[mythtv-users] Architecture Idea - Raspberry Pi, VM, XBMC

[Raymond Wagner]

On 1/15/2013 10:57, Mike Perkins wrote:
> On 15/01/13 15:50, Raymond Wagner wrote:
>> On 1/15/2013 06:45, Mike Perkins wrote:
>>> On 14/01/13 19:48, Matt Emmott wrote:
>>>> The one sticking point is that my Poweredge is a gen 2 which
>>>> does not have the necessary magic to 'pin' USB ports to VMs
>>>> that a gen 3 has. This means I can't use my HD-PVR with the BE.
>>>> Overall I'm happy with my setup.
>>>>
>>> Have you thought of trying USB over IP?
>>> http://usbip.sourceforge.net/
>>>
>>> That should work independent of whatever virtual host/guest
>>> system you are using. I'm using it with a xen system for other
>>> purposes and it seems to work fine, once you figure out how to
>>> set up the configuration scripts - mostly a case of udev rules.
>>
>> That sounds like it would be considerably worse, in terms of
>> screwing with communications latencies assumed by tuner drivers,
>> than any form of VM passthrough.
>>
> I'm not sure why. I don't know VMWare but for my xen setup there's a
>  bridge inside the host so that the packets never leave the box. The
>  latency is probably better than if you had an IP-connected HDHR,
> after all, where the packets have to traverse wires and optionally
> switches.

On an HDHR, the "driver" runs on the box itself, not over the network.
MythTV just captures a UDP stream pushed by the box. It's a completely
different situation.

What I'm saying is that the drivers are going to make certain reasonable
assumptions about access to the hardware, and the reasons people have
trouble using tuners from within VMs is because those assumptions are no
longer valid. Running some USB-over-IP would be even worse in that
regard, even if it does never leave the physical system, and is only IP
over a local bridged.