示例#1
0
/******************************************************************************
 This routine should be called before any other DGif calls. Note that
 this routine is called automatically from DGif file open routines.
******************************************************************************/
int
DGifGetScreenDesc(GifFileType *GifFile)
{
    int BitsPerPixel;
    bool SortFlag;
    GifByteType Buf[3];
    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;

    if (!IS_READABLE(Private)) {
        /* This file was NOT open for reading: */
        GifFile->Error = D_GIF_ERR_NOT_READABLE;
        return GIF_ERROR;
    }

    /* Put the screen descriptor into the file: */
    if (DGifGetWord(GifFile, &GifFile->SWidth) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->SHeight) == GIF_ERROR)
        return GIF_ERROR;

    if (READ(GifFile, Buf, 3) != 3) {
        GifFile->Error = D_GIF_ERR_READ_FAILED;
	GifFreeMapObject(GifFile->SColorMap);
	GifFile->SColorMap = NULL;
        return GIF_ERROR;
    }
    GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1;
    SortFlag = (Buf[0] & 0x08) != 0;
    BitsPerPixel = (Buf[0] & 0x07) + 1;
    GifFile->SBackGroundColor = Buf[1];
    GifFile->AspectByte = Buf[2]; 
    if (Buf[0] & 0x80) {    /* Do we have global color map? */
	int i;

        GifFile->SColorMap = GifMakeMapObject(1 << BitsPerPixel, NULL);
        if (GifFile->SColorMap == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }

        /* Get the global color map: */
	GifFile->SColorMap->SortFlag = SortFlag;
        for (i = 0; i < GifFile->SColorMap->ColorCount; i++) {
	    /* coverity[check_return] */
            if (READ(GifFile, Buf, 3) != 3) {
                GifFreeMapObject(GifFile->SColorMap);
                GifFile->SColorMap = NULL;
                GifFile->Error = D_GIF_ERR_READ_FAILED;
                return GIF_ERROR;
            }
            GifFile->SColorMap->Colors[i].Red = Buf[0];
            GifFile->SColorMap->Colors[i].Green = Buf[1];
            GifFile->SColorMap->Colors[i].Blue = Buf[2];
        }
    } else {
        GifFile->SColorMap = NULL;
    }

    return GIF_OK;
}
示例#2
0
static int DGifGetScreenDesc(GifFileType * GifFile)
{
	int i, BitsPerPixel;
	GifByteType Buf[3];
	GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;

	if (!IS_READABLE(Private))
	{
		_GifError = D_GIF_ERR_NOT_READABLE;
		return GIF_ERROR;
	}

	if (DGifGetWord(GifFile, &GifFile->SWidth) == GIF_ERROR || DGifGetWord(GifFile, &GifFile->SHeight) == GIF_ERROR)
		return GIF_ERROR;

	if (READ(GifFile, Buf, 3) != 3)
	{
		_GifError = D_GIF_ERR_READ_FAILED;
		return GIF_ERROR;
	}
	GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1;
	BitsPerPixel = (Buf[0] & 0x07) + 1;
	GifFile->SBackGroundColor = Buf[1];
	if (Buf[0] & 0x80)
	{

		GifFile->SColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
		if (GifFile->SColorMap == NULL)
		{
			_GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
			return GIF_ERROR;
		}

		for (i = 0; i < GifFile->SColorMap->ColorCount; i++)
		{
			if (READ(GifFile, Buf, 3) != 3)
			{
				FreeMapObject(GifFile->SColorMap);
				GifFile->SColorMap = NULL;
				_GifError = D_GIF_ERR_READ_FAILED;
				return GIF_ERROR;
			}
			GifFile->SColorMap->Colors[i].Red = Buf[0];
			GifFile->SColorMap->Colors[i].Green = Buf[1];
			GifFile->SColorMap->Colors[i].Blue = Buf[2];
		}
	}
	else
	{
		GifFile->SColorMap = NULL;
	}

