ungif.c File Reference

#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include "windef.h"
#include "winbase.h"
#include "ungif.h"
#include "wine/debug.h"

Include dependency graph for ungif.c:

Go to the source code of this file.

Classes
struct	GifFilePrivateType

Macros
#define	LZ_MAX_CODE   4095 /* Biggest code possible in 12 bits. */
#define	LZ_BITS   12
#define	NO_SUCH_CODE   4098 /* Impossible code, to signal empty. */
#define	READ(_gif, _buf, _len)    ((GifFilePrivateType*)_gif->Private)->Read(_gif,_buf,_len)

Typedefs
typedef struct GifFilePrivateType	GifFilePrivateType

Functions
	WINE_DEFAULT_DEBUG_CHANNEL (wincodecs)
static int	DGifGetWord (GifFileType *GifFile, GifWord *Word)
static int	DGifSetupDecompress (GifFileType *GifFile)
static int	DGifDecompressLine (GifFileType *GifFile, GifPixelType *Line, int LineLen)
static int	DGifGetPrefixChar (const GifPrefixType *Prefix, int Code, int ClearCode)
static int	DGifDecompressInput (GifFileType *GifFile, int *Code)
static int	DGifBufferedInput (GifFileType *GifFile, GifByteType *Buf, GifByteType *NextByte)
static int	DGifGetExtensionNext (GifFileType *GifFile, GifByteType **GifExtension)
static int	DGifGetCodeNext (GifFileType *GifFile, GifByteType **GifCodeBlock)
static int	BitSize (int n)
static ColorMapObject *	MakeMapObject (int ColorCount, const GifColorType *ColorMap)
static void	FreeMapObject (ColorMapObject *Object)
static int	AddExtensionBlock (Extensions *New, int Len, const unsigned char ExtData[])
static int	AppendExtensionBlock (Extensions *New, int Len, const unsigned char ExtData[])
static void	FreeExtension (Extensions *Extensions)
static void	FreeSavedImages (GifFileType *GifFile)
static int	DGifGetScreenDesc (GifFileType *GifFile)
static int	DGifGetRecordType (GifFileType *GifFile, GifRecordType *Type)
static int	DGifGetImageDesc (GifFileType *GifFile)
static int	DGifGetLine (GifFileType *GifFile, GifPixelType *Line, int LineLen)
static int	DGifGetExtension (GifFileType *GifFile, int *ExtCode, GifByteType **Extension)
int	DGifSlurp (GifFileType *GifFile)
GifFileType *	DGifOpen (void *userData, InputFunc readFunc)
int	DGifCloseFile (GifFileType *GifFile)

Macro Definition Documentation

LZ_BITS

#define LZ_BITS   12

Definition at line 62 of file ungif.c.

LZ_MAX_CODE

#define LZ_MAX_CODE   4095 /* Biggest code possible in 12 bits. */

Definition at line 61 of file ungif.c.

NO_SUCH_CODE

#define NO_SUCH_CODE   4098 /* Impossible code, to signal empty. */

Definition at line 64 of file ungif.c.

READ

#define READ	(		_gif,
			_buf,
			_len
	)		((GifFilePrivateType*)_gif->Private)->Read(_gif,_buf,_len)

Definition at line 87 of file ungif.c.

Typedef Documentation

GifFilePrivateType

typedef struct GifFilePrivateType GifFilePrivateType

Function Documentation

AddExtensionBlock()

static int AddExtensionBlock ( Extensions *  New, int  Len, const unsigned char  ExtData[]  )

static

Definition at line 177 of file ungif.c.

