| 1 | #------------------------------------------------------------------------------
|
|---|
| 2 | # File: Shift.pl
|
|---|
| 3 | #
|
|---|
| 4 | # Description: ExifTool time shifting routines
|
|---|
| 5 | #
|
|---|
| 6 | # Revisions: 10/28/2005 - P. Harvey Created
|
|---|
| 7 | # 03/13/2019 - PH Added single-argument form of ShiftTime()
|
|---|
| 8 | #------------------------------------------------------------------------------
|
|---|
| 9 |
|
|---|
| 10 | package Image::ExifTool;
|
|---|
| 11 |
|
|---|
| 12 | use strict;
|
|---|
| 13 |
|
|---|
| 14 | sub ShiftTime($;$$$);
|
|---|
| 15 |
|
|---|
| 16 | #------------------------------------------------------------------------------
|
|---|
| 17 | # apply shift to value in new value hash
|
|---|
| 18 | # Inputs: 0) ExifTool ref, 1) shift type, 2) shift string, 3) raw date/time value,
|
|---|
| 19 | # 4) new value hash ref
|
|---|
| 20 | # Returns: error string or undef on success and updates value in new value hash
|
|---|
| 21 | sub ApplyShift($$$$;$)
|
|---|
| 22 | {
|
|---|
| 23 | my ($self, $func, $shift, $val, $nvHash) = @_;
|
|---|
| 24 |
|
|---|
| 25 | # get shift direction from first character in shift string
|
|---|
| 26 | my $pre = ($shift =~ s/^(\+|-)//) ? $1 : '+';
|
|---|
| 27 | my $dir = ($pre eq '+') ? 1 : -1;
|
|---|
| 28 | my $tagInfo = $$nvHash{TagInfo};
|
|---|
| 29 | my $tag = $$tagInfo{Name};
|
|---|
| 30 | my $shiftOffset;
|
|---|
| 31 | if ($$nvHash{ShiftOffset}) {
|
|---|
| 32 | $shiftOffset = $$nvHash{ShiftOffset};
|
|---|
| 33 | } else {
|
|---|
| 34 | $shiftOffset = $$nvHash{ShiftOffset} = { };
|
|---|
| 35 | }
|
|---|
| 36 |
|
|---|
| 37 | # initialize handler for eval warnings
|
|---|
| 38 | local $SIG{'__WARN__'} = \&SetWarning;
|
|---|
| 39 | SetWarning(undef);
|
|---|
| 40 |
|
|---|
| 41 | # shift is applied to ValueConv value, so we must ValueConv-Shift-ValueConvInv
|
|---|
| 42 | my ($type, $err);
|
|---|
| 43 | foreach $type ('ValueConv','Shift','ValueConvInv') {
|
|---|
| 44 | if ($type eq 'Shift') {
|
|---|
| 45 | #### eval ShiftXxx function
|
|---|
| 46 | $err = eval "Shift$func(\$val, \$shift, \$dir, \$shiftOffset)";
|
|---|
| 47 | } elsif ($$tagInfo{$type}) {
|
|---|
| 48 | my $conv = $$tagInfo{$type};
|
|---|
| 49 | if (ref $conv eq 'CODE') {
|
|---|
| 50 | $val = &$conv($val, $self);
|
|---|
| 51 | } else {
|
|---|
| 52 | return "Can't handle $type for $tag in ApplyShift()" if ref $$tagInfo{$type};
|
|---|
| 53 | #### eval ValueConv/ValueConvInv ($val, $self)
|
|---|
| 54 | $val = eval $$tagInfo{$type};
|
|---|
| 55 | }
|
|---|
| 56 | } else {
|
|---|
| 57 | next;
|
|---|
| 58 | }
|
|---|
| 59 | # handle errors
|
|---|
| 60 | $err and return $err;
|
|---|
| 61 | $@ and SetWarning($@);
|
|---|
| 62 | GetWarning() and return CleanWarning();
|
|---|
| 63 | }
|
|---|
| 64 | # update value in new value hash
|
|---|
| 65 | $nvHash->{Value} = [ $val ];
|
|---|
| 66 | return undef; # success
|
|---|
| 67 | }
|
|---|
| 68 |
|
|---|
| 69 | #------------------------------------------------------------------------------
|
|---|
| 70 | # Check date/time shift
|
|---|
| 71 | # Inputs: 0) shift type, 1) shift string (without sign)
|
|---|
| 72 | # Returns: updated shift string, or undef on error (and may update shift)
|
|---|
| 73 | sub CheckShift($$)
|
|---|
| 74 | {
|
|---|
| 75 | my ($type, $shift) = @_;
|
|---|
| 76 | my $err;
|
|---|
| 77 | if ($type eq 'Time') {
|
|---|
| 78 | return "No shift direction" unless $shift =~ s/^(\+|-)//;
|
|---|
| 79 | # do a test shift to validate the shift string
|
|---|
| 80 | my $testTime = '2005:11:02 09:00:13.25-04:00';
|
