1170 lines
40 KiB
C
1170 lines
40 KiB
C
|
/******************************************************************************
|
||
|
|
|
||
|
|
dgif_lib.c - GIF decoding
|
||
|
|
|
||
|
|
The functions here and in egif_lib.c are partitioned carefully so that
|
||
|
|
if you only require one of read and write capability, only one of these
|
||
|
|
two modules will be linked. Preserve this property!
|
||
|
|
|
||
|
|
*****************************************************************************/
|
||
|
|
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <limits.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
/* #include <unistd.h> */
|
||
|
|
/* #include <stdio.h> */
|
||
|
|
#include <string.h>
|
||
|
|
|
||
|
|
#ifdef _WIN32
|
||
|
|
#include <io.h>
|
||
|
|
#endif /* _WIN32 */
|
||
|
|
|
||
|
|
#include "gif_lib.h"
|
||
|
|
#include "gif_lib_private.h"
|
||
|
|
|
||
|
|
/* compose unsigned little endian value */
|
||
|
|
#define UNSIGNED_LITTLE_ENDIAN(lo, hi) ((lo) | ((hi) << 8))
|
||
|
|
|
||
|
|
/* avoid extra function call in case we use fread (TVT) */
|
||
|
|
#define READ(_gif,_buf,_len) \
|
||
|
|
(((GifFilePrivateType*)_gif->Private)->Read ? \
|
||
|
|
((GifFilePrivateType*)_gif->Private)->Read(_gif,_buf,_len) : \
|
||
|
|
fread(_buf,1,_len,((GifFilePrivateType*)_gif->Private)->File))
|
||
|
|
|
||
|
|
static int DGifGetWord(GifFileType *GifFile, GifWord *Word);
|
||
|
|
static int DGifSetupDecompress(GifFileType *GifFile);
|
||
|
|
static int DGifDecompressLine(GifFileType *GifFile, GifPixelType *Line,
|
||
|
|
int LineLen);
|
||
|
|
static int DGifGetPrefixChar(GifPrefixType *Prefix, int Code, int ClearCode);
|
||
|
|
static int DGifDecompressInput(GifFileType *GifFile, int *Code);
|
||
|
|
static int DGifBufferedInput(GifFileType *GifFile, GifByteType *Buf,
|
||
|
|
GifByteType *NextByte);
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Open a new GIF file for read, given by its name.
|
||
|
|
Returns dynamically allocated GifFileType pointer which serves as the GIF
|
||
|
|
info record.
|
||
|
|
******************************************************************************/
|
||
|
|
GifFileType *
|
||
|
|
DGifOpenFileName(const char *FileName, int *Error)
|
||
|
|
{
|
||
|
|
int FileHandle;
|
||
|
|
GifFileType *GifFile;
|
||
|
|
|
||
|
|
if ((FileHandle = rb->open(FileName, O_RDONLY)) == -1) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_OPEN_FAILED;
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
GifFile = DGifOpenFileHandle(FileHandle, Error);
|
||
|
|
// cppcheck-suppress resourceLeak
|
||
|
|
return GifFile;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Update a new GIF file, given its file handle.
|
||
|
|
Returns dynamically allocated GifFileType pointer which serves as the GIF
|
||
|
|
info record.