                                                 {
 
    ExtensionBlock *ep;
 
    New->ExtensionBlocks = realloc(New->ExtensionBlocks,
                                   sizeof(ExtensionBlock) *
                                   (New->ExtensionBlockCount + 1));
 
    if (New->ExtensionBlocks == NULL)
        return (GIF_ERROR);
 
    ep = &New->ExtensionBlocks[New->ExtensionBlockCount++];
 
    ep->ByteCount=Len + 3;
    ep->Bytes = malloc(ep->ByteCount + 3);
    if (ep->Bytes == NULL)
        return (GIF_ERROR);
 
    /* Extension Header */
    ep->Bytes[0] = 0x21;
    ep->Bytes[1] = New->Function;
    ep->Bytes[2] = Len;
 
    if (ExtData) {
        memcpy(ep->Bytes + 3, ExtData, Len);
        ep->Function = New->Function;
    }
 
    return (GIF_OK);
}

Referenced by DGifSlurp().

AppendExtensionBlock()

static int AppendExtensionBlock ( Extensions *  New, int  Len, const unsigned char  ExtData[]  )

static

Definition at line 211 of file ungif.c.

{
    ExtensionBlock *ep;
 
    if (New->ExtensionBlocks == NULL)
        return (GIF_ERROR);
 
    ep = &New->ExtensionBlocks[New->ExtensionBlockCount - 1];
 
    ep->Bytes = realloc(ep->Bytes, ep->ByteCount + Len + 1);
    if (ep->Bytes == NULL)
        return (GIF_ERROR);
 
    ep->Bytes[ep->ByteCount] = Len;
 
    if (ExtData)
        memcpy(ep->Bytes + ep->ByteCount + 1, ExtData, Len);
 
    ep->ByteCount += Len + 1;
 
    return (GIF_OK);
}

Referenced by DGifSlurp().

BitSize()

static int BitSize ( int  n )

static

Definition at line 107 of file ungif.c.

               {
 
    register int i;
 
    for (i = 1; i <= 8; i++)
        if ((1 << i) >= n)
            break;
    return (i);
}

Referenced by MakeMapObject().

DGifBufferedInput()

static int DGifBufferedInput ( GifFileType *  GifFile, GifByteType *  Buf, GifByteType *  NextByte  )

static

Definition at line 811 of file ungif.c.

                                          {
 
    if (Buf[0] == 0) {
        /* Needs to read the next buffer - this one is empty: */
        if (READ(GifFile, Buf, 1) != 1) {
            return GIF_ERROR;
        }
        /* There shouldn't be any empty data blocks here as the LZW spec
         * says the LZW termination code should come first.  Therefore we
         * shouldn't be inside this routine at that point.
         */
        if (Buf[0] == 0) {
            return GIF_ERROR;
        }
        if (READ(GifFile, &Buf[1], Buf[0]) != Buf[0]) {
            return GIF_ERROR;
        }
        *NextByte = Buf[1];
        Buf[1] = 2;    /* We use now the second place as last char read! */
        Buf[0]--;
    } else {
        *NextByte = Buf[Buf[1]++];
        Buf[0]--;
    }
 
    return GIF_OK;
}

Referenced by DGifDecompressInput().

DGifCloseFile()

int DGifCloseFile

(

GifFileType *

GifFile

)

Definition at line 1018 of file ungif.c.

                                     {
 
    GifFilePrivateType *Private;
 
    if (GifFile == NULL)
        return GIF_ERROR;
 
    Private = GifFile->Private;
 
    if (GifFile->Image.ColorMap) {
        FreeMapObject(GifFile->Image.ColorMap);
        GifFile->Image.ColorMap = NULL;
    }
 
    if (GifFile->SColorMap) {
        FreeMapObject(GifFile->SColorMap);
        GifFile->SColorMap = NULL;
    }
 
    free(Private);
    Private = NULL;
 
    if (GifFile->SavedImages) {
        FreeSavedImages(GifFile);
        GifFile->SavedImages = NULL;
    }
 
    FreeExtension(&GifFile->Extensions);
 
    free(GifFile);
 
    return GIF_OK;
}

Referenced by GifDecoder_Release().

DGifDecompressInput()

static int DGifDecompressInput ( GifFileType *  GifFile, int *  Code  )

static

Definition at line 759 of file ungif.c.

