TRACE("Recreating giflib objects/n");    image_gif_finish(im);    if (im->fh != NULL) {      // reset file to begining of image      PerlIO_seek(im->fh, im->image_offset, SEEK_SET);    }    else {      // reset SV read      im->sv_offset = im->image_offset;    }    buffer_clear(im->buf);    image_gif_read_header(im);  }  do {    if (DGifGetRecordType(im->gif, &RecordType) == GIF_ERROR) {      warn("Image::Scale unable to read GIF file (%s)/n", SvPVX(im->path));      image_gif_finish(im);      return 0;    }    switch (RecordType) {      case IMAGE_DESC_RECORD_TYPE:        if (DGifGetImageDesc(im->gif) == GIF_ERROR) {          warn("Image::Scale unable to read GIF file (%s)/n", SvPVX(im->path));          image_gif_finish(im);          return 0;        }        sp = &im->gif->SavedImages[im->gif->ImageCount - 1];        im->width  = sp->ImageDesc.Width;        im->height = sp->ImageDesc.Height;        BackGround = im->gif->SBackGroundColor; // XXX needed?        ColorMap = im->gif->Image.ColorMap ? im->gif->Image.ColorMap : im->gif->SColorMap;        if (ColorMap == NULL) {          warn("Image::Scale GIF image has no colormap (%s)/n", SvPVX(im->path));          image_gif_finish(im);          return 0;        }        // Allocate storage for decompressed image        image_alloc(im, im->width, im->height);        New(0, line, im->width, GifPixelType);        if (im->gif->Image.Interlace) {          int i;          for (i = 0; i < 4; i++) {            for (x = InterlacedOffset[i]; x < im->height; x += InterlacedJumps[i]) {              ofs = x * im->width;              if (DGifGetLine(im->gif, line, 0) != GIF_OK) {                warn("Image::Scale unable to read GIF file (%s)/n", SvPVX(im->path));                image_gif_finish(im);                return 0;              }              for (y = 0; y < im->width; y++) {                ColorMapEntry = &ColorMap->Colors[line[y]];                im->pixbuf[ofs++] = COL_FULL(                  ColorMapEntry->Red,                  ColorMapEntry->Green,                  ColorMapEntry->Blue,                  trans_index == line[y] ? 0 : 255                );              }            }          }        }        else {          ofs = 0;          for (x = 0; x < im->height; x++) {            if (DGifGetLine(im->gif, line, 0) != GIF_OK) {              warn("Image::Scale unable to read GIF file (%s)/n", SvPVX(im->path));              image_gif_finish(im);//.........这里部分代码省略.........

/******************************************************************************* Interpret the command line and scan the given GIF file.		      *******************************************************************************/void main(int argc, char **argv){    int	Error, NumFiles, ExtCode;    GifRecordType RecordType;    GifByteType *Extension;    char **FileName = NULL;    GifRowType *ImageBuffer;    GifFileType *GifFileIn = NULL, *GifFileOut = NULL;    if ((Error = GAGetArgs(argc, argv, CtrlStr, &GifQuitePrint,		&InterlacedFlag, &SequencialFlag, &HelpFlag,		&NumFiles, &FileName)) != FALSE ||		(NumFiles > 1 && !HelpFlag)) {	if (Error)	    GAPrintErrMsg(Error);	else if (NumFiles > 1)	    GIF_MESSAGE("Error in command line parsing - one GIF file please.");	GAPrintHowTo(CtrlStr);	exit(1);    }    if (HelpFlag) {	fprintf(stderr, VersionStr);	GAPrintHowTo(CtrlStr);	exit(0);    }    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) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);    /* Scan the content of the GIF file and load the image(s) in: */    do {	if (DGifGetRecordType(GifFileIn, &RecordType) == GIF_ERROR)	    QuitGifError(GifFileIn, GifFileOut);	switch (RecordType) {	    case IMAGE_DESC_RECORD_TYPE:		if (DGifGetImageDesc(GifFileIn) == GIF_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) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		/* Load the image (either Interlaced or not), and dump it as */		/* defined in GifFileOut -> IInterlaced.		     */		if (LoadImage(GifFileIn, &ImageBuffer) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		if (DumpImage(GifFileOut, ImageBuffer) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		break;	    case EXTENSION_RECORD_TYPE:		/* Skip any extension blocks in file: */		if (DGifGetExtension(GifFileIn, &ExtCode, &Extension) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		if (EGifPutExtension(GifFileOut, ExtCode, Extension[0],							Extension) == GIF_ERROR)		    QuitGifError(GifFileIn, GifFileOut);		/* No support to more than one extension blocks, so discard: */		while (Extension != NULL) {		    if (DGifGetExtensionNext(GifFileIn, &Extension) == GIF_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) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);//.........这里部分代码省略.........

