mythtv and digital tv

[Frank DiPrete]

Jarod Wilson wrote:
> On Thu, 2008-07-24 at 21:17 -0400, Ben Scott wrote:
>> On Thu, Jul 24, 2008 at 6:36 PM, Frank DiPrete <fdiprete at comcast.net> wrote:
>>> I like the HDHomeRun card ...
>>   Just to make sure it's clear, the HDHomeRun isn't a card, it's an
>> external box (about the size of a cigar box).  It uses a wall-wart
>> type power supply transformer.
>>
>>> If the card had hardware encoding it would be perfect.
>>   Encoding or decoding?
>>
>>   For digital broadcast -- be it cable or ATSC OTA -- the stream is
>> already encoded and compressed as part of the transmission process.
>> There's no need for an encoder.
>>
>>   The HDHomeRun is digital only; it doesn't even have an NTSC tuner.
>> So, to the best of understanding, the HDHomeRun has no use for a
>> hardware encoder.  The HD-5500 does have an NTSC tuner; I don't know
>> if it has a hardware encoder or not.
> 
> It does not. Its only much more recently that cards with both digital
> and analog support also included a hardware encoder for the analog side.
> The only one I know for sure actually works under linux is the Hauppauge
> WinTV HVR-1600 though.
> 
>>   For decoding, I believe you'd still be able to use the "small quiet
>> diskless box frontend".  The one thing I'm not sure about is: I expect
>> not all hardware decoders are created equal.  It may be the decoder in
>> your front-end box can't handle this new-fangeled high-def stuff.
> 
> Definitely a concern. It takes a heck of a lot more for decoding HDTV
> than SDTV. Although not nearly so much as it used to. My frontend is a
> mere core duo 1.66 with intel gma950 graphics, and it handles the job
> just fine. "Small quiet diskless" often implies a Via processor
> though... Which may or may not be enough, depending on the video
> chipset, the openchrome driver, and the options mythtv was built with...
> 
> 

The frontent is a via 1G. Current mpeg playback takes about 25% of the 
cpu. myth / xorg is using the openchrome driver.