Just catching up on the threads...
1) the device does not currently have the ability to overlay audio, however, all the wires are there to do it. The FPGA is connected to a PCM audio port on the Marvell chip. In order to complete this, one needs to build an audio formatter that takes PCM data and wraps a CRC around it, packetizes it, and injects it into the stream. Most of the infrastructure is already there to do this, but it wasn't a development priority to add audio overlay since the core use case of the product is as a passive news viewer. However, as Duane has mentioned, all the source is available and there are free (as in beer) tools available to compile the FPGA from Xilinx. It's..."SMOP" in the sense that you don't have to even open the case to upgrade the functionality.
2) For USB host functionality, Duane is correct, NeTV is stripped down to the bone to deal with the brutal price pressure in today's recession-depressed consumer gadget market. However, do not fear. There is a simple way to add host functionality. We have prepared an expansion board that screws firmly onto the main board that includes a USB hub and it breaks out extra USB ports without losing wifi functionality. The schematics for the breakout are also available on the website.
Also, the mini-USB connector is err...used only for power...long story, there's some nanny-state regulatory hurdles that prevents us from advertising it as being live. However, an astute user would note certain features that could lead to useful behavior if, at their own risk, they tried to see what happens if it's plugged into a computer, or a cable adapter that could convert an OTG port into a host-like port with power supply. But that is entirely at the user's own risk and not an officially supported mode of operation.
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