[Tfug] Radio/TV cards?

[Bexley Hall]

Hi John,

--- On Sat, 9/29/12, John Gruenenfelder <jetpackjohn at gmail.com> wrote:

> > I'm looking for hardware so I can receive 2 AM/FM radio stations
> > and 2 broadcast (CATV or OTA) video channels.
> 
> I'll +1 what Harry said as well and add a few small bits...
> 
> You didn't mention what quality is acceptable for the video,
> that is, whether standard definition video is okay.  I've been a
> very happy used of MythTV for just under ten years now.  I have
> not yet got a big enough push to fully upgrade my system to HDTV.
> The CPU and video card can handle it as can the HDTV/monitor it
> is plugged into.  The video encoder is still SD, though.

Let me step back and go into the thoughts behind my criteria...

There's just two of us.  And, we tend NOT to be big TV consumers.
Radio tends to see some regular use.  And, sometimes we're both
watching TV but different programs.  Or, some of the content we
are listening to/viewing is "canned", etc.

So, more than two "content sources" seems wasteful.  Yes, it's
possible that you might want to record one thing while watching
(listening) another.  But, do you allow *both* of us to record
while viewing?

And, what about things like PiP?  Should I be able to watch
something, see something else PiP *and* record something else
at the same time?

In school, we would often *watch* something (sound muted) while
*listening* to something else, entirely.  So, watch two video
programs (main + PiP), record a third and *listen* to something
else??

<grin>  Where does it end??

(Hint:  go out and take a WALK instead of sitting in front of
the tube!!  :> )

But, I don't want to let our household drive the design.  I would
like others to be able to take what I've done and just scale it
to their needs.  So, dealing with households of > 2 souls is an
issue.  I figured:
   active_users = ceil(household_members * .75)
is about the right ballpark.  I.e., a family of 4 is likely to
need to be able to support 3 concurrent users.  The same for
a family of 3!  OTOH, a family of 5 only needs to support 4
users, etc.

I'm not sure how to inflate this for "multiple source viewing"
(or listening).  I.e., if one active_user wants PiP, does that
come at the expense of one less active_user?  Or, do you add
in some sort of multiplier to address those potential needs?

(recall, every add-on costs real hardware, etc.)

This is why I was willing to treat a device that handles
TV *and* radio as a single entity.  It handles one "active_user"
regardless of whether he wants to watch TV *or* listen to the 
radio.

With this in mind, SD is acceptable to us, currently.  But, would
probably NOT be "desirable" to someone else undertaking a similar
effort after me.  I.e., like you, if I had SD kit already, I
probably wouldn't discard it just to have the latest and greatest;
but, starting from scratch, it seems like there's not much to
gain ($?) in going that route vs. the HD (dunno).

> I've been using Hauppauge products for a long time now.  Their SD
> products were always top notch, however I cannot say much about their
> HDTV products as I haven't used any.

I know they used to make TV tuners prior to the DTV devolution
but don't know what their offerings are, currently.

> I am using a Hauppauge WinTV PVR-250 which can take SD input from
> S-video, RCA, or coax and output an MPEG-2 stream of configurable
> quality.

OK, so it's essentially a "capture card" with MPEG encoder?  I had
thought of tying the DTV STB's that I have to such a capture card
as an interim measure (the STB's have an external serial port
which can be used to control them).  But, I'm thinking that might
be more work that I will eventually have to "do over" (I'm getting
too old to be queuing that many projects!  :> ).

And, it would be of little use to anyone else trying to replicate
my efforts (do they even *sell* those boxes anymore?)

> This model also has an FM tuner available at /dev/radio0, but I am
> not currently using it (no antenna).

I've run feeds from DTV and FM antennae (as well as CATV feed) to the
"equipment closet" so I have access to whatever sources I want/need
with the intent of getting rid of these two "bookshelf" stereos.
I.e., going the digital route takes *less* space -- all the CD's
can go into storage, etc.

> If your card already has an OTA (old non-digital) TV audio
> tuner then it makes sense to add the few extra bits to allow
> the user to also tune in FM radio stations.  Of course, this
> also means that the two functions are mutually exclusive.

Yes.

> I've also used the PVR-150 card in another system.  It seems to have
> some different hardware/chipsets, but as near as I could tell it has
> identical functionality to the PVR-250, at least for the parts I used.
>  At the time, though, it was a decent amount cheaper than the PVR-250.