                               {
 
    GifFilePrivateType *Private = GifFile->Private;
 
    GifByteType NextByte;
    static const unsigned short CodeMasks[] = {
        0x0000, 0x0001, 0x0003, 0x0007,
        0x000f, 0x001f, 0x003f, 0x007f,
        0x00ff, 0x01ff, 0x03ff, 0x07ff,
        0x0fff
    };
    /* The image can't contain more than LZ_BITS per code. */
    if (Private->RunningBits > LZ_BITS) {
        return GIF_ERROR;
    }
 
    while (Private->CrntShiftState < Private->RunningBits) {
        /* Needs to get more bytes from input stream for next code: */
        if (DGifBufferedInput(GifFile, Private->Buf, &NextByte) == GIF_ERROR) {
            return GIF_ERROR;
        }
        Private->CrntShiftDWord |=
           ((unsigned long)NextByte) << Private->CrntShiftState;
        Private->CrntShiftState += 8;
    }
    *Code = Private->CrntShiftDWord & CodeMasks[Private->RunningBits];
 
    Private->CrntShiftDWord >>= Private->RunningBits;
    Private->CrntShiftState -= Private->RunningBits;
 
    /* If code cannot fit into RunningBits bits, must raise its size. Note
     * however that codes above 4095 are used for special signaling.
     * If we're using LZ_BITS bits already and we're at the max code, just
     * keep using the table as it is, don't increment Private->RunningCode.
     */
    if (Private->RunningCode < LZ_MAX_CODE + 2 &&
            ++Private->RunningCode > Private->MaxCode1 &&
            Private->RunningBits < LZ_BITS) {
        Private->MaxCode1 <<= 1;
        Private->RunningBits++;
    }
    return GIF_OK;
}

Referenced by DGifDecompressLine().

DGifDecompressLine()

static int DGifDecompressLine ( GifFileType *  GifFile, GifPixelType *  Line, int  LineLen  )

static

Definition at line 615 of file ungif.c.

                                {
 
    int i = 0;
    int j, CrntCode, EOFCode, ClearCode, CrntPrefix, LastCode, StackPtr;
    GifByteType *Stack, *Suffix;
    GifPrefixType *Prefix;
    GifFilePrivateType *Private = GifFile->Private;
 
    StackPtr = Private->StackPtr;
    Prefix = Private->Prefix;
    Suffix = Private->Suffix;
    Stack = Private->Stack;
    EOFCode = Private->EOFCode;
    ClearCode = Private->ClearCode;
    LastCode = Private->LastCode;
 
    if (StackPtr != 0) {
        /* Let pop the stack off before continuing to read the gif file: */
        while (StackPtr != 0 && i < LineLen)
            Line[i++] = Stack[--StackPtr];
    }
 
    while (i < LineLen) {    /* Decode LineLen items. */
        if (DGifDecompressInput(GifFile, &CrntCode) == GIF_ERROR)
            return GIF_ERROR;
 
        if (CrntCode == EOFCode) {
            /* Note, however, that usually we will not be here as we will stop
             * decoding as soon as we got all the pixel, or EOF code will
             * not be read at all, and DGifGetLine/Pixel clean everything.  */
            if (i != LineLen - 1 || Private->PixelCount != 0) {
                return GIF_ERROR;
            }
            i++;
        } else if (CrntCode == ClearCode) {
            /* We need to start over again: */
            for (j = 0; j <= LZ_MAX_CODE; j++)
                Prefix[j] = NO_SUCH_CODE;
            Private->RunningCode = Private->EOFCode + 1;
            Private->RunningBits = Private->BitsPerPixel + 1;
            Private->MaxCode1 = 1 << Private->RunningBits;
            LastCode = Private->LastCode = NO_SUCH_CODE;
        } else {
            /* It's a regular code - if in pixel range simply add it to output
             * stream, otherwise trace to codes linked list until the prefix
             * is in pixel range: */
            if (CrntCode < ClearCode) {
                /* This is simple - its pixel scalar, so add it to output: */
                Line[i++] = CrntCode;
            } else {
                /* It's a code to be traced: trace the linked list
                 * until the prefix is a pixel, while pushing the suffix
                 * pixels on our stack. If we done, pop the stack in reverse
                 * order (that's what stack is good for!) for output.  */
                if (Prefix[CrntCode] == NO_SUCH_CODE) {
                    /* Only allowed if CrntCode is exactly the running code:
                     * In that case CrntCode = XXXCode, CrntCode or the
                     * prefix code is last code and the suffix char is
                     * exactly the prefix of last code! */
                    if (CrntCode == Private->RunningCode - 2) {
                        CrntPrefix = LastCode;
                        Suffix[Private->RunningCode - 2] =
                           Stack[StackPtr++] = DGifGetPrefixChar(Prefix,
                                                                 LastCode,
                                                                 ClearCode);
                    } else {
                        return GIF_ERROR;
                    }
                } else
                    CrntPrefix = CrntCode;
 
