diff options
Diffstat (limited to 'src/main/jni/giflib/dgif_lib.c')
| -rw-r--r-- | src/main/jni/giflib/dgif_lib.c | 1167 |
1 files changed, 1167 insertions, 0 deletions
diff --git a/src/main/jni/giflib/dgif_lib.c b/src/main/jni/giflib/dgif_lib.c new file mode 100644 index 000000000..92442408b --- /dev/null +++ b/src/main/jni/giflib/dgif_lib.c @@ -0,0 +1,1167 @@ +/****************************************************************************** + +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 = open(FileName, O_RDONLY)) == -1) { + if (Error != NULL) + *Error = D_GIF_ERR_OPEN_FAILED; + return NULL; + } + GifFile = DGifOpenFileHandle(FileHandle, Error); + 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; + FILE *f; + + GifFile = (GifFileType *)malloc(sizeof(GifFileType)); + if (GifFile == NULL) { + if (Error != NULL) + *Error = D_GIF_ERR_NOT_ENOUGH_MEM; + (void)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)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 = 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); + *Error = D_GIF_ERR_NO_SCRN_DSCR; + 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; + case TERMINATOR_INTRODUCER: + *Type = TERMINATE_RECORD_TYPE; + break; + default: + *Type = UNDEFINED_RECORD_TYPE; + GifFile->Error = D_GIF_ERR_WRONG_RECORD; + return GIF_ERROR; + } + + 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, bool changeImageCount) +{ + 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) { + 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 (changeImageCount) + { + 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; + if (changeImageCount) + GifFile->ImageCount++; + + 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, ExtCode); +} + +/****************************************************************************** + 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, int* ExtCode) +{ + 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) + { + if (*ExtCode==GRAPHICS_EXT_FUNC_CODE) + Buf=4; + *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->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] == 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; +} + +/****************************************************************************** + 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]; + if (GifFile->ExtensionBlocks) { + sp->ExtensionBlocks = GifFile->ExtensionBlocks; + sp->ExtensionBlockCount = GifFile->ExtensionBlockCount; + + GifFile->ExtensionBlocks = NULL; + GifFile->ExtensionBlockCount = 0; + } + // 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); + } + 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, &ExtFunction) == 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); +} + + end */ |