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

[Richard King]

On Wed, 19 Mar 2003, Martyn Weber wrote:

> On Wednesday 19 March 2003 21:36, Matthew S. Hallacy wrote:
> 
> > 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.
> >
> Does this mean that you have the WinTV PVR-250 working with Linux? If so what 
> capabilities does it offer under Linux and what drivers do you use? Are you 
> grabbing/creating and MPEG2 file?
I don't use this card but http://ivtv.sourceforge.net/ seems to be making 
alot of progress with a driver for this board.

> 
> The other thing I cant understand, but Im a complete novice to video so thats 
> no surprise, is why to encode the mpg stream in a nuv file anyway. Cant 
> MythTV be changed to support mpg files directly? A lot of people, myself 
I'm no expert either but I believe the reasons to be mainly based around
the fact that originally Myth did not support MPEG, but used the
NuppelVideo codec and its NUV file format. When incorporating MPEG video
encoding support it was easier to add it to the NUV format than to add
support for native MPEG files. The MPEG specifications define many
different things.  How to compress video, how to compress audio, how to
combine these and other streams into one file, how to package these files
for broadcast, etc. Implementing full MPEG support is alot more work.

> included are trying to export recorded programs to VCD or DVD and are having 
> to convert the nuv files to mpg(1 or 2) and recombine the audio and video 
> streams (together with the associated sync problems). Wouldn't using mpg file 
> format directly simplify this? What am I missing?
It definately would simplify this, but it would also need alot of work to 
integrate it. Things like teletext/subtitle support would be more 
difficult. Myths existing mechanisms for audio/video syncing would need 
attention. Seeking would also need attention. Given that external programs 
can already convert the files (syncing issues are a bug that can be fixed) 
why bother with all the work to integrate support into myth?

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