Mailing List Archive: MythTV: Users

LCD and traditional CRT TVs, overscan and UI size and widget placement

Index | Next | Previous | View Threaded

brian at interlinx

Nov 11, 2009, 5:53 AM

Post #1 of 25 (2029 views)
Permalink

LCD and traditional CRT TVs, overscan and UI size and widget placement

Hey everyone,

I have a traditional CRT TV (am I the only one left with one of
these? :-). I am driving that with an nvidia 5200 via S-Video.

As everyone knows, these TVs have an "overscan" feature where they only
make a portion of the original broadcasted picture visible to the
viewer. Historically, this is done because the outer edges of the
broadcast signal are rough and therefore hidden in this "overscan" area.

But the TV broadcasters know that TVs do this and they compensate by not
putting anything they want visible too close to the edge of the signal
they are broadcasting. This becomes obvious if you watch a TV station
that does have something at the edge of the visible picture, like CNN's
ticker at the bottom. If you look at CNN on a device that does not hide
the overscan (i.e. like mythfrontend in a window on your computer) you
can see how much picture is available between the bottom edge of the
ticker and the bottom edge of your window.

Anyway, that's a bit about overscan.

The problem with this overscan though is that unless you adjust it, the
MythUI will draw outside the visible area and thus, you won't see some
of the widgets. But MythUI has adjustments for this, allowing you to
bring the UI back inside the viewable area. The problem is that it's
not leaving the UI the same size and just drawing the widgets closer to
center (i.e. to bring them into the viewable area on all sides), but
rather it's just reducing the size of the UI.

The problem with this approach is that it's futile trying to make the
edge of the UI "canvas" meet the visible portion of the picture as the
borders of this visible portion of the picture are never straight an
square. Frequently they are curved and/or have wows in them.

See this picture I took of my TV:
http://svn.mythtv.org/trac/attachment/ticket/7545/P1010451.JPG

You can see a "wow" on the top half of the left border. But this is
just how CRT TVs are. This is exactly why overscan exists.

The solution, as I see it is rather than scaling the UI canvas down to
fit inside the visible window, the canvas needs to stay the same size
and the positioning of the widgets on the canvas needs to be offset to
fit them inside the visible area.

This effect is not limited to CRT TVs though.

I have an LCD TV that has some overscan as well. It's not as much as
the TV, but it's still about 20 pixels per side.

On this LDC TV, I run a gnome desktop and the effect of the overscan is
that the panels at the top and bottom are only half visible on the
screen. When I start a mythfrontend on that screen, with it's
dimensions the full size of the screen, gnome takes this hint and puts
the window on top of the panels.

This same problem of the UI widgets being drawn outside the visible area
exists though, and naturally I want to use the adjustment tool to bring
them back inside the visible area. But instead of leaving the UI window
the same size as the screen (1280x720) and just moving the widgets in
tighter, this adjustment actually makes the mythfrontend window smaller
and them blam, gnome notices that the window is no longer the same
dimension as the screen and puts the panels on top of the mythfrontend
window again.

So another case to be made for leaving the canvas size alone and simply
moving the UI widgets so that they are on the visible portion of the
canvas.

Thots?

b.

Attachments:

signature.asc (0.19 KB)

