[mythtv-users] [mythtv] Best quality SD TV picture from DVB-T source

Paul Gardiner lists at glidos.net
Mon Sep 22 08:46:10 UTC 2008


Nick Morrott wrote:
> On 19/09/2008, Paul Gardiner <lists at glidos.net> wrote:
>> I've just built a MythTV frontend using a J7F2 board and minimyth,
>>  for driving an old SD but top quality CRT TV. Works great, except
>>  the image quality is not as good as my old DVRs. From what I've
>>  read, the loss of quality is partly the use of an S-Video connection
>>  and is partly the processing of the interlace. I want to build
>>  something better, but I just can't work out what my options are.
> 
> This isn't a -dev question, so if you want to carry on the discussion,
> please bring it over to the -users list. The "devs" do read the -users
> list, so may help with your quest :)
> 
> In the UK (PAL), I use a homebuilt RGB SCART cable, which takes the
> VGA output from my ATI Radeon card (running at very low dot clock),
> and outputs an RGB signal straight into my big Sony Wega CRT (audio
> via SPDIF to a receiver).
> 
> I use deinterlacing (because getting the interlacing perfectly
> synchronised without tearing is either very difficult or impossible,
> depending on video card capability) and think the picture is very good
> for DVB-T recordings which have zero noise (unless encoded within the
> picture). The frontend machine in question in not particularly
> high-powered, so I only use the kernel deinterlacer. The difference in
> moving from a composite/S-Video signal to RGB was very noticeable.

Was it composite or S-Video? And what differences did you notice? I
believe my slightly washed out colours are due to S-Video, but I'm
not sure what is making the image slightly softer than my DVRs. It
could again be S-Video, or it good be the interlace processing? It
would be interesting if you felt you achieved a sharper picture
with RGB, because one option for me is to buy an EN12000E board
which has component video via a JTV header. That would be great
because I can stick with my small and silent box. The trouble is
though that it's £150 to try it out - fine if it works, but a
lot to pay if it only gets me half way there. There's also a risk
that the openchrome drivers for that board's TV out chip (VT1625M)
wont support component video, and then I'd end up with just a
second board that gives me S-Video.

Cheers,
	Paul.



More information about the mythtv-users mailing list