If you on a TMD shared server, you can forget video conversion unless the video is a few seconds or minutes long. They should just come out and tell you that. But they don't.

Funny that a cheap smart-phone can convert and send short videos but a shared server environment at TMD cannot do it. They claim it ties up too many "resources". So they just stop the process without notifying you. If you go to the control panel, you can see where you were "limited."

Good luck!