libgif库以及提供libgif的c++封装类

// g++ gif_wrapper.cpp -o testgif -L./lib -lgif -I./lib -I./ #include <stdlib.h> #include <stdio.h> #include <ctype.h> #include <string.h> #include <stdbool.h> #include <fcntl.h> #include "gif_wrapper.h" CGifImage::CGifImage():mpGifFile(NULL),mpScreenBuffer(NULL) { } CGifImage::~CGifImage() { close(); } void CGifImage::close() { if (NULL != mpScreenBuffer) { (void)free(mpScreenBuffer); mpScreenBuffer=NULL; } if (NULL != mpGifFile) { int Error=0; DGifCloseFile(mpGifFile, &Error); mpGifFile=NULL; } } bool CGifImage::open( const char* gif_path ) { GifFileType *GifFile=NULL; GifRowType * ScreenBuffer=NULL; int i, j, Size, Row, Col, Width, Height, ExtCode, Count,Error; GifRecordType RecordType; GifByteType *Extension; int ImageNum = 0; int InterlacedOffset[] = { 0, 4, 2, 1 }; /* The way Interlaced image should. */ int InterlacedJumps[] = { 8, 8, 4, 2 }; /* be read - offsets and jumps... */ if ((GifFile = DGifOpenFileName(gif_path, &Error)) == NULL) { close(); return false; } /* * * Allocate the screen as vector of column of rows. Note this * * screen is device independent - it's the screen defined by the * * GIF file parameters. * */ if ((ScreenBuffer = (GifRowType *)malloc(GifFile->SHeight * sizeof(GifRowType))) == NULL) { //GIF_EXIT("Failed to allocate memory required, aborted."); close(); return false; } Size = GifFile->SWidth * sizeof(GifPixelType);/* Size in bytes one row.*/ if ((ScreenBuffer[0] = (GifRowType) malloc(Size)) == NULL) /* First row. */ { //GIF_EXIT("Failed to allocate memory required, aborted."); close(); return false; } for (i = 0; i < GifFile->SWidth; i++) /* Set its color to BackGround. */ ScreenBuffer[0][i] = GifFile->SBackGroundColor; for (i = 1; i < GifFile->SHeight; i++) { /* Allocate the other rows, and set their color to background too: */ if ((ScreenBuffer[i] = (GifRowType) malloc(Size)) == NULL) { //GIF_EXIT("Failed to allocate memory required, aborted."); close(); return false; } memcpy(ScreenBuffer[i], ScreenBuffer[0], Size); } /* Scan the content of the GIF file and load the image(s) in: */ do { if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR) { //PrintGifError(GifFile->Error); //exit(EXIT_FAILURE); close(); return false; } switch (RecordType) { case IMAGE_DESC_RECORD_TYPE: if (DGifGetImageDesc(GifFile) == GIF_ERROR) { //PrintGifError(GifFile->Error); //exit(EXIT_FAILURE); close(); return false; } Row = GifFile->Image.Top; /* Image Position relative to Screen. */ Col = GifFile->Image.Left; Width = GifFile->Image.Width; Height = GifFile->Image.Height; //GifQprintf("\n%s: Image %d at (%d, %d) [%dx%d]: ", PROGRAM_NAME, ++ImageNum, Col, Row, Width, Height); if (GifFile->Image.Left + GifFile->Image.Width > GifFile->SWidth || GifFile->Image.Top + GifFile->Image.Height > GifFile->SHeight) { //fprintf(stderr, "Image %d is not confined to screen dimension, aborted.\n",ImageNum); //exit(EXIT_FAILURE); close(); return false; } if (GifFile->Image.Interlace) { /* Need to perform 4 passes on the images: */ for (Count = i = 0; i < 4; i++) for (j = Row + InterlacedOffset[i]; j < Row + Height;j += InterlacedJumps[i]) { //GifQprintf("\b\b\b\b%-4d", Count++); if (DGifGetLine(GifFile, &ScreenBuffer[j][Col],Width) == GIF_ERROR) { //PrintGifError(GifFile->Error); //exit(EXIT_FAILURE); close(); return false; } } } else { for (i = 0; i < Height; i++) { //GifQprintf("\b\b\b\b%-4d", i); if (DGifGetLine(GifFile, &ScreenBuffer[Row++][Col],Width) == GIF_ERROR) { //PrintGifError(GifFile->Error); //exit(EXIT_FAILURE); close(); return false; } } } break; case EXTENSION_RECORD_TYPE: /* Skip any extension blocks in file: */ if (DGifGetExtension(GifFile, &ExtCode, &Extension) == GIF_ERROR) { //PrintGifError(GifFile->Error); //exit(EXIT_FAILURE); close(); return false; } while (Extension != NULL) { if (DGifGetExtensionNext(GifFile, &Extension) == GIF_ERROR) { //PrintGifError(GifFile->Error); //exit(EXIT_FAILURE); close(); return false; } } break; case TERMINATE_RECORD_TYPE: break; default: /* Should be trapped by DGifGetRecordType. */ break; } } while (RecordType != TERMINATE_RECORD_TYPE); // printf("open finish:GifFile=%x width=%d,height=%d ScreenBuffer=%x\n",GifFile,GifFile->SWidth,GifFile->SHeight,ScreenBuffer); mpGifFile=GifFile; mpScreenBuffer=ScreenBuffer; return true; } int main() { CGifImage gif; if (false == gif.open("0.gif")) { printf("Error: gif.open\n"); return 1; } ColorMapObject *ColorMap = (gif.mpGifFile->Image.ColorMap? gif.mpGifFile->Image.ColorMap: gif.mpGifFile->SColorMap); if (ColorMap == NULL) { printf("Error: ColorMap NULL\n"); return 2; } printf("info:gif=%x width=%d,height=%d\n",(void*)&gif,gif.mpGifFile->SWidth,gif.mpGifFile->SHeight); GifRowType GifRow; GifColorType *ColorMapEntry; for (int i = 0; i < gif.mpGifFile->SHeight; i++) { GifRow = gif.mpScreenBuffer[i]; for (int j = 0; j < gif.mpGifFile->SWidth; j++) { ColorMapEntry = &ColorMap->Colors[GifRow[j]]; printf("row-col=(%d,%d) color=%d rgb=(%d %d %d)\n",i,j,GifRow[j],ColorMapEntry->Red,ColorMapEntry->Green,ColorMapEntry->Blue); } } printf("ok\n"); return 0; }