[mythtv] Re: Adding DVB-T support to MythTV

[Matthew S. Hallacy]

On Wed, Mar 19, 2003 at 12:41:50PM +0000, Richard King wrote:

> I aggree that its not worth it. I can see why its been suggested though 
> and yes it is like using the AV inputs on a wintv card but a) the nova 
> cards dont have a tv out and if you have a nova card why bother buying a 
> wintv card in the first place.

Why bother using MythTV for it at all, if it's not done (reasonably) right?

For my WinTV PVR-250, I use the 'player6' application to write to a ringbuffer,
then I open that with xine/mplayer/etc. I can pause/rewind/fastforward with ease.

Something similar could be done with the DVB cards (and perhaps it already has),
but an ugly hack that wastes that much cpu (and yes, it will be more than even
some of the higher-end systems can handle at any decent res/quality) is just
dumb, IMHO. 

> > > The proper way to do this, does NOT require a 'rewrite' of MythTV. As

> I wasnt suggesting this. Just rearranging the NuppelVideo bits with bit of 
> glue.

I was responding to Mr. Jarvis. 

> If you've been following the thread its not quite as simple as that. Thats 
> all you need to do if you've got one of the Hauppauge PVR cards but DVB is 
> not quite the same. Though for simple support its still not that difficult 
> if you pipe data in from external commands.

The multiple stream issues, right? Even from my limited knowledge of A/V codecs
I know that it's not hard to select which stream ID you want, or to demux
the audio and video for further processing (although, if the target storage
format is MPEG-2, you don't really need to do any processing on it) 

> I don't think you need to modify the storage format at all. Issac has 
> added support for 'ffmpeg' streams in NUV files. an MPEG2 stream can be 
> considered just that given specifying the right codec in the header.

Excellent.


I do have some questions about the streams produced by the DVB cards:

1) If channels 100 through 120 are in the same 'block', then I change to
channel '110' does the 'block' contain 110-130, or 100-120? If it's 100-120
then MythTV would have to know how the blocks are setup so that it can 
pick the proper stream ID, otherwise it could pick stream 0 and use it.
(With added support for pseudo multiple tuners at a later point in time,
assuming the other channels are within the same block)

2) Are the blocks of channels hardset, or can you pick and choose which
ones you want? It would be very nice if you could actually pick 24 (or
whatever the number is) channels to get in the stream, but I suspect this
is not the case.

> -- 
> Richard King
> E-mail: rak at cs.man.ac.uk

-- 
Matthew S. Hallacy                            FUBAR, LART, BOFH Certified
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