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author | Upstream <upstream-import@none> | 1970-01-12 13:46:40 +0000 |
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committer | Upstream <upstream-import@none> | 1970-01-12 13:46:40 +0000 |
commit | 1bc4596b116b3c829824c8b929ce48f864ca4a3c (patch) | |
tree | 332339626bc83390de46cf38346f76effc46009b /dgif_lib.c | |
download | android_external_giflib-1bc4596b116b3c829824c8b929ce48f864ca4a3c.tar.gz android_external_giflib-1bc4596b116b3c829824c8b929ce48f864ca4a3c.tar.bz2 android_external_giflib-1bc4596b116b3c829824c8b929ce48f864ca4a3c.zip |
external/giflib 4.1.6
Diffstat (limited to 'dgif_lib.c')
-rw-r--r-- | dgif_lib.c | 1098 |
1 files changed, 1098 insertions, 0 deletions
diff --git a/dgif_lib.c b/dgif_lib.c new file mode 100644 index 0000000..760d053 --- /dev/null +++ b/dgif_lib.c @@ -0,0 +1,1098 @@ +/****************************************************************************** + * "Gif-Lib" - Yet another gif library. + * + * Written by: Gershon Elber IBM PC Ver 1.1, Aug. 1990 + ****************************************************************************** + * The kernel of the GIF Decoding process can be found here. + ****************************************************************************** + * History: + * 16 Jun 89 - Version 1.0 by Gershon Elber. + * 3 Sep 90 - Version 1.1 by Gershon Elber (Support for Gif89, Unique names). + *****************************************************************************/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <stdlib.h> +#if defined (__MSDOS__) && !defined(__DJGPP__) && !defined(__GNUC__) +#include <io.h> +#include <alloc.h> +#include <sys\stat.h> +#else +#include <sys/types.h> +#include <sys/stat.h> +#endif /* __MSDOS__ */ + +#ifdef HAVE_IO_H +#include <io.h> +#endif + +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif /* HAVE_FCNTL_H */ +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif /* HAVE_UNISTD_H */ +#include <stdio.h> +#include <string.h> +#include "gif_lib.h" +#include "gif_lib_private.h" + +#define COMMENT_EXT_FUNC_CODE 0xfe /* Extension function code for + comment. */ + +/* 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); +#ifndef _GBA_NO_FILEIO + +/****************************************************************************** + * Open a new gif file for read, given by its name. + * Returns GifFileType pointer dynamically allocated which serves as the gif + * info record. _GifError is cleared if succesfull. + *****************************************************************************/ +GifFileType * +DGifOpenFileName(const char *FileName) { + int FileHandle; + GifFileType *GifFile; + + if ((FileHandle = open(FileName, O_RDONLY +#if defined(__MSDOS__) || defined(WINDOWS32) || defined(_OPEN_BINARY) + | O_BINARY +#endif /* __MSDOS__ || _OPEN_BINARY */ + )) == -1) { + _GifError = D_GIF_ERR_OPEN_FAILED; + return NULL; + } + + GifFile = DGifOpenFileHandle(FileHandle); + return GifFile; +} + +/****************************************************************************** + * Update a new gif file, given its file handle. + * Returns GifFileType pointer dynamically allocated which serves as the gif + * info record. _GifError is cleared if succesfull. + *****************************************************************************/ +GifFileType * +DGifOpenFileHandle(int FileHandle) { + + unsigned char Buf[GIF_STAMP_LEN + 1]; + GifFileType *GifFile; + GifFilePrivateType *Private; + FILE *f; + + GifFile = (GifFileType *)malloc(sizeof(GifFileType)); + if (GifFile == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + close(FileHandle); + return NULL; + } + + memset(GifFile, '\0', sizeof(GifFileType)); + + Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType)); + if (Private == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + close(FileHandle); + free((char *)GifFile); + return NULL; + } +#if defined(__MSDOS__) || defined(WINDOWS32) || defined(_OPEN_BINARY) + setmode(FileHandle, O_BINARY); /* Make sure it is in binary mode. */ +#endif /* __MSDOS__ */ + + f = fdopen(FileHandle, "rb"); /* Make it into a stream: */ + +#if defined(__MSDOS__) || defined(WINDOWS32) + setvbuf(f, NULL, _IOFBF, GIF_FILE_BUFFER_SIZE); /* And