You can't put variables in template functions. SSViewer does not yet support that. <% control Parent %> will crap itself when in the Attachment control because Attachment doesn't have a parent.
To do some thing like this, you need to put the function in your controller.
function Videos()
{
$videos = new DataObjectSet();
foreach($this->Attachments() as $att) {
$att->Video = $att->VideoPopup($this->VideoWidth, $this->VideoHeight);
$videos->push($att);
}
return $videos;
}
Something like that..
As for the audio files, go ahead and add your other files types to the $allowed_file_types array in MP3.php. It may work. I don't have much experience with the flash player being used. It used mp3 in the example, but for all I know AAC may work just fine. Let me know the result.
Also, what do you mean when you say "the page errors out?"