[mythtv-users] mythtv hardware plans

Brian Wood beww at beww.org
Sun Feb 4 01:15:52 UTC 2007

On Feb 3, 2007, at 5:07 PM, Steven Adeff wrote:

> as well, the pcHDTV cards will require cpu power to encode, which may
> or may not be an issue depending on the CPU you end up with. I don't
> know if the quality ends up being any better than a  PVR card though.
> Its just that for the price of a PVR-150 its just nice knowing you
> don't have to worry about using your CPU.

I think the "quality you end up with" can in fact be better with a  
frame grabber, as you have more control over the encoding parameters  
and can devote more power  to the task, assuming you have a very fast  
CPU.  You also have more flexibility in terms of the codec used etc.  
Myth offers a very small subset of the available possibilities, which  
was chosen to be workable on underpowered machines as well as to try  
and avoid software patent/licensing problems, it was not chosen to be  
the best technical solution.

This is assuming that the RF components and video processing are of  
equal quality in both cases, which of course they are not.

But the PVR's output is certainly "good enough" to watch, and as you  
say offloading the processing is a tremendous benefit.

Remember that we are using general purpose computers to run Myth, as  
opposed to dedicated special purpose processors. This is not  
efficient economically, thermally, environmentally or even logically.  
Look what a TiVo can do with less than what we spend on just a CPU chip.

That's why this is a "hobby".

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