                /* Now (if image is O.K.) we should not get a NO_SUCH_CODE
                 * during the trace. As we might loop forever, in case of
                 * defective image, we count the number of loops we trace
                 * and stop if we got LZ_MAX_CODE. Obviously we cannot
                 * loop more than that.  */
                j = 0;
                while (j++ <= LZ_MAX_CODE &&
                       CrntPrefix > ClearCode && CrntPrefix <= LZ_MAX_CODE) {
                    Stack[StackPtr++] = Suffix[CrntPrefix];
                    CrntPrefix = Prefix[CrntPrefix];
                }
                if (j >= LZ_MAX_CODE || CrntPrefix > LZ_MAX_CODE) {
                    return GIF_ERROR;
                }
                /* Push the last character on stack: */
                Stack[StackPtr++] = CrntPrefix;
 
                /* Now lets pop all the stack into output: */
                while (StackPtr != 0 && i < LineLen)
                    Line[i++] = Stack[--StackPtr];
            }
            if (LastCode != NO_SUCH_CODE) {
                Prefix[Private->RunningCode - 2] = LastCode;
 
                if (CrntCode == Private->RunningCode - 2) {
                    /* Only allowed if CrntCode is exactly the running code:
                     * In that case CrntCode = XXXCode, CrntCode or the
                     * prefix code is last code and the suffix char is
                     * exactly the prefix of last code! */
                    Suffix[Private->RunningCode - 2] =
                       DGifGetPrefixChar(Prefix, LastCode, ClearCode);
                } else {
                    Suffix[Private->RunningCode - 2] =
                       DGifGetPrefixChar(Prefix, CrntCode, ClearCode);
                }
            }
            LastCode = CrntCode;
        }
    }
 
    Private->LastCode = LastCode;
    Private->StackPtr = StackPtr;
 
    return GIF_OK;
}

Referenced by DGifGetLine().

DGifGetCodeNext()

static int DGifGetCodeNext ( GifFileType *  GifFile, GifByteType **  GifCodeBlock  )

static

Definition at line 550 of file ungif.c.

                                          {
 
    GifByteType Buf;
    GifFilePrivateType *Private = GifFile->Private;
 
    if (READ(GifFile, &Buf, 1) != 1) {
        return GIF_ERROR;
    }
 
    if (Buf > 0) {
        *CodeBlock = Private->Buf;    /* Use private unused buffer. */
        (*CodeBlock)[0] = Buf;  /* Pascal strings notation (pos. 0 is len.). */
        if (READ(GifFile, &((*CodeBlock)[1]), Buf) != Buf) {
            return GIF_ERROR;
        }
    } else {
        *CodeBlock = NULL;
        Private->Buf[0] = 0;    /* Make sure the buffer is empty! */
        Private->PixelCount = 0;    /* And local info. indicate image read. */
    }
 
    return GIF_OK;
}

Referenced by DGifGetLine().

DGifGetExtension()

static int DGifGetExtension ( GifFileType *  GifFile, int *  ExtCode, GifByteType **  Extension  )

static

Definition at line 486 of file ungif.c.

