on second thought, if you do not plan to make the hardware part a commerial-product that people buy but rather a open/public-project where people has to buy the parts themself and build the box, then the modular design of a
via embedded platform (or similar) might be a best way to go, (even though it will be much more expensive to for end-users to build, it will be very easy to put together and find/buy parts for it).
exampels of possible via embedded platform solutions for this project:
-
micro form-factor:
nano-itx epia n mainboard, mini-disto linux-os on compact flash memory card with
ide to compactflash adapter,
tv-turner can either be a custom mini-pci adapter* or a standard usb tv-adapter (preferable with built-in hardware mpeg-2 encoder).
use an
internal mini-itx psu or a
dc-dc adapter/convertor with a suitable external ac-dc power-supply. then put in all in a small box.
-
medium to small form-factor:
mini-itx epia series-mainboard**, mini-disto linux on compactflash memory in a built-in compactflash slot,
(**there's many models in via mini-itx series to choose from, even a few with built-in compactflash and/or cardbus/pcmcia slots)
tv-turner can either be a custom/retail pci adapter* or a standard usb tv-adapter (preferable with built-in hardware mpeg-2 encoder).
use an
internal mini-itx psu or a
dc-dc adapter/convertor with a suitable external ac-dc power-supply. then put in all in a small box.
* = custom mini-pci adapter, or custom (low-profile) pci adapter, an own designed adapter the project create/build (and sell) yourself.
this way you get control over what exacly the adapter feature, (you can even make different models) (make them fw upgradable)
since all via epia mainboard series are all native x86 cpu platforms which is ideal to run linux and existing applications on, same goes for hardware and their device drivers. you could quitte easily code a specicial mini/micro-distro of linux-os os it and make it boot really fast by using a hybernation image. using a small compact flash memory module for storage of the os is a cheap and noise-less option. an cardbus (pcmcia) slot would be ideal for an optional wireless-network-adapter. one downside with the via epia mainboard series is that none have a built-in tv-turner/encoder so you would have to add that either via a mini-pci adapter if select the nano-itx platform (don't think there are any existing mini-pci adapters on the market so a custom built adapter would be the only option then), or a existing usb adapter (whcih is not ideal since more expnsive and would have to be plugged in externaly), or best a pci adapter if choose to use a mini-itx platform, that pci adapter could either be a custom built one or an existing retail one, with a pci adapter you also have an option of selecting a half-hight/low-profile one or standard size plus you can either install it direct in the via epia mainboards pci slot or you can get a "v" bracket/covertor to install the card horisontaly so the adapter lies paralell with the mainboard so can fit it all in a smaller box. of course choosing a modular designed x86 platform also has other percs such as the already mentioned options of having/selling different models, one model could have one pci adapter for analog-tv/radio and a other model have a pci adapter for digital-tv/radio, a third with both, a forth with a pci card with multiple tv-turners so can record more than one channel at once, and a fifth be in a bigger box with harddrive slot(s) so could be used as a nas (network attatched storage) box with samba and/or local-storage for the pvr or even function as a vcr-server. ...hell, it could even work as a standalone tunnel-box with
xlink kai or xbconnect for xbox system-link online gaming if the pc-side if it was ported to it.
i will stop ranting for this time, just rememeber that even though existing via platform is easy to use and flexible, it's much more expensive.
ps! if any case, no matter if you plan to use existing hardware or built your own from scratch if you plan to make the project open source and platform independand then ask other relative osd developers if they like to help/join, such as devs from mplayer, xine, xmms, vlc, mythtv, etc.