[mythtv-users] please explain XvMC

[Joseph A. Caputo]

Brian Stults wrote:
> Chris Wieringa wrote:
> 
>> Yep, X video Motion Compensation is a feature that can be enabled on some
>> cards (Nvidia mainly, but some ATI cards have support for it AFAIK) to 
>> do MPEG2
>> decoding.  Usually this is used with playing DVDs, however, the Hauppauge
>> PVR-x50 cards capture streams in MPEG2.  Therefore, decoding of these 
>> streams
>> are done on the video card with little impact on the CPU.  If you are 
>> using a
>> an analog bttv capture card, you will not be capturing your streams in 
>> MPEG2,
>> so there is no point in compiling in XvMC.
>>
> 
> I thought the PVR-x50's do their own decoding, so their wouldn't be any 
> need for the video card to do any decoding.

Only the PVR-350 is capable of decoding.  The PVR-250, AverMedia M-179 & 
   Yuan MPGxxx cards only encode.

-JAC