static void Gif2Icon(char *FileName,		     int fdin, int fdout,		     char NameTable[]){    int i, ExtCode, ImageNum = 1;    GifPixelType *Line, *cp;    GifRecordType RecordType;    GifByteType *Extension;    GifFileType *GifFile;    if (fdin == -1) {	if ((GifFile = DGifOpenFileName(FileName)) == NULL) {	    PrintGifError();	    exit(EXIT_FAILURE);	}    }    else {	/* Use stdin instead: */	if ((GifFile = DGifOpenFileHandle(fdin)) == NULL) {	    PrintGifError();	    exit(EXIT_FAILURE);	}    }    printf("screen width %d/nscreen height %d/n",	   GifFile->SWidth, GifFile->SHeight);    printf("screen colors %d/nscreen background %d/n/n",	   GifFile->SColorResolution,	   GifFile->SBackGroundColor);    if (GifFile->SColorMap)    {	if (GifFile->SColorMap->ColorCount >= (int)strlen(NameTable))	{	    (void) fprintf(stderr,			   "%s: global color map has unprintable pixels/n",			   FileName);	    exit(EXIT_FAILURE);	}	printf("screen map/n");	for (i = 0; i < GifFile->SColorMap->ColorCount; i++)	    printf("/trgb %03d %03d %03d is %c/n",		   GifFile->SColorMap ->Colors[i].Red,		   GifFile->SColorMap ->Colors[i].Green,		   GifFile->SColorMap ->Colors[i].Blue,		   NameTable[i]);	printf("end/n/n");    }    do {	if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR) {	    PrintGifError();	    exit(EXIT_FAILURE);	}	switch (RecordType) {	case IMAGE_DESC_RECORD_TYPE:	    if (DGifGetImageDesc(GifFile) == GIF_ERROR) {		PrintGifError();		exit(EXIT_FAILURE);	    }	    printf("image # %d/nimage left %d/nimage top %d/n",		   ImageNum++,		   GifFile->Image.Left, GifFile->Image.Top);	    if (GifFile->Image.Interlace)		printf("interlaced/n");	    if (GifFile->Image.ColorMap)	    {		if (GifFile->Image.ColorMap->ColorCount >= (int)strlen(NameTable))		{		    (void) fprintf(stderr,				   "%s: global color map has unprintable pixels/n",				   FileName);		    exit(EXIT_FAILURE);		}		printf("image map/n");		for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++)		    printf("/trgb %03d %03d %03d is %c/n",			   GifFile->Image.ColorMap ->Colors[i].Red,			   GifFile->Image.ColorMap ->Colors[i].Green,			   GifFile->Image.ColorMap ->Colors[i].Blue,			   NameTable[i]);		printf("end/n/n");	    }	    printf("image bits %d by %d/n",		   GifFile->Image.Width, GifFile->Image.Height);	    Line = (GifPixelType *) malloc(GifFile->Image.Width *					   sizeof(GifPixelType));	    for (i = 0; i < GifFile->Image.Height; i++) {		if (DGifGetLine(GifFile, Line, GifFile->Image.Width)		    == GIF_ERROR) {		    PrintGifError();		    exit(EXIT_FAILURE);//.........这里部分代码省略.........

/* * Read enough of the stream to initialize the SkGifCodec. * Returns a bool representing success or failure. * * @param codecOut * If it returned true, and codecOut was not nullptr, * codecOut will be set to a new SkGifCodec. * * @param gifOut * If it returned true, and codecOut was nullptr, * gifOut must be non-nullptr and gifOut will be set to a new * GifFileType pointer. * * @param stream * Deleted on failure. * codecOut will take ownership of it in the case where we created a codec. * Ownership is unchanged when we returned a gifOut. * */bool SkGifCodec::ReadHeader(SkStream* stream, SkCodec** codecOut, GifFileType** gifOut) {    SkAutoTDelete<SkStream> streamDeleter(stream);    // Read gif header, logical screen descriptor, and global color table    SkAutoTCallVProc<GifFileType, CloseGif> gif(open_gif(stream));    if (nullptr == gif) {        gif_error("DGifOpen failed./n");        return false;    }    // Read through gif extensions to get to the image data.  Set the    // transparent index based on the extension data.    uint32_t transIndex;    SkCodec::Result result = ReadUpToFirstImage(gif, &transIndex);    if (kSuccess != result){        return false;    }    // Read the image descriptor    if (GIF_ERROR == DGifGetImageDesc(gif)) {        return false;    }    // If reading the image descriptor is successful, the image count will be    // incremented.    