For just a tv and DVD player, we use a portable 400W pure sine inverter. We have used modified sine wave inverters as low as 200W which also worked just fine but they tend to 'alarm' more frequently due to draw.
In one tt, there was already a 12V outlet. In a second tt, we added a 12V outlet on the radio wire for one (LR) and a fanatastic fan wire for the other(BR). Both had 15 Amp fuses. It didn't work trying to run the fantastic fan and the inverter with a load at the same time. We also had a third 12V outlet next to our converter with larger wiring for larger loads. In our current class A, there is a 12V outlet in the bedroom which we use at night instead of the power hog 1200W house inverter.
The advantage of using a portable for that small a load is you can use the outlets for charging phones and such without using the inverter. Our TV and sat receiver or DVD player had a total draw around 100W. YMMV
