[mythtv-users] PVR350 + MythTv behaviour

[Olivier]

Torsten,

Thanks for the good description. This is pretty exciting.

There has been some discussion in the last few days about channel change
delay; With the 350 hardware, is it possible to feed both the tv out
directly, *and* writing the mpeg stream to disk ? This would allow live tv
mode to be really live as opposed to have the 2-3 second buffering delay. I
understand that  for other cards that do not have tv in and out on the same
board, this ring buffer is always required, even when watching live, but
with the PVR350, I guess we could have a mode where if you are almost live
(i.e. 2-3 second behind), it switches to real live tv where tv-out is feed
with tv-in and not the ring buffer.

What is you though on that ? if pvr hardware supports that, it would be a
pretty nivce feature especially for setup with an external tv tuner...

Olivier.



----- Original Message -----
From: "Torsten Schenkel" <torsten.schenkel at web.de>
To: "Discussion about mythtv" <mythtv-users at mythtv.org>
Sent: Monday, November 10, 2003 1:27 PM
Subject: Re: [mythtv-users] PVR350 + MythTv behaviour


> On Mon, 2003-11-10 at 18:44, Olivier wrote:
>
> Hi Olivier,
>
> > I have been following ivtv and mythtv discussion latelly,
>
> hmm, are you sure you followed it closely :-)
>
> >  and my
> > understanding is that pvr350 tv-out will only spit out a mpeg stream to
the
> > tv-out. This means that if we want to see tv with an overlayed OSD,
mythtv
> > has to modify the tv mpeg stream on the fly and encode osd information
into
> > it, and this is not implemented yet. I also read that mythtv currently
> > support PVR350 tv out by switching between tv mode (mpeg out) and osd
> > (framebuffer). My understanding from this statement is that mythtv would
> > switch between these two mode and thus, we are getting either tv or an
osd
> > with a black background.
>
> The TV-Out has two main functions at the moment:
>
> 1. decoding, scaling and displaying mpeg stream
> 2. framebuffer, this is used for X (mythtv gui) and osd.
>
> The two modes are displayed simultaneously. They are independend of each
> other. The framebuffer content is lying "on top" of the video picture.
> When viewing tv, the frambuffer content is made "transparent". When
> exiting out of tv/video mode, the framebuffer is made opaque again.
>
> The transparency setting can be set to differnt levels between opaque
> and fully transparent. This can be controlled by setting an alpha value
> via ivtvfbctl. The OSD (some themes at least) make use of this, so a
> very stylish translucent osd is possible.
>
> Or short: Your conception is wrong; the pvr tv-out is capable of all
> that's necessary to drive an otherwise headless system.
>
> What's missing in the driver (but being worked at) is yuv output to
> enable streaming of decoded video (divx etc.).
>
> The driver is under heavy development and stability changes every day.
> If you want to use mythtv 0.12 and not the current cvs version, the last
> driver known to work (known to me that is) is the 311003 edition by Jens
> Axboe.
>
> Torsten
> --
> Config files for PVR350 TV-Out:
> http://www-isl.mach.uni-karlsruhe.de/~hi93/ivtv-pvr-350-conf.tgz
>
>


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