	return GIF_OK;
}
示例#3
0
文件: gif.c 项目: scanlime/picogui
/******************************************************************************
*   This routine should be called before any attemp to read an image.         *
*   Note it is assumed the Image desc. header (',') has been read.	      *
******************************************************************************/
int DGifGetImageDesc(GifFileType *GifFile)
{
    int i, BitsPerPixel;
    GifByteType Buf[3];
    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;

    if (!IS_READABLE(Private)) {
	/* This file was NOT open for reading: */
	_GifError = D_GIF_ERR_NOT_READABLE;
	return GIF_ERROR;
    }

    if (DGifGetWord(Private, &GifFile->Image.Left) == GIF_ERROR ||
	DGifGetWord(Private, &GifFile->Image.Top) == GIF_ERROR ||
	DGifGetWord(Private, &GifFile->Image.Width) == GIF_ERROR ||
	DGifGetWord(Private, &GifFile->Image.Height) == GIF_ERROR)
	return GIF_ERROR;
    if (my_fread(Buf, 1, 1, Private) != 1) {
	_GifError = D_GIF_ERR_READ_FAILED;
	return GIF_ERROR;
    }
    BitsPerPixel = (Buf[0] & 0x07) + 1;
    GifFile->Image.Interlace = (Buf[0] & 0x40);
    if (Buf[0] & 0x80) {	    /* Does this image have local color map? */

	if (GifFile->Image.ColorMap)
	    FreeMapObject(GifFile->Image.ColorMap);

	GifFile->Image.ColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
    
	/* Get the image local color map: */
	for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++) {
	    if (my_fread(Buf, 1, 3, Private) != 3) {
		_GifError = D_GIF_ERR_READ_FAILED;
		return GIF_ERROR;
	    }
	    GifFile->Image.ColorMap->Colors[i].Red = Buf[0];
	    GifFile->Image.ColorMap->Colors[i].Green = Buf[1];
	    GifFile->Image.ColorMap->Colors[i].Blue = Buf[2];
	}
    }

    GifFile->ImageCount++;

    Private->PixelCount = (s32) GifFile->Image.Width *
			    (s32) GifFile->Image.Height;

    DGifSetupDecompress(GifFile);  /* Reset decompress algorithm parameters. */

    return GIF_OK;
}
示例#4
0
文件: ungif.c 项目: hoangduit/reactos
/******************************************************************************
 * This routine should be called before any other DGif calls. Note that
 * this routine is called automatically from DGif file open routines.
 *****************************************************************************/
static int
DGifGetScreenDesc(GifFileType * GifFile) {

    int i, BitsPerPixel, SortFlag;
    GifByteType Buf[3];

    /* Put the screen descriptor into the file: */
    if (DGifGetWord(GifFile, &GifFile->SWidth) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->SHeight) == GIF_ERROR)
        return GIF_ERROR;

    if (READ(GifFile, Buf, 3) != 3) {
        return GIF_ERROR;
    }
    GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1;
    SortFlag = (Buf[0] & 0x08) != 0;
    BitsPerPixel = (Buf[0] & 0x07) + 1;
    GifFile->SBackGroundColor = Buf[1];
    GifFile->SAspectRatio = Buf[2];
    if (Buf[0] & 0x80) {    /* Do we have global color map? */

        GifFile->SColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
        if (GifFile->SColorMap == NULL) {
            return GIF_ERROR;
        }

        /* Get the global color map: */
        GifFile->SColorMap->SortFlag = SortFlag;
        for (i = 0; i < GifFile->SColorMap->ColorCount; i++) {
            if (READ(GifFile, Buf, 3) != 3) {
                FreeMapObject(GifFile->SColorMap);
                GifFile->SColorMap = NULL;
                return GIF_ERROR;
            }
            GifFile->SColorMap->Colors[i].Red = Buf[0];
            GifFile->SColorMap->Colors[i].Green = Buf[1];
            GifFile->SColorMap->Colors[i].Blue = Buf[2];
        }
    } else {
        GifFile->SColorMap = NULL;
    }

    return GIF_OK;
}
示例#5
0
/******************************************************************************
*   This routine should be called before any other DGif calls. Note that      *
* this routine is called automatically from DGif file open routines.	      *
******************************************************************************/
int DGifGetScreenDesc(GifFileType *GifFile)
{
    int i, BitsPerPixel;
    GifByteType Buf[3];
    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;

    if (!IS_READABLE(Private)) {
	/* This file was NOT open for reading: */
	_GifError = D_GIF_ERR_NOT_READABLE;
	return GIF_ERROR;
    }

