+ bin/ssa-retime : draft

bin/ssa-retime

@@ -0,0 +1,141 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw(switch);
+use lib 'lib';
+use utf8;
+
+use Getopt::Long;
+use File::Slurp;
+use Subtitle::SSA;
+
+sub usage {
+  my ($msg) = @_;
+  print $msg, "\n" if $msg;
+  print <<USAGE;
+Usage: ssa-retime <mode> [<options>] -i <file> [ -o <file>]
+
+Modes are:
+  * framerate       Retime whole file from one fps to another.
+  * points          Retime file specifying point(s) & time shift for it.
+  * shift           Shift whole file or it's part for given time.
+
+Common options:
+  -h                This help.
+  -i <file>         Input file. (mandatory).
+  -o <file>         Output file. Default: write to stdout.
+  -v                Be verbose.
+
+Specific options for 'shift' mode:
+  -S <string>       Retime only events with specified style.
+                    This option may be given more than once.
+  -s <time>         Start time of period, that will be changed.
+                    Default: first event.
+  -e <time>         End time of period, that will be changed.
+                    Default: the latest time found in file.
+  -l <time>         Duration of period above. This option require '-s'
+                    You may select either '-o' or '-e' at the same time.
+  -t <time>         Change time for this value.
+
+Specific options for 'framerate' mode:
+  -f <float>        Source framerate. Default: 25.0 fps.
+  -F <float>        Target framerate.
+
+Specific options for 'points' mode:
+  -p <time>/<time>  Point of fixup & time shift in it. Option can be
+                    specified more than once. (see man for details)
+                    Both args must be in form of [-][[h:]m:]s[.ms].
+USAGE
+  exit 1;
+}
+
+########### init ###################
+$| = 1;
+
+my $mode = shift @ARGV;
+
+my @points;
+my %opts = ( loglevel => 0, inrate => 25.0 );
+#GetOptions("qvhi:o:S:f:F:p:t:s:e:l:", \%opts)
+GetOptions(
+  'h|help'        => \&usage,
+  'v|verbose+'    => \$opts{loglevel},
+  'i|infile=s'    => \$opts{infile},
+  'o|outfile=s'   => \$opts{outfile},
+
+  'S|style=s'     => \$opts{style},
+  's|shiftstart=s'=> \$opts{shiftstart},
+  'e|shiftend=s'  => \$opts{shiftend},
+  'l|shiftlen=f'  => \$opts{shiftlen},
+
+  't|shifttime=f' => \$opts{shifttime},
+
+  'f|inrate=f'    => \$opts{inrate},
+  'F|outrate=f'   => \$opts{outrate},
+
+  'p|point'       => \@points,
+);
+
+($opts{infile} and -f $opts{infile})
+  or usage("Input file not exists");
+
+given ($mode) {
+  when ('framerate') {
+    $opts{outrate}
+      or usage("You should set at least '-F' option in this mode");
+    ($opts{inrate} != 0.0 and $opts{outrate} != 0.0)
+      or usage("Framerate can't be zero");
+  }
+  when ('shift') {
+    $opts{shifttime}
+      or usage("You should set '-t' option in this mode");
+    (not $opts{shiftstart} or $opts{shiftstart} > 0.0)
+      or usage("Shift start must be positive time");
+    (not $opts{shiftend}   or $opts{shiftend} > 0.0)
+      or usage("Shift end must be positive time");
+    (not $opts{shiftlen}   or $opts{shiftlen} > 0.0)
+      or usage("Shift length must be positive time");
+  }
+  when ('points') {
+    scalar(@points)
+      or usage("You should specify at least one shift point");
+    foreach my $point (@points) {
+      ...
+    }
+  }
+  default {
+    usage("Incorrect mode: $mode (see help below)");
+  }
+}
+
+my @lines = read_file($ARGV[0]);
+my $ssa = Subtitle::SSA->new(debug => !!$opts{loglevel});
+$ssa->parse(\@lines);
+
+given ($mode) {
+  when ('framerate') {
+    my $mod = $opts{inrate} / $opts{outrate};
+    foreach my $event ($ssa->events) {
+      $event->{start} *= $mod;
+      $event->{end}   *= $mod;
+    }
+  }
+  when ('shift') {
+    my $style = $opts{style};
+    my $start = $opts{shiftstart} // 0.0;
+    my $end   = $opts{shiftend} // (($opts{shiftlen}) ? $start + $opts{shiftend} : undef);
+    my $mod   = $opts{shifttime};
+    foreach my $event ($ssa->events) {
+      next if ($style and $event->{style} ne $style);
+      next if ($start and $event->{start} < $start);
+      next if ($end   and $event->{end}   > $end);
+      $event->{start} += $mod;
+      $event->{end}   += $mod;
+    }
+  }
+  when ('points') {
+  }
+}
+
+exit 0;