while (<>) {
    while (m#-/(.*?)\?srt=#g) {
        say $1;
    }
}
[download]

(Because this is reading the input line by line, it's assuming the items to search don't cross line boundaries.  In case your data isn't all that huge, you could of course also read it as one record instead, by setting $/ to undef.)

The while (m#...#g) allows more than one search item to occur on one line.