    /* Put the screen descriptor into the file: */
    if (DGifGetWord(GifFile, &GifFile->SWidth) == GIF_ERROR ||
	DGifGetWord(GifFile, &GifFile->SHeight) == GIF_ERROR)
	return GIF_ERROR;

    if (READ( GifFile, Buf, 3) != 3) {
	_GifError = D_GIF_ERR_READ_FAILED;
	return GIF_ERROR;
    }
    GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1;
    BitsPerPixel = (Buf[0] & 0x07) + 1;
    GifFile->SBackGroundColor = Buf[1];
    if (Buf[0] & 0x80) {		     /* Do we have global color map? */

	GifFile->SColorMap = MakeMapObject(1 << BitsPerPixel, NULL);

	/* Get the global color map: */
	for (i = 0; i < GifFile->SColorMap->ColorCount; i++) {
	    if (READ(GifFile, Buf, 3) != 3) {
		_GifError = D_GIF_ERR_READ_FAILED;
		return GIF_ERROR;
	    }
	    GifFile->SColorMap->Colors[i].Red = Buf[0];
	    GifFile->SColorMap->Colors[i].Green = Buf[1];
	    GifFile->SColorMap->Colors[i].Blue = Buf[2];
	}
    }

    return GIF_OK;
}
示例#6
0
static int DGifGetImageDesc(GifFileType * GifFile)
{
	int i, BitsPerPixel;
	GifByteType Buf[3];
	GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
	SavedImage *sp;

	if (!IS_READABLE(Private))
	{
		_GifError = D_GIF_ERR_NOT_READABLE;
		return GIF_ERROR;
	}

	if (DGifGetWord(GifFile, &GifFile->Image.Left) == GIF_ERROR || DGifGetWord(GifFile, &GifFile->Image.Top) == GIF_ERROR || DGifGetWord(GifFile, &GifFile->Image.Width) == GIF_ERROR
			|| DGifGetWord(GifFile, &GifFile->Image.Height) == GIF_ERROR)
		return GIF_ERROR;
	if (READ(GifFile, Buf, 1) != 1)
	{
		_GifError = D_GIF_ERR_READ_FAILED;
		return GIF_ERROR;
	}
	BitsPerPixel = (Buf[0] & 0x07) + 1;
	GifFile->Image.Interlace = (Buf[0] & 0x40);
	if (Buf[0] & 0x80)
	{
		if (GifFile->Image.ColorMap && GifFile->SavedImages == NULL)
			FreeMapObject(GifFile->Image.ColorMap);

		GifFile->Image.ColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
		if (GifFile->Image.ColorMap == NULL)
		{
			_GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
			return GIF_ERROR;
		}

		for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++)
		{
			if (READ(GifFile, Buf, 3) != 3)
			{
				FreeMapObject(GifFile->Image.ColorMap);
				_GifError = D_GIF_ERR_READ_FAILED;
				GifFile->Image.ColorMap = NULL;
				return GIF_ERROR;
			}
			GifFile->Image.ColorMap->Colors[i].Red = Buf[0];
			GifFile->Image.ColorMap->Colors[i].Green = Buf[1];
			GifFile->Image.ColorMap->Colors[i].Blue = Buf[2];
		}
	}
	else if (GifFile->Image.ColorMap)
	{
		FreeMapObject(GifFile->Image.ColorMap);
		GifFile->Image.ColorMap = NULL;
	}

	if (GifFile->SavedImages)
	{
		if ((GifFile->SavedImages = (SavedImage *) realloc(GifFile->SavedImages, sizeof(SavedImage) * (GifFile->ImageCount + 1))) == NULL)
		{
			_GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
			return GIF_ERROR;
		}
	}
	else
	{
		if ((GifFile->SavedImages = (SavedImage *) gif_malloc(sizeof(SavedImage))) == NULL)
		{
			_GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
			return GIF_ERROR;
		}
	}