|
||
|
|
******************************************************************************/
|
||
|
|
GifFileType *
|
||
|
|
DGifOpenFileHandle(int FileHandle, int *Error)
|
||
|
|
{
|
||
|
|
char Buf[GIF_STAMP_LEN + 1];
|
||
|
|
GifFileType *GifFile;
|
||
|
|
GifFilePrivateType *Private;
|
||
|
|
int f;
|
||
|
|
|
||
|
|
GifFile = (GifFileType *)malloc(sizeof(GifFileType));
|
||
|
|
if (GifFile == NULL) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_NOT_ENOUGH_MEM;
|
||
|
|
(void)rb->close(FileHandle);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*@i1@*/memset(GifFile, '\0', sizeof(GifFileType));
|
||
|
|
|
||
|
|
/* Belt and suspenders, in case the null pointer isn't zero */
|
||
|
|
GifFile->SavedImages = NULL;
|
||
|
|
GifFile->SColorMap = NULL;
|
||
|
|
|
||
|
|
Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType));
|
||
|
|
if (Private == NULL) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_NOT_ENOUGH_MEM;
|
||
|
|
(void)rb->close(FileHandle);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
#ifdef _WIN32
|
||
|
|
_setmode(FileHandle, O_BINARY); /* Make sure it is in binary mode. */
|
||
|
|
#endif /* _WIN32 */
|
||
|
|
|
||
|
|
f = fdopen(FileHandle, "rb"); /* Make it into a stream: */
|
||
|
|
|
||
|
|
/*@-mustfreeonly@*/
|
||
|
|
GifFile->Private = (void *)Private;
|
||
|
|
Private->FileHandle = FileHandle;
|
||
|
|
Private->File = f;
|
||
|
|
Private->FileState = FILE_STATE_READ;
|
||
|
|
Private->Read = NULL; /* don't use alternate input method (TVT) */
|
||
|
|
GifFile->UserData = NULL; /* TVT */
|
||
|
|
/*@=mustfreeonly@*/
|
||
|
|
|
||
|
|
/* Let's see if this is a GIF file: */
|
||
|
|
if (READ(GifFile, (unsigned char *)Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
(void)fclose(f);
|
||
|
|
free((char *)Private);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Check for GIF prefix at start of file */
|
||
|
|
Buf[GIF_STAMP_LEN] = 0;
|
||
|
|
if (strncmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_NOT_GIF_FILE;
|
||
|
|
(void)fclose(f);
|
||
|
|
free((char *)Private);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (DGifGetScreenDesc(GifFile) == GIF_ERROR) {
|
||
|
|
(void)fclose(f);
|
||
|
|
free((char *)Private);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
GifFile->Error = 0;
|
||
|
|
|
||
|
|
/* What version of GIF? */
|
||
|
|
Private->gif89 = (Buf[GIF_VERSION_POS] == '9');
|
||
|
|
|
||
|
|
return GifFile;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
GifFileType constructor with user supplied input function (TVT)
|
||
|
|
******************************************************************************/
|
||
|
|
GifFileType *
|
||
|
|
DGifOpen(void *userData, InputFunc readFunc, int *Error)
|
||
|
|
{
|
||
|
|
char Buf[GIF_STAMP_LEN + 1];
|
||
|
|
GifFileType *GifFile;
|
||
|
|
GifFilePrivateType *Private;
|
||
|
|
|
||
|
|
GifFile = (GifFileType *)malloc(sizeof(GifFileType));
|
||
|
|
if (GifFile == NULL) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_NOT_ENOUGH_MEM;
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
memset(GifFile, '\0', sizeof(GifFileType));
|
||
|
|
|
||
|
|
/* Belt and suspenders, in case the null pointer isn't zero */
|
||
|
|
GifFile->SavedImages = NULL;
|
||
|
|
GifFile->SColorMap = NULL;
|
||
|
|
|
||
|
|
Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType));
|
||
|
|
if (!Private) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_NOT_ENOUGH_MEM;
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
GifFile->Private = (void *)Private;
|
||
|
|
Private->FileHandle = 0;
|
||
|
|
Private->File = 0; /* NULL */
|
||
|
|
Private->FileState = FILE_STATE_READ;
|
||
|
|
|
||
|
|
Private->Read = readFunc; /* TVT */
|
||
|
|
GifFile->UserData = userData; /* TVT */
|
||
|
|
|
||
|
|
/* Lets see if this is a GIF file: */
|
||
|
|
if (READ(GifFile, (unsigned char *)Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
free((char *)Private);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Check for GIF prefix at start of file */
|
||
|
|
Buf[GIF_STAMP_LEN] = '\0';
|
||
|
|
if (strncmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) {
|
||
|
|
if (Error != NULL)
|
||
|
|
*Error = D_GIF_ERR_NOT_GIF_FILE;
|
||
|
|
free((char *)Private);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (DGifGetScreenDesc(GifFile) == GIF_ERROR) {
|
||
|
|
free((char *)Private);
|
||
|
|
free((char *)GifFile);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
GifFile->Error = 0;
|
||
|
|
|
||
|
|
/* What version of GIF? */
|
||
|
|
Private->gif89 = (Buf[GIF_VERSION_POS] == '9');
|
||
|
|
|
||
|
|
return GifFile;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
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++) {
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
This routine should be called before any attempt to read an image.
