[mythtv-users] 16:9 video playback cutting off 10% on right side
mythtv at varga.co.uk
Wed Sep 21 20:41:21 UTC 2005
> > >> > System specs:
> > >> >
> > >> > Myth 0.18
> > >> > Nvidia FX5200, 7667 drivers
> > >> > 2x HD-3000 capture card
> > >> > 800x600 through TV-out over s-video.
> > >> >
> > >> > I had my Myth system setup and everything was working
> > great...until
> > >> the fan on the video card went bad and the system started
> > >> up.
> > >> >
> > >> > I was using a Nvidia 6200 AGP video card but I replaced
> it with a
> > >> fanless FX5200 card. After I replaced the video card and
> > >> the Myth interface looked exactly the same as before,
> filling the
> > >> screen with very little overscan. I then attempted to
> playback some
> > >> recorded TV and discovered that on 16:9 material, at least
> > 10-15% of
> > >> the picture is missing on the right side. 4:3 material
> seems to
> > work
> > >> fine.
> > >> >
> > >> > This did not happen with the 6200 card. I didn't change any
> > settings
> > >> in .nvidia-settings-rc or in XF86Config-4, so I don't
> know what's
> > >> causing this. Does anybody have any ideas?
> > >>
> > >> Different video cards sit the screen in slightly
> different places,
> > >> it's just a fact of life. You'll need to tinker with the
> > modeline in
> > >> the XF86Config-4 file, just take it slowly.
> > > I don't think that's the problem. The X desktop and the
> Myth UI both
> > > look correct. Neither of them is getting 10-15% of the
> > chopped
> > > off on the right side. I only see the problem during 16:9
> > > playback. I have Myth configured to use the same video
> mode for
> > the GUI
> > > and for playback, so it isn't that either.
> > Are you definitely running your desktop in the same 16:9 mode?
> > Do you have any other modelines defined?
> > I really appreciate the help.
> > My desktop is definitely running at 800x600. This is a 4:3 mode.
> > There are other modelines defined, but as I said before I didn't
> > change anything in XF86Config-4 when I switched video cards. I'll
> > delete everything besides 800x600 to see if it makes a difference.
> > The Myth UI is running full screen.
> > Let me try to clarify the problem.
> > Desktop resolution is 4:3, displaying on my TV via s-video.
> > I'm recording OTA HD.
> > 4:3 shows that were broadcast with 16:9 aspect ratio display
> with grey
> > bars on the sides. Changing Myth to 16:9 Zoom aspect ratio makes it
> > use the full screen. This is the behavior I expect.
> > 16:9 shows that used to take the full width of the screen with
> > bars at the top and bottom now have 10-15% of the picture pushed off
> > the right hand side of the screen. Regardless of what aspect
> ratio I
> > tell Myth to use for display, some of the picture is always lost.
> > 16:9 stretch seems to be the closest to keeping all the
> picture. With
> > my old video card, I could leave the myth aspect ratio set to
> > "default" and I wouldn't lose any picture.
> That's exactly my point, 16:9 goes off the screen, it doesn't
> matter if
> it's the desktop or Xine.
> All s-video out graphics cards generate an analogue signal, just
> you're using the same modeline with the new card as with the old one
> doesn't necessarily mean that the picture will appear in the same
> on the tv/monitor. The modeline controls the pixels x-y, the physical
> width-height and the x-y positioning on the screen, but it's all
> relative due to inconstancies in the hardware.
> Remove all the modelines apart from the ones you need, find a good
> modeline explanation on Google and start tinkering.
> Adjust them a little at a time and with a bit of work, you'll be
> able to
> tweak it so it's perfect.
> I understand what you are saying, but could you please explain to me
> how or why Myth is switching to a different modeline during video
> playback? It shouldn't be doing that should it? The modeline I'm
> running is 4:3, and the picture doesn't go off the screen when viewing
> the X desktop or the Myth UI. Why would it suddenly switch to a
> different modeline for video playback? Shouldn't it just scale the
> 16:9 video to fit the 4:3 modeline?
Is it the Myth video player or Xine? As I understand it, if you try and
view 16:9 content it will change resolution, rather than rescale the video.
Your modelines say that's OK, so that's what it's doing... If you don't
want it to do that, then remove the modelines (except the 800x600) and
it won't be able to...
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