inc. stream + buffer. */ +#endif /* __MSDOS__ */ + + GifFile->Private = (VoidPtr)Private; + Private->FileHandle = FileHandle; + Private->File = f; + Private->FileState = FILE_STATE_READ; + Private->Read = 0; /* don't use alternate input method (TVT) */ + GifFile->UserData = 0; /* TVT */ + + /* Lets see if this is a GIF file: */ + if (READ(GifFile, Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) { + _GifError = D_GIF_ERR_READ_FAILED; + fclose(f); + free((char *)Private); + free((char *)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 (strncmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) { + _GifError = D_GIF_ERR_NOT_GIF_FILE; + fclose(f); + free((char *)Private); + free((char *)GifFile); + return NULL; + } + + if (DGifGetScreenDesc(GifFile) == GIF_ERROR) { + fclose(f); + free((char *)Private); + free((char *)GifFile); + return NULL; + } + + _GifError = 0; + + return GifFile; +} + +#endif /* _GBA_NO_FILEIO */ + +/****************************************************************************** + * GifFileType constructor with user supplied input function (TVT) + *****************************************************************************/ +GifFileType * +DGifOpen(void *userData, + InputFunc readFunc) { + + unsigned char Buf[GIF_STAMP_LEN + 1]; + GifFileType *GifFile; + GifFilePrivateType *Private; + + GifFile = (GifFileType *)malloc(sizeof(GifFileType)); + if (GifFile == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + return NULL; + } + + memset(GifFile, '\0', sizeof(GifFileType)); + + Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType)); + if (!Private) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + free((char *)GifFile); + return NULL; + } + + GifFile->Private = (VoidPtr)Private; + Private->FileHandle = 0; + Private->File = 0; + Private->FileState = FILE_STATE_READ; + + 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) { + _GifError = D_GIF_ERR_READ_FAILED; + free((char *)Private); + free((char *)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 (strncmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) { + _GifError = 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; + } + + _GifError = 0; + + 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 i, BitsPerPixel; + GifByteType Buf[3]; + GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private; + + if (!IS_READABLE(Private)) { + /* This file was NOT open for reading: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } + + /* Put the screen descriptor into the file: */ + if (DGifGetWord(GifFile, &GifFile->SWidth) == GIF_ERROR || + DGifGetWord(GifFile, &GifFile->SHeight) == GIF_ERROR) + return GIF_ERROR; + + if (READ(GifFile, Buf, 3) != 3) { + _GifError = D_GIF_ERR_READ_FAILED; + return GIF_ERROR; + } + GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1; + BitsPerPixel = (Buf[0] & 0x07) + 1; + GifFile->SBackGroundColor = Buf[1]; + if (Buf[0] & 0x80) { /* Do we have global color map? */ + + GifFile->SColorMap = MakeMapObject(1 << BitsPerPixel, NULL); + if (GifFile->SColorMap == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + return GIF_ERROR; + } + + /* Get the global color map: */ + for (i = 0; i < GifFile->SColorMap->ColorCount; i++) { + if (READ(GifFile, Buf, 3) != 3) { + FreeMapObject(GifFile->SColorMap); + GifFile->SColorMap = NULL; + _GifError = D_GIF_ERR_READ_FAILED; + return GIF_ERROR; + } + GifFile->SColorMap->Colors[i].Red = Buf[0]; + GifFile->SColorMap->Colors[i].Green = Buf[1]; + GifFile->SColorMap->Colors[i].Blue = Buf[2]; + } + } else { + GifFile->SColorMap = NULL; + } + + return GIF_OK; +} + +/****************************************************************************** + * 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: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } + + if (READ(GifFile, &Buf, 1) != 1) { + _GifError = D_GIF_ERR_READ_FAILED; + return GIF_ERROR; + } + + 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; + _GifError = 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) { + + int i, BitsPerPixel; + GifByteType Buf[3]; + GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private; + SavedImage *sp; + + if (!IS_READABLE(Private)) { + /* This file was NOT open for reading: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } + + if (DGifGetWord(GifFile, &GifFile->Image.Left) == GIF_ERROR || + DGifGetWord(GifFile, &GifFile->Image.Top) == GIF_ERROR || + DGifGetWord(GifFile, &GifFile->Image.Width) == GIF_ERROR || + DGifGetWord(GifFile, &GifFile->Image.Height) == GIF_ERROR) + return GIF_ERROR; + if (READ(GifFile, Buf, 1) != 1) { + _GifError = D_GIF_ERR_READ_FAILED; + return GIF_ERROR; + } + BitsPerPixel = (Buf[0] & 0x07) + 1; + GifFile->Image.Interlace = (Buf[0] & 0x40); + if (Buf[0] & 0x80) { /* Does this image have local color map? */ + + /*** FIXME: Why do we check both of these in order to do this? + * Why do we have both Image and SavedImages? */ + if (GifFile->Image.ColorMap && GifFile->SavedImages == NULL) + FreeMapObject(GifFile->Image.ColorMap); + + GifFile->Image.ColorMap = MakeMapObject(1 << BitsPerPixel, NULL); + if (GifFile->Image.ColorMap == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + return GIF_ERROR; + } + + /* Get the image local color map: */ + for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++) { + if (READ(GifFile, Buf, 3) != 3) { + FreeMapObject(GifFile->Image.ColorMap); + _GifError = D_GIF_ERR_READ_FAILED; + GifFile->Image.ColorMap = NULL; + return GIF_ERROR; + } + GifFile->Image.ColorMap->Colors[i].Red = Buf[0]; + GifFile->Image.ColorMap->Colors[i].Green = Buf[1]; + GifFile->Image.ColorMap->Colors[i].Blue = Buf[2]; + } + } else if (GifFile->Image.ColorMap) { + FreeMapObject(GifFile->Image.ColorMap); + GifFile->Image.ColorMap = NULL; + } + + if (GifFile->SavedImages) { + if ((GifFile->SavedImages = (SavedImage *)realloc(GifFile->SavedImages, + sizeof(SavedImage) * + (GifFile->ImageCount + 1))) == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + return GIF_ERROR; + } + } else { + if ((GifFile->SavedImages = + (SavedImage *) malloc(sizeof(SavedImage))) == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + return GIF_ERROR; + } + } + + sp = &GifFile->SavedImages[GifFile->ImageCount]; + memcpy(&sp->ImageDesc, &GifFile->Image, sizeof(GifImageDesc)); + if (GifFile->Image.ColorMap != NULL) { + sp->ImageDesc.ColorMap = MakeMapObject( + GifFile->Image.ColorMap->ColorCount, + GifFile->Image.ColorMap->Colors); + if (sp->ImageDesc.ColorMap == NULL) { + _GifError = D_GIF_ERR_NOT_ENOUGH_MEM; + return GIF_ERROR; + } + } + sp->RasterBits = (unsigned char *)NULL; + sp->ExtensionBlockCount = 0; + sp->ExtensionBlocks = (ExtensionBlock *) NULL; + + GifFile->ImageCount++; + + Private->PixelCount = (long)GifFile->Image.Width * + (long)GifFile->Image.Height; + + DGifSetupDecompress(GifFile); /* Reset decompress algorithm parameters. */ + + 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: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } + + if (!LineLen) + LineLen = GifFile->Image.Width; + +#if defined(__MSDOS__) || defined(WINDOWS32) || defined(__GNUC__) + if ((Private->PixelCount -= LineLen) > 0xffff0000UL) { +#else + if ((Private->PixelCount -= LineLen) > 0xffff0000) { +#endif /* __MSDOS__ */ + _GifError = D_GIF_ERR_DATA_TOO_BIG; + 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) + 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: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } +#if defined(__MSDOS__) || defined(WINDOWS32) || defined(__GNUC__) + if (--Private->PixelCount > 0xffff0000UL) +#else + if (--Private->PixelCount > 0xffff0000) +#endif /* __MSDOS__ */ + { + _GifError = D_GIF_ERR_DATA_TOO_BIG; + return GIF_ERROR; + } + + if (DGifDecompressLine(GifFile, &Pixel, 1) == 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) + 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 desc. 