Mythtv – More decoder cards

I mentioned the other day about the new MythTV software, all it’s glories and wonderful new features. I am still happy with it, more now than before as I test it further, find it’s features, but also struggle with some issues.

The big thing is the ability to decode digital television signals and turn them into a picture or recording. This is done with set-top-boxes, digital DVD recorders, Tivo, Foxtel IQ’s and everything in that line. The limitation is always that you want to watch one and record another, and for this you would need two decoders.

My TV has a built in decoder, but only one at a time, it doesn’t let me do much with the picture-in-picture ability because that would require two decoders. Even back in the day of a simple video recorder, one channel at a time, and always it seems two good movies were on the same night so neighbour or family friend to help out and coordinate and swap tapes later.

This can even get a little more involved. What if one show finishes at 8:30 and the next one starts on a different station at 8:30? Do you think you will get your recoding times right, will the stations be dead on and not run overtime, fat chance.

To solve this I have three (yes 3) decoder cards in my Myth TV box. Not only could I record up to three things at once (which did happen occasionally) but also I can set a show to record from 7:30-8:30 and have a 9 minute over-run, and while that’s happening start a new one from (a little before) 8:30 and not miss anything.

So having three decoder cards almost filling the slots in my PC is enough right? Well no, it’ still happened that with this overlapping and all the new digital stations here in Aus now that there was still conflict.

This can be helped a little with priorities. When setting a recording you can set a priority so in preference to others, some are ‘not-to-miss’ +50, some are ‘don’t-care’ –50 and all levels in between. If a conflict occurs then the lowest priorities are just not recorded… Not good enough

The solution now is that decoder cards may actually record more than one thing at a time.

MythTV now allows for multiplexing. This means that two channels from the same carrier (like 7, 7HD and 7Two) all work on the same basic signal elements and can each be decoded on one card at the same time.

When you setup the decoding card info in the ‘back-end’ there is a ‘recoding options’ button and you can bump up the ‘number of simultaneous’ recordings above the default 1. I probably suggest only setting this two 2 in the first test. But now with each of my cards set to 2 I have 6 decoder cards listed. Yes, there are some limitations but Myth works this out as to what can be allocated to each of the virtual decoder cards at the same time, what will work and what wont.

My first test included two shows running inline. I like ‘Big Bang Theory’ and they show runs of these and Seinfeld etc on channel GO! Marathon sessions, or in this case at least two in a row.

On a video I would set and record the two one hour shows from 7:30 – 9:30, simple. With these systems however, they go by the TV guide and set each shows start and end time separately, thus two recordings, with padding, in a row. Normally this would take two decoder cards, during the transition, to handle the overlap.

Now with multiplexing, it recorded the overlap simply with the one card and left the other two free for other shows and movies on at the same time, which happens.

Just a quick note for now, to let you know some cool tricks, I will look at writing up my minor issues soon.