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetRecordType(GifFileType *GifFile, GifRecordType* Type)
|
||
|
|
{
|
||
|
|
GifByteType Buf;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (READ(GifFile, &Buf, 1) != 1) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
switch (Buf) {
|
||
|
|
case DESCRIPTOR_INTRODUCER:
|
||
|
|
*Type = IMAGE_DESC_RECORD_TYPE;
|
||
|
|
break;
|
||
|
|
case EXTENSION_INTRODUCER:
|
||
|
|
*Type = EXTENSION_RECORD_TYPE;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
*Type = TERMINATE_RECORD_TYPE;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
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) ? true : false;
|
||
|
|
|
||
|
|
/* 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) {
|
||
|
|
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 0
|
||
|
|
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++;
|
||
|
|
#endif
|
||
|
|
Private->PixelCount = (long)GifFile->Image.Width *
|
||
|
|
(long)GifFile->Image.Height;
|
||
|
|
|
||
|
|
/* Reset decompress algorithm parameters. */
|
||
|
|
(void)DGifSetupDecompress(GifFile);
|
||
|
|
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Get one full scanned line (Line) of length LineLen from GIF file.
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetLine(GifFileType *GifFile, GifPixelType *Line, int LineLen)
|
||
|
|
{
|
||
|
|
GifByteType *Dummy;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!LineLen)
|
||
|
|
LineLen = GifFile->Image.Width;
|
||
|
|
|
||
|
|
if ((Private->PixelCount -= LineLen) > 0xffff0000UL) {
|
||
|
|
GifFile->Error = D_GIF_ERR_DATA_TOO_BIG;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (DGifDecompressLine(GifFile, Line, LineLen) == GIF_OK) {
|
||
|
|
if (Private->PixelCount == 0) {
|
||
|
|
/* We probably won't be called any more, so let's clean up
|
||
|
|
* everything before we return: need to flush out all the
|
||
|
|
* rest of image until an empty block (size 0)
|
||
|
|
* detected. We use GetCodeNext.
|
||
|
|
*/
|
||
|
|
do
|
||
|
|
if (DGifGetCodeNext(GifFile, &Dummy) == GIF_ERROR)
|
||
|
|
return GIF_ERROR;
|
||
|
|
while (Dummy != NULL) ;
|
||
|
|
}
|
||
|
|
return GIF_OK;
|
||
|
|
} else
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Put one pixel (Pixel) into GIF file.
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetPixel(GifFileType *GifFile, GifPixelType Pixel)
|
||
|
|
{
|
||
|
|
GifByteType *Dummy;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
if (--Private->PixelCount > 0xffff0000UL)
|
||
|
|
{
|
||
|
|
GifFile->Error = D_GIF_ERR_DATA_TOO_BIG;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (DGifDecompressLine(GifFile, &Pixel, 1) == GIF_OK) {
|
||
|
|
if (Private->PixelCount == 0) {
|
||
|
|
/* We probably won't be called any more, so let's clean up
|
||
|
|
* everything before we return: need to flush out all the
|
||
|
|
* rest of image until an empty block (size 0)
|
||
|
|
* detected. We use GetCodeNext.
