DEBUG ACTIVO
URL original: [https://www.youtube.com/embed/r9Y9cFuUmd0?si=r1jzZCIlrNUbID44]
Largo: 61
Array
(
    [scheme] => https
    [host] => www.youtube.com
    [path] => /embed/r9Y9cFuUmd0
    [query] => si=r1jzZCIlrNUbID44
)

Video ID detectado: [r9Y9cFuUmd0]
Pasa el regex? SI