beww at beww

Nov 11, 2009, 6:14 AM

Post #2 of 25 (2001 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Wednesday 11 November 2009 06:53:58 Brian J. Murrell wrote:
> Hey everyone,
>
> I have a traditional CRT TV (am I the only one left with one of
> these? :-). I am driving that with an nvidia 5200 via S-Video.
>
> As everyone knows, these TVs have an "overscan" feature where they only
> make a portion of the original broadcasted picture visible to the
> viewer. Historically, this is done because the outer edges of the
> broadcast signal are rough and therefore hidden in this "overscan" area.
>
> But the TV broadcasters know that TVs do this and they compensate by not
> putting anything they want visible too close to the edge of the signal
> they are broadcasting. This becomes obvious if you watch a TV station
> that does have something at the edge of the visible picture, like CNN's
> ticker at the bottom. If you look at CNN on a device that does not hide
> the overscan (i.e. like mythfrontend in a window on your computer) you
> can see how much picture is available between the bottom edge of the
> ticker and the bottom edge of your window.
>
> Anyway, that's a bit about overscan.
>
> The problem with this overscan though is that unless you adjust it, the
> MythUI will draw outside the visible area and thus, you won't see some
> of the widgets. But MythUI has adjustments for this, allowing you to
> bring the UI back inside the viewable area. The problem is that it's
> not leaving the UI the same size and just drawing the widgets closer to
> center (i.e. to bring them into the viewable area on all sides), but
> rather it's just reducing the size of the UI.
>
> The problem with this approach is that it's futile trying to make the
> edge of the UI "canvas" meet the visible portion of the picture as the
> borders of this visible portion of the picture are never straight an
> square. Frequently they are curved and/or have wows in them.
>
> See this picture I took of my TV:
> http://svn.mythtv.org/trac/attachment/ticket/7545/P1010451.JPG
>
> You can see a "wow" on the top half of the left border. But this is
> just how CRT TVs are. This is exactly why overscan exists.
>
> The solution, as I see it is rather than scaling the UI canvas down to
> fit inside the visible window, the canvas needs to stay the same size
> and the positioning of the widgets on the canvas needs to be offset to
> fit them inside the visible area.
>
> This effect is not limited to CRT TVs though.
>
> I have an LCD TV that has some overscan as well. It's not as much as
> the TV, but it's still about 20 pixels per side.
>
> On this LDC TV, I run a gnome desktop and the effect of the overscan is
> that the panels at the top and bottom are only half visible on the
> screen. When I start a mythfrontend on that screen, with it's
> dimensions the full size of the screen, gnome takes this hint and puts
> the window on top of the panels.
>
> This same problem of the UI widgets being drawn outside the visible area
> exists though, and naturally I want to use the adjustment tool to bring
> them back inside the visible area. But instead of leaving the UI window
> the same size as the screen (1280x720) and just moving the widgets in
> tighter, this adjustment actually makes the mythfrontend window smaller
> and them blam, gnome notices that the window is no longer the same
> dimension as the screen and puts the panels on top of the mythfrontend
> window again.
>
> So another case to be made for leaving the canvas size alone and simply
> moving the UI widgets so that they are on the visible portion of the
> canvas.
>
> Thots?

The SMPTE (Society of Motion Picture and Television Engineers) actually
defines three areas in the TV (NTSC) picture (RP-218). I think RP-219 is a
similar RP for HD television.

("RP"s are "recommended practices")

Safe Title: The area where it is safe to put graphics like Chyron titles etc.

Safe Action: The area where "action" is safe.

The rest: The rest of the available picture area, generally the outside areas,
where it is not "safe" to have things happen.

This is similar to the "zone 1, 2 and 3" used to spec things like registration
for cameras and convergence for CRTs. IE: The registration/convergence near
the center of the picture is generally better than it is towards the edges.

I'd include a link to the specifications here, but they are available only
with a subscription or membership. Greedy SMPTE.

Originally TV sets were set up to overscan, so that as the set aged and the
voltages dropped (due to capacitors becoming leaky mainly) the CRT would
still be filled with "stuff". They (probably rightly) figured that viewers
would be more unhappy with black at the edges than they would be with an
overscanned image, especially since directors were careful to pay attention
to safe action and safe title areas. The basic idea was to minimize sets
being returned for repair (or, with console sets, repairmen needing to be
sent to the home).

One more case of the manufacturers driving content. The bottom line drives
everything.

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

watkinshome at gmail

Nov 11, 2009, 8:56 AM

Post #3 of 25 (1979 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

2009/11/11 Brian J. Murrell <brian [at] interlinx>:
> Hey everyone,
>
> I have a traditional CRT TV (am I the only one left with one of
> these? �:-). �I am driving that with an nvidia 5200 via S-Video.

No, there's me too, same setup though my CRT TV is wide screen.

>
> See this picture I took of my TV:
> http://svn.mythtv.org/trac/attachment/ticket/7545/P1010451.JPG

My picture looks much better than that. I'm definately using overscan
(via nvidia_settings) though I can't remember if I made changes to the
UI window position.

