jack.chaney wrote:I haven't done any checking with the hardware or schematics on this, but an idea struck me about a possible project to pursue. I just want to avoid a blind alley before getting started, in case anyone already knows the answer.
Does the HDMI port on the RPi serve as an input as well as an output? The idea I have is to use an RPi 2 as a TiVo type of recording device for general broadcast TV. Using the Pi, with an outboard hard drive, and some clever programming, could make a very inexpensive solution for me not missing Big Bang when I have an evening meeting across town.
DougieLawson is spot on: the Pi's HDMI port is output only.
But what you're after isn't impossible on a Pi - you're basically describing a PVR server. What you need is a computer capable of recording/transcoding video signals, some kind of USB TV input (TV tuner, satellite receiver, etc), and PVR server software (this can be a standalone application or a whole distro). The PVR server receives the live TV signal and can distribute that across the network to client devices, but can also schedule recordings like a TiVo. You'd access the live broadcasts and recorded shows using front-end software - Kodi has TV/PVR add-ons which are just fine. The "server" and "front-end" can be installed on one single PC but they can also be separate devices on the same network.
With most PVR servers you're not actually watching the live stream from your capture device when you watch "live" TV: you're watching a video stream that is buffered to disk. Which leads me to my next point: even if the software to do this is available for the Raspberry Pi (and it more than likely is) then you're going to want a USB hard drive and I'm not sure that the Pi, even the Pi2, could manage HD recording/broadcast.
I've done this using MediaPortal as a back-end, Kodi as a front-end, and a USB DVB-T2 receiver. It works really well, but the PC in question is a "gaming"-class x86 machine, not a comparatively low-powered Raspberry Pi. It's worth investigating though: I can't provide many links because a lot of stuff is blocked in work, but Google suggests
that plenty of people have done the same thing.