[mythtv-users] A few newbie type questions

[Torsten Schenkel]

On Wed, 2004-01-14 at 15:50, Nick Gilbert wrote:
> Hi all,
> 
> I'm considering setting up a MythTV box to play with, but as I'm not 
> very linux proficient and I don't have a spare box yet, it'll probably 
> take me a while. Before I waste my time and set up a system to realise 
> that it's not really for me, I'd like to know the answer to a few questions:
> 
> 1. I'm in the UK and I have a cable feed from NTL. Therefore my 
> programmes are usually transmitted in 16:9 widescreen and my TV is also 
> 16:9 widescreen (PAL). HOWEVER, all the screen shots I've seen are all 
> in 4:3 format and probably NTSC. Does mythtv support PAL and 16:9 
> anamorphic transmissions properly? I can't really see how it can as I'm 
> pretty sure that there aren't any video cards that could output a proper 
> 16:9 format PAL signal.

I don't have a 16:9 TV, so I may be completely wrong here :-)

MythTv supports PAL settings, 16:9 PAL is 720x576 like a 4:3 signal,
your TV stretches it to be 16:9, but there aren't more pixels in it,
it's simply the geometry of the pixel that changes. So if all you
transmissions are 16:9 you can just feed the signal to your TV and let
the TV handle the anamorphic stretching.  

I think there is no way to tell the TV if the signal it receives is 4:3
or 16:9 at the moment. But maybe someone with a 16:9 source and TV can
tell more about that.

> 2. I really care about the quality of the recordings I get. How does the 
> quality compare to say, the original digital feed? Presumably it'll only 
> be a bit worse than the original feed?

If you are concerned about quality, you should get a pvr250 or 350. Or
one of the "clones" that support hardware mpeg encoding.

> 3. UK TVs are 576 lines (I think). But most applications like this only 
> work in 640x480. Does this mean that all cards with TV out, will have to 
> scale/resample the 640x480 signal up to 576 lines for display on the TV 
> and therefore may appear to be slightly soft all the time? Or can it put 
> the graphics card into 720x576 to get UK PAL resolution?

MythTV will happily work with 576 scan lines.

> 4. Does it work like a TIVO in the sense that you are always watching a 
> recompressed version of the signal rather than the original? Or does it 
> show you the raw output of the TV card if you're not currently watching 
> a recording?

The former is true. It writes the compressed stream to disk and plays it
back from there to give you the possibility to pause and rewind the live
tv stream. 


-- 
Walkthrough: MythTV on Epia with PVR350 using Debian:
http://www-isl.mach.uni-karlsruhe.de/~hi93/myth/mythtv_debian_epia_pvr350_walkthrough