> You can see a "wow" on the top half of the left border. �But this is
> just how CRT TVs are. �This is exactly why overscan exists.

My wavy edges are hidden by the overscan and I've never noticed
widgets overlapping the edge of the screen. I'll have a look tonight.

> This same problem of the UI widgets being drawn outside the visible area
> exists though, and naturally I want to use the adjustment tool to bring
> them back inside the visible area. �But instead of leaving the UI window
> the same size as the screen (1280x720) and just moving the widgets in
> tighter, this adjustment actually makes the mythfrontend window smaller
> and them blam, gnome notices that the window is no longer the same
> dimension as the screen and puts the panels on top of the mythfrontend
> window again.

I experimented with higher resolution settings but found that I
preferred the picture with the resolution set to 800x600.

I'm not sure how higher resolutions get translated into S-Video.

I did try and set a 720x576 (PAL?) modeline which I thought should
match the S-Video signal best, but never got that working.
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

tortise at paradise

Nov 11, 2009, 10:31 AM

Post #4 of 25 (1966 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

> The problem with this approach is that it's futile trying to make the
> edge of the UI "canvas" meet the visible portion of the picture as the
> borders of this visible portion of the picture are never straight an
> square. Frequently they are curved and/or have wows in them.
>
> See this picture I took of my TV:
> http://svn.mythtv.org/trac/attachment/ticket/7545/P1010451.JPG
>
> You can see a "wow" on the top half of the left border. But this is
> just how CRT TVs are. This is exactly why overscan exists.

It seemed to me this wow effect is really the "edge artefact" that overscan was made to hide.

I have a 32" "semi HD" CRT TV which has the "wow" shown but on the right hand side, I was going to get the dealer to come and adjust
the set as I had assumed that was a minor malignment of the tube that they might be able to correct. 2 others similar TV's / setups
I have do not have that bendy "feature".

Interestingly the inner bow moves depending on content movement and it is a little disconcerting however I can seem to come to
ignore it. Test videos can well demonstrate the edge movement bending and straightening. See http://www.w6rz.net/

Does anyone know if a degree of tube malignment can accentuate this and will it be possible to have the dealer adjust and improve
this?

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

brian at interlinx

Nov 11, 2009, 10:52 AM

Post #5 of 25 (1977 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Thu, 2009-11-12 at 07:31 +1300, Tortise wrote:
>
> It seemed to me this wow effect is really the "edge artefact" that overscan was made to hide.

Exactly, and overscan will hide it if you actually overscan the image
you give to the TV.

The myth UI is not overscanning though once you adjust it to get all of
the widgets (i.e. in setup screens) inside the viewable area because
rather than just moving widgets on the overscanned canvas, they are just
making the canvas smaller, to fit inside the viewable area and not into
the overscan area.

To put it more clearly, my X screen is 640x480 and that stretches out
into the overscan area once I use /usr/bin/nvidia-settings to enable the
overscan. When I view a television station I see the same visible
portion of the picture as I would watching real TV.

However, when I go into the setup menus the various widgets (checkboxes
down the left for example) are off the visible area because by default
the myth UI starts at 0,0 and stretches the canvas out to 640,480, with
the edges hidden in the overscan area. So I go to the screen adjustment
to bring it all back into the visible area again but that simply reduces
the size of the canvas (and sets an offset so it's centered) to try make
the edges of the UI meet the spot where visible area turns into
overscan. In my case, it's reduced the UI to 571x443 offeset to display
at 31,22 which is roughly (I say roughly because of the in-exactness of
the visible area borders) where visible area turns into overscan.

But as expected with analog CRTs, this "meeting" is not exact
everywhere. Which is why this resizing of the canvas is the wrong
approach. IMHO.

> I have a 32" "semi HD" CRT TV which has the "wow" shown but on the right hand side, I was going to get the dealer to come and adjust
> the set as I had assumed that was a minor malignment of the tube that they might be able to correct.

No. AFAIK, this is normal and to be expected with the analog nature of
a CRT.

> Interestingly the inner bow moves depending on content movement

Indeed. Again, an artifact of the analog-ness of the CRT.

> and it is a little disconcerting however I can seem to come to
> ignore it.