|---|
| 81 | $err = ShiftTime($testTime, $shift, $1 eq '+' ? 1 : -1);
|
|---|
| 82 | } else {
|
|---|
| 83 | $err = "Unknown shift type ($type)";
|
|---|
| 84 | }
|
|---|
| 85 | return $err;
|
|---|
| 86 | }
|
|---|
| 87 |
|
|---|
| 88 | #------------------------------------------------------------------------------
|
|---|
| 89 | # return the number of days in a month
|
|---|
| 90 | # Inputs: 0) month number (Jan=1, may be outside range), 1) year
|
|---|
| 91 | # Returns: number of days in month
|
|---|
| 92 | sub DaysInMonth($$)
|
|---|
| 93 | {
|
|---|
| 94 | my ($mon, $year) = @_;
|
|---|
| 95 | my @days = (31,28,31,30,31,30,31,31,30,31,30,31);
|
|---|
| 96 | # adjust to the range [0,11]
|
|---|
| 97 | while ($mon < 1) { $mon += 12; --$year; }
|
|---|
| 98 | while ($mon > 12) { $mon -= 12; ++$year; }
|
|---|
| 99 | # return standard number of days unless february on a leap year
|
|---|
| 100 | return $days[$mon-1] unless $mon == 2 and not $year % 4;
|
|---|
| 101 | # leap years don't occur on even centuries except every 400 years
|
|---|
| 102 | return 29 if $year % 100 or not $year % 400;
|
|---|
| 103 | return 28;
|
|---|
| 104 | }
|
|---|
| 105 |
|
|---|
| 106 | #------------------------------------------------------------------------------
|
|---|
| 107 | # split times into corresponding components: YYYY mm dd HH MM SS tzh tzm
|
|---|
| 108 | # Inputs: 0) date/time or shift string 1) reference to list for returned components
|
|---|
| 109 | # 2) optional reference to list of time components (if shift string)
|
|---|
| 110 | # Returns: true on success
|
|---|
| 111 | # Returned components are 0-Y, 1-M, 2-D, 3-hr, 4-min, 5-sec, 6-tzhr, 7-tzmin
|
|---|
| 112 | sub SplitTime($$;$)
|
|---|
| 113 | {
|
|---|
| 114 | my ($val, $vals, $time) = @_;
|
|---|
| 115 | # insert zeros if missing in shift string
|
|---|
| 116 | if ($time) {
|
|---|
| 117 | $val =~ s/(^|[-+:\s]):/${1}0:/g;
|
|---|
| 118 | $val =~ s/:([:\s]|$)/:0$1/g;
|
|---|
| 119 | }
|
|---|
| 120 | # change dashes to colons in date (for XMP dates)
|
|---|
| 121 | if ($val =~ s/^(\d{4})-(\d{2})-(\d{2})/$1:$2:$3/) {
|
|---|
| 122 | $val =~ tr/T/ /; # change 'T' separator to ' '
|
|---|
| 123 | }
|
|---|
| 124 | # add space before timezone to split it into a separate word
|
|---|
| 125 | $val =~ s/(\+|-)/ $1/;
|
|---|
| 126 | my @words = split ' ', $val;
|
|---|
| 127 | my $err = 1;
|
|---|
| 128 | my @v;
|
|---|
| 129 | for (;;) {
|
|---|
| 130 | my $word = shift @words;
|
|---|
| 131 | last unless defined $word;
|
|---|
| 132 | # split word into separate numbers (allow decimal points but no signs)
|
|---|
| 133 | my @vals = $word =~ /(?=\d|\.\d)\d*(?:\.\d*)?/g or last;
|
|---|
| 134 | if ($word =~ /^(\+|-)/) {
|
|---|
| 135 | # this is the timezone
|
|---|
| 136 | (defined $v[6] or @vals > 2) and $err = 1, last;
|
|---|
| 137 | my $sign = ($1 ne '-') ? 1 : -1;
|
|---|
| 138 | # apply sign to both minutes and seconds
|
|---|
| 139 | $v[6] = $sign * shift(@vals);
|
|---|
| 140 | $v[7] = $sign * (shift(@vals) || 0);
|
|---|
| 141 | } elsif ((@words and $words[0] =~ /^\d+/) or # there is a time word to follow
|
|---|
| 142 | (not $time and $vals[0] =~ /^\d{3}/) or # first value is year (3 or more digits)
|
|---|
| 143 | ($time and not defined $$time[3] and not defined $v[0])) # we don't have a time
|
|---|
| 144 | {
|
|---|
| 145 | # this is a date (must come first)
|
|---|
| 146 | (@v or @vals > 3) and $err = 1, last;
|
|---|
| 147 | not $time and @vals != 3 and $err = 1, last;
|
|---|
| 148 | $v[2] = pop(@vals); # take day first if only one specified
|
|---|
| 149 | $v[1] = pop(@vals) || 0;