|
||
|
|
*/
|
||
|
|
do
|
||
|
|
if (DGifGetCodeNext(GifFile, &Dummy) == GIF_ERROR)
|
||
|
|
return GIF_ERROR;
|
||
|
|
while (Dummy != NULL) ;
|
||
|
|
}
|
||
|
|
return GIF_OK;
|
||
|
|
} else
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Get an extension block (see GIF manual) from GIF file. This routine only
|
||
|
|
returns the first data block, and DGifGetExtensionNext should be called
|
||
|
|
after this one until NULL extension is returned.
|
||
|
|
The Extension should NOT be freed by the user (not dynamically allocated).
|
||
|
|
Note it is assumed the Extension description header has been read.
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetExtension(GifFileType *GifFile, int *ExtCode, GifByteType **Extension)
|
||
|
|
{
|
||
|
|
GifByteType Buf;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (READ(GifFile, &Buf, 1) != 1) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
*ExtCode = Buf;
|
||
|
|
|
||
|
|
return DGifGetExtensionNext(GifFile, Extension);
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Get a following extension block (see GIF manual) from GIF file. This
|
||
|
|
routine should be called until NULL Extension is returned.
|
||
|
|
The Extension should NOT be freed by the user (not dynamically allocated).
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetExtensionNext(GifFileType *GifFile, GifByteType ** Extension)
|
||
|
|
{
|
||
|
|
GifByteType Buf;
|
||
|
|
GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
|
||
|
|
|
||
|
|
if (READ(GifFile, &Buf, 1) != 1) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
if (Buf > 0) {
|
||
|
|
*Extension = Private->Buf; /* Use private unused buffer. */
|
||
|
|
(*Extension)[0] = Buf; /* Pascal strings notation (pos. 0 is len.). */
|
||
|
|
/* coverity[tainted_data] */
|
||
|
|
if (READ(GifFile, &((*Extension)[1]), Buf) != Buf) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
} else
|
||
|
|
*Extension = NULL;
|
||
|
|
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Extract a Graphics Control Block from raw extension data
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
int DGifExtensionToGCB(const size_t GifExtensionLength,
|
||
|
|
const GifByteType *GifExtension,
|
||
|
|
GraphicsControlBlock *GCB)
|
||
|
|
{
|
||
|
|
if (GifExtensionLength != 4) {
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
GCB->DisposalMode = (GifExtension[0] >> 2) & 0x07;
|
||
|
|
GCB->UserInputFlag = (GifExtension[0] & 0x02) != 0;
|
||
|
|
GCB->DelayTime = UNSIGNED_LITTLE_ENDIAN(GifExtension[1], GifExtension[2]);
|
||
|
|
if (GifExtension[0] & 0x01)
|
||
|
|
GCB->TransparentColor = (int)GifExtension[3];
|
||
|
|
else
|
||
|
|
GCB->TransparentColor = NO_TRANSPARENT_COLOR;
|
||
|
|
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Extract the Graphics Control Block for a saved image, if it exists.
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
int DGifSavedExtensionToGCB(GifFileType *GifFile,
|
||
|
|
int ImageIndex, GraphicsControlBlock *GCB)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (ImageIndex < 0 || ImageIndex > GifFile->ImageCount - 1)
|
||
|
|
return GIF_ERROR;
|
||
|
|
|
||
|
|
GCB->DisposalMode = DISPOSAL_UNSPECIFIED;
|
||
|
|
GCB->UserInputFlag = false;
|
||
|
|
GCB->DelayTime = 0;
|
||
|
|
GCB->TransparentColor = NO_TRANSPARENT_COLOR;
|
||
|
|
|
||
|
|
for (i = 0; i < GifFile->SavedImages[ImageIndex].ExtensionBlockCount; i++) {
|
||
|
|
ExtensionBlock *ep = &GifFile->SavedImages[ImageIndex].ExtensionBlocks[i];
|
||
|
|
if (ep->Function == GRAPHICS_EXT_FUNC_CODE)
|
||
|
|
return DGifExtensionToGCB(ep->ByteCount, ep->Bytes, GCB);
|
||
|
|
}
|
||
|
|
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
This routine should be called last, to close the GIF file.
