| //-------------------------------------------------------------------------- |
| // Parsing of GPS info from exif header. |
| // |
| // Matthias Wandel, Dec 1999 - Dec 2002 |
| //-------------------------------------------------------------------------- |
| #include "jhead.h" |
| |
| #include <string.h> |
| #include <utils/Log.h> |
| |
| |
| #define TAG_GPS_LAT_REF 1 |
| #define TAG_GPS_LAT 2 |
| #define TAG_GPS_LONG_REF 3 |
| #define TAG_GPS_LONG 4 |
| #define TAG_GPS_ALT_REF 5 |
| #define TAG_GPS_ALT 6 |
| #define TAG_GPS_TIMESTAMP 7 |
| #define TAG_GPS_DATESTAMP 29 |
| |
| static TagTable_t GpsTags[]= { |
| { 0x00, "GPSVersionID", FMT_BYTE, 4}, |
| { 0x01, "GPSLatitudeRef", FMT_STRING, 2}, |
| { 0x02, "GPSLatitude", FMT_URATIONAL, 3}, |
| { 0x03, "GPSLongitudeRef", FMT_STRING, 2}, |
| { 0x04, "GPSLongitude", FMT_URATIONAL, 3}, |
| { 0x05, "GPSAltitudeRef", FMT_BYTE, 1}, |
| { 0x06, "GPSAltitude", FMT_SRATIONAL, 1}, |
| { 0x07, "GPSTimeStamp", FMT_SRATIONAL, 3}, |
| { 0x08, "GPSSatellites", FMT_STRING, -1}, |
| { 0x09, "GPSStatus", FMT_STRING, 2}, |
| { 0x0A, "GPSMeasureMode", FMT_STRING, 2}, |
| { 0x0B, "GPSDOP", FMT_SRATIONAL, 1}, |
| { 0x0C, "GPSSpeedRef", FMT_STRING, 2}, |
| { 0x0D, "GPSSpeed", FMT_SRATIONAL, 1}, |
| { 0x0E, "GPSTrackRef", FMT_STRING, 2}, |
| { 0x0F, "GPSTrack", FMT_SRATIONAL, 1}, |
| { 0x10, "GPSImgDirectionRef", FMT_STRING, -1}, |
| { 0x11, "GPSImgDirection", FMT_SRATIONAL, 1}, |
| { 0x12, "GPSMapDatum", FMT_STRING, -1}, |
| { 0x13, "GPSDestLatitudeRef", FMT_STRING, 2}, |
| { 0x14, "GPSDestLatitude", FMT_SRATIONAL, 3}, |
| { 0x15, "GPSDestLongitudeRef", FMT_STRING, 2}, |
| { 0x16, "GPSDestLongitude", FMT_SRATIONAL, 3}, |
| { 0x17, "GPSDestBearingRef", FMT_STRING, 1}, |
| { 0x18, "GPSDestBearing", FMT_SRATIONAL, 1}, |
| { 0x19, "GPSDestDistanceRef", FMT_STRING, 2}, |
| { 0x1A, "GPSDestDistance", FMT_SRATIONAL, 1}, |
| { 0x1B, "GPSProcessingMethod", FMT_STRING, -1}, |
| { 0x1C, "GPSAreaInformation", FMT_STRING, -1}, |
| { 0x1D, "GPSDateStamp", FMT_STRING, 11}, |
| { 0x1E, "GPSDifferential", FMT_SSHORT, 1}, |
| }; |
| |
| #define MAX_GPS_TAG (sizeof(GpsTags) / sizeof(TagTable_t)) |
| |
| // Define the line below to turn on poor man's debugging output |
| #undef SUPERDEBUG |
| |
| #ifdef SUPERDEBUG |
| #define printf LOGE |
| #endif |
| |
| |
| int IsGpsTag(const char* tag) { |
| return strstr(tag, "GPS") == tag; |
| } |
| |
| TagTable_t* GpsTagToTagTableEntry(unsigned short tag) |
| { |
| unsigned int i; |
| for (i = 0; i < MAX_GPS_TAG; i++) { |
| if (GpsTags[i].Tag == tag) { |
| printf("found tag %d", tag); |
| int format = GpsTags[i].Format; |
| if (format == 0) { |
| printf("tag %s format not defined", GpsTags[i].Desc); |
| return NULL; |
| } |
| return &GpsTags[i]; |
| } |
| } |
| printf("tag %d NOT FOUND", tag); |
| return NULL; |
| } |
| |
| int GpsTagToFormatType(unsigned short tag) |
| { |
| unsigned int i; |
| for (i = 0; i < MAX_GPS_TAG; i++) { |
| if (GpsTags[i].Tag == tag) { |
| printf("found tag %d", tag); |
| int format = GpsTags[i].Format; |