SkASSERT(gif->ImageCount >= 1);    if (nullptr != codecOut) {        SkISize size;        SkIRect frameRect;        if (!GetDimensions(gif, &size, &frameRect)) {            gif_error("Invalid gif size./n");            return false;        }        bool frameIsSubset = (size != frameRect.size());        // Determine the recommended alpha type.  The transIndex might be valid if it less        // than 256.  We are not certain that the index is valid until we process the color        // table, since some gifs have color tables with less than 256 colors.  If        // there might be a valid transparent index, we must indicate that the image has        // alpha.        // In the case where we must support alpha, we have the option to set the        // suggested alpha type to kPremul or kUnpremul.  Both are valid since the alpha        // component will always be 0xFF or the entire 32-bit pixel will be set to zero.        // We prefer kPremul because we support kPremul, and it is more efficient to use        // kPremul directly even when kUnpremul is supported.        SkAlphaType alphaType = (transIndex < 256) ? kPremul_SkAlphaType : kOpaque_SkAlphaType;        // Return the codec        // kIndex is the most natural color type for gifs, so we set this as        // the default.        SkImageInfo imageInfo = SkImageInfo::Make(size.width(), size.height(), kIndex_8_SkColorType,                alphaType);        *codecOut = new SkGifCodec(imageInfo, streamDeleter.detach(), gif.detach(), transIndex,                frameRect, frameIsSubset);    } else {        SkASSERT(nullptr != gifOut);        streamDeleter.detach();        *gifOut = gif.detach();    }    return true;}

bool img_load_gif(img_t *img, const fileinfo_t *file){	GifFileType *gif;	GifRowType *rows = NULL;	GifRecordType rec;	ColorMapObject *cmap;	DATA32 bgpixel, *data, *ptr;	DATA32 *prev_frame = NULL;	Imlib_Image im;	int i, j, bg, r, g, b;	int x, y, w, h, sw, sh;	int px, py, pw, ph;	int intoffset[] = { 0, 4, 2, 1 };	int intjump[] = { 8, 8, 4, 2 };	int transp = -1;	unsigned int disposal = 0, prev_disposal = 0;	unsigned int delay = 0;	bool err = false;	if (img->multi.cap == 0) {		img->multi.cap = 8;		img->multi.frames = (img_frame_t*)		                    s_malloc(sizeof(img_frame_t) * img->multi.cap);	}	img->multi.cnt = img->multi.sel = 0;	img->multi.length = 0;#if defined(GIFLIB_MAJOR) && GIFLIB_MAJOR >= 5	gif = DGifOpenFileName(file->path, NULL);#else	gif = DGifOpenFileName(file->path);#endif	if (gif == NULL) {		warn("could not open gif file: %s", file->name);		return false;	}	bg = gif->SBackGroundColor;	sw = gif->SWidth;	sh = gif->SHeight;	px = py = pw = ph = 0;	do {		if (DGifGetRecordType(gif, &rec) == GIF_ERROR) {			err = true;			break;		}		if (rec == EXTENSION_RECORD_TYPE) {			int ext_code;			GifByteType *ext = NULL;			DGifGetExtension(gif, &ext_code, &ext);			while (ext) {				if (ext_code == GRAPHICS_EXT_FUNC_CODE) {					if (ext[1] & 1)						transp = (int) ext[4];					else						transp = -1;					delay = 10 * ((unsigned int) ext[3] << 8 | (unsigned int) ext[2]);					disposal = (unsigned int) ext[1] >> 2 & 0x7;				}				ext = NULL;				DGifGetExtensionNext(gif, &ext);			}		} else if (rec == IMAGE_DESC_RECORD_TYPE) {			if (DGifGetImageDesc(gif) == GIF_ERROR) {				err = true;				break;			}			x = gif->Image.Left;			y = gif->Image.Top;			w = gif->Image.Width;			h = gif->Image.Height;			rows = (GifRowType*) s_malloc(h * sizeof(GifRowType));			for (i = 0; i < h; i++)				rows[i] = (GifRowType) s_malloc(w * sizeof(GifPixelType));			if (gif->Image.Interlace) {				for (i = 0; i < 4; i++) {					for (j = intoffset[i]; j < h; j += intjump[i])						DGifGetLine(gif, rows[j], w);				}			} else {				for (i = 0; i < h; i++)					DGifGetLine(gif, rows[i], w);			}			ptr = data = (DATA32*) s_malloc(sizeof(DATA32) * sw * sh);			cmap = gif->Image.ColorMap ? gif->Image.ColorMap : gif->SColorMap;			r = cmap->Colors[bg].Red;			g = cmap->Colors[bg].Green;			b = cmap->Colors[bg].Blue;			bgpixel = 0x00ffffff & (r << 16 | g << 8 | b);			for (i = 0; i < sh; i++) {				for (j = 0; j < sw; j++) {					if (i < y || i >= y + h || j < x || j >= x + w ||					    rows[i-y][j-x] == transp)					{						if (prev_frame != NULL && (prev_disposal != 2 ||//.........这里部分代码省略.........

