[mythtv] [ivtv-devel] [ivtv-users] PVR-350 and MythTV support

[Erik Mouw]

On Tue, Feb 06, 2007 at 10:04:56AM -0500, Jeff Simpson wrote:
> On 2/1/07, Hans Verkuil <hverkuil at xs4all.nl> wrote:
> > Hi all,
> >
> > Recently I've seen several comments that PVR350 support would not work
> > or would be removed from MythTV. While it is true that there is no
> > current maintainer for the PVR350 code in MythTV (AFAIK), that doesn't
> > mean that it doesn't work. The ivtv API is still unchanged and as long
> > as the code remains in MythTV it should work just fine.
> 
> As I was probably a person who made some of those comments, I feel I
> should back them up:
> 
> #1, MPEG Output on the PVR-350 is working, but mostly unsupported by
> advanced features. Things like fast forward and rewind don't work,
> frequency scaling doesn't work, things like that. It does technically
> still play video, but only native MPEG2 (no mpeg4, no alternate
> formats, etc). The only way to play anything that isn't a native
> recording is to use the framebuffer or xdriver, whose faults are
> described later.

However, the PVR350 allows you to use rather moderate hardware for a
front- and backend (i.e.: my old P3 850 as combined front+backend and
a PII 300 as a second frontend).

> #2, Myth is moving to OpenGL for menus. It now supports OpenGL and qt
> and you can switch between them. I can't imagine they will continue to
> provide both options for much longer. The PVR-350 doesn't support
> OpenGL and never will.

I don't know the reason for switching to OpenGL, the Qt engine still
works fine. One way to support OpenGL on the 350 would be to use Mesa,
but that would be another layer of indirection that will slow down the
system.

> #3, Framebuffer is slow slow slow slow, and it EATS cpu. I have a 3ghz
> machine, but the menus are still slow. I often find the X session
> using 50 or 60% of my cpu, just SITTING there.

Never seen that. An idle machine is just idle over here. Occasionally
Xorg tends to eat 100% CPU time, but that seems to be unrelated to Myth
cause the same happens occasionally on my desktop.

> Forget trying to run it
> at the same time as another X session, it jumps to a full 100%.
> Playing anything that isn't a native mpeg2 video makes the system
> crawl.

If you only use PVR x50 cards to record the problem doesn't exist.

> #3 XDriver is a great project, but it's always been buggy at best, and
> difficult to compile (with each version of X, the driver has needed
> another patch or hack just to compile). I think now that it's in some
> repositories (gentoo), it's better? (I've still had to patch it, but
> maybe by now it's better).

FWIW, it never crashed on me.

> So in summary, the PVR-350 *does* work, it just isn't as fully
> supported as say, any nvidia or ati tv out card made in the last 5
> years for 1/4 of the cost. The video encoding is well supported, just
> like the 150/250/500, it's just the output that's flaky. In my own
> personal opinion, having owned a PVR-350, I would say that I'd be
> better off owning a 150 and an nvidia geforce card with TV Out.

I diagree. A PVR 150 is about 85 EUR, for 140 EUR you have a 350. That
difference does buy you a ati or nvidia card with tv out (cheapest is
around 40 EUR), but doesn't buy you a CPU fast enough to do the
decoding, especially when you have some old hardware lying around.


Erik

-- 
They're all fools. Don't worry. Darwin may be slow, but he'll
eventually get them. -- Matthew Lammers in alt.sysadmin.recovery
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