In php.ini, upload_max_filesize and post_max_size were set to 10G per http://php.net/manual/en/faq.using.php#faq.using.shorthandbytes
In practice only videos up to 10MB could be uploaded. This is due to code in islandora_video_upload_form() (and similar functions for file upload in other solution packs) that ignores the byte designator and assumes megabytes are specified (so 10G is stripped down to 10, then applied as a 10MB limit).
Work around is to specify size as (say) 10000M in php.ini
A better solution would be to honour the php.ini shorthand byte values.