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.........

int
DGifSlurp(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().
 ******************************************************************************/
int
DGifSlurp(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.........