Regular Expression to get all links with certain extensions

Im looking for a regular expression that will grab all of the urls that have the extensions int he following array:

Array
(
    [0] => mp4
    [1] => m4v
    [2] => webm
    [3] => ogv
    [4] => wmv
    [5] => flv
)

This array is returned by an internal WordPress function called wp_get_video_extensions() and are video URls that WordPress recognizes.

A block of content would look like this with URls inside it:

‘Yes, but I grow at a reasonable pace,’ said the Dormouse: ‘not in
that ridiculous fashion.’ And he got up very sulkily and crossed over
to the other side of the court.

All this time the Queen had never left off staring at the Hatter, and,
just as the Dormouse crossed the court, she said to one of the
officers of the court, ‘Bring me the list of the singers in the last
concert!’ on which the wretched Hatter trembled so, that he shook both
his shoes off.

‘Give your evidence,’ the King repeated angrily, ‘or I’ll have you
executed, whether you’re nervous or not.’

http://www.example.com/files/video/video2.flv

‘I’m a poor man, your Majesty,’ the Hatter began, in a trembling
voice, ‘—and I hadn’t begun my tea—not above a week or so—and what
with the bread-and-butter getting so thin—and the twinkling of the
tea—’

I am trying to get it to find both the video urls in there and return the entire URL in the array.

Here is what i have:

preg_match_all( '/^https?://(?:[a-z-]+.)+[a-z]{2,6}(?:/[^/#?]+)+.(?:' . implode( '|', wp_get_video_extensions() ) . ')$/', $post->post_content, $matches);

And i am getting this:

Warning: preg_match_all(): Unknown modifier ‘[‘

Ideally, i would like to get this:

Array
(
    [0] => Array
           (
               [0] => http://www.example.com/files/video/video1.mp4
               [1] => http://www.example.com/files/video/video2.flv
           )
    [1] => Array
           (
               [0] => http://www.example.com/
               [1] => http://www.example.com/
           )
    [2] => Array
           (
               [0] => files/video/
               [1] => files/video/
           )
    [3] => Array
           (
               [0] => video1.mp4
               [1] => video2.flv
           )
)

But this would also be perfect as i can use parse_url() to break the rest out later on:

Array
(
    [0] => http://www.example.com/files/video/video1.mp4
    [1] => http://www.example.com/files/video/video2.flv
)