                                           {
 
    GifByteType Buf;
 
    if (READ(GifFile, &Buf, 1) != 1) {
        return GIF_ERROR;
    }
    *ExtCode = Buf;
 
    return DGifGetExtensionNext(GifFile, Extension);
}

Referenced by DGifSlurp().

DGifGetExtensionNext()

static int DGifGetExtensionNext ( GifFileType *  GifFile, GifByteType **  GifExtension  )

static

Definition at line 506 of file ungif.c.

                                               {
 
    GifByteType Buf;
    GifFilePrivateType *Private = GifFile->Private;
 
    if (READ(GifFile, &Buf, 1) != 1) {
        return GIF_ERROR;
    }
    if (Buf > 0) {
        *Extension = Private->Buf;    /* Use private unused buffer. */
        (*Extension)[0] = Buf;  /* Pascal strings notation (pos. 0 is len.). */
        if (READ(GifFile, &((*Extension)[1]), Buf) != Buf) {
            return GIF_ERROR;
        }
    } else
        *Extension = NULL;
 
    return GIF_OK;
}

Referenced by DGifGetExtension(), and DGifSlurp().

DGifGetImageDesc()

static int DGifGetImageDesc ( GifFileType *  GifFile )

static

Definition at line 368 of file ungif.c.

                                        {
 
    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 = realloc(GifFile->SavedImages,
                                        sizeof(SavedImage) *
                                        (GifFile->ImageCount + 1))) == 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 = GifFile->Image.Width * GifFile->Image.Height;
 
    DGifSetupDecompress(GifFile);  /* Reset decompress algorithm parameters. */
 
    return GIF_OK;
}

Referenced by DGifSlurp().

DGifGetLine()

static int DGifGetLine ( GifFileType *  GifFile, GifPixelType *  Line, int  LineLen  )

static

Definition at line 446 of file ungif.c.

                         {
 
    GifByteType *Dummy;
    GifFilePrivateType *Private = GifFile->Private;
 
    if (!LineLen)
        LineLen = GifFile->Image.Width;
 
    if ((Private->PixelCount -= LineLen) > 0xffff0000UL) {
        return GIF_ERROR;
    }
 
    if (DGifDecompressLine(GifFile, Line, LineLen) == GIF_OK) {
        if (Private->PixelCount == 0) {
            /* We probably would not be called any more, so lets clean
             * everything before we return: need to flush out all rest of
             * image until empty block (size 0) detected. We use GetCodeNext. */
            do
                if (DGifGetCodeNext(GifFile, &Dummy) == GIF_ERROR)
                {
                    WARN("GIF is not properly terminated\n");
                    break;
                }
            while (Dummy != NULL) ;
        }
        return GIF_OK;
    } else
        return GIF_ERROR;
}

Referenced by DGifSlurp().

DGifGetPrefixChar()

static int DGifGetPrefixChar ( const GifPrefixType *  Prefix, int  Code, int  ClearCode  )

static

Definition at line 741 of file ungif.c.

                                 {
 
    int i = 0;
 
    while (Code > ClearCode && i++ <= LZ_MAX_CODE)
        Code = Prefix[Code];
    return Code;
}

Referenced by DGifDecompressLine().

DGifGetRecordType()

static int DGifGetRecordType ( GifFileType *  GifFile, GifRecordType *  Type  )

static

Definition at line 333 of file ungif.c.

                                        {
 
    GifByteType Buf;
 
    if (READ(GifFile, &Buf, 1) != 1) {
        /* Wine-specific behavior: Native accepts broken GIF files that have no
         * terminator, so we match this by treating EOF as a terminator. */
        *Type = TERMINATE_RECORD_TYPE;
        return GIF_OK;
    }
 
    switch (Buf) {
      case ',':
          *Type = IMAGE_DESC_RECORD_TYPE;
          break;
      case '!':
          *Type = EXTENSION_RECORD_TYPE;
          break;
      case ';':
          *Type = TERMINATE_RECORD_TYPE;
          break;
      default:
          *Type = UNDEFINED_RECORD_TYPE;
          return GIF_ERROR;
    }
 
    return GIF_OK;
}

Referenced by DGifSlurp().

