[mythtv-users] Some first impressions

[Simon Hobson]

Ross Boylan wrote:

>Getting it sort of set up was difficult, partly because I was trying to
>do it in a chroot.  My system is Debian Lenny; the chroot is debian
>testing, getting packages from Marillat's repository.

Probably not an ideal method for your first setup

>There were more components than I expected:
>capture cards, video sources and inputs all sounded as if they were the
>same thing.  The name "video source" seems misleading; this seems to be
>the source of programming information rather than video.

It's explained (in part at least, there used to be a diagram in the 
docs but I can't find it now) in the Wiki : 
http://www.mythtv.org/wiki/User_Manual:MythTV_structure

It's more complicated than it needs to be for most simple setups 
because it allows some quite complicated setups. It will handle, for 
example, the case where a capture/tuner card could have the ability 
to digitise the output from an external source (eg satellite or cable 
tuner) OR digitise analogue signals via it's tuner OR handle digital 
signals via it's tuner. So that's three sources of video, mutually 
exclusive via one card. However, the digital channels available 
through that card may also be available through a separate digital 
tuner.

Myth can handle the complexities of this where :
It has two digital tuners available (which may have the same or 
different channels available)
It has one analogue tuner & digitiser available
It has one digitiser for an external device - and it can manage 
controlling that external device to switch channels (tune it).
One of the digital tuners is part of a 3 way mutual exclusion with 
the analogue tuner and external tuner.

And of course, on the digital tuners, it typically can do "multirec" 
where it can record more than one channel from a single digital 
multiplex with one tuner.


The downside of this power and flexibility is the complexity you've found.

>I have an HDHomeRun tuner (newer version, HDHR3-US) with US over-the-air
>signals.  The ability of the Myth to handle more than one tunerwas very
>important to me.  However, after setting everything up (including
>setting # of tuners to 2 in the HDHR setup) I discovered I could not
>record 2 shows at once.  Googling around turned up that I needed to
>create a separate entry for each tuner, as well as the info that I could
>identify them by their tuner id rather than IP address.  The
>instructions I found were quite involved, and currently I show that I
>have 4 tuners, probably because I didn't set the individual tuner counts
>to 1.  I can record 2 shows at once.  It would be nice if HDHR handling
>were more automatic, or at least documented in the installation manual.

I think you are confusing physical and logical tuners. Digital (ATSC 
or DVB) is a relative newcomer, and supporting multirec was therefore 
a "grafted in" feature that might not have been done the same way if 
starting with a clean sheet. For a digital tuner, you can set the 
number of tuners and this controls how many virtual instances are 
created. Setting the tuner count to 2 means that you have two virtual 
tuners (they show as separate tuners elsewhere in Myth) - but with 
the limitation that they share a single physical tuner and hence must 
both be working with the same digital multiplex.

What you should find is that you can record up to four programs at 
once with your current setup - but 2 of them must be from a single 
multiplex, and the other two must be from a single multiplex.
Part of the confusion is down to the historical practice of treating 
"channel" (=frequency) and "channel" (=collection of broadcast 
content) as the same. With DVB, there are typically multiple 
"channels" on each frequency.

>I was confused by mythfrontend offering 2 different routes to setup.
>The initial screen has "TV" and "setup", and then if you go to "TV"
>there is another "setup" screen.  I wasn't sure which control operated
>which options; I have only just realized these are 2 routes to exactly
>the same spot (right?).

I'm as confused as you on this.
I *think* that in general, things accessed via TV->Setup tend to be 
related to the frontend and it's attached display, which things 
accessed directly via Setup apply to the system. But there is 
considerable overlap and you can cycle through a set of screens where 
some control the frontend (local options) and some control the system 
(global options).

>I was absolutely delighted by the commercial skipping/deletion.

It's more variable over here in the UK - but tends to work 
brilliantly on imports from the US. When it doesn't work well, it 
highlights just how great it is when it does work.

>There are slots for jobs, but I have no idea what goes in them.

Jobs are typically commercial flagging or transcoding jobs. If you 
have a recording schedule which specifies to commflag, then you'll 
see a commflag job appear in the queue - either during recording or 
after it's finished according to your settings. Similarly for 
transcode jobs.

>I probably have not grasped the various recording options or the
>deletion options.  In particular, when I thought I was deleting a
>particular recording I think I ended up deleting the general
>instructions to record the show.

Things that have been recorded are referred to as recordings, the 
rules on what to record are referred to as recording schedules. 
Deleting a schedule won't delete recordings already made, and 
deleting a recording won't delete the schedule that triggered the 
recording.

Just to add more into the mix ...
You'll find global settings for recording schedules - these set the 
defaults for new schedules. Changing them doesn't change existing 
schedules which you'd need to edit individually.

Recording schedules are another area where there is immense power but 
requiring some "geekery". If the standard options (eg click a program 
in the listings, set it to record all episodes) then you can use 
power settings. You can write SQL, of arbitrary complexity to select 
programs to record - immensely powerful, but with that power comes a 
requirement for more knowledge.

-- 
Simon Hobson

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