[mythtv-users] Got smooth playback? please post your setup & configuratio

Sun Aug 6 18:06:05 UTC 2006

I've been down this road before...

I'm using an 37" LG 37LP1D. It takes 1360x768 @ 50Hz without a hitch (infact
it's taken almost every modeline I've ever given it!). But it's getting the
refresh to be exactly 50Hz which I find the hardest. On xtiming, if I type
50 for the refresh rate, when it's calculated it normally says something
like "Actually 50.04". If I use a refresh like 49.98, I can get it to say
50, but I think the value is still being rounded. How important is it to get
a perfect 50Hz refresh.

Also, I think some of the jerkyness is caused by the rubbishy graphics card.
If I run glxgears, it uses 100% CPU (basically as much as it can), and if I
do some CPU intensive task (like opening openoffice.org :P) it stutters
really bad. I think that may be causing some of the erratic stutters I get
(on top of the generally stuttery playback), and may be leading to the
prebuffer pauses.

I think I need a decent (i.e. normal) graphics card. :(

Thanks so far

On 06/08/06, Wim Fokkens <wimfokkens at planet.nl> wrote:
>
>
>
>
> > -----Oorspronkelijk bericht-----
> > Van: mythtv-users-bounces at mythtv.org [mailto:mythtv-users-
> > bounces at mythtv.org] Namens Joe Votour
> > Verzonden: zondag 6 augustus 2006 18:42
> > Aan: Discussion about mythtv
> > Onderwerp: Re: [mythtv-users] Got smooth playback? please post your
> setup
> > & configuratio
> >
> > > OK, I think the trouble is my graphics card (the nvidia 6150), which
> is
> > > built onto my motherboard. The only thing stopping me from switching
> to
> > a
> > > card like the nvidia 7300GS, is that the only reason I bought my
> > > motherboard
> > > (an MSI mini-atx thing with PCI-E, and DVI out) was because it has
> > onboard
> > > DVI. And I can't find a 5300FX anywhere (I need a PCI Express GFX
> card).
> > >
> > > I don't surpose you know what the TV setting does in mythtv-setup, I
> can
> > > select multiple different types of PAL, but it doesn't seem to make
> any
> > > difference.
> > >
> > > You said your refresh rate is 60Hz, is that "exactly" 60 or close,
> like
> > > 60.02
> > >
> > > thanks so far, James
> > >
> > > On 06/08/06, Joe Votour <joevph at yahoo.com> wrote:
> > >>
> > >> > (sorry if this was posted twice, didn't know if it sent
> properly...)
> > >> >
> > >> > Hi, I am having great trouble getting smooth playback (live tv or
> > >> > recorded).
> > >> > I've tried everything (that I can think of), and still can't get TV
> > to
> > >> > look
> > >> > anything like as good as Sky. The ticker tape on BBC news (I'm in
> the
> > >> UK)
> > >> > is
> > >> > really jerky compared to any set-top-box output of the same
> channel.
> > >> >
> > >> > Could anyone who's got smooth playback (and I mean as smooth as a
> > >> > set-top-box gives out), please post there setup and configuration.
> > >> >
> > >> > I'm looking for:
> > >> > - what kind of tv link are you using (dvi, component etc...)
> > >> > - what refresh rate you are using (ie, 50Hz, 60Hz)
> > >> > - what settings do you use for playback (Deinterlacer, opengl sync
> > >> etc..)
> > >> >
> > >> > I would like to know so that I'm sure I'm not missing something
> > vital.
> > >> > Also,
> > >> > I'm mostly interested in HDTV capable setups, i.e. people who are
> > >> using
> > >> > resolutions which are capable of HDTV.
> > >> >
> > >> > I have a pretty powerful Rig (AMD 3500+, 1gig of RAM, 200gb hdd),
> and
> > >> am
> > >> > using a DVI->DVI connection to my TV (which gives out a correct
> > >> modeline
> > >> > (1360x768), but only for a 75Hz refresh). My graphics card is an
> > >> > intergrated
> > >> > nvidia 6150. Everything seems to work (except XvMC, don't know why,
> > >> but
> > >> > shoudn't be required with this rig), but when I watch any TV it's
> > real
> > >> > jerky.
> > >> >
> > >> > Not meaning to make this like a survey, just I've been trying since
> > >> Easter
> > >> > to get this thing to work (was an Easter project), and I'm
> beginning
> > >> to
> > >> > give
> > >> > up.
> > >> >
> > >> > Thanks in advance, James Buckley
> > >> > _______________________________________________
> > >> > mythtv-users mailing list
> > >> > mythtv-users at mythtv.org
> > >> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> > >> >
> > >>
> > >>
> > >> I don't mean to discourage you, but having actually worked on a
> set-top
> > >> box, I'll say this up front - with MythTV (or any other Windows/Linux