int main(int argc, char **argv) {   //   // local vars   //   GifFileType *GIFfile;   GifRecordType GIFtype;   GifByteType *GIFextension;   GifPixelType *GIFline;   uint32_t **lower_array,**upper_array;   double **image_array;   double f,fmin,fmax;   int x,y,z,h,i,j,k,n,p;   int image_width,image_height,image_count,color_resolution,GIFcode,ret;   float pixel_size,arg,rx,ry,rz;   char type,comment[256];   struct fab_vars v;   init_vars(&v);   //   // command line args   //   if (!((argc == 3) || (argc == 4) || (argc == 5) || (argc == 6) || (argc == 7) || (argc == 10))) {      printf("command line: gif_png in.gif out.png [type [arg [points [size [rx ry rz]]]]]/n");      printf("   in.gif = input gif file/n");      printf("   out.png = output PNG file/n");      printf("   type = 'z' of density, 'h' for height (default z)/n");      printf("   arg = gamma for 'z', threshold for 'h' (default 1)/n");      printf("   points = points to interpolate per point (linear, default 0)/n");      printf("   size = voxel size (mm, default from file))/n");      printf("   to be implemented: rx,ry,rz = x,y,z rotation angles (degrees; default 0)/n");      exit(-1);      }   type = 'z';   p = 0;   arg = 1;   rx = ry = rz = 0;   pixel_size = -1;   image_width = -1;   image_height = -1;   if (argc >= 4) {      sscanf(argv[3],"%c",&type);      if (!((type == 'z') || (type == 'h'))) {         printf("gif_png: oops -- type must be 'z' or 'h'/n");         exit(-1);         }   if (argc >= 5)      sscanf(argv[4],"%f",&arg);      }   if (argc >= 6)      sscanf(argv[5],"%d",&p);   if (argc >= 7)      sscanf(argv[6],"%f",&pixel_size);   if (argc >= 10) {      sscanf(argv[7],"%f",&rx);      sscanf(argv[8],"%f",&ry);      sscanf(argv[9],"%f",&rz);      }   //   // scan the file    //   printf("read %s/n",argv[1]);   color_resolution = -1;   GIFfile = DGifOpenFileName(argv[1]);   if (GIFfile == NULL) {      printf("gif_png: oops -- can not open %s/n",argv[1]);      exit(-1);      }   GIFline = malloc(MAX_LINE*sizeof(GifPixelType));   do {      DGifGetRecordType(GIFfile,&GIFtype);      switch (GIFtype) {         case IMAGE_DESC_RECORD_TYPE:            DGifGetImageDesc(GIFfile);            image_width = GIFfile->SWidth;            image_height = GIFfile->SHeight;            image_count = GIFfile->ImageCount;            color_resolution = GIFfile->SColorResolution;            for (y = 0; y < GIFfile->SHeight; ++y) {               ret = DGifGetLine(GIFfile,GIFline,GIFfile->SWidth);               if (ret != GIF_OK) {                  printf("gif_png: oops -- error reading line/n");                  exit(-1);                  }               }            break;         case EXTENSION_RECORD_TYPE:            DGifGetExtension(GIFfile,&GIFcode,&GIFextension);            if (GIFcode == COMMENT_EXT_FUNC_CODE) {               n = GIFextension[0];               for (i = 1; i <= n; ++i)                  comment[i-1] = GIFextension[i];               comment[n] = 0;               if (pixel_size == -1)                  sscanf(comment,"mm per pixel: %f;",&pixel_size);               }            while (GIFextension != NULL)               DGifGetExtensionNext(GIFfile,&GIFextension);            break;         case SCREEN_DESC_RECORD_TYPE:            DGifGetScreenDesc(GIFfile);            break;//.........这里部分代码省略.........

