Mailing List Archive: MythTV: Users

screen resolutions - am confused about the basics

Index | Next | Previous | View Threaded

craig at 8010

Jul 29, 2004, 8:00 AM

Post #1 of 6 (1037 views)
Permalink

screen resolutions - am confused about the basics

I have a sanya 28" tv.. it's a widescreen.. but whenever I play a
widescreen movie.. in mplayer for example.. I still get black bands at
the top and bottom...

I think I've figured out the problem.. but not sure how to fix it.. I
have a Radeon 9200SE thats running at 800x600

Am I right in thinking that I need to change the resolution so that it's
16:9 "shaped"? if so.. how'd I do it.. I only know about the regular
resolutions.. 640,800,1024 etc etc.. and which resolution would I go for?

Thanks again

Craig (confused)

mythtv at ultratux

Jul 29, 2004, 10:35 AM

Post #2 of 6 (1031 views)
Permalink

Re: screen resolutions - am confused about the basics [In reply to]

On Thursday 29 July 2004 17:00, Craig Tinson wrote:
> I have a sanya 28" tv.. it's a widescreen.. but whenever I play a
> widescreen movie.. in mplayer for example.. I still get black bands at
> the top and bottom...
>
> I think I've figured out the problem.. but not sure how to fix it.. I
> have a Radeon 9200SE thats running at 800x600
>
> Am I right in thinking that I need to change the resolution so that it's
> 16:9 "shaped"? if so.. how'd I do it.. I only know about the regular
> resolutions.. 640,800,1024 etc etc.. and which resolution would I go for?

Well, youi could try ;-) to multiply 480 by 16:9... which gives 853.33.
Or divide 640 by 16:9 which gives 360. Or do that with 800 --> 450.

Of these, certainly the 800x450 and 640x360 sound quite nice, and they are
exact, whereas the first needs to be rounded up to 854. But either will
work; it needn't be precise. Then what I do (and did, back in 1998 when a
resolution of 1400x1050 was still unheard of) I take the modeline of a good
working resolution and multiply all figures by my calculated factor. If
you're lucky it works right away, if you're unlucky it's a starting point.
But... In your case you need to do more work for two reasons: one is that a
TV, unlike a monitor, cannot be driven at any desired frequency. And the
other is that you need two multiplication factors, one for horizontal and
another different one for vertical. So instead I'd recommend to google for
"800x450 + modeline" or so and see if something useful comes up.

Good luck.

> Thanks again
> Craig (confused)

Don't be. It's not rocket science. ;-)

Maarten

--
Linux: Because rebooting is for adding hardware.

_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

adam at ngindex

Jul 30, 2004, 4:30 AM

Post #3 of 6 (1017 views)
Permalink

Re: screen resolutions - am confused about the basics [In reply to]

In mplayer, you need to append -monitoraspect 16/9 to the command line.
And for mythtv to use the correct aspect, you need to set the
DisplaySize (?) in the XF86Config file.

Adam

Craig Tinson wrote:

> I have a sanya 28" tv.. it's a widescreen.. but whenever I play a
> widescreen movie.. in mplayer for example.. I still get black bands at
> the top and bottom...
>
> I think I've figured out the problem.. but not sure how to fix it.. I
> have a Radeon 9200SE thats running at 800x600
>
> Am I right in thinking that I need to change the resolution so that
> it's 16:9 "shaped"? if so.. how'd I do it.. I only know about the
> regular resolutions.. 640,800,1024 etc etc.. and which resolution
> would I go for?
>
> Thanks again
>
> Craig (confused)
>
>------------------------------------------------------------------------
>
>_______________________________________________
>mythtv-users mailing list
>mythtv-users [at] mythtv
>http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
>

mail01 at iarmst

Jul 30, 2004, 5:04 AM

Post #4 of 6 (1007 views)
Permalink

Re: screen resolutions - am confused about the basics [In reply to]

On Thursday 29 Jul 2004 16:00, Craig Tinson wrote:
> I have a sanya 28" tv.. it's a widescreen.. but whenever I play a
> widescreen movie.. in mplayer for example.. I still get black bands at
> the top and bottom...
>
> I think I've figured out the problem.. but not sure how to fix it.. I
> have a Radeon 9200SE thats running at 800x600
>
> Am I right in thinking that I need to change the resolution so that it's
> 16:9 "shaped"? if so.. how'd I do it.. I only know about the regular
> resolutions.. 640,800,1024 etc etc.. and which resolution would I go for?