> > >> program), it will be very difficult to get set-top box quality.  Set-
> > top
> > >> boxes have video output chips that are optimized for MPEG-2 playback,
> > >> and
> > >> they also take into account all the little things that are necessary,
> > >> such
> > >> as perfect vertical sync timing (for page flipping without
> tearing).  A
> > >> general purpose Linux system just can't get *that* good, but it can
> get
> > >> pretty close.  A lot of good discussion can be found here:
> > >>
> > >> http://www.gossamer-
> >
> threads.com/lists/engine?do=post_view_flat;post6194;page=1;sb=post_late
> > st_reply;so=ASC;mh%;list=mythtv
> > >>
> > >> That said, I get pretty good quality output on my system, especially
> > >> using
> > >> HD.  I only get the odd noticable jitter when I'm watching a ticker
> on
> > >> CNN
> > >> or ESPN (ESPN has fast tickers, so any artifacting in the display is
> > >> really noticable).
> > >>
> > >> Here's what I've got:
> > >> - GeForce 5200FX connected to an HDTV monitor running at 720p
> > (1280x720)
> > >> via VGA (60Hz)
> > >> - Using XvMC because my CPU (an Athlon64 3200+) can barely keep up
> > >> - OpenGL Vsync enabled
> > >> - Bob deinterlacing enabled
> > >>
> > >> -- Joe
> > >>
> > >>
> > >> ___________________________________________________________
> > >> $0 Web Hosting with up to 200MB web space, 1000 MB Transfer
> > >> 10 Personalized POP and Web E-mail Accounts, and much more.
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> > >>
> > >> _______________________________________________
> > >> mythtv-users mailing list
> > >> mythtv-users at mythtv.org
> > >> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> > >>
> > > _______________________________________________
> > > mythtv-users mailing list
> > > mythtv-users at mythtv.org
> > > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> > >
> >
> > I certainly hope that the 6150 isn't the problem (and I somehow doubt
> that
> > it is), because I plan to move to an Asus motherboard that hasa built-in
> > 6150 on it.  There's an attraction to having the graphics built-in, and
> > having VGA, DVI, S-Video, Composite and Component all available to me
> > (although, not necessarily at the same time).
> >
> > Since I live in the United States, I pick "NTSC" for my TV-standard.
> > (Technically, it would be "NTSC-M", but I suppose it's left as NTSC,
> since
> > they have a "NTSC-JP" for Japan, which should be
> "NTSC-J".)  Nonetheless,
> > you need to pick the standard appropriate for the area that you're
> living
> > in - there are slight changes in the different PAL modes, and they are
> > geography specific.  I believe (but am not totally sure) that this
> setting
> > is used for programming an analog capture card (in the case that the
> tuner
> > supports multiple variants of PAL, for instance).
> >
> > My TV (and the manual that come with it) indicate that I am running at
> > exactly 60.0Hz in 720p (but it only shows one decimal place of
> accuracy).
> > However, one thing to keep in mind is that this is a CRT HDTV, and I
> > believe that it's more of a VGA monitor than it is a real TV (although
> it
> > does have standard TV connections like an RF in for an antenna/cable
> > connection and component/S-Video inputs)
> >
> > -- Joe
> >
> >
> > ___________________________________________________________
> > $0 Web Hosting with up to 200MB web space, 1000 MB Transfer
> > 10 Personalized POP and Web E-mail Accounts, and much more.
> > Signup at www.doteasy.com
> >
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
> Hi James
>
> Before you buy any new hardware. You have to know that if you living in
> the
> UK your are in pal area, so that means 50Hz video content. So if you want
> that to look smooth your refresh rate has to be 50Hz or a multiple.
> (basicly
> 50 or 100hz)
> If you play 50Hz video content on a 60Hz refresh rate screen it will never
> look smooth.
> Altough it is very easy to make a modeline with 1360 x 768 at 50hz with for
> example the following modeline calculator.
> http://xtiming.sourceforge.net/cgi-bin/xtiming.pl
> Modeline "1360x768 at 50" 67.86 1360 1392 1648 1680 768 784 791 807
>
> Most LCD tv sets don't accept 50Hz at there native resolution.
>
> So you probably have to use a HDTV compatible modeline @50Hz.
> For example 1280x720p50
> Modeline "1280x720 at 50" 59.42 1280 1312 1536 1568 720 735 741 757
>
> What brand and type of LCD TV are you using?
>
> Wim
>
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
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