//.........这里部分代码省略.........    if ((ScreenBuffer[0] = (GifRowType) malloc(Size)) == NULL)    /* First row. */	GIF_EXIT("Failed to allocate memory required, aborted.");    for (i = 0; i < GifFile -> SWidth; i++)  /* Set its color to BackGround. */	ScreenBuffer[0][i] = GifFile -> SBackGroundColor;    MaximumScreenHeight = GifFile -> SHeight - 1;    for (i = 1; i < GifFile -> SHeight; i++) {	/* Allocate the other rows, and set their color to background too: */	if ((ScreenBuffer[i] = (GifRowType) malloc(Size)) == NULL) {	    if (i > 30) {		/* Free some memory for the BGI driver and auxilary. */		for (j = 1; j < 28; j++)	    	    free((char *) ScreenBuffer[i - j]);	    	MaximumScreenHeight = i - 28;	    	fprintf(stderr, "/n%s: Failed to allocate all memory required, last line %d./n",			PROGRAM_NAME, MaximumScreenHeight);	    	break;	    }	    else		GIF_EXIT("Failed to allocate memory required, aborted.");	}	memcpy(ScreenBuffer[i], ScreenBuffer[0], Size);    }    /* Scan the content of the GIF file and load the image(s) in: */    do {	if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR) {	    PrintGifError();	    break;	}	switch (RecordType) {	    case IMAGE_DESC_RECORD_TYPE:		if (DGifGetImageDesc(GifFile) == GIF_ERROR) {		    PrintGifError();		    exit(-1);		}		Row = GifFile -> ITop; /* Image Position relative to Screen. */		Col = GifFile -> ILeft;		Width = GifFile -> IWidth;		Height = GifFile -> IHeight;		GifQprintf("/n%s: Image %d at (%d, %d) [%dx%d]:     ",		    PROGRAM_NAME, ++ImageNum, Col, Row, Width, Height);		if (GifFile -> ILeft + GifFile -> IWidth > GifFile -> SWidth ||		   GifFile -> ITop + GifFile -> IHeight > GifFile -> SHeight) {		    fprintf(stderr, "Image %d is not confined to screen dimension, aborted./n");		    exit(-2);		}		if (GifFile -> IInterlace) {		    /* Need to perform 4 passes on the images: */		    for (Count = i = 0; i < 4; i++)			for (j = Row + InterlacedOffset[i]; j < Row + Height;						 j += InterlacedJumps[i]) {			    GifQprintf("/b/b/b/b%-4d", Count++);			    if (DGifGetLine(GifFile,				&ScreenBuffer[MIN(j, MaximumScreenHeight)][Col],				Width) == GIF_ERROR) {				PrintGifError();				exit(-1);			    }			}		}		else {		    for (i = 0; i < Height; i++, Row++) {			GifQprintf("/b/b/b/b%-4d", i);

/******************************************************************************* Perform the disassembly operation - take one input files into few output.   *******************************************************************************/static int DoDisassemblyNum(const char *InFileName, char *OutFileName, int FileNum){    int	ExtCode, CodeSize, FileEmpty;    GifRecordType RecordType;    char CrntFileName[80], *p;    GifByteType *Extension, *CodeBlock;    GifFileType *GifFileIn = NULL, *GifFileOut = NULL;	int ErrorCode;    /* If name has type postfix, strip it out, and make sure name is less    */    /* or equal to 6 chars, so we will have 2 chars in name for numbers.     */    //strupr(OutFileName);		      /* Make sure all is upper case */	#if 0	printf("OutFileName : %s/n", OutFileName);	if ((p = strrchr(OutFileName, '.')) != NULL && strlen(p) <= 4) p[0] = 0;    if ((p = strrchr(OutFileName, '/')) != NULL ||	(p = strrchr(OutFileName, '//')) != NULL ||	(p = strrchr(OutFileName, ':')) != NULL) {	if (strlen(p) > 7) p[7] = 0;   /* p includes the '/', '//', ':' char */    }    else {	/* Only name is given for current directory: */	//if (strlen(OutFileName) > 6) OutFileName[6] = 0;    }	printf("OutFileName : %s/n", OutFileName);	#endif    /* Open input file: */    if (InFileName != NULL) {	if ((GifFileIn = DGifOpenFileName(InFileName, &ErrorCode)) == NULL)	    return QuitGifError(GifFileIn, GifFileOut);    }    else {	/* Use the stdin instead: */	if ((GifFileIn = DGifOpenFileHandle(0, &ErrorCode)) == NULL)	    return QuitGifError(GifFileIn, GifFileOut);    }    /* Scan the content of GIF file and dump image(s) to seperate file(s): */	//sprintf(CrntFileName, "%s_%02d.gif", OutFileName, FileNum);	sprintf(CrntFileName, "%s", OutFileName);	if ((GifFileOut = EGifOpenFileName(CrntFileName, TRUE, &ErrorCode)) == NULL)	    return QuitGifError(GifFileIn, GifFileOut);	FileEmpty = TRUE;	/* And dump out its exactly same screen information: */	if (EGifPutScreenDesc(GifFileOut,	    GifFileIn->SWidth, GifFileIn->SHeight,	    GifFileIn->SColorResolution, GifFileIn->SBackGroundColor,	    GifFileIn->SColorMap) == GIF_ERROR)	    return QuitGifError(GifFileIn, GifFileOut);	do {	    if (DGifGetRecordType(GifFileIn, &RecordType) == GIF_ERROR)			return QuitGifError(GifFileIn, GifFileOut);	    switch (RecordType) {		case IMAGE_DESC_RECORD_TYPE:		    FileEmpty = FALSE;		    if (DGifGetImageDesc(GifFileIn) == GIF_ERROR)				return QuitGifError(GifFileIn, GifFileOut);		    /* Put same image descriptor to out file: */		    if (EGifPutImageDesc(GifFileOut,			GifFileIn->Image.Left, GifFileIn->Image.Top,			GifFileIn->Image.Width, GifFileIn->Image.Height,			GifFileIn->Image.Interlace,			GifFileIn->Image.ColorMap) == GIF_ERROR)				return 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) == GIF_ERROR		     || EGifPutCode(GifFileOut, CodeSize, CodeBlock) == GIF_ERROR)				return QuitGifError(GifFileIn, GifFileOut);		    while (CodeBlock != NULL)			if (DGifGetCodeNext(GifFileIn, &CodeBlock) == GIF_ERROR ||			    EGifPutCodeNext(GifFileOut, CodeBlock) == GIF_ERROR)				return QuitGifError(GifFileIn, GifFileOut);		    break;		case EXTENSION_RECORD_TYPE:		    FileEmpty = FALSE;		    /* Skip any extension blocks in file: */		    if (DGifGetExtension(GifFileIn, &ExtCode, &Extension)			== GIF_ERROR)				return QuitGifError(GifFileIn, GifFileOut);		    if (EGifPutExtension(GifFileOut, ExtCode, Extension[0],							Extension) == GIF_ERROR)				return QuitGifError(GifFileIn, GifFileOut);		    /* No support to more than one extension blocks, discard */		    while (Extension != NULL)			if (DGifGetExtensionNext(GifFileIn, &Extension)			    == GIF_ERROR)			    return QuitGifError(GifFileIn, GifFileOut);		    break;		case TERMINATE_RECORD_TYPE:		    break;//.........这里部分代码省略.........