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifCloseFile(GifFileType *GifFile)
|
||
|
|
{
|
||
|
|
GifFilePrivateType *Private;
|
||
|
|
|
||
|
|
if (GifFile == NULL || GifFile->Private == NULL)
|
||
|
|
return GIF_ERROR;
|
||
|
|
|
||
|
|
if (GifFile->Image.ColorMap) {
|
||
|
|
GifFreeMapObject(GifFile->Image.ColorMap);
|
||
|
|
GifFile->Image.ColorMap = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (GifFile->Image.GCB) {
|
||
|
|
free(GifFile->Image.GCB);
|
||
|
|
GifFile->Image.GCB = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (GifFile->SColorMap) {
|
||
|
|
GifFreeMapObject(GifFile->SColorMap);
|
||
|
|
GifFile->SColorMap = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (GifFile->SavedImages) {
|
||
|
|
GifFreeSavedImages(GifFile);
|
||
|
|
GifFile->SavedImages = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
GifFreeExtensions(&GifFile->ExtensionBlockCount, &GifFile->ExtensionBlocks);
|
||
|
|
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (Private->File && (fclose(Private->File) != 0)) {
|
||
|
|
GifFile->Error = D_GIF_ERR_CLOSE_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
free((char *)GifFile->Private);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Without the #ifndef, we get spurious warnings because Coverity mistakenly
|
||
|
|
* thinks the GIF structure is freed on an error return.
|
||
|
|
*/
|
||
|
|
#ifndef __COVERITY__
|
||
|
|
free(GifFile);
|
||
|
|
#endif /* __COVERITY__ */
|
||
|
|
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Get 2 bytes (word) from the given file:
|
||
|
|
******************************************************************************/
|
||
|
|
static int
|
||
|
|
DGifGetWord(GifFileType *GifFile, GifWord *Word)
|
||
|
|
{
|
||
|
|
unsigned char c[2];
|
||
|
|
|
||
|
|
if (READ(GifFile, c, 2) != 2) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
*Word = (GifWord)UNSIGNED_LITTLE_ENDIAN(c[0], c[1]);
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Get the image code in compressed form. This routine can be called if the
|
||
|
|
information needed to be piped out as is. Obviously this is much faster
|
||
|
|
than decoding and encoding again. This routine should be followed by calls
|
||
|
|
to DGifGetCodeNext, until NULL block is returned.
|
||
|
|
The block should NOT be freed by the user (not dynamically allocated).
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetCode(GifFileType *GifFile, int *CodeSize, GifByteType **CodeBlock)
|
||
|
|
{
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
*CodeSize = Private->BitsPerPixel;
|
||
|
|
|
||
|
|
return DGifGetCodeNext(GifFile, CodeBlock);
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Continue to get the image code in compressed form. This routine should be
|
||
|
|
called until NULL block is returned.
|
||
|
|
The block should NOT be freed by the user (not dynamically allocated).