Sure. And I have ignored mine for years now, but this problem is also
now having the ripple effect of not working on a gnome desktop properly
when the UI window is not the same size as the gnome screen, but when it
is the same size, and overlaying the task bars properly, the edges are
off into the overscan again.

b.

Attachments:

signature.asc (0.19 KB)

fatgerman at ntlworld

Nov 11, 2009, 11:49 AM

Post #6 of 25 (1965 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Wednesday 11 Nov 2009 13:53:58 Brian J. Murrell wrote:
>
> I have an LCD TV that has some overscan as well. It's not as much as
> the TV, but it's still about 20 pixels per side.
>
It's not really a solution to your generic problem, but I've never seen an LCD TV that doesn't allow you to switch overscan off.

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

gull at gull

Nov 11, 2009, 12:25 PM

Post #7 of 25 (1970 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

Tortise wrote:
> I have a 32" "semi HD" CRT TV which has the "wow" shown but on the right
> hand side, I was going to get the dealer to come and adjust the set as I
> had assumed that was a minor malignment of the tube that they might be
> able to correct. 2 others similar TV's / setups I have do not have that
> bendy "feature".

You can try, but it probably won't help. Some computer monitors have
elaborate adjustments for that sort of thing but TV's often don't,
unless they're really expensive or designed to be professional video
monitors. The assumption is that overscan will hide these minor
alignment variations.

You may even find the "wow" moves around depending on the screen
content. Often lines with bright areas will bow one way and dark areas
another. Sometimes the whole picture will shrink slightly on bright
scenes and grow slightly on dark scenes, due to poor power supply
regulation.

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

tortise at paradise

Nov 11, 2009, 12:30 PM

Post #8 of 25 (1966 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

----- Original Message -----
From: "Brian J. Murrell" <brian [at] interlinx>
To: "Discussion about mythtv" <mythtv-users [at] mythtv>
Sent: Thursday, November 12, 2009 7:52 AM
Subject: Re: [mythtv-users] LCD and traditional CRT TVs, overscan and UI size and widget placement

But as expected with analog CRTs, this "meeting" is not exact
everywhere. Which is why this resizing of the canvas is the wrong
approach. IMHO.

_______________________________________________

What are you suggesting, then is the correct approach?

To outline more my analysis of the problem it seems to me that when a group of electrons get fired at a screen they have a magnetic
effect along the path they take. If these electrons streams are not balanced across the whole image then there is a magnetic
distorting effect on the surrounding electrons. For example a small image moves fast around a largely otherwise static image then
this effect is maximised. Another approach may have been to do some very clever image correction for these effects and effectively
eliminate wow and "edge artefact" however LCD's came along and as they do have some advantages the manufacturers effort changed to
be directed at LCD's

This correction would have been best done in the TV, however I suppose correction could also be generated externally, for example in
mythtv, however I cannot see anyone making that a priority to write code for, that would be a major exercise. Different CRT tubes
would probably have different characteristics that would also need accommodation.

To me the goal is seeing the full image in the full screen. How else do you propose to do that?

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

brian at interlinx

Nov 11, 2009, 12:47 PM

Post #9 of 25 (1968 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Thu, 2009-11-12 at 09:30 +1300, Tortise wrote:
>
> What are you suggesting, then is the correct approach?

To continue to overscan the "canvas" (I hope the meaning of this term is
obvious, if not, this whole explanation will probably not make sense),
meaning it should _always_ be screen size, but allow the repositioning
of the widgets on the canvas to be altered to allow them to be brought
within the viewable area, rather than trying to bring the edges of the
canvas into the viewable area.

> To outline more my analysis of the problem it seems to me that when a group of electrons get fired at a screen

The solution has nothing to do with electrons being fired.

The solution is to simply do what a broadcaster does and that's to
recognize that the outer edges of the picture will not be visible and
allow tuning in myth's UI of how far from the edge of the picture the
widgets will be drawn. This is what television broadcasters do. Read a
previous post in this thread for a good description of the various areas
defined within a "broadcast frame".

> This correction would have been best done in the TV,

No no. It's got to do with just recognizing how TV works and how people
account for how it works and doing what they do.

> To me the goal is seeing the full image in the full screen.

