[mythtv-users] numerous newbie questions

Michael T. Dean mtdean at thirdcontact.com
Fri May 27 06:55:08 UTC 2005


Peter T. Abplanalp wrote:

>hi all.  i have been interested in setting up a myth box for
>quite some time but as i've seen a number of people do, i
>wanted to kick the tires a bit.  that being the case, i went
>out and bought a ati tv wonder pro card, put it in my p2 450
>mhz box, installed a fresh fedora core 3 and followed
>jarod's howto.  well, i got everything pretty much done but
>i am having some issues.
>
>at first i set up my card as an mpeg2 card because i thought
>it did onboard mpeg2 encoding but that gave me ivtv codec
>errors.  i checked the list and found that this could mean i
>had a v4l card so i changed my setup and now i get live tv
>but it is very jerky and my cpu is maxed.  i think this
>means that my cpu is doing the encoding/decoding and can't
>keep up.  is that true?  does anyone know if the ati wonder
>pro does onboard encoding and if so, how do i get that
>working?
>  
>
No.  It's a frame grabber.  Requires software encoding, so your P2/450 
is a bit underpowered.

>so, eventhough i don't have a setup that is working very
>well, i've decided to take the plunge.  it looks from my
>reading that most people use the pvr-250/350.  i believe the
>difference is that with the 250 you need to plug the audio
>out of the card into the audio in of the sound card and with
>the 350 you don't.  is this true and if so, why?
>  
>
Vice versa.  If you use TV out from the PVR-350, TV audio is also output 
by the PVR-350.  Since any sound that comes from anything other than 
MPEG-2 (PVR-x50) recordings comes out the sound card and the sound from 
recordings comes out the PVR-350, routing the PVR-350's output into the 
sound card allows you to hear TV, videos, music, etc. with a single 
output to your speakers/audio receiver.

The PVR-250 does not have any outputs--only inputs.  With it, you do 
software decoding and output using your video card and sound card.

>my next question is about video.  from what i understand,
>the video comes in via the cable, into the tv card, from
>there it gets processed/buffered and sent out via the
>graphics card.  is that accurate?  is the graphics card an
>absolute necessity?  do i need to look for a graphics card
>with some sort of "normal" video out like s-video or
>component video?
>  
>
If you get a PVR-350, you don't need a video card with TV out.  (Also, 
if you don't upgrade your CPU, you'll probably want to go with the 
PVR-350, but as a PVR-350 owner who's not using PVR-350 TV out because 
of its shortcomings, I would recommend you instead spend the extra money 
you would have spent on the 350 to buy a better CPU/motherboard/video 
card.  It's far more useful because of commercial flagging, transcoding, 
etc.  Plus with a good video card, you can get OpenGL and hardware 
acceleration of the video--for MythMusic, MythGallery, MythGame, etc.)

>actually, can someone please explain how the video and audio
>is handled?  specifically, how do things need to be wired to
>and from the computer.
>  
>
Depends on what you're hooking up--analog cable, digital cable with 
serial control, digital cable with IR control, digital cable with 
firewire, satellite with serial control, satellite with IR control, ...

>finally, the video is pretty awful when viewed on the
>screen.  why might that be?
>  
>
P2/450 and a frame grabber instead of a hardware encoder.  Might also be 
a bad choice of resolution/bitrate, but you should probably focus on the 
encoding problem first (i.e. either get a hardware encoder, a better 
CPU/motherboard, or--better yet--both).

Mike


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