[mythtv-users] PVR-250 and MPEG2 question

Gert van der Knokke gertk at xs4all.nl
Tue Sep 21 15:20:20 EDT 2004


Jarod Wilson wrote:

>On Tuesday 21 September 2004 10:44, Michael J. Lynch wrote:
>  
>
>>Any idea how much P3 CPU crank is needed to view 720x480 8Mb/s MPEG2
>>video?
>>    
>>
>
>My Athlon 800 with a GeForce 4 MX had no problems handling that exact MPEG2 
>spec.
>
>  
>
>>Is MPEG2 decoding 
>>significantly more processor intesive than MPEG4 decoding?
>>    
>>
>
>MPEG2 decoding is less processor-intensive than MPEG4. Less decompression to 
>do. MPEG2 is also at least somewhat standardized, while there are umpteen 
>different MPEG4 variants...
>
>  
>
Maybe this is true but my experience is that because the PVR cards are 
recording in quite a high resolution, a slower P3 (read < 600 MHz) might 
choke. I found out for example that a Celeron 400 could handle live TV 
and recordings from a bttv card fine and played most AVI files without 
problems too but stuttered terribly on playing the files recorded by the 
backend after upgrading it to a PVR250 instead of the bttv.

The Celeron 400 was replaced by a 1 GHz version (albeit running at only 
667 Mhz  because of the Intel Desktop board motherboard/bios limitations 
of this system: an Intel Dot.station) and it runs smooth (and rather 
cool..) now. It now only stutters slightly when the OSD fades out.

It could be that to decode the MPEG2 stuff the extra instructions of the 
newer Celerons and P3's are (automatically) used.

So I would advise not using a P3 under 600 MHz.
 
Gert





More information about the mythtv-users mailing list