[mythtv-users] PVR-350 TV-Out user experience

[jose rubio]

On Thu, 2004-01-15 at 20:11, Tim Harvey wrote:
> Greetings,
> 
> I've just gotten my PVR-350 TV-Out working and have a few questions for
> the others that are doing so.
> 
> In your opinions, what are the Pro's / Con's of using the PVR-350
> TV-Out?  Here's what I have come up with via my experimentations:
> 
> Pro's: 
> 
> - Quality
> It would seem that you get a better picture quality when using MythTV
> (Live TV or pre-recorded non-transcoded nuv files from MythTV).  I
> believe this is simply because its not having to do any scaling of the
> video.
> 
This is the main reson I use mine.

> - Dual headed display
> Using the PVR-350's output via ivtv-fb and XFree86, you get a 2nd
> X-Windows screen (output to your TV) for MythTV to run on while your
> video card still provides another X-Windows screen that you can develop
> with or what not
You'd get this with most video cards with tv-out

> 
> - No need for another TV-Out solution
> Most video cards today seem to have a TV-Out anyway.  Personally I
> haven't gotten mine to work quite right yet (NVidia GeForce 440MX...
> should work fine, I just have to hammer some more on it)
> 
It'll work...but you won't be happy with the quality.  Not after you've
seen the tv-out of the 350.



> Anything else???
Yep, CPU usage is next to zip.  You can be compiling a new kernel while
recording a show and playing a recording and there's no problem... CPU
might not be a problem with you but my plan is to eventually have four
(I have two right now) 250/350 cards in my machine while still use it as
the main server for my entire house for both video, music, and pictures.

Another thing is the FM tuner the 350 has...  I've been following a
couple of threads at the ivtv list and it's on its way...


> 
> 
> Con's:
> 
> - The performace of MythVideo playing back DivX and VOB's is pretty bad
> on my Athlon 2600+ system via the ivtv-fb.  IMHO that makes the PVR-350
> a poor choice for me as I greatly value the MythVideo plugin for my
> movie collection.  I've seen others post that they believed the playback
> framerate via ivtv-fb should be acceptable, but I haven't been able to
> see it.  Perhaps I'm doing something wrong?  I've experimented with
> cmdline args for mplayer and haven't been able to boost the performance
> enough to be acceptable for the larger bitrate files (the Divx files I
> have at 760kbps video or lower are just about acceptable, but the VOB's
> are definitely horrible)
The ivtv driver does not really support the above yet.  It will soon
though.  IMHO it would be hard to use ivtv-fb (ie the frame buffer) to
provide quality display of video IIRC it is only about 1 frame per
second or so.  The way it is going to work is with the yuv support
(don't ask me what that means I just know the buzz words :-).  In the
ivtv list they are saying that it will come out with the 0.2.0 driver
(by the end of the month ???)  of course, there'll be bugs but that's
just fun.

As Far as mplayer is concerned. you need to build it with a patch for it
to work(search the ivtv archives for mpegpes and you'll find out how). 
Video is absolutely great (in between frame skips anyway :-) but there
are some issues with the sound sync.

Anyway, it's supossed to be just a temporary hack.  The real stuff is on
the way.


> 
> - The TV-Out is overscanned (which is appropriate) causing you to have
> to tweak your gui size and offsets, and your OSD overscan within MythTV.
> This itself is not a problem however to get my GUI fitting appropriately
> I've had to use a GUI size of 648/432 (offset of 35x30) which isn't
> large enough to show many of the setup screens entirely (a bunch of them
> have no buttons visible as they can't fit vertically).
> 
TV-out has to be overscanned.  It is the way tv is designed.  Yes
there's some tweaking to be done but much less than you'll have to do
with any other tv-out method.  Plus, I rather my OSD be a little bit off
frame than the tv be off.

> 
> I'm using MythTV v0.13 and ivtv-0.1.9.  Perhaps I'm missing something by
> not having the latest CVS of MythTV?  I know David Engel has been
> submitting some patches but I haven't tried them out yet and am not
> really sure what effect they could have as this seems to be a general
> ivtv-fb performance issue and nothing to do with MythTV.
> 
I'm not sure that's right.  I thought that you needed myth-cvs to be
running the 0.1.9 driver (I know the converse is true though...methink
that's the right word :-)

Anyway, there is a lot of work being done on the ivtv side of things. 
So if you want stable you want to keep your tivo around...  I know I
do... but not for much longer.


> Thanks for sharing any feedback,
> 
you're welcome.

> Tim
> 
-jose-