CPLErr BIGGIFDataset::ReOpen(){/* -------------------------------------------------------------------- *//*      If the file is already open, close it so we can restart.        *//* -------------------------------------------------------------------- */    if( hGifFile != NULL )        GIFAbstractDataset::myDGifCloseFile( hGifFile );/* -------------------------------------------------------------------- *//*      If we are actually reopening, then we assume that access to     *//*      the image data is not strictly once through sequential, and     *//*      we will try to create a working database in a temporary         *//*      directory to hold the image as we read through it the second    *//*      time.                                                           *//* -------------------------------------------------------------------- */    if( hGifFile != NULL )    {        GDALDriver *poGTiffDriver = (GDALDriver*) GDALGetDriverByName("GTiff");        if( poGTiffDriver != NULL )        {            /* Create as a sparse file to avoid filling up the whole file */            /* while closing and then destroying this temporary dataset */            const char* apszOptions[] = { "COMPRESS=LZW", "SPARSE_OK=YES", NULL };            CPLString osTempFilename = CPLGenerateTempFilename("biggif");            osTempFilename += ".tif";            poWorkDS = poGTiffDriver->Create( osTempFilename,                                              nRasterXSize, nRasterYSize, 1,                                              GDT_Byte, const_cast<char**>(apszOptions));        }    }/* -------------------------------------------------------------------- *//*      Open                                                            *//* -------------------------------------------------------------------- */    VSIFSeekL( fp, 0, SEEK_SET );    nLastLineRead = -1;    hGifFile = GIFAbstractDataset::myDGifOpen( fp, GIFAbstractDataset::ReadFunc );    if( hGifFile == NULL )    {        CPLError( CE_Failure, CPLE_OpenFailed,                  "DGifOpen() failed.  Perhaps the gif file is corrupt?/n" );        return CE_Failure;    }/* -------------------------------------------------------------------- *//*      Find the first image record.                                    *//* -------------------------------------------------------------------- */    GifRecordType RecordType = FindFirstImage(hGifFile);    if( RecordType != IMAGE_DESC_RECORD_TYPE )    {        GIFAbstractDataset::myDGifCloseFile( hGifFile );        hGifFile = NULL;        CPLError( CE_Failure, CPLE_OpenFailed,                  "Failed to find image description record in GIF file." );        return CE_Failure;    }    if (DGifGetImageDesc(hGifFile) == GIF_ERROR)    {        GIFAbstractDataset::myDGifCloseFile( hGifFile );        hGifFile = NULL;        CPLError( CE_Failure, CPLE_OpenFailed,                  "Image description reading failed in GIF file." );        return CE_Failure;    }    return CE_None;}

bool CxImageGIF::Decode(CxFile *fp){	if (fp == NULL) return false;	GifFileType *GifFile = NULL;	GifRecordType RecordType;	GifByteType *Extension;	GifColorType *ColorMap;	int i, j, Count, Row, Col, Width, Height, ExtCode, ColorMapSize;	static int InterlacedOffset[] = { 0, 4, 2, 1 }, /* The way Interlaced image should. */	    InterlacedJumps[] = { 8, 8, 4, 2 };    /* be read - offsets and jumps... */	try	{		GifFile = DGifOpen(fp, readCxFile);		if (!Create(GifFile->SWidth,GifFile->SHeight,8,CXIMAGE_FORMAT_GIF))			throw "Can't allocate memory";		do		{			DGifGetRecordType(GifFile, &RecordType);			switch (RecordType)			{			case IMAGE_DESC_RECORD_TYPE:				DGifGetImageDesc(GifFile);				Row = GifFile->Image.Top; /* Image Position relative to Screen. */				Col = GifFile->Image.Left;				Width = GifFile->Image.Width;				Height = GifFile->Image.Height;				if (GifFile->Image.Left + GifFile->Image.Width > GifFile->SWidth ||					GifFile->Image.Top + GifFile->Image.Height > GifFile->SHeight)						throw "Image is not confined to screen dimension, aborted./n";				if (GifFile->Image.Interlace)				{					/* Need to perform 4 passes on the images: */					for (Count = i = 0; i < 4; i++)						for (j = Row + InterlacedOffset[i]; j < Row + Height; j += InterlacedJumps[i])								DGifGetLine(GifFile, GetBits(GifFile->SHeight - j - 1) + Col, Width);				}				else {					for (i = 0; i < Height; i++)						DGifGetLine(GifFile,GetBits(GifFile->SHeight - Row++ - 1) + Col,Width);			    }				break;			case EXTENSION_RECORD_TYPE:				/* Skip any extension blocks in file: */				DGifGetExtension(GifFile, &ExtCode, &Extension);				while (Extension != NULL)					DGifGetExtensionNext(GifFile, &Extension);				