Black Hole
May contain traces of nut
Early external USB drives (and a IDE/SATA to USB adapter I have in my toolbox) came with "Y" USB cables which connected to data on one port and power on both, to get more current headroom - so it should work. I don't think TV USB ports will be particularly highly spec'ed, and there has been success running an RPi from there, so my approach would be to try it on one port and see if it works, and if not double up.Oh! it is USB2 and the RPi needs up to 700ma apparently. However, if I do away with the drive that is now connected as I rarely use it, I could use both ports and get up to 1A?
Something to keep in the back pocket: USB chargers for Apple products (particularly iPad) are able to kick out significantly more current, I think 1.2A in the case of iPad. Indeed, my iPod Touch charger refused to charge my iPad!