	sp = &GifFile->SavedImages[GifFile->ImageCount];
	memcpy(&sp->ImageDesc, &GifFile->Image, sizeof(GifImageDesc));
	if (GifFile->Image.ColorMap != NULL)
	{
		sp->ImageDesc.ColorMap = MakeMapObject(GifFile->Image.ColorMap->ColorCount, GifFile->Image.ColorMap->Colors);
		if (sp->ImageDesc.ColorMap == NULL)
		{
			_GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
			return GIF_ERROR;
		}
	}
	sp->RasterBits = (unsigned char *) NULL;
	sp->ExtensionBlockCount = 0;
	sp->ExtensionBlocks = (ExtensionBlock *) NULL;

	GifFile->ImageCount++;

	Private->PixelCount = (long) GifFile->Image.Width * (long) GifFile->Image.Height;

	DGifSetupDecompress(GifFile);

	return GIF_OK;
}
示例#7
0
文件: dgif_lib.c 项目: 9miao/CrossApp
/******************************************************************************
 This routine should be called before any attempt to read an image.
 Note it is assumed the Image desc. header has been read.
******************************************************************************/
int
DGifGetImageDesc(GifFileType *GifFile)
{
    unsigned int BitsPerPixel;
    GifByteType Buf[3];
    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
    SavedImage *sp;

    if (!IS_READABLE(Private)) {
        /* This file was NOT open for reading: */
        GifFile->Error = D_GIF_ERR_NOT_READABLE;
        return GIF_ERROR;
    }

    if (DGifGetWord(GifFile, &GifFile->Image.Left) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Top) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Width) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Height) == GIF_ERROR)
        return GIF_ERROR;
    if (READ(GifFile, Buf, 1) != 1) {
        GifFile->Error = D_GIF_ERR_READ_FAILED;
	GifFreeMapObject(GifFile->Image.ColorMap);
	GifFile->Image.ColorMap = NULL;
        return GIF_ERROR;
    }
    BitsPerPixel = (Buf[0] & 0x07) + 1;
    GifFile->Image.Interlace = (Buf[0] & 0x40) ? giftrue : giffalse;

    /* Setup the colormap */
    if (GifFile->Image.ColorMap) {
        GifFreeMapObject(GifFile->Image.ColorMap);
        GifFile->Image.ColorMap = NULL;
    }
    /* Does this image have local color map? */
    if (Buf[0] & 0x80) {
	unsigned int i;

        GifFile->Image.ColorMap = GifMakeMapObject(1 << BitsPerPixel, NULL);
        if (GifFile->Image.ColorMap == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }

        /* Get the image local color map: */
        for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++) {
            if (READ(GifFile, Buf, 3) != 3) {
                GifFreeMapObject(GifFile->Image.ColorMap);
                GifFile->Error = D_GIF_ERR_READ_FAILED;
                GifFile->Image.ColorMap = NULL;
                return GIF_ERROR;
            }
            GifFile->Image.ColorMap->Colors[i].Red = Buf[0];
            GifFile->Image.ColorMap->Colors[i].Green = Buf[1];
            GifFile->Image.ColorMap->Colors[i].Blue = Buf[2];
        }
    }

    if (GifFile->SavedImages) {
        if ((GifFile->SavedImages = (SavedImage *)realloc(GifFile->SavedImages,
                                      sizeof(SavedImage) *
                                      (GifFile->ImageCount + 1))) == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }
    } else {
        if ((GifFile->SavedImages =
             (SavedImage *) malloc(sizeof(SavedImage))) == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }
    }

    sp = &GifFile->SavedImages[GifFile->ImageCount];
    memcpy(&sp->ImageDesc, &GifFile->Image, sizeof(GifImageDesc));
    if (GifFile->Image.ColorMap != NULL) {
        sp->ImageDesc.ColorMap = GifMakeMapObject(
                                 GifFile->Image.ColorMap->ColorCount,
                                 GifFile->Image.ColorMap->Colors);
        if (sp->ImageDesc.ColorMap == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }
    }
    sp->RasterBits = (unsigned char *)NULL;
    sp->ExtensionBlockCount = 0;
    sp->ExtensionBlocks = (ExtensionBlock *) NULL;