I've got a little USB-based device that seems similar to that
which I use for transcribing video tape.  Never peeked inside
it, though.  And, it is used in an entirely different manner
(i.e., more like a workstation application than a TV-watching)

> I haven't had the time or resources to upgrade since that means
> getting a new DirecTV set-top box that outputs HD, that I can still
> control from the PC (changing channels, etc.), and that preferably
> doesn't have its own DVR built-in.  I'll also need to upgrade the
> drives in my RAID to increase capacity and move from RAID-5
> to RAID-6.

Yes, everything takes longer than you can imagine!  <frown>
Originally, I had thought of trying to buy a TiVo style box
from Worldcare and repurpose it.  But, that looked like a lot
of work that would be tangential to my ultimate goal, so...
<shrug>

> Oh, and a new HDTV encoder/receiver of some sort, probably
> the HD HomeRun that Harry suggested.

At first glance, these look like they will handle my TV needs.
Though I may have to go the route of buying two separate units
(antenna issue I mentioned).  This would also make it easier
to physically route network traffic.

> You mentioned two broadcast channels and multiple cards, so
> I'm guessing you want to receive/record both simultaneously.

As above... mainly so two of us could watch different programs.
Of course, with more than one source, there are other
possibilities as well (PiP, record+watch, record+record).

> Again, if SD is acceptable, you can try the Hauppauge WinTV
> PVR-500.  This card is essentially two PVR-150s on a single card.

But, a single processor would have to handle all of the load?

I've looked into a variety of different hardware architectures
as I've tinkered with this design.

Early on, I dismissed the "single server" approach because it
required too much horsepower to handle "everything"... and,
only needed all that capacity in a few (rare?) circumstances.

So, I have been gravitating towards multiple small, dedicated
"servers" that can be brought on line as needed.  As the
functionality that they provided was needed!

E.g., I looked at an "audio server" concept where stored content
and "(my 2) radio peripherals" were accessed and served up by that
box.  So, any time anyone wanted to listen to music -- whether
canned or live -- that box was brought on-line.  Handling two
audio streams seems to be relatively trivial task -- regardless
of whether you're pulling the content off a radio card or
some sort of storage medium.

OTOH, how far can you scale that before it starts to tax a
single processor (given that you want to downgrade the processor's
capabilities/resources to save money, power, heat, etc.)?

And, handling two *video* sources in a single box is a considerably
more intense undertaking!  I.e., it might be more prudent to
move to a single video source (OTA/CATV/stored) per server than
worrying about scaling a single server would fare!

With a single video source per server, then *replacing* that
with audio, instead, is a cake walk.  So, having a server
handle one audio *or* video service seems like it might be a
nice, scalable unit!  Want PiP?  Or, to be able to watch
TV while listening to the radio?  Add another server!

[Then, size the resources on that server to fit that need and
nothing more]

> Its inputs are a bit odd... it has two coax input connectors, 
> one for TV and one for FM radio.

Separate tuners?

> Internally, the TV input's signal is split, and this means
> that actually finding a way to use this card now that OTA
> analog signals are gone is rather difficult.  Again, with some
> older hardware set-top boxes, you could configure one to output
> on channel 3 and the other on channel 4, and then use PC
> connections to those set-top boxes to actually control channel
> changing.  Probably too limiting and more trouble than it's worth.

Yes.  That;s similar to my idea of controlling the DTV STB
while routing it's "component/composite/S- video" to a
capture card.  OK for a "one off" but not the sort of thing
you'd want to offer to others as a complete solution.

> Harry also mentioned the BTTV chipset cards.  The first TV/radio card
> I had was one of these and it was on this card that I made use of the
> FM tuner.  I do not know if it is true for all of these cards, but the
> one I had contained only a framebuffer for the TV data and no MPEG
> encoder.  This meant that it was mostly suitable for live video.
> 
> As for performance:  the BTTV card I had (this was just over ten years
> ago) had very high system requirements if you wanted to record video
> since it was a lot of data to move and it had to be encoded by the
> CPU.

Yeah, I think that has changed with the advent of COTS encoders.
I just have to see how much flexibility there is in accessing
that signal/data in a form that is easiest for me to trasncode
to fit *my* needs.

(sigh)  Easier to just listen to music!  :-/

Thanks!
--don