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetCodeNext(GifFileType *GifFile, GifByteType **CodeBlock)
|
||
|
|
{
|
||
|
|
GifByteType Buf;
|
||
|
|
GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
|
||
|
|
|
||
|
|
/* coverity[tainted_data_argument] */
|
||
|
|
if (READ(GifFile, &Buf, 1) != 1) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* coverity[lower_bounds] */
|
||
|
|
if (Buf > 0) {
|
||
|
|
*CodeBlock = Private->Buf; /* Use private unused buffer. */
|
||
|
|
(*CodeBlock)[0] = Buf; /* Pascal strings notation (pos. 0 is len.). */
|
||
|
|
/* coverity[tainted_data] */
|
||
|
|
if (READ(GifFile, &((*CodeBlock)[1]), Buf) != Buf) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Setup the LZ decompression for this image:
|
||
|
|
******************************************************************************/
|
||
|
|
static int
|
||
|
|
DGifSetupDecompress(GifFileType *GifFile)
|
||
|
|
{
|
||
|
|
int i, BitsPerPixel;
|
||
|
|
GifByteType CodeSize;
|
||
|
|
GifPrefixType *Prefix;
|
||
|
|
GifFilePrivateType *Private = (GifFilePrivateType *)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;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
The LZ decompression routine:
|
||
|
|
This version decompress the given GIF file into Line of length LineLen.
|
||
|
|
This routine can be called few times (one per scan line, for example), in
|
||
|
|
order the complete the whole image.
|
||
|
|
******************************************************************************/
|
||
|
|
static int
|
||
|
|
DGifDecompressLine(GifFileType *GifFile, GifPixelType *Line, int LineLen)
|
||
|
|
{
|
||
|
|
int i = 0;
|
||
|
|
int j, CrntCode, EOFCode, ClearCode, CrntPrefix, LastCode, StackPtr;
|
||
|
|
GifByteType *Stack, *Suffix;
|
||
|
|
GifPrefixType *Prefix;
|
||
|
|
GifFilePrivateType *Private = (GifFilePrivateType *) 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 > LZ_MAX_CODE) {
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (StackPtr != 0) {
|
||
|
|
/* Let pop the stack off before continueing 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. */
|
||
|
|
GifFile->Error = D_GIF_ERR_EOF_TOO_SOON;
|
||
|
|
return GIF_ERROR;
|
||
|
|
} 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 {
|
||
|
|
/* Its 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 {
|
||
|
|
/* Its a code to needed 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
|
||
|
|
* (thats what stack is good for!) order to 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 {
|
||
|
|
GifFile->Error = D_GIF_ERR_IMAGE_DEFECT;
|
||
|
|
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 use StackPtr as loop counter and stop
|
||
|
|
* before overflowing Stack[]. */
|
||
|
|
while (StackPtr < LZ_MAX_CODE &&
|
||
|
|
CrntPrefix > ClearCode && CrntPrefix <= LZ_MAX_CODE) {
|
||
|
|
Stack[StackPtr++] = Suffix[CrntPrefix];
|
||
|
|
CrntPrefix = Prefix[CrntPrefix];
|
||
|
|
}
|
||
|
|
if (StackPtr >= LZ_MAX_CODE || CrntPrefix > LZ_MAX_CODE) {
|
||
|
|
GifFile->Error = D_GIF_ERR_IMAGE_DEFECT;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Routine to trace the Prefixes linked list until we get a prefix which is
|
||
|
|
not code, but a pixel value (less than ClearCode). Returns that pixel value.
|
||
|
|
If image is defective, we might loop here forever, so we limit the loops to
|
||
|
|
the maximum possible if image O.k. - LZ_MAX_CODE times.
|
||
|
|
******************************************************************************/
|
||
|
|
static int
|
||
|
|
DGifGetPrefixChar(GifPrefixType *Prefix, int Code, int ClearCode)
|
||
|
|
{
|
||
|
|
int i = 0;
|
||
|
|
|
||
|
|
while (Code > ClearCode && i++ <= LZ_MAX_CODE) {
|
||
|
|
if (Code > LZ_MAX_CODE) {
|
||
|
|
return NO_SUCH_CODE;
|
||
|
|
}
|
||
|
|
Code = Prefix[Code];
|
||
|
|
}
|
||
|
|
return Code;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
Interface for accessing the LZ codes directly. Set Code to the real code
|
||
|
|
(12bits), or to -1 if EOF code is returned.