|
|---|
| 150 | $v[0] = pop(@vals) || 0;
|
|---|
| 151 | } else {
|
|---|
| 152 | # this is a time (can't come after timezone)
|
|---|
| 153 | (defined $v[3] or defined $v[6] or @vals > 3) and $err = 1, last;
|
|---|
| 154 | not $time and @vals != 3 and @vals != 2 and $err = 1, last;
|
|---|
| 155 | $v[3] = shift(@vals); # take hour first if only one specified
|
|---|
| 156 | $v[4] = shift(@vals) || 0;
|
|---|
| 157 | $v[5] = shift(@vals) || 0;
|
|---|
| 158 | }
|
|---|
| 159 | $err = 0;
|
|---|
| 160 | }
|
|---|
| 161 | return 0 if $err or not @v;
|
|---|
| 162 | if ($time) {
|
|---|
| 163 | # zero any required shift entries which aren't yet defined
|
|---|
| 164 | $v[0] = $v[1] = $v[2] = 0 if defined $$time[0] and not defined $v[0];
|
|---|
| 165 | $v[3] = $v[4] = $v[5] = 0 if defined $$time[3] and not defined $v[3];
|
|---|
| 166 | $v[6] = $v[7] = 0 if defined $$time[6] and not defined $v[6];
|
|---|
| 167 | }
|
|---|
| 168 | @$vals = @v; # return split time components
|
|---|
| 169 | return 1;
|
|---|
| 170 | }
|
|---|
| 171 |
|
|---|
| 172 | #------------------------------------------------------------------------------
|
|---|
| 173 | # shift date/time by components
|
|---|
| 174 | # Inputs: 0) split date/time list ref, 1) split shift list ref,
|
|---|
| 175 | # 2) shift direction, 3) reference to output list of shifted components
|
|---|
| 176 | # 4) number of decimal points in seconds
|
|---|
| 177 | # 5) reference to return time difference due to rounding
|
|---|
| 178 | # Returns: error string or undef on success
|
|---|
| 179 | sub ShiftComponents($$$$$;$)
|
|---|
| 180 | {
|
|---|
| 181 | my ($time, $shift, $dir, $toTime, $dec, $rndPt) = @_;
|
|---|
| 182 | # min/max for Y, M, D, h, m, s
|
|---|
| 183 | my @min = ( 0, 1, 1, 0, 0, 0);
|
|---|
| 184 | my @max = (10000,12,28,24,60,60);
|
|---|
| 185 | my $i;
|
|---|
| 186 | #
|
|---|
| 187 | # apply the shift
|
|---|
| 188 | #
|
|---|
| 189 | my $c = 0;
|
|---|
| 190 | for ($i=0; $i<@$time; ++$i) {
|
|---|
| 191 | my $v = ($$time[$i] || 0) + $dir * ($$shift[$i] || 0) + $c;
|
|---|
| 192 | # handle fractional values by propagating remainders downwards
|
|---|
| 193 | if ($v != int($v) and $i < 5) {
|
|---|
| 194 | my $iv = int($v);
|
|---|
| 195 | $c = ($v - $iv) * $max[$i+1];
|
|---|
| 196 | $v = $iv;
|
|---|
| 197 | } else {
|
|---|
| 198 | $c = 0;
|
|---|
| 199 | }
|
|---|
| 200 | $$toTime[$i] = $v;
|
|---|
| 201 | }
|
|---|
| 202 | # round off seconds to the required number of decimal points
|
|---|
| 203 | my $sec = $$toTime[5];
|
|---|
| 204 | if (defined $sec and $sec != int($sec)) {
|
|---|
| 205 | my $mult = 10 ** $dec;
|
|---|
| 206 | my $rndSec = int($sec * $mult + 0.5 * ($sec <=> 0)) / $mult;
|
|---|
| 207 | $rndPt and $$rndPt = $sec - $rndSec;
|
|---|
| 208 | $$toTime[5] = $rndSec;
|
|---|
| 209 | }
|
|---|
| 210 | #
|
|---|
| 211 | # handle overflows, starting with least significant number first (seconds)
|
|---|
| 212 | #
|
|---|
| 213 | $c = 0;
|
|---|
| 214 | for ($i=5; $i>=0; $i--) {
|
|---|
| 215 | defined $$time[$i] or $c = 0, next;
|
|---|
| 216 | # apply shift and adjust for previous overflow
|
|---|
| 217 | my $v = $$toTime[$i] + $c;
|
|---|
| 218 | $c = 0; # set carry to zero
|
|---|
| 219 | # adjust for over/underflow
|
|---|
| 220 | my ($min, $max) = ($min[$i], $max[$i]);
|
|---|
| 221 | if ($v < $min) {
|
|---|
| 222 | if ($i == 2) { # 2 = day of month
|
|---|
| 223 | do {
|
|---|
| 224 | # add number of days in previous month
|
|---|
| 225 | --$c;
|
|---|
| 226 | my $mon = $$toTime[$i-1] + $c;
|
|---|
| 227 | $v += DaysInMonth($mon, $$toTime[$i-2]);
|
