gpsinfo.c - platform/external/jhead - Git at Google

 //--------------------------------------------------------------------------
 // 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_PROCESSING_METHOD 27
 #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_URATIONAL, 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_UNDEFINED, -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 EXIF_ASCII_PREFIX_LEN (sizeof(ExifAsciiPrefix))

 // Define the line below to turn on poor man's debugging output
 #undef SUPERDEBUG

 #ifdef SUPERDEBUG
 #define printf ALOGE
 #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;

     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[MAX_BUF_SIZE];
             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, MAX_BUF_SIZE);
                 }else{
                     strncpy(ImageInfo.GpsLongRaw, TempString, MAX_BUF_SIZE);
                 }
                 break;

             case TAG_GPS_ALT_REF:
                 ImageInfo.GpsAlt[0] = (char)(ValuePtr[0] ? '-' : ' ');
                 ImageInfo.GpsAltRef = (char)ValuePtr[0];
                 break;

             case TAG_GPS_ALT:
                 sprintf(ImageInfo.GpsAlt + 1, "%.2fm",
                     ConvertAnyFormat(ValuePtr, Format));
                 ImageInfo.GpsAltRaw.num = Get32u(ValuePtr);
                 ImageInfo.GpsAltRaw.denom = Get32u(4+(char *)ValuePtr);
                 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;

             case TAG_GPS_PROCESSING_METHOD:
                 if (ByteCount > EXIF_ASCII_PREFIX_LEN &&
                     memcmp(ValuePtr, ExifAsciiPrefix, EXIF_ASCII_PREFIX_LEN) == 0) {
                     int length =
                         ByteCount < GPS_PROCESSING_METHOD_LEN + EXIF_ASCII_PREFIX_LEN ?
                         ByteCount - EXIF_ASCII_PREFIX_LEN : GPS_PROCESSING_METHOD_LEN;
                     memcpy(ImageInfo.GpsProcessingMethod,
                         (char*)(ValuePtr + EXIF_ASCII_PREFIX_LEN), length);
                     ImageInfo.GpsProcessingMethod[length] = 0;
                 } else {
                     ALOGW("Unsupported encoding for GPSProcessingMethod");
                 }
                 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");
             }
         }
     }
 }
	//--------------------------------------------------------------------------
	// 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_PROCESSING_METHOD 27
	#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_URATIONAL, 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_UNDEFINED, -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 EXIF_ASCII_PREFIX_LEN (sizeof(ExifAsciiPrefix))

	// Define the line below to turn on poor man's debugging output
	#undef SUPERDEBUG

	#ifdef SUPERDEBUG
	#define printf ALOGE
	#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;

	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[MAX_BUF_SIZE];
	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, MAX_BUF_SIZE);
	}else{
	strncpy(ImageInfo.GpsLongRaw, TempString, MAX_BUF_SIZE);
	}
	break;

	case TAG_GPS_ALT_REF:
	ImageInfo.GpsAlt[0] = (char)(ValuePtr[0] ? '-' : ' ');
	ImageInfo.GpsAltRef = (char)ValuePtr[0];
	break;

	case TAG_GPS_ALT:
	sprintf(ImageInfo.GpsAlt + 1, "%.2fm",
	ConvertAnyFormat(ValuePtr, Format));
	ImageInfo.GpsAltRaw.num = Get32u(ValuePtr);
	ImageInfo.GpsAltRaw.denom = Get32u(4+(char *)ValuePtr);
	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;

	case TAG_GPS_PROCESSING_METHOD:
	if (ByteCount > EXIF_ASCII_PREFIX_LEN &&
	memcmp(ValuePtr, ExifAsciiPrefix, EXIF_ASCII_PREFIX_LEN) == 0) {
	int length =
	ByteCount < GPS_PROCESSING_METHOD_LEN + EXIF_ASCII_PREFIX_LEN ?
	ByteCount - EXIF_ASCII_PREFIX_LEN : GPS_PROCESSING_METHOD_LEN;
	memcpy(ImageInfo.GpsProcessingMethod,
	(char*)(ValuePtr + EXIF_ASCII_PREFIX_LEN), length);
	ImageInfo.GpsProcessingMethod[length] = 0;
	} else {
	ALOGW("Unsupported encoding for GPSProcessingMethod");
	}
	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");
	}
	}
	}
	}