DGifGetScreenDesc()

static int DGifGetScreenDesc ( GifFileType *  GifFile )

static

Definition at line 284 of file ungif.c.

                                         {
 
    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->SColorTableSize = 1 << BitsPerPixel;
    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;
}

Referenced by DGifOpen().

DGifGetWord()

static int DGifGetWord ( GifFileType *  GifFile, GifWord *  Word  )

static

Definition at line 531 of file ungif.c.

                           {
 
    unsigned char c[2];
 
    if (READ(GifFile, c, 2) != 2) {
        return GIF_ERROR;
    }
 
    *Word = (((unsigned int)c[1]) << 8) + c[0];
    return GIF_OK;
}

Referenced by DGifGetImageDesc(), and DGifGetScreenDesc().

DGifOpen()

GifFileType * DGifOpen	(	void *	userData,
		InputFunc	readFunc
	)

Definition at line 964 of file ungif.c.

                             {
 
    unsigned char Buf[GIF_STAMP_LEN + 1];
    GifFileType *GifFile;
    GifFilePrivateType *Private;
 
    GifFile = malloc(sizeof(GifFileType));
    if (GifFile == NULL) {
        return NULL;
    }
 
    memset(GifFile, '\0', sizeof(GifFileType));
 
    Private = malloc(sizeof(GifFilePrivateType));
    if (!Private) {
        free(GifFile);
        return NULL;
    }
 
    GifFile->Private = (void*)Private;
 
    Private->Read = readFunc;    /* TVT */
    GifFile->UserData = userData;    /* TVT */
 
    /* Lets see if this is a GIF file: */
    if (READ(GifFile, Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) {
        free(Private);
        free(GifFile);
        return NULL;
    }
 
    /* The GIF Version number is ignored at this time. Maybe we should do
     * something more useful with it. */
    Buf[GIF_STAMP_LEN] = 0;
    if (memcmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) {
        free(Private);
        free(GifFile);
        return NULL;
    }
 
    if (DGifGetScreenDesc(GifFile) == GIF_ERROR) {
        free(Private);
        free(GifFile);
        return NULL;
    }
 
    return GifFile;
}

Referenced by GifDecoder_Initialize().

DGifSetupDecompress()

static int DGifSetupDecompress ( GifFileType *  GifFile )

static

Definition at line 579 of file ungif.c.

                                           {
 
    int i, BitsPerPixel;
    GifByteType CodeSize;
    GifPrefixType *Prefix;
    GifFilePrivateType *Private = GifFile->Private;
 
    READ(GifFile, &CodeSize, 1);    /* Read Code size from file. */
    BitsPerPixel = CodeSize;
 
    Private->Buf[0] = 0;    /* Input Buffer empty. */
    Private->BitsPerPixel = BitsPerPixel;
    Private->ClearCode = (1 << BitsPerPixel);
    Private->EOFCode = Private->ClearCode + 1;
    Private->RunningCode = Private->EOFCode + 1;
    Private->RunningBits = BitsPerPixel + 1;    /* Number of bits per code. */
    Private->MaxCode1 = 1 << Private->RunningBits;    /* Max. code + 1. */
    Private->StackPtr = 0;    /* No pixels on the pixel stack. */
    Private->LastCode = NO_SUCH_CODE;
    Private->CrntShiftState = 0;    /* No information in CrntShiftDWord. */
    Private->CrntShiftDWord = 0;
 
    Prefix = Private->Prefix;
    for (i = 0; i <= LZ_MAX_CODE; i++)
        Prefix[i] = NO_SUCH_CODE;
 
    return GIF_OK;
}

Referenced by DGifGetImageDesc().

DGifSlurp()

int DGifSlurp

(

GifFileType *

GifFile

)

Definition at line 847 of file ungif.c.