|---|
| 228 | } while ($v < 1);
|
|---|
| 229 | } else {
|
|---|
| 230 | my $fc = ($v - $min) / $max;
|
|---|
| 231 | # carry ($c) must be largest integer equal to or less than $fc
|
|---|
| 232 | $c = int($fc);
|
|---|
| 233 | --$c if $c > $fc;
|
|---|
| 234 | $v -= $c * $max;
|
|---|
| 235 | }
|
|---|
| 236 | } elsif ($v >= $max + $min) {
|
|---|
| 237 | if ($i == 2) {
|
|---|
| 238 | for (;;) {
|
|---|
| 239 | # test against number of days in current month
|
|---|
| 240 | my $mon = $$toTime[$i-1] + $c;
|
|---|
| 241 | my $days = DaysInMonth($mon, $$toTime[$i-2]);
|
|---|
| 242 | last if $v <= $days;
|
|---|
| 243 | $v -= $days;
|
|---|
| 244 | ++$c;
|
|---|
| 245 | last if $v <= 28;
|
|---|
| 246 | }
|
|---|
| 247 | } else {
|
|---|
| 248 | my $fc = ($v - $max - $min) / $max;
|
|---|
| 249 | # carry ($c) must be smallest integer greater than $fc
|
|---|
| 250 | $c = int($fc);
|
|---|
| 251 | ++$c if $c <= $fc;
|
|---|
| 252 | $v -= $c * $max;
|
|---|
| 253 | }
|
|---|
| 254 | }
|
|---|
| 255 | $$toTime[$i] = $v; # save the new value
|
|---|
| 256 | }
|
|---|
| 257 | # handle overflows in timezone
|
|---|
| 258 | if (defined $$toTime[6]) {
|
|---|
| 259 | my $m = $$toTime[6] * 60 + $$toTime[7];
|
|---|
| 260 | $m += 0.5 * ($m <=> 0); # avoid round-off errors
|
|---|
| 261 | $$toTime[6] = int($m / 60);
|
|---|
| 262 | $$toTime[7] = int($m - $$toTime[6] * 60);
|
|---|
| 263 | }
|
|---|
| 264 | return undef; # success
|
|---|
| 265 | }
|
|---|
| 266 |
|
|---|
| 267 | #------------------------------------------------------------------------------
|
|---|
| 268 | # Shift an integer or floating-point number
|
|---|
| 269 | # Inputs: 0) date/time string, 1) shift string, 2) shift direction (+1 or -1)
|
|---|
| 270 | # 3) (unused)
|
|---|
| 271 | # Returns: undef and updates input value
|
|---|
| 272 | sub ShiftNumber($$$;$)
|
|---|
| 273 | {
|
|---|
| 274 | my ($val, $shift, $dir) = @_;
|
|---|
| 275 | $_[0] = $val + $shift * $dir; # return shifted value
|
|---|
| 276 | return undef; # success!
|
|---|
| 277 | }
|
|---|
| 278 |
|
|---|
| 279 | #------------------------------------------------------------------------------
|
|---|
| 280 | # Shift date/time string
|
|---|
| 281 | # Inputs: 0) date/time string, 1) shift string, 2) shift direction (+1 or -1),
|
|---|
| 282 | # or 0 or undef to take shift direction from sign of shift,
|
|---|
| 283 | # 3) reference to ShiftOffset hash (with Date, DateTime, Time, Timezone keys)
|
|---|
| 284 | # or 0) shift string (and operates on $_)
|
|---|
| 285 | # Returns: error string or undef on success and date/time string is updated
|
|---|
| 286 | sub ShiftTime($;$$$)
|
|---|
| 287 | {
|
|---|
| 288 | my ($val, $shift, $dir, $shiftOffset);
|
|---|
| 289 | my (@time, @shift, @toTime, $mode, $needShiftOffset, $dec);
|
|---|
| 290 |
|
|---|
| 291 | if (@_ == 1) { # single argument form of ShiftTime()?
|
|---|
| 292 | $val = $_;
|
|---|
| 293 | $shift = $_[0];
|
|---|
| 294 | } else {
|
|---|
| 295 | ($val, $shift, $dir, $shiftOffset) = @_;
|
|---|
| 296 | }
|
|---|
| 297 | $dir or $dir = ($shift =~ s/^(\+|-)// and $1 eq '-') ? -1 : 1;
|
|---|
| 298 | #
|
|---|
| 299 | # figure out what we are dealing with (time, date or date/time)
|
|---|
| 300 | #
|
|---|
| 301 | SplitTime($val, \@time) or return "Invalid time string ($val)";
|
|---|
| 302 | if (defined $time[0]) {
|
|---|
| 303 | return "Can't shift from year 0000" if $time[0] eq '0000';
|
|---|
| 304 | $mode = defined $time[3] ? 'DateTime' : 'Date';
|
|---|
| 305 | } elsif (defined $time[3]) {
|
|---|
| 306 | $mode = 'Time';
|
|---|
| 307 | }
|
|---|