|
||
|
|
******************************************************************************/
|
||
|
|
int
|
||
|
|
DGifGetLZCodes(GifFileType *GifFile, int *Code)
|
||
|
|
{
|
||
|
|
GifByteType *CodeBlock;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (DGifDecompressInput(GifFile, Code) == GIF_ERROR)
|
||
|
|
return GIF_ERROR;
|
||
|
|
|
||
|
|
if (*Code == Private->EOFCode) {
|
||
|
|
/* Skip rest of codes (hopefully only NULL terminating block): */
|
||
|
|
do {
|
||
|
|
if (DGifGetCodeNext(GifFile, &CodeBlock) == GIF_ERROR)
|
||
|
|
return GIF_ERROR;
|
||
|
|
} while (CodeBlock != NULL) ;
|
||
|
|
|
||
|
|
*Code = -1;
|
||
|
|
} else if (*Code == Private->ClearCode) {
|
||
|
|
/* We need to start over again: */
|
||
|
|
Private->RunningCode = Private->EOFCode + 1;
|
||
|
|
Private->RunningBits = Private->BitsPerPixel + 1;
|
||
|
|
Private->MaxCode1 = 1 << Private->RunningBits;
|
||
|
|
}
|
||
|
|
|
||
|
|
return GIF_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
The LZ decompression input routine:
|
||
|
|
This routine is responsable for the decompression of the bit stream from
|
||
|
|
8 bits (bytes) packets, into the real codes.
|
||
|
|
Returns GIF_OK if read successfully.
|
||
|
|
******************************************************************************/
|
||
|
|
static int
|
||
|
|
DGifDecompressInput(GifFileType *GifFile, int *Code)
|
||
|
|
{
|
||
|
|
static const unsigned short CodeMasks[] = {
|
||
|
|
0x0000, 0x0001, 0x0003, 0x0007,
|
||
|
|
0x000f, 0x001f, 0x003f, 0x007f,
|
||
|
|
0x00ff, 0x01ff, 0x03ff, 0x07ff,
|
||
|
|
0x0fff
|
||
|
|
};
|
||
|
|
|
||
|
|
GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
|
||
|
|
|
||
|
|
GifByteType NextByte;
|
||
|
|
|
||
|
|
/* The image can't contain more than LZ_BITS per code. */
|
||
|
|
if (Private->RunningBits > LZ_BITS) {
|
||
|
|
GifFile->Error = D_GIF_ERR_IMAGE_DEFECT;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
This routines read one GIF data block at a time and buffers it internally
|
||
|
|
so that the decompression routine could access it.
|
||
|
|
The routine returns the next byte from its internal buffer (or read next
|
||
|
|
block in if buffer empty) and returns GIF_OK if succesful.
|
||
|
|
******************************************************************************/
|
||
|
|
static int
|
||
|
|
DGifBufferedInput(GifFileType *GifFile, GifByteType *Buf, GifByteType *NextByte)
|
||
|
|
{
|
||
|
|
if (Buf[0] == 0) {
|
||
|
|
/* Needs to read the next buffer - this one is empty: */
|
||
|
|
if (READ(GifFile, Buf, 1) != 1) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
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) {
|
||
|
|
GifFile->Error = D_GIF_ERR_IMAGE_DEFECT;
|
||
|
|
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) {
|
||
|
|
GifFile->Error = D_GIF_ERR_IMAGE_DEFECT;
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
if (READ(GifFile, &Buf[1], Buf[0]) != Buf[0]) {
|
||
|
|
GifFile->Error = D_GIF_ERR_READ_FAILED;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
#if 0
|
||
|
|
/******************************************************************************
|
||
|
|
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)
|
||
|
|
{
|
||
|
|
size_t ImageSize;
|
||
|
|
GifRecordType RecordType;
|
||
|
|
