You need a composite video capture device. Most of these take composit and convert to USB, they are relatively inexpensive. TVs have several inputs but don't typically have video out.
If you want to copy HD video, unless its over the air broadcast, they are usually copy protected. In addition to a HDMI capture device you need some way to make the source (DIRECTV) happy that there is a monitor attached and validating the signal. There are ways, but it gets complicated.