| 308 | # get number of digits after the seconds decimal point
|
|---|
| 309 | if (defined $time[5] and $time[5] =~ /\.(\d+)/) {
|
|---|
| 310 | $dec = length($1);
|
|---|
| 311 | } else {
|
|---|
| 312 | $dec = 0;
|
|---|
| 313 | }
|
|---|
| 314 | if ($shiftOffset) {
|
|---|
| 315 | $needShiftOffset = 1 unless defined $$shiftOffset{$mode};
|
|---|
| 316 | $needShiftOffset = 1 if defined $time[6] and not defined $$shiftOffset{Timezone};
|
|---|
| 317 | } else {
|
|---|
| 318 | $needShiftOffset = 1;
|
|---|
| 319 | }
|
|---|
| 320 | if ($needShiftOffset) {
|
|---|
| 321 | #
|
|---|
| 322 | # apply date/time shift the hard way
|
|---|
| 323 | #
|
|---|
| 324 | SplitTime($shift, \@shift, \@time) or return "Invalid shift string ($shift)";
|
|---|
| 325 |
|
|---|
| 326 | # change 'Z' timezone to '+00:00' only if necessary
|
|---|
| 327 | if (@shift > 6 and @time <= 6) {
|
|---|
| 328 | $time[6] = $time[7] = 0 if $val =~ s/Z$/\+00:00/;
|
|---|
| 329 | }
|
|---|
| 330 | my $rndDiff;
|
|---|
| 331 | my $err = ShiftComponents(\@time, \@shift, $dir, \@toTime, $dec, \$rndDiff);
|
|---|
| 332 | $err and return $err;
|
|---|
| 333 | #
|
|---|
| 334 | # calculate and save the shift offsets for next time
|
|---|
| 335 | #
|
|---|
| 336 | if ($shiftOffset) {
|
|---|
| 337 | if (defined $time[0] or defined $time[3]) {
|
|---|
| 338 | my @tm1 = (0, 0, 0, 1, 0, 2000);
|
|---|
| 339 | my @tm2 = (0, 0, 0, 1, 0, 2000);
|
|---|
| 340 | if (defined $time[0]) {
|
|---|
| 341 | @tm1[3..5] = reverse @time[0..2];
|
|---|
| 342 | @tm2[3..5] = reverse @toTime[0..2];
|
|---|
| 343 | --$tm1[4]; # month should start from 0
|
|---|
| 344 | --$tm2[4];
|
|---|
| 345 | }
|
|---|
| 346 | my $diff = 0;
|
|---|
| 347 | if (defined $time[3]) {
|
|---|
| 348 | @tm1[0..2] = reverse @time[3..5];
|
|---|
| 349 | @tm2[0..2] = reverse @toTime[3..5];
|
|---|
| 350 | # handle fractional seconds separately
|
|---|
| 351 | $diff = $tm2[0] - int($tm2[0]) - ($tm1[0] - int($tm1[0]));
|
|---|
| 352 | $diff += $rndDiff if defined $rndDiff; # un-do rounding
|
|---|
| 353 | $tm1[0] = int($tm1[0]);
|
|---|
| 354 | $tm2[0] = int($tm2[0]);
|
|---|
| 355 | }
|
|---|
| 356 | eval q{
|
|---|
| 357 | require Time::Local;
|
|---|
| 358 | $diff += Time::Local::timegm(@tm2) - Time::Local::timegm(@tm1);
|
|---|
| 359 | };
|
|---|
| 360 | # not a problem if we failed here since we'll just try again next time,
|
|---|
| 361 | # so don't return error message
|
|---|
| 362 | unless (@$) {
|
|---|
| 363 | my $mode;
|
|---|
| 364 | if (defined $time[0]) {
|
|---|
| 365 | $mode = defined $time[3] ? 'DateTime' : 'Date';
|
|---|
| 366 | } else {
|
|---|
| 367 | $mode = 'Time';
|
|---|
| 368 | }
|
|---|
| 369 | $$shiftOffset{$mode} = $diff;
|
|---|
| 370 | }
|
|---|
| 371 | }
|
|---|
| 372 | if (defined $time[6]) {
|
|---|
| 373 | $$shiftOffset{Timezone} = ($toTime[6] - $time[6]) * 60 +
|
|---|
| 374 | $toTime[7] - $time[7];
|
|---|
| 375 | }
|
|---|
| 376 | }
|
|---|
| 377 |
|
|---|
| 378 | } else {
|
|---|
| 379 | #
|
|---|
| 380 | # apply shift from previously calculated offsets
|
|---|
| 381 | #
|
|---|
| 382 | if ($$shiftOffset{Timezone} and @time <= 6) {
|
|---|
| 383 | # change 'Z' timezone to '+00:00' only if necessary
|
|---|
| 384 | $time[6] = $time[7] = 0 if $val =~ s/Z$/\+00:00/;
|
|---|
| 385 | }
|
|---|
| 386 | # apply the previous date/time shift if necessary
|
|---|
| 387 | if ($mode) {
|
|---|
| 388 | my @tm = (0, 0, 0, 1, 0, 2000);
|
|---|
| 389 | if (defined $time[0]) {
|
|---|
| 390 | @tm[3..5] = reverse @time[0..2];
|
|---|
| 391 | --$tm[4]; # month should start from 0
|
|---|
| 392 | }
|
|---|