SavedImage *sp;
|
||
|
|
GifByteType *ExtData;
|
||
|
|
int ExtFunction;
|
||
|
|
|
||
|
|
GifFile->ExtensionBlocks = NULL;
|
||
|
|
GifFile->ExtensionBlockCount = 0;
|
||
|
|
|
||
|
|
do {
|
||
|
|
if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
|
||
|
|
switch (RecordType) {
|
||
|
|
case IMAGE_DESC_RECORD_TYPE:
|
||
|
|
if (DGifGetImageDesc(GifFile) == GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
|
||
|
|
sp = &GifFile->SavedImages[GifFile->ImageCount - 1];
|
||
|
|
/* Allocate memory for the image */
|
||
|
|
if (sp->ImageDesc.Width < 0 && sp->ImageDesc.Height < 0 &&
|
||
|
|
sp->ImageDesc.Width > (INT_MAX / sp->ImageDesc.Height)) {
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
ImageSize = sp->ImageDesc.Width * sp->ImageDesc.Height;
|
||
|
|
|
||
|
|
if (ImageSize > (SIZE_MAX / sizeof(GifPixelType))) {
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
sp->RasterBits = (unsigned char *)malloc(ImageSize *
|
||
|
|
sizeof(GifPixelType));
|
||
|
|
|
||
|
|
if (sp->RasterBits == NULL) {
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (sp->ImageDesc.Interlace) {
|
||
|
|
int i, j;
|
||
|
|
/*
|
||
|
|
* The way an interlaced image should be read -
|
||
|
|
* offsets and jumps...
|
||
|
|
*/
|
||
|
|
int InterlacedOffset[] = { 0, 4, 2, 1 };
|
||
|
|
int InterlacedJumps[] = { 8, 8, 4, 2 };
|
||
|
|
/* Need to perform 4 passes on the image */
|
||
|
|
for (i = 0; i < 4; i++)
|
||
|
|
for (j = InterlacedOffset[i];
|
||
|
|
j < sp->ImageDesc.Height;
|
||
|
|
j += InterlacedJumps[i]) {
|
||
|
|
if (DGifGetLine(GifFile,
|
||
|
|
sp->RasterBits+j*sp->ImageDesc.Width,
|
||
|
|
sp->ImageDesc.Width) == GIF_ERROR)
|
||
|
|
return GIF_ERROR;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
if (DGifGetLine(GifFile,sp->RasterBits,ImageSize)==GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (GifFile->ExtensionBlocks) {
|
||
|
|
sp->ExtensionBlocks = GifFile->ExtensionBlocks;
|
||
|
|
sp->ExtensionBlockCount = GifFile->ExtensionBlockCount;
|
||
|
|
|
||
|
|
GifFile->ExtensionBlocks = NULL;
|
||
|
|
GifFile->ExtensionBlockCount = 0;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case EXTENSION_RECORD_TYPE:
|
||
|
|
if (DGifGetExtension(GifFile,&ExtFunction,&ExtData) == GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
/* Create an extension block with our data */
|
||
|
|
if (GifAddExtensionBlock(&GifFile->ExtensionBlockCount,
|
||
|
|
&GifFile->ExtensionBlocks,
|
||
|
|
ExtFunction, ExtData[0], &ExtData[1])
|
||
|
|
== GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
while (ExtData != NULL) {
|
||
|
|
if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
/* Continue the extension block */
|
||
|
|
if (ExtData != NULL)
|
||
|
|
if (GifAddExtensionBlock(&GifFile->ExtensionBlockCount,
|
||
|
|
&GifFile->ExtensionBlocks,
|
||
|
|
CONTINUE_EXT_FUNC_CODE,
|
||
|
|
ExtData[0], &ExtData[1]) == GIF_ERROR)
|
||
|
|
return (GIF_ERROR);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case TERMINATE_RECORD_TYPE:
|
||
|
|
break;
|
||
|
|
|
||
|
|
default: /* Should be trapped by DGifGetRecordType */
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
} while (RecordType != TERMINATE_RECORD_TYPE);
|
||
|
|
|
||
|
|
return (GIF_OK);
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
/* end */
|