[mythtv-users] Good TV Out (long -sorry)

[Chris Martin]

I started playing with MythTv in January when I decided it would be a
fun project with which to learn Linux.  Knowing I'd be less likely to
give up on it if I had some money involved, I went out an bought the
following equipment:

Asus Pundit-R
Celeron 2.4GHz
512Mb DDR RAM
200GB Maxtor SATA
PVR 350

Having precisely zero Linux experience I went with FC3 and Jarod's
excellent guide as it seemed like the easiest solution. My aim was
(and still is) to create a combined frontend/backend that hooks up to
a standard PAL TV and can a) be used as a PVR and b) play films stored
as MPEG4.

Thanks both to Jarod's guide and the help from this mailing list I had
a usable system up with a couple of weeks and have been playing ever
since.  While I've been incredibley impressed by the features and
usability of MythTV, there's been one thing that I've never been able
to get quite right; namely TV OUT.  This has come as quite a surprise
to me, seeing as I have two options in this area with both the PVR 350
and the onboard graphics of the Pundit-R.  Here is what I've found so
far:

PVR 350.
The quality of live tv on the PVR 350 is fantastic: I can't distingish
it from 'regular tv', although admittedly neither my signal nor my
television is particularly amazing. The problem, however, is the PVR
350's ability (or lack of it) to play MPEG 4.  I initially tried the
framebuffer driver (mplayer -vo x11) but found this to be too slow and
so investigated using the ivtv driver with the command:

mplayer -vo ivtv fileName 

which causes the video to be played, but not to be visible as it is
being displayed behind the X window currently in the PVR 350's
framebuffer.  Following the advice of somebody on this list I then
used the command:

ivtvfbctrl /dev/fb1 -alpha 0; mplayer -vo ivtv fileName ; ivtvfbctrl
/dev/fb1 -alpha 255;

which makes the video video visible (and play perfectly smoothly I
might add).  Unfortunately the sound is now well out of sync (I'd
estimate around  5 seconds), and no amount of -framedrops or --delays
will help the situation.   I've been at this stage for around a month
now and have not found any solution, except for a post by Chris
Kennedy on IVTV-devel which suggests that playing with ivtvfbctrl can
cause the 350's a/v sync to mess up.  My hope therefore is that if I'm
somehow able to configure my ststem so that I no longer need to change
the alpha then the sync issue may sort itself.  Until then, the PVR
350 doesn't seem to be able to do what I want it to do.

Pundit-R Tv Out.
To get the Pundit-R's TV out to work most people use the 3.12 ATI
driver and then a hex edit trick in order to enable TV out. 
Unfortuatlely the 3.12 driver only works with XFree86 and therefore
not with Fedora which uses XOrg. Taking advice from soemone else on
the list I tried the hex edited file with the newer  8.8.25 driver
which does work with XOrg.  Amazingly it worked fine.

The live Tv quality on the Pundit-R is more than acceptable, providing
bob deinterlacing is used. Unfortunately using bob deinterlacing
casues the picture to get jittery and flickery with time, to the point
that after about 5 minutes it is unwatchable. Quickly pausing and
unpausing the picture resolves the problem but only for 5 minutes at
which point the flickeryness returns.  I've been advised by somebody
on the mailing list to use Open GL as this should provice VSync
support which will resolve the problem.  At the time I thought I might
not have open gl support, however the open gl picture transitions in
myth gallery worked fine so maybe I do.

Anyway there are still some avenues to explore but before I go any
further I thought I'd post this to the mailing list in the hope that
someone has my hardware (either the pundit-r or the 350) and has it
working as I envisaged it.