| 393 | @tm[0..2] = reverse @time[3..5] if defined $time[3];
|
|---|
| 394 | # save fractional seconds
|
|---|
| 395 | my $frac = $tm[0] - int($tm[0]);
|
|---|
| 396 | $tm[0] = int($tm[0]);
|
|---|
| 397 | my $tm;
|
|---|
| 398 | eval q{
|
|---|
| 399 | require Time::Local;
|
|---|
| 400 | $tm = Time::Local::timegm(@tm) + $frac;
|
|---|
| 401 | };
|
|---|
| 402 | $@ and return CleanWarning($@);
|
|---|
| 403 | $tm += $$shiftOffset{$mode}; # apply the shift
|
|---|
| 404 | $tm < 0 and return 'Shift results in negative time';
|
|---|
| 405 | # save fractional seconds in shifted time
|
|---|
| 406 | $frac = $tm - int($tm);
|
|---|
| 407 | if ($frac) {
|
|---|
| 408 | $tm = int($tm);
|
|---|
| 409 | # must account for any rounding that could occur
|
|---|
| 410 | $frac + 0.5 * 10 ** (-$dec) >= 1 and ++$tm, $frac = 0;
|
|---|
| 411 | }
|
|---|
| 412 | @tm = gmtime($tm);
|
|---|
| 413 | @toTime = reverse @tm[0..5];
|
|---|
| 414 | $toTime[0] += 1900;
|
|---|
| 415 | ++$toTime[1];
|
|---|
| 416 | $toTime[5] += $frac; # add the fractional seconds back in
|
|---|
| 417 | }
|
|---|
| 418 | # apply the previous timezone shift if necessary
|
|---|
| 419 | if (defined $time[6]) {
|
|---|
| 420 | my $m = $time[6] * 60 + $time[7];
|
|---|
| 421 | $m += $$shiftOffset{Timezone};
|
|---|
| 422 | $m += 0.5 * ($m <=> 0); # avoid round-off errors
|
|---|
| 423 | $toTime[6] = int($m / 60);
|
|---|
| 424 | $toTime[7] = int($m - $toTime[6] * 60);
|
|---|
| 425 | }
|
|---|
| 426 | }
|
|---|
| 427 | #
|
|---|
| 428 | # insert shifted time components back into original string
|
|---|
| 429 | #
|
|---|
| 430 | my $i;
|
|---|
| 431 | for ($i=0; $i<@toTime; ++$i) {
|
|---|
| 432 | next unless defined $time[$i] and defined $toTime[$i];
|
|---|
| 433 | my ($v, $d, $s);
|
|---|
| 434 | if ($i != 6) { # not timezone hours
|
|---|
| 435 | last unless $val =~ /((?=\d|\.\d)\d*(\.\d*)?)/g;
|
|---|
| 436 | next if $toTime[$i] == $time[$i];
|
|---|
| 437 | $v = $1; # value
|
|---|
| 438 | $d = $2; # decimal part of value
|
|---|
| 439 | $s = ''; # no sign
|
|---|
| 440 | } else {
|
|---|
| 441 | last if $time[$i] == $toTime[$i] and $time[$i+1] == $toTime[$i+1];
|
|---|
| 442 | last unless $val =~ /((?:\+|-)(?=\d|\.\d)\d*(\.\d*)?)/g;
|
|---|
| 443 | $v = $1;
|
|---|
| 444 | $d = $2;
|
|---|
| 445 | if ($toTime[6] >= 0 and $toTime[7] >= 0) {
|
|---|
| 446 | $s = '+';
|
|---|
| 447 | } else {
|
|---|
| 448 | $s = '-';
|
|---|
| 449 | $toTime[6] = -$toTime[6];
|
|---|
| 450 | $toTime[7] = -$toTime[7];
|
|---|
| 451 | }
|
|---|
| 452 | }
|
|---|
| 453 | my $nv = $toTime[$i];
|
|---|
| 454 | my $pos = pos $val;
|
|---|
| 455 | my $len = length $v;
|
|---|
| 456 | my $sig = $len - length $s;
|
|---|
| 457 | my $dec = $d ? length($d) - 1 : 0;
|
|---|
| 458 | my $newNum = sprintf($dec ? "$s%0$sig.${dec}f" : "$s%0${sig}d", $nv);
|
|---|
| 459 | substr($val, $pos - $len, $len) = $newNum;
|
|---|
| 460 | pos($val) = $pos + length($newNum) - $len;
|
|---|
| 461 | }
|
|---|
| 462 | if (@_ == 1) {
|
|---|
| 463 | $_ = $val; # set $_ to the returned value
|
|---|
| 464 | } else {
|
|---|
| 465 | $_[0] = $val; # return shifted value
|
|---|
| 466 | }
|
|---|
| 467 | return undef; # success!
|
|---|
| 468 | }
|
|---|
| 469 |
|
|---|
| 470 |
|
|---|
| 471 | 1; # end
|
|---|
| 472 |
|
|---|
| 473 | __END__
|
|---|
| 474 |
|
|---|
| 475 | =head1 NAME
|
|---|
| 476 |
|
|---|
| 477 | Image::ExifTool::Shift.pl - ExifTool time shifting routines
|
|---|
| 478 |
|
|---|
| 479 | =head1 DESCRIPTION
|
|---|
| 480 |
|
|---|
| 481 | This module contains routines used by ExifTool to shift date and time
|
|---|
| 482 | values.
