[mythtv-users] Recommendations for front end replacement

[Andre]

On 6 Dec 2011, at 12:34, Brent Bolin wrote:

> On Tue, Dec 6, 2011 at 3:02 AM, Andre <mythtv-list at dinkum.org.uk> wrote:
>> 
>> On 6 Dec 2011, at 08:37, Tim Draper wrote:
>> 
>>> On 6 December 2011 08:14, Kevin Ross <kevin at familyross.net> wrote:
>>>> On 12/05/2011 03:36 PM, Mark Carbonaro wrote:
>>>>> No problems running 1080p with vdpau high profile
>>>> 
>>>> Yes, but how about 1080i?
>>> 
>>> unless i've misunderstood something with the various formats, it's as
>>> simple as 'p' required more processing than 'i'.
>>> so...1080i uses half the bandwidth of 1080p
>> 
>> Sadly that's not the whole story.
>> 
>> 1080i needs de-interlacing for any flat panel display and pretty much for any myth system, de-interlacing is a far more resource hungry process than decoding mpeg2 and maybe even h264 in some senses. With vdpau there are some excellent de-interlacers provided your graphic card has the capability, for sports, news and any other live TV you need advanced 2x de-interlacing but if you only ever watch films or drama on TV then you may be able to get away with one of the 1x spacial or advanced de-interlacers.
>> 
>> If you have a smaller TV <40" and no-one in the family is especially aware of or sensitive to motion problems in TV then you may not notice the difference, everyone's eyesight and perception is slightly different this is why you will get some posters telling you an ION is great and others (like me) telling you to buy a GT220 or GT430 or everything will look terrible.
>> 
>> The issues are also the sort of thing that some people can miss entirely until it's pointed out after which time the problems cannot be unseen! If a broadcast engineer wants to be cruel to you they can point out a whole host of unpleasant effects in modern TV that might put you off watching TV for life ;-) I sent my new girlfriend out of the room while setting up her new TV as she was wanting me to point out the problems I was fixing as I went along, sometimes ignorance is bliss!
>> 
>> 1080p encoding often uses higher bandwidth when compressed, mostly because it has usually come from a bluray but in some cases lower bandwidth 1080p (from some satellite & cable feeds) can be harder for the decoder. Due to this one posters "1080p/i works for me" is pretty meaningless unless [s]he's watching the same sources as you recorded in the same way.
>> 
>> While it's true that 1080i uses half the bandwidth of 1080p when uncompressed, pretty much any 1080p you find outside of a broadcasters R&D lab uses exactly the same bandwidth as it's 1080i equivalent, potentially a little less. Uncompressed bandwidth is irrelevant for anything other than very long HDMI cables or de-interlacing.
>> 
>> Andre
>>> 
>>> in other words - no problems :)
>>> my 330ion handles 1080i broadcast material fine; I've not tested 1080p
>>> yet though.
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>>> 
>> 
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://www.mythtv.org/mailman/listinfo/mythtv-users
> 
> Thanks for your reply.
> 
> What you say is very true.  I'm not sure my wife see's the issues as
> much as I do.  It drives me nuts.
> 
> ION looks fine for OTA mpeg2 HD broadcast when the scenes are close up
> and slower.  Even some football games are pretty good.  But when you
> get a large panned scenery shots stutter shows up.
> 
> I don't know all that much about good video cards.  I've looked at
> both GT220 and GT430
> 
> Core Clock
> Stream Processors

Yes, well I have both a GT220 and a GT430, the GT 220 is a Sparkle 1GB DDR2 with 400Mhz ramdac and this seems to handle all unencrypted HDTV in the UK, BBC, ITV & Ch4 which are h264 1080i at 1440 and 1920 for BBC & CH4 respectively. I am able to use 2x Advanced de-interlace with minimal issues (some stutter on dark credits or full white). The GT430 is a Gigabyte GV-N430OC-1GL, I took some care to buy one with a higher than average shader clock to give the best possible headroom for 1080i. I have some 1080i30 mpeg2 sports material for work.

I have some older generation vdpau cards too but the GT220 was the first one that produced good quality video IMPO (professional opinion).


I think core clock is important for de-interlacing but I don't think number of stream processors makes any difference for MythTV purposes.

I found that neither card is powerful enough to use inverse telecine (ivtc) but I'm not convinced that Myth drives that right yet anyway. I only got the GT430 for bit streaming bluray & hddvd audio codecs, my surround amp doesn't apply room profile post processing when given multichannel LPCM.

I have a 90" screen from a 1080p DLP projector and work in sports television so I'm a fussy viewer but it means I appreciate when things are done well and MythTV's video playback processing is the best of any OSS media player I've tested to date.

> 
> I can tell you about Veritas clustering and all kinds of other fun
> stuff, but this is a little greek to me.
> 
> Don't see a huge price difference between them.
> 
> The zotac's that I have don't have any slots for video cards.  So I
> need to build a new front end if I'm going to do this.
> 
> Any suggestions other then maybe the GT430 being a newer product?

If you want to play ripped bluray & hddvd and bitstream the audio.

> 
> Thanks
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://www.mythtv.org/mailman/listinfo/mythtv-users
>