vc读取相片拍摄日期及相机手机类型

/* * File: exif.cpp * Purpose: cpp EXIF reader * 16/Mar/2003 <ing.davide.pizzolato@libero.it> * based on jhead-1.8 by Matthias Wandel <mwandel(at)rim(dot)net> */ #include "exif.h" //////////////////////////////////////////////////////////////////////////////// Cexif::Cexif(EXIFINFO* info) { if (info) { m_exifinfo = info; freeinfo = false; } else { m_exifinfo = new EXIFINFO; memset(m_exifinfo,0,sizeof(EXIFINFO)); freeinfo = true; } m_szLastError[0]='\0'; ExifImageWidth = MotorolaOrder = 0; SectionsRead=0; memset(&Sections, 0, MAX_SECTIONS * sizeof(Section_t)); } //////////////////////////////////////////////////////////////////////////////// Cexif::~Cexif() { for(int i=0;i<MAX_SECTIONS;i++) if(Sections[i].Data) free(Sections[i].Data); if (freeinfo) delete m_exifinfo; } //////////////////////////////////////////////////////////////////////////////// bool Cexif::DecodeExif(FILE * hFile) { int a; int HaveCom = 0; a = fgetc(hFile); if (a != 0xff || fgetc(hFile) != M_SOI){ return 0; } for(;;){ int itemlen; int marker = 0; int ll,lh, got; unsigned char * Data; if (SectionsRead >= MAX_SECTIONS){ strcpy(m_szLastError,"Too many sections in jpg file"); return 0; } for (a=0;a<7;a++){ marker = fgetc(hFile); if (marker != 0xff) break; if (a >= 6){ printf("too many padding unsigned chars\n"); return 0; } } if (marker == 0xff){ // 0xff is legal padding, but if we get that many, something's wrong. strcpy(m_szLastError,"too many padding unsigned chars!"); return 0; } Sections[SectionsRead].Type = marker; // Read the length of the section. lh = fgetc(hFile); ll = fgetc(hFile); itemlen = (lh << 8) | ll; if (itemlen < 2){ strcpy(m_szLastError,"invalid marker"); return 0; } Sections[SectionsRead].Size = itemlen; Data = (unsigned char *)malloc(itemlen); if (Data == NULL){ strcpy(m_szLastError,"Could not allocate memory"); return 0; } Sections[SectionsRead].Data = Data; // Store first two pre-read unsigned chars. Data[0] = (unsigned char)lh; Data[1] = (unsigned char)ll; got = fread(Data+2, 1, itemlen-2,hFile); // Read the whole section. if (got != itemlen-2){ strcpy(m_szLastError,"Premature end of file?"); return 0; } SectionsRead += 1; switch(marker){ case M_SOS: // stop before hitting compressed data // If reading entire image is requested, read the rest of the data. /*if (ReadMode & READ_IMAGE){ int cp, ep, size; // Determine how much file is left. cp = ftell(infile); fseek(infile, 0, SEEK_END); ep = ftell(infile); fseek(infile, cp, SEEK_SET); size = ep-cp; Data = (uchar *)malloc(size); if (Data == NULL){ strcpy(m_szLastError,"could not allocate data for entire image"); return 0; } got = fread(Data, 1, size, infile); if (got != size){ strcpy(m_szLastError,"could not read the rest of the image"); return 0; } Sections[SectionsRead].Data = Data; Sections[SectionsRead].Size = size; Sections[SectionsRead].Type = PSEUDO_IMAGE_MARKER; SectionsRead ++; HaveAll = 1; }*/ return 1; case M_EOI: // in case it's a tables-only JPEG stream printf("No image in jpeg!\n"); return 0; case M_COM: // Comment section if (HaveCom){ // Discard this section. free(Sections[--SectionsRead].Data); Sections[SectionsRead].Data=0; }else{ process_COM(Data, itemlen); HaveCom = 1; } break; case M_JFIF: // Regular jpegs always have this tag, exif images have the exif // marker instead, althogh ACDsee will write images with both markers. // this program will re-create this marker on absence of exif marker. // hence no need to keep the copy from the file. free(Sections[--SectionsRead].Data); Sections[SectionsRead].Data=0; break; case M_EXIF: // Seen files from some 'U-lead' software with Vivitar scanner // that uses marker 31 for non exif stuff. Thus make sure // it says 'Exif' in the section before treating it as exif. if (memcmp(Data+2, "Exif", 4) == 0){ m_exifinfo->IsExif = process_EXIF((unsigned char *)Data+2, itemlen); }else{ // Discard this section. free(Sections[--SectionsRead].Data); Sections[SectionsRead].Data=0; } break; case M_SOF0: case M_SOF1: case M_SOF2: case M_SOF3: case M_SOF5: case M_SOF6: case M_SOF7: case M_SOF9: case M_SOF10: case M_SOF11: case M_SOF13: case M_SOF14: case M_SOF15: process_SOFn(Data, marker); break; default: // Skip any other sections. //if (ShowTags) printf("Jpeg section marker 0x%02x size %d\n",marker, itemlen); break; } } return 1; } //////////////////////////////////////////////////////////////////////////////// /*-------------------------------------------------------------------------- Process a EXIF marker Describes all the drivel that most digital cameras include... --------------------------------------------------------------------------*/ bool Cexif::process_EXIF(unsigned char * CharBuf, unsigned int length) { m_exifinfo->FlashUsed = 0; /* If it's from a digicam, and it used flash, it says so. */ m_exifinfo->Comments[0] = '\0'; /* Initial value - null string */ ExifImageWidth = 0; { /* Check the EXIF header component */ static const unsigned char ExifHeader[] = "Exif\0\0"; if (memcmp(CharBuf+0, ExifHeader,6)){ strcpy(m_szLastError,"Incorrect Exif header"); return 0; } } if (memcmp(CharBuf+6,"II",2) == 0){ MotorolaOrder = 0; }else{ if (memcmp(CharBuf+6,"MM",2) == 0){ MotorolaOrder = 1; }else{ strcpy(m_szLastError,"Invalid Exif alignment marker."); return 0; } } /* Check the next two values for correctness. */ if (Get16u(CharBuf+8) != 0x2a){ strcpy(m_szLastError,"Invalid Exif start (1)"); return 0; } int FirstOffset = Get32u(CharBuf+10); if (FirstOffset < 8 || FirstOffset > 16){ // I used to ensure this was set to 8 (website I used indicated its 8) // but PENTAX Optio 230 has it set differently, and uses it as offset. (Sept 11 2002) strcpy(m_szLastError,"Suspicious offset of first IFD value"); return 0; } unsigned char * LastExifRefd = CharBuf; /* First directory starts 16 unsigned chars in. Offset