It is not impossible to modify myAlbum-P like YouTube
But you can add extensions for videos into "File extensions that can be uploaded" in myAlbum-P's admin.
eg)
jpg|jpeg|gif|png|wmv|avi|mov
Perhaps, users can upload just small videos (<= 2Mbyte or 8Mbyte) default.
If you can, change directives of PHP by .htaccess
- 'upload_max_filesize'
- 'post_max_size'