    GifFile->ImageCount++;

    Private->PixelCount = (long)GifFile->Image.Width *
       (long)GifFile->Image.Height;

    /* Reset decompress algorithm parameters. */
    (void)DGifSetupDecompress(GifFile);

    return GIF_OK;
}
示例#8
0
文件: ungif.c 项目: hoangduit/reactos
/******************************************************************************
 * This routine should be called before any attempt to read an image.
 * Note it is assumed the Image desc. header (',') has been read.
 *****************************************************************************/
static int
DGifGetImageDesc(GifFileType * GifFile) {

    int i, BitsPerPixel, SortFlag;
    GifByteType Buf[3];
    GifFilePrivateType *Private = GifFile->Private;
    SavedImage *sp;

    if (DGifGetWord(GifFile, &GifFile->Image.Left) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Top) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Width) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Height) == GIF_ERROR)
        return GIF_ERROR;
    if (READ(GifFile, Buf, 1) != 1) {
        return GIF_ERROR;
    }
    BitsPerPixel = (Buf[0] & 0x07) + 1;
    SortFlag = (Buf[0] & 0x20) != 0;
    GifFile->Image.Interlace = (Buf[0] & 0x40);
    if (Buf[0] & 0x80) {    /* Does this image have local color map? */

        FreeMapObject(GifFile->Image.ColorMap);

        GifFile->Image.ColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
        if (GifFile->Image.ColorMap == NULL) {
            return GIF_ERROR;
        }

        /* Get the image local color map: */
        GifFile->Image.ColorMap->SortFlag = SortFlag;
        for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++) {
            if (READ(GifFile, Buf, 3) != 3) {
                FreeMapObject(GifFile->Image.ColorMap);
                GifFile->Image.ColorMap = NULL;
                return GIF_ERROR;
            }
            GifFile->Image.ColorMap->Colors[i].Red = Buf[0];
            GifFile->Image.ColorMap->Colors[i].Green = Buf[1];
            GifFile->Image.ColorMap->Colors[i].Blue = Buf[2];
        }
    } else if (GifFile->Image.ColorMap) {
        FreeMapObject(GifFile->Image.ColorMap);
        GifFile->Image.ColorMap = NULL;
    }

    if (GifFile->SavedImages) {
        if ((GifFile->SavedImages = ungif_realloc(GifFile->SavedImages,
                                      sizeof(SavedImage) *
                                      (GifFile->ImageCount + 1))) == NULL) {
            return GIF_ERROR;
        }
    } else {
        if ((GifFile->SavedImages = ungif_alloc(sizeof(SavedImage))) == NULL) {
            return GIF_ERROR;
        }
    }

    sp = &GifFile->SavedImages[GifFile->ImageCount];
    sp->ImageDesc = GifFile->Image;
    if (GifFile->Image.ColorMap != NULL) {
        sp->ImageDesc.ColorMap = MakeMapObject(
                                 GifFile->Image.ColorMap->ColorCount,
                                 GifFile->Image.ColorMap->Colors);
        if (sp->ImageDesc.ColorMap == NULL) {
            return GIF_ERROR;
        }
        sp->ImageDesc.ColorMap->SortFlag = GifFile->Image.ColorMap->SortFlag;
    }
    sp->RasterBits = NULL;
    sp->Extensions.ExtensionBlockCount = 0;
    sp->Extensions.ExtensionBlocks = NULL;

    GifFile->ImageCount++;

    Private->PixelCount = (long)GifFile->Image.Width *
       (long)GifFile->Image.Height;