You don't really need to play with the resolution. All you should need to do
is ensure DisplaySize in the X config is set to a 16:9 size. For example, in
the Monitor section of xorg.conf I use 'DisplaySize 300 170'. It's not quite
right, but it's close enough.

Although MythTV & xine honour the size, mplayer seems to ignore it, so you
need to run it with the command line option '-monitoraspect 16:9' Not ideal
if, like me, you have both 4:3 & 16:9 displays connected & move between them.

--
Ian
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

craig at 8010

Jul 30, 2004, 8:19 AM

Post #5 of 6 (997 views)
Permalink

RE: screen resolutions - am confused about the basics [In reply to]

-----Original Message-----
From: mythtv-users-bounces [at] mythtv
[mailto:mythtv-users-bounces [at] mythtv] On Behalf Of Ian Armstrong
Sent: 30 July 2004 13:05
To: Discussion about mythtv
Subject: Re: [mythtv-users] screen resolutions - am confused about the
basics

On Thursday 29 Jul 2004 16:00, Craig Tinson wrote:
> I have a sanya 28" tv.. it's a widescreen.. but whenever I play a
> widescreen movie.. in mplayer for example.. I still get black bands at
> the top and bottom...
>
> I think I've figured out the problem.. but not sure how to fix it.. I
> have a Radeon 9200SE thats running at 800x600
>
> Am I right in thinking that I need to change the resolution so that it's
> 16:9 "shaped"? if so.. how'd I do it.. I only know about the regular
> resolutions.. 640,800,1024 etc etc.. and which resolution would I go for?

You don't really need to play with the resolution. All you should need to do

is ensure DisplaySize in the X config is set to a 16:9 size. For example, in

the Monitor section of xorg.conf I use 'DisplaySize 300 170'. It's not quite

right, but it's close enough.

Although MythTV & xine honour the size, mplayer seems to ignore it, so you
need to run it with the command line option '-monitoraspect 16:9' Not ideal
if, like me, you have both 4:3 & 16:9 displays connected & move between
them.

-------------------------------

Thanks for the ideas guys.. am gonna give this a go..

Am still confused about the modeline stuff.. I found a "modeline calculator"
which came up with the following:

Modeline "800x450 [at] 6" 27.48 800 832 936 968 450 459 464 473

I tried it but about an inch was missing of the bottom of the screen.. so I
guess I did something wrong..

If I set the 'DisplaySize 300 170' option that you mentioned.. I just
checked in the man page for XF86Config and it says those numbers are in
millimetres.. if I set DisplaySize and the above mentioned Modeline.. would
that sort out the "inch missing from the bottom" problem?

Am just worried about screwing up my TV.. this is new territory for me.. :)

Thanks again for the helps guys..

Cheers

Craig

mail01 at iarmst

Jul 30, 2004, 9:56 AM

Post #6 of 6 (1005 views)
Permalink

Re: screen resolutions - am confused about the basics [In reply to]

On Friday 30 Jul 2004 16:19, Craig Tinson wrote:
[...]
> Thanks for the ideas guys.. am gonna give this a go..
>
> Am still confused about the modeline stuff.. I found a "modeline
> calculator" which came up with the following:
>
> Modeline "800x450 [at] 6" 27.48 800 832 936 968 450 459 464 473
>
> I tried it but about an inch was missing of the bottom of the screen.. so I
> guess I did something wrong..
>
> If I set the 'DisplaySize 300 170' option that you mentioned.. I just
> checked in the man page for XF86Config and it says those numbers are in
> millimetres.. if I set DisplaySize and the above mentioned Modeline.. would
> that sort out the "inch missing from the bottom" problem?
>
> Am just worried about screwing up my TV.. this is new territory for me.. :)

You don't need to play with the modelines to correct the aspect ratio. That's
what DisplaySize is for. So an 800x600 display with the correct DisplaySize
would remove the borders. If you play back any 4:3 material, the screen will
be 'compressed' horizontally to give a border on the left & right edges, but
16:9 will be full-screen.

Also 300 170 does not reflect the true size of my TV, but it gives the correct
aspect ratio & has the effect of making the fonts larger and more readable
without messing up the font selection on a monitor connected to the same
machine.

--
Ian
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

Index | Next | Previous | View Threaded

Interested in having your list archived? Contact Gossamer Threads