break;			default:				break;			}		}while (RecordType != TERMINATE_RECORD_TYPE);		ColorMap = (GifFile->Image.ColorMap ? GifFile->Image.ColorMap->Colors : GifFile->SColorMap->Colors);		ColorMapSize = GifFile->Image.ColorMap ? GifFile->Image.ColorMap->ColorCount : GifFile->SColorMap->ColorCount;		if(ColorMap && ColorMapSize)		{			RGBQUAD* ppal=GetPalette();			for (i=0; i < ColorMapSize; i++) {				ppal[i].rgbRed = ColorMap[i].Red;				ppal[i].rgbGreen = ColorMap[i].Green;				ppal[i].rgbBlue = ColorMap[i].Blue;			}			head.biClrUsed = ColorMapSize;			if(GifFile->SBackGroundColor)			{				info.nBkgndIndex = GifFile->SBackGroundColor;				info.nBkgndColor.rgbRed = ColorMap[info.nBkgndIndex].Red;				info.nBkgndColor.rgbGreen = ColorMap[info.nBkgndIndex].Green;				info.nBkgndColor.rgbBlue = ColorMap[info.nBkgndIndex].Blue;			}		}		DGifCloseFile(GifFile);		GifFile = NULL;	} catch (int errid) {		strncpy(info.szLastError,GifGetErrorMessage(errid),255);		if(GifFile != NULL) DGifCloseFile(GifFile);		return false;	} catch (char *message) {		strncpy(info.szLastError,message,255);		if(GifFile != NULL) DGifCloseFile(GifFile);		return false;	}	return true;}

/****************************************************************************** This routine reads an entire GIF into core, hanging all its state info off the GifFileType pointer.  Call DGifOpenFileName() or DGifOpenFileHandle() first to initialize I/O.  Its inverse is EGifSpew().*******************************************************************************/intDGifSlurp(GifFileType *GifFile){    size_t ImageSize;    GifRecordType RecordType;    SavedImage *sp;    GifByteType *ExtData;    int ExtFunction;    GifFile->ExtensionBlocks = NULL;    GifFile->ExtensionBlockCount = 0;    do {        if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR)            return (GIF_ERROR);        switch (RecordType) {          case IMAGE_DESC_RECORD_TYPE:              if (DGifGetImageDesc(GifFile) == GIF_ERROR)                  return (GIF_ERROR);              sp = &GifFile->SavedImages[GifFile->ImageCount - 1];              /* Allocate memory for the image */              if (sp->ImageDesc.Width < 0 && sp->ImageDesc.Height < 0 &&                      sp->ImageDesc.Width > (INT_MAX / sp->ImageDesc.Height)) {                  return GIF_ERROR;              }              ImageSize = sp->ImageDesc.Width * sp->ImageDesc.Height;              if (ImageSize > (SIZE_MAX / sizeof(GifPixelType))) {                  return GIF_ERROR;              }              sp->RasterBits = (unsigned char *)malloc(ImageSize *                      sizeof(GifPixelType));              if (sp->RasterBits == NULL) {                  return GIF_ERROR;              }	      if (sp->ImageDesc.Interlace) {		  int i, j;		   /*		    * The way an interlaced image should be read -		    * offsets and jumps...		    */		  int InterlacedOffset[] = { 0, 4, 2, 1 };		  int InterlacedJumps[] = { 8, 8, 4, 2 };		  /* Need to perform 4 passes on the image */		  for (i = 0; i < 4; i++)		      for (j = InterlacedOffset[i];			   j < sp->ImageDesc.Height;			   j += InterlacedJumps[i]) {			  if (DGifGetLine(GifFile,					  sp->RasterBits+j*sp->ImageDesc.Width,					  sp->ImageDesc.Width) == GIF_ERROR)			      return GIF_ERROR;		      }	      }	      else {		  if (DGifGetLine(GifFile,sp->RasterBits,ImageSize)==GIF_ERROR)		      return (GIF_ERROR);	      }              if (GifFile->ExtensionBlocks) {                  sp->ExtensionBlocks = GifFile->ExtensionBlocks;                  sp->ExtensionBlockCount = GifFile->ExtensionBlockCount;                  GifFile->ExtensionBlocks = NULL;                  GifFile->ExtensionBlockCount = 0;              }              break;          case EXTENSION_RECORD_TYPE:              if (DGifGetExtension(GifFile,&ExtFunction,&ExtData) == GIF_ERROR)                  return (GIF_ERROR);	      /* Create an extension block with our data */              if (ExtData != NULL) {		  if (GifAddExtensionBlock(&GifFile->ExtensionBlockCount,					   &GifFile->ExtensionBlocks,					   ExtFunction, ExtData[0], &ExtData[1])		      == GIF_ERROR)		      return (GIF_ERROR);	      }              while (ExtData != NULL) {                  if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR)                      return (GIF_ERROR);                  /* Continue the extension block */		  if (ExtData != NULL)		      if (GifAddExtensionBlock(&GifFile->ExtensionBlockCount,					       &GifFile->ExtensionBlocks,					       CONTINUE_EXT_FUNC_CODE,					       ExtData[0], &ExtData[1]) == GIF_ERROR)                      return (GIF_ERROR);              }              break;//.........这里部分代码省略.........