    DGifSetupDecompress(GifFile);  /* Reset decompress algorithm parameters. */

    return GIF_OK;
}
示例#9
0
 //读取单个帧的图片信息(图片的上下左右坐标,帧的局部颜色空间等)
int
DGifGetImageDesc(GifFileType *GifFile)
{
    unsigned int BitsPerPixel;
    GifByteType Buf[3];
    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
    SavedImage *sp;

    if (!IS_READABLE(Private)) {
        /* This file was NOT open for reading: */
        GifFile->Error = D_GIF_ERR_NOT_READABLE;
        return GIF_ERROR;
    }

    //读取当前帧的上下左右坐标
    if (DGifGetWord(GifFile, &GifFile->Image.Left) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Top) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Width) == GIF_ERROR ||
        DGifGetWord(GifFile, &GifFile->Image.Height) == GIF_ERROR)
        return GIF_ERROR;

    //读取长度1字节的信息(即当前帧的Packed Field)
    if (READ(GifFile, Buf, 1) != 1) {
        GifFile->Error = D_GIF_ERR_READ_FAILED;
	GifFreeMapObject(GifFile->Image.ColorMap);
	GifFile->Image.ColorMap = NULL;
        return GIF_ERROR;
    }

    //局部颜色空间的大小
    BitsPerPixel = (Buf[0] & 0x07) + 1;

    //判断当前帧是否交错模式
    GifFile->Image.Interlace = (Buf[0] & 0x40) ? true : false;

    /* Setup the colormap */
    if (GifFile->Image.ColorMap) {
        GifFreeMapObject(GifFile->Image.ColorMap);
        GifFile->Image.ColorMap = NULL;
    }

    //判断当前帧是否使用局部的颜色空间
    if (Buf[0] & 0x80) {
	unsigned int i;

        GifFile->Image.ColorMap = GifMakeMapObject(1 << BitsPerPixel, NULL);
        if (GifFile->Image.ColorMap == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }

        //获取局部颜色空间 并储存到临时的帧描述内
        for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++) {
	    /* coverity[check_return] */
            if (READ(GifFile, Buf, 3) != 3) {
                GifFreeMapObject(GifFile->Image.ColorMap);
                GifFile->Error = D_GIF_ERR_READ_FAILED;
                GifFile->Image.ColorMap = NULL;
                return GIF_ERROR;
            }
            GifFile->Image.ColorMap->Colors[i].Red = Buf[0];
            GifFile->Image.ColorMap->Colors[i].Green = Buf[1];
            GifFile->Image.ColorMap->Colors[i].Blue = Buf[2];
        }
    }

    //判断之前是否已经有储存帧图像
    if (GifFile->SavedImages) {
        //如果有已经储存的帧图像 需要重新分配空间
        SavedImage* new_saved_images =
            (SavedImage *)realloc(GifFile->SavedImages,
                            sizeof(SavedImage) * (GifFile->ImageCount + 1));
        if (new_saved_images == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }
        GifFile->SavedImages = new_saved_images;
    } else {
        if ((GifFile->SavedImages =
             (SavedImage *) malloc(sizeof(SavedImage))) == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }
    }

    //指向新的SavedImage
    sp = &GifFile->SavedImages[GifFile->ImageCount];
    //写入之前获取的帧图像描述
    memcpy(&sp->ImageDesc, &GifFile->Image, sizeof(GifImageDesc));
    //写入局部颜色空间
    if (GifFile->Image.ColorMap != NULL) {
        sp->ImageDesc.ColorMap = GifMakeMapObject(
                                 GifFile->Image.ColorMap->ColorCount,
                                 GifFile->Image.ColorMap->Colors);
        if (sp->ImageDesc.ColorMap == NULL) {
            GifFile->Error = D_GIF_ERR_NOT_ENOUGH_MEM;
            return GIF_ERROR;
        }
    }
    sp->RasterBits = (unsigned char *)NULL;
    sp->ExtensionBlockCount = 0;
    sp->ExtensionBlocks = (ExtensionBlock *) NULL;

    GifFile->ImageCount++;

    Private->PixelCount = (long)GifFile->Image.Width *
       (long)GifFile->Image.Height;

    /* Reset decompress algorithm parameters. */
    //DGifSetupDecompress
    return DGifSetupDecompress(GifFile);
}