Well, for the UI, yes. Seeing the full UI in the screen and not having
some of the UI bleed out beyond the visible portion. As for the
playback of captured streams, they can bleed out into the overscan area,
just like they do when you watch live TV.

b.

Attachments:

signature.asc (0.19 KB)

brian at interlinx

Nov 11, 2009, 1:57 PM

Post #10 of 25 (1972 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

Attachments:

signature.asc (0.19 KB)

DEPontius at edgehp

Nov 11, 2009, 2:57 PM

Post #11 of 25 (1949 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

Brian J. Murrell wrote:
> Hey everyone,
>
> I have a traditional CRT TV (am I the only one left with one of
> these? :-). I am driving that with an nvidia 5200 via S-Video.
>
> As everyone knows, these TVs have an "overscan" feature where they only
> make a portion of the original broadcasted picture visible to the
> viewer. Historically, this is done because the outer edges of the
> broadcast signal are rough and therefore hidden in this "overscan" area.
>
> But the TV broadcasters know that TVs do this and they compensate by not
> putting anything they want visible too close to the edge of the signal
> they are broadcasting. This becomes obvious if you watch a TV station
> that does have something at the edge of the visible picture, like CNN's
> ticker at the bottom. If you look at CNN on a device that does not hide
> the overscan (i.e. like mythfrontend in a window on your computer) you
> can see how much picture is available between the bottom edge of the
> ticker and the bottom edge of your window.
>
> Anyway, that's a bit about overscan.
>
> The problem with this overscan though is that unless you adjust it, the
> MythUI will draw outside the visible area and thus, you won't see some
> of the widgets. But MythUI has adjustments for this, allowing you to
> bring the UI back inside the viewable area. The problem is that it's
> not leaving the UI the same size and just drawing the widgets closer to
> center (i.e. to bring them into the viewable area on all sides), but
> rather it's just reducing the size of the UI.
>
> The problem with this approach is that it's futile trying to make the
> edge of the UI "canvas" meet the visible portion of the picture as the
> borders of this visible portion of the picture are never straight an
> square. Frequently they are curved and/or have wows in them.
>
> See this picture I took of my TV:
> http://svn.mythtv.org/trac/attachment/ticket/7545/P1010451.JPG
>
> You can see a "wow" on the top half of the left border. But this is
> just how CRT TVs are. This is exactly why overscan exists.
>
> The solution, as I see it is rather than scaling the UI canvas down to
> fit inside the visible window, the canvas needs to stay the same size
> and the positioning of the widgets on the canvas needs to be offset to
> fit them inside the visible area.
>
> This effect is not limited to CRT TVs though.
>
> I have an LCD TV that has some overscan as well. It's not as much as
> the TV, but it's still about 20 pixels per side.
>
> On this LDC TV, I run a gnome desktop and the effect of the overscan is
> that the panels at the top and bottom are only half visible on the
> screen. When I start a mythfrontend on that screen, with it's
> dimensions the full size of the screen, gnome takes this hint and puts
> the window on top of the panels.
>
> This same problem of the UI widgets being drawn outside the visible area
> exists though, and naturally I want to use the adjustment tool to bring
> them back inside the visible area. But instead of leaving the UI window
> the same size as the screen (1280x720) and just moving the widgets in
> tighter, this adjustment actually makes the mythfrontend window smaller
> and them blam, gnome notices that the window is no longer the same
> dimension as the screen and puts the panels on top of the mythfrontend
> window again.
>
> So another case to be made for leaving the canvas size alone and simply
> moving the UI widgets so that they are on the visible portion of the
> canvas.
>
> Thots?

I've got a CRT also, and was quite vocally complaining about here, a
month or so back. I used the Setup option to resize the UI, but that
has a bad side-effect, namely that it's also resizing the TV that you're
trying to play. Worse yet, it's a near-fit resizing, and sometimes
those look worse. My wife, who isn't very picky about TV quality, noticed.

Then nVidia finally added the overscan adjustment back in for my 8400GS
card, so now I'm happy. I'm still fiddling with the overscan a bit,
trying to figure out what just-right should be.

