The HD 4670 1GB has a core clock frequency of 750 MHz and a memory frequency of 1100 MHz. It also features a 128-bit bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare all of that to the R7 240, which comes with a core clock frequency of 730 MHz and a memory frequency of 900 MHz. It also makes use of a 128-bit memory bus, and uses a 28 nm design. It is comprised of 320 SPUs, 20 TAUs, and 8 Raster Operation Units
320 stream processor count should be fine for a media card and is on par with the r7 240. the 55nm is less energy efficient than the 28nm 240, but if it works, how bad could it be?
the vga is analog, if it signals through to your TV then all is good, i am not sure about the hdmi config, but most tvs have the hdmi port nowadays to get signals from the gfx card hdmi port.