[mythtv-users] HDHomeRun Prime up for pre-order at Amazon

[Don Lewis]

On  3 May, Eric Sharkey wrote:
> On Tue, May 3, 2011 at 1:31 PM, Don Lewis <dl-mythtv at catspoiler.org> wrote:
>> On  2 May, Raymond Wagner wrote:
>>> On 5/2/2011 12:00, Josh Rosenberg wrote:
>>>> So do people expect that a Prime will work in Myth as it exists now?
>>>> If you just plug in the Prime and tell Myth to look for your HDHR,
>>>> will it just work?
>>>
>>> The Silicondust folks were kind enough to update our libraries about a
>>> year ago to support the device.  As I understand it, several of their
>>> employees have been testing the device with MythTV since then.  Support
>>> exists the same as before, with MythTV accessing the device directly
>>> over the network, and no drivers required.
>>
>> Cool!
>>
>> Does anyone know if the Myth will be able to do overlapping recordings
>> on the same channel using the same tuner with the HDHR Prime?  It works
>> with the current HDHR, but I don't remember if Myth needs to use the
>> virtual tuner feature.
> 
> In another thread on this list, Raymond Wagner wrote this:
> 
>   I don't know if this is a technical limitation of the CableCard system,
>   or just one in Silicondust's design.  The HDHomeRun Prime has two
>   operating modes.  With no installed card, it functions just like a
>   3-tuner HDHomeRun.  Each tuner can record multiple streams through
>   multirec, up to the soft limit of 5 imposed by MythTV.  With a card
>   installed, each tuner only allows a single stream, meaning you can only
>   record three shows simultaneously.
> 
> So, yes and no.

Yeah, I saw that message, but the answer is still not clear to me in
this particular case.  It's pretty clear to me that CableCard won't
allow Myth to record multiple channels from one multiplex.

I get the impression that the the HDHR "classic" just transmits the
entire multiplex and libhdhomerun just passes on the stream for the
desired channel(s) (one for each virtual tuner) to Myth.  In the case of
overlapping recordings of the same channel, I suspect that libhdhomerun
is just creating an extra copy of the desired stream.

I sort of hate to resurrect this old thread from March/April of last
year, but this message has a good summary of the technical details:
<http://www.mythtv.org/pipermail/mythtv-users/2010-April/285288.html>.

Since the HDHR code in Myth already supports multirec, if Myth doesn't
distinguish between the CableCard and !CableCard cases other than how to
do tuning, maybe overlapping recordings of the same channel might
already work in the Prime with a CableCard, or only a limited amount of
support might need to be added to the low-level Myth code or to to
libhdhomerun.

This isn't a big issue for me, I'm just curious at this point.  My
current setup uses an HDHR "classic", a DVB card, and two STBs connected
via firewire, one of which also drives a HD-PVR in the same input group.
My current recording schedule has three instances of overlaps.  Two of
those are on a clear QAM channel, which my HDHR handles fine with
multirec.  I think it also handles a couple instances of simultaneous
recordings on the same multiplex.  I also have an overlap on the same
encrypted channel, which requires the use of both STBs.

At this point I'm anxiously awaiting the availability of the HDHR Prime.
Once I get my hands on one, I'll return one of the two STBs and ditch
the firewire recording stuff.  I'll have two more physical tuners so
conflicts will be less of a problem than they are now.  If The HDHR
Prime with a CableCard can overlap recordings on the same channel,
that's just a bonus.

I'm somewhat tempted by the six tuner version.  I'd run three tuners
with a CableCard and three without so that I could take advantage of the
multirec capabilities of the second three.  That would allow me to
retire one STB, my HDHR "classic", and the DVB card, which would allow
me to greatly simplify all of the RF cabling.  The hardware cost could
be an issue ...