Of course with your 5200 this doesn't apply, since you're on legacy
drivers. But I think they should have always had adjustable overscan.
I'd start there, then look into fiddling with the Myth UI.

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

brian at interlinx

Nov 11, 2009, 7:08 PM

Post #12 of 25 (1938 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Wed, 2009-11-11 at 17:57 -0500, Dale Pontius wrote:
>
> I've got a CRT also, and was quite vocally complaining about here, a
> month or so back. I used the Setup option to resize the UI, but that
> has a bad side-effect, namely that it's also resizing the TV that you're
> trying to play.

Well, if by "TV that you are trying to play" you mean the content
playback, you can actually separate the size of the UI from the playback
size in the Playback setup menu. That I do to maintain the correct
overscanning of the content playback regardless of what myth is doing
with the UI.

> Worse yet, it's a near-fit resizing, and sometimes
> those look worse.

Indeed. Exactly my point too. But I'm only complaining about the UI
due to the ability to decouple the playback size from the UI size per
the above.

> Then nVidia finally added the overscan adjustment back in for my 8400GS
> card, so now I'm happy. I'm still fiddling with the overscan a bit,
> trying to figure out what just-right should be.

Right. But rather than just doing "full overscan" so that what you see
being played back on your nvidia card exactly matches what you'd see
with live TV, you are trying to find some "happy medium" where happy
medium is not being equal to "as if you were watching on TV".

> Of course with your 5200 this doesn't apply, since you're on legacy
> drivers.

I am on the 96 drivers, but I still get that overscan that
nvidia-settings can do.

> I'd start there, then look into fiddling with the Myth UI.

Well, I have the overscan in the nvidia settings set perfectly, so that
playback looks exactly like it would direct from cable to my TV.

It's getting the UI to fit inside the visible area *without* reducing
the size of the UI canvas that is the problem here.

b.

Attachments:

signature.asc (0.19 KB)

tortise at paradise

Nov 11, 2009, 7:55 PM

Post #13 of 25 (1942 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

----- Original Message -----
From: "Brian J. Murrell" <brian [at] interlinx>
To: "Discussion about mythtv" <mythtv-users [at] mythtv>
Sent: Thursday, November 12, 2009 4:08 PM
Subject: Re: [mythtv-users] LCD and traditional CRT TVs, overscan and UI size and widget placement

On Wed, 2009-11-11 at 17:57 -0500, Dale Pontius wrote:
>
> I've got a CRT also, and was quite vocally complaining about here, a
> month or so back. I used the Setup option to resize the UI, but that
> has a bad side-effect, namely that it's also resizing the TV that you're
> trying to play.

Well, if by "TV that you are trying to play" you mean the content
playback, you can actually separate the size of the UI from the playback
size in the Playback setup menu. That I do to maintain the correct
overscanning of the content playback regardless of what myth is doing
with the UI.

> Worse yet, it's a near-fit resizing, and sometimes
> those look worse.

Indeed. Exactly my point too. But I'm only complaining about the UI
due to the ability to decouple the playback size from the UI size per
the above.

> Then nVidia finally added the overscan adjustment back in for my 8400GS
> card, so now I'm happy. I'm still fiddling with the overscan a bit,
> trying to figure out what just-right should be.

Right. But rather than just doing "full overscan" so that what you see
being played back on your nvidia card exactly matches what you'd see
with live TV, you are trying to find some "happy medium" where happy
medium is not being equal to "as if you were watching on TV".

> Of course with your 5200 this doesn't apply, since you're on legacy
> drivers.

I am on the 96 drivers, but I still get that overscan that
nvidia-settings can do.

> I'd start there, then look into fiddling with the Myth UI.

Well, I have the overscan in the nvidia settings set perfectly, so that
playback looks exactly like it would direct from cable to my TV.

It's getting the UI to fit inside the visible area *without* reducing
the size of the UI canvas that is the problem here.

_______________________________________________

Sorry Brian I am not getting this. If you adjust overscan correctly using NVIDIA settings for the Desktop UI, then mythtv should
just scale / work using default settings. If you are using a non standard UI setting, I'd set the UI right first, and then
re-adjust mythtv to the size you want. The other way around I'd expect to give grief.

