[mythtvnz] DVB-T signal strength and CPU usage

[Stephen Worthington]

On Mon, 18 Aug 2008 10:58:45 +1200, you wrote:

>I got Freeview HD going on my myth box last night, it has an dual core 
>3600+ AMD processor.
>There are times where the video is shudder free and others where it 
>seems to struggle.  Most of the time the CPU is sitting at 103% usage.
>
>What is a acceptable signal strength?  I have 22% and 4 ish db which 
>seems very low.

Yes, that would be way low on either of my tuners.  But the numbers
seem to vary from tuner to tuner so it is not always clear what are
good or bad numbers.  Also, where are you?  The lowest frequency UHF
channels are normally the ones with the best signal, and from Wharite
that is the TVNZ multiplex, which I can pick up with the tiny portable
antenna that came with my HVR-900.  But getting the TV3 or Kordia
multiplexes requires using the main external antenna on the roof.

>I have only had success watching the TVNZ multiplexes, no luck with TV3, 
>C4 etc.  They are detected but no lock.
>
>Also are there low cost NVidia based graphics cards that people know of 
>that have a SPDIF input for injection into the HDMI cable?
>I have a 8600GT card in another PC that has it, but I'm  hoping not to 
>spend  as much as that cost...
>
>Thank you Paul and others for the huge amount of work you have put in, 
>it's much appreciated! :-)

At present, there is no hardware acceleration of H.264 in the Linux
Nvidia drivers, so an 8600GT is not going to help with playback. Under
Vista, I can play back on my 8600M GT with only 10-15% CPU usage, but
under Linux it is all done in the main CPU.  So, from the reports I
have seen so far, a 3600+ AMD is not quite sufficient to do HD
playback.  It might work for TVNZ (720p), but is almost certain not to
work for TV3 (1080i).  And you need some processor left over to record
things at the same time as you are playing a file.