| if (format == 0) { |
| printf("tag %s format not defined", GpsTags[i].Desc); |
| return -1; |
| } |
| return format; |
| } |
| } |
| printf("tag %d NOT FOUND", tag); |
| return -1; |
| } |
| |
| int GpsTagNameToValue(const char* tagName) |
| { |
| unsigned int i; |
| for (i = 0; i < MAX_GPS_TAG; i++) { |
| if (strcmp(GpsTags[i].Desc, tagName) == 0) { |
| printf("found GPS tag %s val %d", GpsTags[i].Desc, GpsTags[i].Tag); |
| return GpsTags[i].Tag; |
| } |
| } |
| printf("GPS tag %s NOT FOUND", tagName); |
| return -1; |
| } |
| |
| |
| //-------------------------------------------------------------------------- |
| // Process GPS info directory |
| //-------------------------------------------------------------------------- |
| void ProcessGpsInfo(unsigned char * DirStart, int ByteCountUnused, unsigned char * OffsetBase, unsigned ExifLength) |
| { |
| int de; |
| unsigned a; |
| int NumDirEntries; |
| |
| NumDirEntries = Get16u(DirStart); |
| #define DIR_ENTRY_ADDR(Start, Entry) (Start+2+12*(Entry)) |
| |
| if (ShowTags){ |
| printf("(dir has %d entries)\n",NumDirEntries); |
| } |
| |
| ImageInfo.GpsInfoPresent = TRUE; |
| strcpy(ImageInfo.GpsLat, "? ?"); |
| strcpy(ImageInfo.GpsLong, "? ?"); |
| ImageInfo.GpsAlt[0] = 0; |
| bzero(ImageInfo.GpsTimeStamp, sizeof(ImageInfo.GpsTimeStamp)); |
| bzero(ImageInfo.GpsDateStamp, sizeof(ImageInfo.GpsDateStamp)); |
| |
| for (de=0;de<NumDirEntries;de++){ |
| unsigned Tag, Format, Components; |
| unsigned char * ValuePtr; |
| int ComponentSize; |
| unsigned ByteCount; |
| unsigned char * DirEntry; |
| DirEntry = DIR_ENTRY_ADDR(DirStart, de); |
| |
| if (DirEntry+12 > OffsetBase+ExifLength){ |
| ErrNonfatal("GPS info directory goes past end of exif",0,0); |
| return; |
| } |
| |
| Tag = Get16u(DirEntry); |
| Format = Get16u(DirEntry+2); |
| Components = Get32u(DirEntry+4); |
| |
| if ((Format-1) >= NUM_FORMATS) { |
| // (-1) catches illegal zero case as unsigned underflows to positive large. |
| ErrNonfatal("Illegal number format %d for tag %04x", Format, Tag); |
| continue; |
| } |
| |
| ComponentSize = BytesPerFormat[Format]; |
| ByteCount = Components * ComponentSize; |
| |
| #ifdef SUPERDEBUG |
| printf("GPS tag %x format %s #components %d componentsize %d bytecount %d", Tag, formatStr(Format), Components, ComponentSize, |
| ByteCount); |
| #endif |
| |
| if (ByteCount > 4){ |
| unsigned OffsetVal; |
| OffsetVal = Get32u(DirEntry+8); |
| // If its bigger than 4 bytes, the dir entry contains an offset. |
| if (OffsetVal+ByteCount > ExifLength){ |
| // Bogus pointer offset and / or bytecount value |
| ErrNonfatal("Illegal value pointer for tag %04x", Tag,0); |
| continue; |
| } |
| ValuePtr = OffsetBase+OffsetVal; |
| }else{ |
| // 4 bytes or less and value is in the dir entry itself |
| ValuePtr = DirEntry+8; |
| } |
| |
| switch(Tag){ |
| char FmtString[21]; |
| char TempString[50]; |
| double Values[3]; |
| |
| case TAG_GPS_LAT_REF: |
| ImageInfo.GpsLat[0] = ValuePtr[0]; |
| ImageInfo.GpsLatRef[0] = ValuePtr[0]; |