|
|---|
| 483 |
|
|---|
| 484 | =head1 METHODS
|
|---|
| 485 |
|
|---|
| 486 | =head2 ShiftTime
|
|---|
| 487 |
|
|---|
| 488 | Shift date/time value
|
|---|
| 489 |
|
|---|
| 490 | use Image::ExifTool;
|
|---|
| 491 | $err = Image::ExifTool::ShiftTime($dateTime, $shift);
|
|---|
| 492 |
|
|---|
| 493 | =over 4
|
|---|
| 494 |
|
|---|
| 495 | =item Inputs:
|
|---|
| 496 |
|
|---|
| 497 | 0) Date/time string in EXIF format (eg. C<2016:01:30 11:45:00>).
|
|---|
| 498 |
|
|---|
| 499 | 1) Shift string (see below) with optional leading sign for shift direction.
|
|---|
| 500 |
|
|---|
| 501 | 2) [optional] Direction of shift (-1 or +1), or 0 or undef to use the sign
|
|---|
| 502 | from the shift string.
|
|---|
| 503 |
|
|---|
| 504 | 3) [optional] Reference to time-shift hash -- filled in by first call to
|
|---|
| 505 | B<ShiftTime>, and used in subsequent calls to shift date/time values by the
|
|---|
| 506 | same relative amount (see L</TRICKY> section below).
|
|---|
| 507 |
|
|---|
| 508 | or
|
|---|
| 509 |
|
|---|
| 510 | 0) Shift string (and $_ contains the input date/time string).
|
|---|
| 511 |
|
|---|
| 512 | =item Return value:
|
|---|
| 513 |
|
|---|
| 514 | Error string, or undef on success and the input date/time string is shifted
|
|---|
| 515 | by the specified amount.
|
|---|
| 516 |
|
|---|
| 517 | =back
|
|---|
| 518 |
|
|---|
| 519 | =head1 SHIFT STRING
|
|---|
| 520 |
|
|---|
| 521 | Time shifts are applied to standard EXIF-formatted date/time values (eg.
|
|---|
| 522 | C<2005:03:14 18:55:00>). Date-only and time-only values may also be
|
|---|
| 523 | shifted, and an optional timezone (eg. C<-05:00>) is also supported. Here
|
|---|
| 524 | are some general rules and examples to explain how shift strings are
|
|---|
| 525 | interpreted:
|
|---|
| 526 |
|
|---|
| 527 | Date-only values are shifted using the following formats:
|
|---|
| 528 |
|
|---|
| 529 | 'Y:M:D' - shift date by 'Y' years, 'M' months and 'D' days
|
|---|
| 530 | 'M:D' - shift months and days only
|
|---|
| 531 | 'D' - shift specified number of days
|
|---|
| 532 |
|
|---|
| 533 | Time-only values are shifted using the following formats:
|
|---|
| 534 |
|
|---|
| 535 | 'h:m:s' - shift time by 'h' hours, 'm' minutes and 's' seconds
|
|---|
| 536 | 'h:m' - shift hours and minutes only
|
|---|
| 537 | 'h' - shift specified number of hours
|
|---|
| 538 |
|
|---|
| 539 | Timezone shifts are specified in the following formats:
|
|---|
| 540 |
|
|---|
| 541 | '+h:m' - shift timezone by 'h' hours and 'm' minutes
|
|---|
| 542 | '-h:m' - negative shift of timezone hours and minutes
|
|---|
| 543 | '+h' - shift timezone hours only
|
|---|
| 544 | '-h' - negative shift of timezone hours only
|
|---|
| 545 |
|
|---|
| 546 | A valid shift value consists of one or two arguments, separated by a space.
|
|---|
| 547 | If only one is provided, it is assumed to be a time shift when applied to a
|
|---|
| 548 | time-only or a date/time value, or a date shift when applied to a date-only
|
|---|
| 549 | value. For example:
|
|---|
| 550 |
|
|---|
| 551 | '1' - shift by 1 hour if applied to a time or date/time
|
|---|
| 552 | value, or by one day if applied to a date value
|
|---|
| 553 | '2:0' - shift 2 hours (time, date/time), or 2 months (date)
|
|---|
| 554 | '5:0:0' - shift 5 hours (time, date/time), or 5 years (date)
|
|---|
| 555 | '0:0:1' - shift 1 s (time, date/time), or 1 day (date)
|
|---|
| 556 |
|
|---|
| 557 | If two arguments are given, the date shift is first, followed by the time
|
|---|
| 558 | shift:
|
|---|
| 559 |
|
|---|
| 560 | '3:0:0 0' - shift date by 3 years
|
|---|
| 561 | '0 15:30' - shift time by 15 hours and 30 minutes
|
|---|
| 562 | '1:0:0 0:0:0+5:0' - shift date by 1 year and timezone by 5 hours
|
|---|
| 563 |
|
|---|
| 564 | A date shift is simply ignored if applied to a time value or visa versa.