                                 {
 
    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 = malloc(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;
 
              if (ExtData)
              {
                  /* Create an extension block with our data */
                  if (AddExtensionBlock(Extensions, ExtData[0], &ExtData[1]) == GIF_ERROR)
                      return (GIF_ERROR);
              }
              else /* Empty extension block */
              {
                  if (AddExtensionBlock(Extensions, 0, NULL) == 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);
 
    /* Just in case the Gif has an extension block without an associated
     * image... (Should we save this into a savefile structure with no image
     * instead? Have to check if the present writing code can handle that as
     * well.... */
    if (temp_save.ExtensionBlocks)
        FreeExtension(&temp_save);
 
    return (GIF_OK);
}

Referenced by GifDecoder_Initialize().

FreeExtension()

static void FreeExtension ( Extensions *  Extensions )

static

Definition at line 237 of file ungif.c.

{
    ExtensionBlock *ep;
 
    if ((Extensions == NULL) || (Extensions->ExtensionBlocks == NULL)) {
        return;
    }
    for (ep = Extensions->ExtensionBlocks;
         ep < (Extensions->ExtensionBlocks + Extensions->ExtensionBlockCount); ep++)
        free(ep->Bytes);
    free(Extensions->ExtensionBlocks);
    Extensions->ExtensionBlocks = NULL;
}

Referenced by DGifCloseFile(), DGifSlurp(), and FreeSavedImages().

FreeMapObject()

static void FreeMapObject ( ColorMapObject *  Object )

static

Definition at line 162 of file ungif.c.

                                       {
 
    if (Object != NULL) {
        free(Object->Colors);
        free(Object);
        /*** FIXME:
         * When we are willing to break API we need to make this function
         * FreeMapObject(ColorMapObject **Object)
         * and do this assignment to NULL here:
         * *Object = NULL;
         */
    }
}

Referenced by DGifCloseFile(), DGifGetImageDesc(), DGifGetScreenDesc(), and FreeSavedImages().

FreeSavedImages()

static void FreeSavedImages ( GifFileType *  GifFile )

static

Definition at line 256 of file ungif.c.

                                       {
 
    SavedImage *sp;
 
    if ((GifFile == NULL) || (GifFile->SavedImages == NULL)) {
        return;
    }
    for (sp = GifFile->SavedImages;
         sp < GifFile->SavedImages + GifFile->ImageCount; sp++) {
        if (sp->ImageDesc.ColorMap) {
            FreeMapObject(sp->ImageDesc.ColorMap);
            sp->ImageDesc.ColorMap = NULL;
        }
 
        free(sp->RasterBits);
 
        if (sp->Extensions.ExtensionBlocks)
            FreeExtension(&sp->Extensions);
    }
    free(GifFile->SavedImages);
    GifFile->SavedImages=NULL;
}

Referenced by DGifCloseFile().

MakeMapObject()

static ColorMapObject * MakeMapObject ( int  ColorCount, const GifColorType *  ColorMap  )

static

Definition at line 126 of file ungif.c.

                                             {
 
    ColorMapObject *Object;
 
    /*** FIXME: Our ColorCount has to be a power of two.  Is it necessary to
     * make the user know that or should we automatically round up instead? */
    if (ColorCount != (1 << BitSize(ColorCount))) {
        return NULL;
    }
 
    Object = malloc(sizeof(ColorMapObject));
    if (Object == NULL) {
        return NULL;
    }
 
    Object->Colors = calloc(ColorCount, sizeof(GifColorType));
    if (Object->Colors == NULL) {
        free(Object);
        return NULL;
    }
 
    Object->ColorCount = ColorCount;
    Object->BitsPerPixel = BitSize(ColorCount);
 
    if (ColorMap) {
        memcpy(Object->Colors, ColorMap, ColorCount * sizeof(GifColorType));
    }
 
    return (Object);
}

Referenced by DGifGetImageDesc(), and DGifGetScreenDesc().

WINE_DEFAULT_DEBUG_CHANNEL()

WINE_DEFAULT_DEBUG_CHANNEL

(

wincodecs

)