/******************************************************************************* Perform the assembly operation - take few input files into one output.      *******************************************************************************/static void DoAssembly(int NumFiles, char **FileNames){    int	i, ExtCode, CodeSize;    GifRecordType RecordType;    GifByteType *Extension, *CodeBlock;    GifFileType *GifFileIn = NULL, *GifFileOut = NULL;    /* Open stdout for the output file: */    if ((GifFileOut = EGifOpenFileHandle(1)) == NULL)	QuitGifError(GifFileIn, GifFileOut);    /* Scan the content of the GIF file and load the image(s) in: */    for (i = 0; i < NumFiles; i++) {	if ((GifFileIn = DGifOpenFileName(FileNames[i])) == NULL)	    QuitGifError(GifFileIn, GifFileOut);	/* And dump out screen descriptor iff its first image.	*/	if (i == 0)	    if (EGifPutScreenDesc(GifFileOut,		GifFileIn -> SWidth, GifFileIn -> SHeight,		GifFileIn -> SColorResolution, GifFileIn -> SBackGroundColor,		GifFileIn -> SBitsPerPixel, GifFileIn -> SColorMap) == GIF_ERROR)		QuitGifError(GifFileIn, GifFileOut);	do {	    if (DGifGetRecordType(GifFileIn, &RecordType) == GIF_ERROR)		QuitGifError(GifFileIn, GifFileOut);	    switch (RecordType) {		case IMAGE_DESC_RECORD_TYPE:		    if (DGifGetImageDesc(GifFileIn) == GIF_ERROR)			QuitGifError(GifFileIn, GifFileOut);		    /* Put image descriptor to out file: */		    if (EGifPutImageDesc(GifFileOut,			GifFileIn -> ILeft, GifFileIn -> ITop,			GifFileIn -> IWidth, GifFileIn -> IHeight,			GifFileIn -> IInterlace, GifFileIn -> IBitsPerPixel,			GifFileIn -> IColorMap) == GIF_ERROR)			QuitGifError(GifFileIn, GifFileOut);		    /* Now read image itself in decoded form as we dont      */		    /* dont care what is there, and this is much faster.     */		    if (DGifGetCode(GifFileIn, &CodeSize, &CodeBlock) == GIF_ERROR		     || EGifPutCode(GifFileOut, CodeSize, CodeBlock) == GIF_ERROR)			QuitGifError(GifFileIn, GifFileOut);		    while (CodeBlock != NULL)			if (DGifGetCodeNext(GifFileIn, &CodeBlock) == GIF_ERROR ||			    EGifPutCodeNext(GifFileOut, CodeBlock) == GIF_ERROR)			    QuitGifError(GifFileIn, GifFileOut);		    break;		case EXTENSION_RECORD_TYPE:		    /* Skip any extension blocks in file: */		    if (DGifGetExtension(GifFileIn, &ExtCode, &Extension)			== GIF_ERROR)			QuitGifError(GifFileIn, GifFileOut);		    if (EGifPutExtension(GifFileOut, ExtCode, Extension[0],						       Extension) == GIF_ERROR)			QuitGifError(GifFileIn, GifFileOut);		    /* No support to more than one extension blocks, discard.*/		    while (Extension != NULL)			if (DGifGetExtensionNext(GifFileIn, &Extension)			    == GIF_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) == GIF_ERROR)	    QuitGifError(GifFileIn, GifFileOut);    }    if (EGifCloseFile(GifFileOut) == GIF_ERROR)	QuitGifError(GifFileIn, GifFileOut);}