[mythtv-users] MythTV and HDTV?

[Tim Tait]

Jeff Dubin wrote:

>On Tuesday 15 June 2004 13:09, various folks wrote:
>
>  
>
>>>setting up Myth to PVR for it... can Myth handle HDTV? I'm assuming I'd
>>>need some special capture card, which I have not seen anywhere... so my
>>>inital thoughts are "No"
>>>      
>>>
>
>  
>
>>Note that decoding HDTV seems to require a fast processor (on the order
>>of 3GHz).
>>    
>>
>
>Some HDTV cards (none of which have linux drivers, sadly) have integrated
>hardware MPEG2 decoders, or have windows-based "DXVA" (DirectX Video
>Acceleration) enabled software decoders which offload a decent bit of the
>MPEG decoding to your graphics card (i.e. ATI Radeon, etc.), significantly
>reducing the CPU requirements.  I don't know what exactly is being done
>under this DXVA mode, or, more specifically, if (read: when) this can be
>accomplished under Linux, but it would be a major step towards lowered CPU
>requirements for HD viewing (my Athlon 2000 runs at ~40% CPU decoding
>1080i with DXVA drivers).
>
>  
>
>>There's a new card out with CAM support that's supposed to be able to
>>tune HDTV over cable; it's supposed to have Linux drivers, but I haven't
>>heard of anyone actually using it yet.  In any event, I doubt it would
>>be useful for DirecTV.
>>    
>>
>
>It sounds like you're talking about QAM (quadrature amplitude modulation)
>support, which is the modulation type used by many (most?) cable systems
>for delivering digital cable.  AFAIK, the only card which officially and
>fully supports this currently is the "FusionHDTV 3 Gold QAM" by Dvico
>(www.dvico.com).  Again, no linux drivers.  That could change though.
>According to posts I've seen on this Australian DVB-T form
>(http://robdvd.radfiles.net/viewforum.php?f=18), Dvico is looking to help
>anyone interested in developing a Linux driver.  There's rumors that
>someone is developing OS X drivers for it, and one person mentioned that
>they were starting Linux development (though, since he's in Australia, it
>probably won't be ready to be used in the US for ATSC or QAM reception
>without some additional code).  So, there is hope.
>  
>
I think for a digital cable tuner to very useful (to me) it would it 
would have to work the cable company encryption scheme - which is very 
unlikely. So what I want is an HDTV baseband capture card, ie component 
or DVI capture. ADC's for XVGA to flat panel conversion run about $20 
per IC. If an MPEG2/4 encoder chip that supports HDTV like rates can be 
found (cheap?), then I don't see why a sub $200 component capture card 
couldn't be made. 

Tim