Post-process asciinema recordings to reduce replay time

asciinema.pl

#!/usr/bin/env perl
use strict;
use warnings;

# Shorten video by limiting the max wait time
my $max_pause = 1;

# To make interactive commands more noticable, insert a longer delay
# after lines with a command prompt.
my $prompt = qr/jan\@zuze/;
my $prompt_pause = 0;

my($pause,$str) = (0, "");
my $duration = 0;

while (<>) {
    next if /^\s+"duration":/;
    print;
    last if /^\s+"stdout": \[/;
}
# Combine multiple strings into a single entry without pauses as long
# as the strings don't include control characters.
while (<>) {
    next if /^\s+\[$/;
    if (/^\s+(\d.*),$/) {
        $pause ||= eval $1 > $max_pause ? $max_pause : eval $1;
    }
    elsif (/\s+"(.*)"$/) {
        $str .= $1;
    }
    elsif (/^\s+\](,?)/) {
        if ($1 eq "" || index($str, "\\") >= 0) {
            print qq(    \[\n      $pause,\n      "$str"\n    \]$1\n);
            $duration += $pause;
            $pause = $str =~ $prompt ? $prompt_pause : 0;
            $str = "";
        }
    }
    else {
       die;
    }
    last if /^\s+\]$/;
}
while (<>) {
    $_ = qq(  \],\n  "duration": $duration\n) if /^  \]$/;
    print;
}