[mythtv-users] PVR350 video out very slow (Nvidia way better)

[Nick Kaijaks]

> I hope this is not one of these questions that have been 
> asked a hundred 
> times. I looked in the archives but did not find a solution.

Do you want the good news or the bad news :-)
 
> Anyway when I try to use the PVR350 TV-out, with a XF86Config file I 
> grabbed from this mailing list, it works but the quality is TERRIBLE 
> choppy video and sound.

<snip />

> mythfrontend output when using PVR350 tv-out
> * Couldn't find Xv support, falling back to non-Xv mode.
> * MythTV performance will be much slower since color
> * conversion and scaling will be done in software.
> * Consider upgrading your video card or X server if
> * you would like better performance.
> * Your system is not capable of displaying the
> * full framerate at 720x480 resolution.  Frames
> * will be skipped in order to keep the audio and
> * video in sync.

OK, AGP is irrelevant with the PVR-350, because all the
processing/bandwidth is handled on the card itself. The logged error
tells you that X is having driver problems (as in:)

http://mythtv.org/pipermail/mythtv-users/2004-January/027133.html

Note that this is the same *symptom* but for a different card, so it
probably needs a *different* solution. Anyway, I'm no guru, but looking
at your XF86Config, the device details for the PVR350 framebuffer are
exactly as written in the archives. Have you actually followed the
instructions in the list?

http://mythtv.org/pipermail/mythtv-users/2003-November/019431.html

or the ivtv wiki?

http://ivtv.writeme.ch/tiki-index.php?page=TvOutHowto

because it isn't all cut and paste - you do have to do *some* work for
yourself, y'know! :-)

In particular, when you do 'modprobe ivtv-fb' and look at
/var/log/messages, do you see something like:

fb1: iTVC15 TV out frame buffer device

Whatever you see at the start of the line indicates the device (in /dev)
that needs to go in your XF86Config, so for me it's:

Option      "fbdev" "/dev/fb1"

instead of /dev/fb0 as listed. Secondly, when I run 'lspci -v | grep
iTVC15', I get:

00:14.0 Multimedia video controller: Internext Compression Inc iTVC15
MPEG-2 Encoder (rev 01)

The first bit is the bus ID in hex. I convert it to decimal (14h = 20d)
and stick it in the XF86Config:

BusID "0:20:0"

instead of 01:08.0 as listed.

Check those out and restart X (rebooting may be easiest if it's your own
box), and see if that gets the drivers talking Xv.

Best,
Nick