[vdr] Re: Interlacing

[Tony Houghton <h@realh.co.uk>]

In <clobq6$c8e$1@sea.gmane.org>, Lucian Muresan wrote:

> Tony Houghton wrote:
> >Some disadvantages with Matrox:
> >
> >AFAIK the TV-out doesn't work with X, at least not with the mga driver,
> >but it might be possible to do something with X's vesafb driver.
> 
> Well, that depends if one sees this as a disadvantage. I bought the G400 
> especially for building a HTPC on which I refuse to install X. The 
> alternative would have been Nvidia + X + hardware Xvmc, but as I opted 
> for DirectFB which simply looks great when properly setup on a Matrox, 
> that's how I see it...

What's hardware Xvmc? Just the stuff that ATI and NVidia cards do to
convert 800x600 non-interlaced to PA or NTSCL?

The reason I want to run X on it is so that I can use the same PC for
torrents and aMule, because I dual boot my main PC and would lose my
place in queues when I wanted to play a Windows game. I think aMule has
a client-server mode though, and I could run the curses version of
torrent if the Matrox FB driver supports the console.

I'd like it to be reasonably easy to play MPEG4 (DivX etc) on it too, ie
easy enough for my parents to manage. Does VDR's mplayer plugin work
with outputs other than a FF card?

I don't really see the point of using a PC if it's not going to do
anything besides play and record TV, there are consumer machines that
can do that with less hassle.

> A dxr3 or a FF DVB card may do MPEG1/2 decoding very well and may have a 
> very good picture quality, but so do most domestic DVB receivers too. If 
> I do DVB on a PC, I want it do more than that, decode various other 
> formats without transcoding first at the expense of CPU cycles which I'd 
> rather put into decoding, decode even HDTV (MB + CPU upgrade) when the 
> time is right for that, so current hardware decoding solutions are too 
> limited for that.

How much power does the transcoding take? I think the software
deinterlacing I'm currently having to use because of defficiencies in my
current hardware is too much for my CPU, so I really need to do
something, and I've been leaning towards the DXR3 route because of the
availability and cost. FWIH 1.2GHz is more than adequate for DivX->MPEG1
transcoding.

I think the main put-off is not being able to use the DXR3's TV-out with
anything except MPEG streams. ISTR seeing Vdr plugins for use as a shell
terminal and even X server, but whether they'll work with the DXR3
output instead of FF DVB output, or even at all with 1.3.x...

> And my curent 1GHz Duron which doesn't know about any 
> power-saving techniques (like modern AMD64 desktop-targeted processors 
> know already at present) is quiet enough when just decoding MPEG2. I 
> only switch on 2 aditional fans when I have to compile things for a 
> longer time (because I'm using Gentoo, compile everything with optimezed 
> flags). So regarding noise levels on software-decoding solutions, things 
> can be improved, and will improve further, especially when choosing the 
> right hardware.

Have you seen the Athlon Powersaving HOWTO? That makes a big difference
for 32-bit AMDs.

My PC is mATX in a fairly small case (a bit thicker than I'd like
because of the full-height PCI/AGP cards) with a Celeron 1.2GHz. Socket
370 and A have compatible heatsinks, so I've got a biggish copper
heatsink with low-noise fan designed for Athlons, and my PSU is also
adequately quiet. It's not silent, but the TV drowns it out easily,
whereas I don't usually bother putting on any background music when I'm
programming/tinkering/ emailing/browsing etc so I like my main PC to be
quieter still.

-- 
TH * http://www.realh.co.uk