[mythtv-users] Confusion about Output Cards.

Bob spam at homeurl.co.uk
Wed Mar 15 05:16:49 UTC 2006

Jesse Guardiani wrote:
> Nick wrote:
>> On 14/03/06, Jesse Guardiani <jesse at wingnet.net> wrote:
>>> One more note: SDTV looks fairly bad using software scaling on an HDTV.
>>> Usually it's perceived
>>> as worse than SDTV on an actual SDTV due to the pixelation. Oh well.
>>> DVDs look nice though,
>>> and of course HDTV looks great.
>> One question about this, as 'HD-ready' 720p panels are now becmoing
>> available in the UK - how does scaled DVD video or DVB look when
>> displayed on such a LCD/plasma screen? Is it better to use the
>> software to do the scaling (ala DScaler on Windows) or use the
>> screen's own resizing capabilities? DVB and DVD have very clean video,
>> whereas PVR-xx0 captured video is much more noisy, so would you expect
>> the same? In other words, would the pixelation observed when playing
>> 480 content on a 720 screen be similar to playing 720 content on a
>> 1080 screen?
> The only difference between an 'HD-ready' TV and an HDTV is the presence 
> of an OTA tuner
> on the latter, as far as I know. So this discussion probably relates to 
> both types of HD TVs.
> I'm currently running a 32" LCD via DVI. Resolution is a common 
> 1360x768. DVDs look excellent,
> as do games and MythTV menus. I literally use the TV as a monitor on 
> ocassion. There is none of the
> blur or distortion one usually experiences with TV out to an SDTV. So 
> think of it like a big-a$$ LCD
> monitor.
> I record my SD content from a PVR 350, same as you. SDTV is 
> blocky/grainy/etc when played
> back in mythfrontend on the LCD. I'm really not sure why DVDs look so 
> much better than SDTV.
> My SDTV comes in via satellite, so it's usually not very noisy. They're 
> both mpeg-2 and they both
> use similar pixel resolutions and bitrates. Since I play back DVDs using 
> xine, it makes me wonder
> if xine just has a superior mpeg scaling engine. I'll have to check this 
> out when I get home tonight.

The recordings off your PVR 350 has been digital -> analogue and back to 
digital which is why they don't look so great, also there's a good 
chance a DVD is progressive scan whereas the MPEG from your PVR 350 is 
interlaced, even if the satellite feed was progressive (don't know, 
probably not).

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