[mythtv-users] Overlapping recordings on SAME channel w/ one tuner

Bill Bogstad bogstad at pobox.com
Sat Mar 27 17:30:03 UTC 2010


On Thu, Mar 25, 2010 at 7:48 PM, Michael T. Dean
<mtdean at thirdcontact.com> wrote:
> On 03/25/2010 07:41 PM, Jeff Evans wrote:
>>>
>>> Given that virtual tuners were already built to solve this
>>> problem, the myth devs probably consider a solution to your
>>> question as a corner case.
>>>
>>
>> Ouch Chris! Surely there are many out there still using analogue and
>> other non-DVB capture devices?
>>
>
> IMHO, your buying additional capture cards is /immensely/ cheaper than the
> amount of code required to do what you're asking.
>
> If you don't have enough capture cards to record what you want, you need
> more capture cards.

And why wasn't this argument made when multirec/virtual tuners was
proposed/implemented?
I don't see how anything that multirec does couldn't have been done
with more physical tuners.

I don't currently have a multirec installation so I have a technical
question.  The wiki page

http://www.mythtv.org/wiki/record_multiple_channels_from_one_multiplex

states:

Multiplex recording also allows overlapping of sequential recordings
of the same program. That avoids the annoying problem with the end of
a broadcast being in the next recording or the beginning of a
broadcast being at the end of a previous recording, as is lately
popular with syndicated reruns of programs like Scrubs and ER.

It sounds like this means that tuners that allow virtual tuners can
copy a single "program" stream
into multiple files.  (i.e. Chop a single stream into potentially
overlapping in time recording files of the same single continuous
video stream.)

Is there any reason that single-stream only tuners couldn't be handled
as if they just happened to be a multi-stream capable tuner where
there was never more then one actual program stream available per
frequency that was tuned?   Could this be implemented as a truly
virtual tuner which simply acted as a front end to the underlying real
tuner and presented a multirec capable view to the rest of the system
(i.e. scheduler).   The underlying real tuners would be configured
into the system, but would never have an input connection made.   Each
truly virtual tuner would have a dedicated physical tuner, be
configured to have two (probably all that would be required) virtual
tuners (in the current sense) tuners and would have the appropriate
input connection.  Doing it this way might add some minor overhead to
recordings but would allow any single video stream physical tuner to
handle overlapping in time recordings.

Or is my total lack of knowledge of  the implementation of multirec
mean that I'm missing some major problem with the above suggestion?

Bill Bogstad




Bill Bogstad


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