| ImageInfo.GpsLatRef[1] = '\0'; |
| break; |
| |
| case TAG_GPS_LONG_REF: |
| ImageInfo.GpsLong[0] = ValuePtr[0]; |
| ImageInfo.GpsLongRef[0] = ValuePtr[0]; |
| ImageInfo.GpsLongRef[1] = '\0'; |
| break; |
| |
| case TAG_GPS_LAT: |
| case TAG_GPS_LONG: |
| if (Format != FMT_URATIONAL){ |
| ErrNonfatal("Inappropriate format (%d) for GPS coordinates!", Format, 0); |
| } |
| strcpy(FmtString, "%0.0fd %0.0fm %0.0fs"); |
| for (a=0;a<3;a++){ |
| int den, digits; |
| |
| den = Get32s(ValuePtr+4+a*ComponentSize); |
| digits = 0; |
| while (den > 1 && digits <= 6){ |
| den = den / 10; |
| digits += 1; |
| } |
| if (digits > 6) digits = 6; |
| FmtString[1+a*7] = (char)('2'+digits+(digits ? 1 : 0)); |
| FmtString[3+a*7] = (char)('0'+digits); |
| |
| Values[a] = ConvertAnyFormat(ValuePtr+a*ComponentSize, Format); |
| } |
| |
| sprintf(TempString, FmtString, Values[0], Values[1], Values[2]); |
| |
| if (Tag == TAG_GPS_LAT){ |
| strncpy(ImageInfo.GpsLat+2, TempString, 29); |
| }else{ |
| strncpy(ImageInfo.GpsLong+2, TempString, 29); |
| } |
| |
| sprintf(TempString, "%d/%d,%d/%d,%d/%d", |
| Get32s(ValuePtr), Get32s(4+(char*)ValuePtr), |
| Get32s(8+(char*)ValuePtr), Get32s(12+(char*)ValuePtr), |
| Get32s(16+(char*)ValuePtr), Get32s(20+(char*)ValuePtr)); |
| if (Tag == TAG_GPS_LAT){ |
| strncpy(ImageInfo.GpsLatRaw, TempString, 31); |
| }else{ |
| strncpy(ImageInfo.GpsLongRaw, TempString, 31); |
| } |
| break; |
| |
| case TAG_GPS_ALT_REF: |
| ImageInfo.GpsAlt[0] = (char)(ValuePtr[0] ? '-' : ' '); |
| break; |
| |
| case TAG_GPS_ALT: |
| sprintf(ImageInfo.GpsAlt + 1, "%.2fm", |
| ConvertAnyFormat(ValuePtr, Format)); |
| break; |
| |
| case TAG_GPS_TIMESTAMP: |
| snprintf(ImageInfo.GpsTimeStamp, |
| sizeof(ImageInfo.GpsTimeStamp), "%d:%d:%d", |
| (int) ConvertAnyFormat(ValuePtr, Format), |
| (int) ConvertAnyFormat(ValuePtr + 8, Format), |
| (int) ConvertAnyFormat(ValuePtr + 16, Format) |
| ); |
| break; |
| |
| case TAG_GPS_DATESTAMP: |
| strncpy(ImageInfo.GpsDateStamp, (char*)ValuePtr, sizeof(ImageInfo.GpsDateStamp)); |
| break; |
| } |
| |
| if (ShowTags){ |
| // Show tag value. |
| if (Tag < MAX_GPS_TAG){ |
| printf(" %s =", GpsTags[Tag].Desc); |
| }else{ |
| // Show unknown tag |
| printf(" Illegal GPS tag %04x=", Tag); |
| } |
| |
| switch(Format){ |
| case FMT_UNDEFINED: |
| // Undefined is typically an ascii string. |
| |
| case FMT_STRING: |
| // String arrays printed without function call (different from int arrays) |
| { |
| printf("\""); |
| for (a=0;a<ByteCount;a++){ |
| int ZeroSkipped = 0; |
| if (ValuePtr[a] >= 32){ |
| if (ZeroSkipped){ |
| printf("?"); |
| ZeroSkipped = 0; |
| } |
| putchar(ValuePtr[a]); |
| }else{ |
| if (ValuePtr[a] == 0){ |
| ZeroSkipped = 1; |
| } |
| } |
| } |
| printf("\"\n"); |
| } |
| break; |
| |
| default: |
| // Handle arrays of numbers later (will there ever be?) |
| for (a=0;;){ |
| PrintFormatNumber(ValuePtr+a*ComponentSize, Format, ByteCount); |
| if (++a >= Components) break; |
| printf(", "); |
| } |
| printf("\n"); |
| } |
| } |
| } |
| } |
| |
| |
