[mythtv-users] Help, PVR-350 TV Out doesn't work

[Michael T. Dean]

Gera Makarov wrote:

>At this stage I've only been trying to output live tv from 350 but the
>intention was to run X through it. I did enable 350 hardware decoding
>in mythfrontend but it didn't do anything.
>
Just to make sure you know what to expect--turning on "enable 350 
hardware decoding" will not cause the Myth GUI to show on the PVR-350 
output.  Instead, it will cause recordings and LiveTV to be decoded 
using the PVR-350's hardware decoder (regardless of where your Myth GUI 
is shown).  To get the Myth GUI on the TV, you'll have to set up X to 
use the ivtv framebuffer for output.  Your X config specifies the 
open-source driver for an NVIDIA video card, so the GUI will not appear 
on the PVR-350's output.

> I was able to get sound
>trhough 350 from the following test:
>
># /usr/bin/ivtvfbctl /dev/fb0 -noglobalalpha -localalpha
># dd if=/dev/video0 of=/dev/video16 bs=64k
>
>but there were diagonal lines that didn't let see the picture. I can't
>even get sound now (can't remember what I did to change it). 
>  
>
You're still seeing the framebuffer.  The proper syntax for the 
ivtvfbctl command is:

ivtvfbctl /dev/fb0 -globalalpha -nolocalalpha -alpha 0

Unfortunately, almost every post on the 'net gets it wrong.  Usually 
recommending something like:

ivtvfbctl /dev/fb0 -alpha -on -globalalpha -nolocalalpha

Interestingly enough, that command works, also, but only by "accident."  
The -alpha option requires a value for alpha from 0 (transparent) to 255 
(opaque) and uses the first "word" after "-alpha" That word happens to 
be "-on" (which is supposed to mean "turn on the framebuffer"--a command 
that's never required, so it doesn't hurt that it's ignored), but it's 
not a numeric value "-alpha" expects, so "-alpha" goes with its default 
of 0.

Note, also, that there's no reason to issue the ivtvfbctl command unless 
you're trying to test things out without Myth.  Myth issues the 
appropriate commands to the PVR card to set the proper mode for the 
framebuffer--however, it's possible that the framebuffer alpha could get 
set wrong if you are outputting video over the PVR-350 output and puttng 
the GUI on the video card (although I've never tried it to see what 
happens)...

Mike