|
|---|
| 565 |
|
|---|
| 566 | Numbers specified in shift fields may contain a decimal point:
|
|---|
| 567 |
|
|---|
| 568 | '1.5' - 1 hour 30 minutes (time, date/time), or 1 day (date)
|
|---|
| 569 | '2.5 0' - 2 days 12 hours (date/time), 12 hours (time) or
|
|---|
| 570 | 2 days (date)
|
|---|
| 571 |
|
|---|
| 572 | And to save typing, a zero is assumed for any missing numbers:
|
|---|
| 573 |
|
|---|
| 574 | '1::' - shift by 1 hour (time, date/time) or 1 year (date)
|
|---|
| 575 | '26:: 0' - shift date by 26 years
|
|---|
| 576 | '+:30' - shift timezone by 30 minutes
|
|---|
| 577 |
|
|---|
| 578 | Below are some specific examples applied to real date and/or time values
|
|---|
| 579 | ('Dir' is the applied shift direction: '+' is positive, '-' is negative):
|
|---|
| 580 |
|
|---|
| 581 | Original Value Shift Dir Shifted Value
|
|---|
| 582 | --------------------- ------- --- ---------------------
|
|---|
| 583 | '20:30:00' '5' + '01:30:00'
|
|---|
| 584 | '2005:01:27' '5' + '2005:02:01'
|
|---|
| 585 | '2005:01:27 20:30:00' '5' + '2005:01:28 01:30:00'
|
|---|
| 586 | '11:54:00' '2.5 0' - '23:54:00'
|
|---|
| 587 | '2005:11:02' '2.5 0' - '2005:10:31'
|
|---|
| 588 | '2005:11:02 11:54:00' '2.5 0' - '2005:10:30 23:54:00'
|
|---|
| 589 | '2004:02:28 08:00:00' '1 1.3' + '2004:02:29 09:18:00'
|
|---|
| 590 | '07:00:00' '-5' + '07:00:00'
|
|---|
| 591 | '07:00:00+01:00' '-5' + '07:00:00-04:00'
|
|---|
| 592 | '07:00:00Z' '+2:30' - '07:00:00-02:30'
|
|---|
| 593 | '1970:01:01' '35::' + '2005:01:01'
|
|---|
| 594 | '2005:01:01' '400' + '2006:02:05'
|
|---|
| 595 | '10:00:00.00' '::1.33' - '09:59:58.67'
|
|---|
| 596 |
|
|---|
| 597 | =head1 NOTES
|
|---|
| 598 |
|
|---|
| 599 | The format of the original date/time value is not changed when the time
|
|---|
| 600 | shift is applied. This means that the length of the date/time string will
|
|---|
| 601 | not change, and only the numbers in the string will be modified. The only
|
|---|
| 602 | exception to this rule is that a 'Z' timezone is changed to '+00:00'
|
|---|
| 603 | notation if a timezone shift is applied. A timezone will not be added to
|
|---|
| 604 | the date/time string.
|
|---|
| 605 |
|
|---|
| 606 | =head1 TRICKY
|
|---|
| 607 |
|
|---|
| 608 | This module is perhaps more complicated than it needs to be because it is
|
|---|
| 609 | designed to be very flexible in the way time shifts are specified and
|
|---|
| 610 | applied...
|
|---|
| 611 |
|
|---|
| 612 | The ability to shift dates by Y years, M months, etc, conflicts with the
|
|---|
| 613 | design goal of maintaining a constant shift for all time values when
|
|---|
| 614 | applying a batch shift. This is because shifting by 1 month can be
|
|---|
| 615 | equivalent to anything from 28 to 31 days, and 1 year can be 365 or 366
|
|---|
| 616 | days, depending on the starting date.
|
|---|
| 617 |
|
|---|
| 618 | The inconsistency is handled by shifting the first tag found with the actual
|
|---|
| 619 | specified shift, then calculating the equivalent time difference in seconds
|
|---|
| 620 | for this shift and applying this difference to subsequent tags in a batch
|
|---|
| 621 | conversion. So if it works as designed, the behaviour should be both
|
|---|
| 622 | intuitive and mathematically correct, and the user shouldn't have to worry
|
|---|
| 623 | about details such as this (in keeping with Perl's "do the right thing"
|
|---|
| 624 | philosophy).
|
|---|
| 625 |
|
|---|
| 626 | =head1 BUGS
|
|---|
| 627 |
|
|---|
| 628 | Due to the use of the standard time library functions, dates are typically
|
|---|
| 629 | limited to the range 1970 to 2038 on 32-bit systems.
|
|---|
| 630 |
|
|---|
| 631 | =head1 AUTHOR
|
|---|
| 632 |
|
|---|
| 633 | Copyright 2003-2021, Phil Harvey (philharvey66 at gmail.com)
|
|---|
| 634 |
|
|---|
| 635 | This library is free software; you can redistribute it and/or modify it
|
|---|
| 636 | under the same terms as Perl itself.
|
|---|
| 637 |
|
|---|
| 638 | =head1 SEE ALSO
|
|---|
| 639 |
|
|---|
| 640 | L<Image::ExifTool(3pm)|Image::ExifTool>
|
|---|
| 641 |
|
|---|
| 642 | =cut
|
|---|