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: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } + + if (READ(GifFile, &Buf, 1) != 1) { + _GifError = 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) { + _GifError = 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.). */ + if (READ(GifFile, &((*Extension)[1]), Buf) != Buf) { + _GifError = D_GIF_ERR_READ_FAILED; + return GIF_ERROR; + } + } else + *Extension = NULL; + + return GIF_OK; +} + +/****************************************************************************** + * This routine should be called last, to close the GIF file. + *****************************************************************************/ +int +DGifCloseFile(GifFileType * GifFile) { + + GifFilePrivateType *Private; + FILE *File; + + if (GifFile == NULL) + return GIF_ERROR; + + Private = (GifFilePrivateType *) GifFile->Private; + + if (!IS_READABLE(Private)) { + /* This file was NOT open for reading: */ + _GifError = D_GIF_ERR_NOT_READABLE; + return GIF_ERROR; + } + + File = Private->File; + + if (GifFile->Image.ColorMap) { + FreeMapObject(GifFile->Image.ColorMap); + GifFile->Image.ColorMap = NULL; + } + + if (GifFile->SColorMap) { + FreeMapObject(GifFile->SColorMap); + GifFile->SColorMap = NULL; + } + + if (Private) { + free((char *)Private); + Private = NULL; + } + + if (GifFile->SavedImages) { + FreeSavedImages(GifFile); + GifFile->SavedImages = NULL; + } + + free(GifFile); + + if (File && (fclose(File) != 0)) { + _GifError = D_GIF_ERR_CLOSE_FAILED; + return GIF_ERROR; + } + 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) { + _GifError = D_GIF_ERR_READ_FAILED; + return GIF_ERROR; + } + + *Word = (((unsigned int)c[1]) << 8) + c[0]; + 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: */ + _GifError = 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; + + if (READ(GifFile, &Buf, 1) != 1) { + _GifError = D_GIF_ERR_READ_FAILED; + 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) { + _GifError = 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. */ + if (i != LineLen - 1 || Private->PixelCount != 0) { + _GifError = D_GIF_ERR_EOF_TOO_SOON; + 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 { + /* 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 { + _GifError = D_GIF_ERR_IMAGE_DEFECT; + return GIF_ERROR; + } + } else + CrntPrefix = CrntCode; + + /* Now (if image is O.K.) we should not get an 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 can not + * 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) { + _GifError = 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: */ + _GifError = 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 succesfully. + *****************************************************************************/ +static int +DGifDecompressInput(GifFileType * GifFile, + int *Code) { + + GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private; + + GifByteType NextByte; + static 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) { + _GifError = 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) { + _GifError = 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) { + _GifError = D_GIF_ERR_IMAGE_DEFECT; + return GIF_ERROR; + } + if (READ(GifFile, &Buf[1], Buf[0]) != Buf[0]) { + _GifError = 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; +} +#ifndef _GBA_NO_FILEIO + +/****************************************************************************** + * This routine reads an entire GIF into core, hanging all its state info off + * the GifFileType pointer. Call DGifOpenFileName() or DGifOpenFileHandle() + * first to initialize I/O. Its inverse is EGifSpew(). + ******************************************************************************/ +int +DGifSlurp(GifFileType * GifFile) { + + int ImageSize; + GifRecordType RecordType; + SavedImage *sp; + GifByteType *ExtData; + SavedImage 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 = (unsigned char *)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->ExtensionBlocks = temp_save.ExtensionBlocks; + sp->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->Function = sp->ExtensionBlocks[0].Function; + } + break; + + case EXTENSION_RECORD_TYPE: + if (DGifGetExtension(GifFile, &temp_save.Function, &ExtData) == + GIF_ERROR) + return (GIF_ERROR); + while (ExtData != NULL) { + + /* Create an extension block with our data */ + if (AddExtensionBlock(&temp_save, ExtData[0], &ExtData[1]) + == GIF_ERROR) + return (GIF_ERROR); + + if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR) + return (GIF_ERROR); + temp_save.Function = 0; + } + 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); +} +#endif /* _GBA_NO_FILEIO */ |