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

tortise at paradise

Nov 11, 2009, 7:55 PM

Post #14 of 25 (1928 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

brian at interlinx

Nov 11, 2009, 8:24 PM

Post #15 of 25 (1928 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Thu, 2009-11-12 at 16:55 +1300, tortise [at] paradise wrote:
>
> Sorry Brian I am not getting this. If you adjust overscan correctly using NVIDIA settings for the Desktop UI,

What do you mean "Desktop UI"? Do you mean like a gnome (or other
"productivity environment"), etc? The machine I run myth on that
displays to a CRT is dedicated to being a myth frontend and tuned for
that function. There is no deskotp. There is only X and the myth UI
window on top of it.

As such, I have tuned the overscan with nvidia settings so that when I
am watching myth, I see the exact same visible area as I would see with
regular TV. This is unlike of course watching that same channel in a
window on a desktop as that mode includes the area around the picture
that would normally be hidden by overscan.

> then mythtv should
> just scale / work using default settings.

No. It doesn't because the design of the UI on the myth window has
never accounted for overscan. I tend to think it's been designed in a
window on a desktop computer where the edge of the "canvas" is visible,
unlike when it's shown on a device that has overscan.

> If you are using a non standard UI setting, I'd set the UI right first, and then
> re-adjust mythtv to the size you want. The other way around I'd expect to give grief.

My UI is the same size as my screen, aka "full-screen", which is
640x480. The problem is that with overscan, the 20-30 pixels around the
edges of that 640x480 are not visible with an overscan display.

b.

Attachments:

signature.asc (0.19 KB)

Jens.Peder.Terjesen at devoteam

Nov 12, 2009, 2:46 AM

Post #16 of 25 (1938 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Wed, 2009-11-11 at 19:49 +0000, Mark Greenwood wrote:
>
> It's not really a solution to your generic problem,

Indeed.

> but I've never seen an LCD TV that doesn't allow you to switch overscan off.

I wish. It would alleviate the problem where it's causing me the most
grief.

It's a Toshiba 26HL37 FWIW. I am connected to it through the DVI port
of my Nvidia video card. It seems quite a number of settings are
"disabled" when I try to configure them on that input.

b.
________________________________________

I think perhaps you should have a look at the TVs menus again.

According to this site: http://www.toshiba.ca/web/product.grp?lg=en&section=2&group=521&product=8013
the TV has Native Mode (HDMI), look at the Features tab.
And according to this site: http://www.toshiba.ca/web/product.grp?lg=en&section=2&group=521&product=8751&category=
this means no overscan, again look at the Features tab.
So unless Toshiba has decided to use the term Native Mode for different things on different models then you should be able to turn off overscan.

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

watkinshome at gmail

Nov 12, 2009, 5:03 AM

Post #17 of 25 (1922 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

> No. It doesn't because the design of the UI on the myth window has
> never accounted for overscan. I tend to think it's been designed in a
> window on a desktop computer where the edge of the "canvas" is visible,
> unlike when it's shown on a device that has overscan.

I presume you're referring to some of the configuration settings screens?

I can't say I've ever noticed a problem in any of the 'user' screens
but I agree that some of the configuration settings pages tend to
disappear off the bottom of the screen, to the point that sometimes I
can't see the "Next" / "Back" buttons.

However, since I don't have a keyboard on my mythbox I mostly do the
setup remotely using vnc, so I get around that problem.

I'd guess it's a theme issue and maybe there are some themes that
allow for overscan properly. Most of the newer themes seem to be
designed for widescreen digital screens, for obvious reasons.
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

brian at interlinx

Nov 12, 2009, 5:12 AM

Post #18 of 25 (1923 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Thu, 2009-11-12 at 13:03 +0000, David Watkins wrote:
>
> I presume you're referring to some of the configuration settings screens?

Indeed.

> I can't say I've ever noticed a problem in any of the 'user' screens

Yeah, agreed. The "user" screens tend to be quite liberal with the
amount of space they leave between the working portion of the screen and
the outside edges.

> but I agree that some of the configuration settings pages tend to
> disappear off the bottom of the screen, to the point that sometimes I
> can't see the "Next" / "Back" buttons.

Yup. And in my case, where I have tuned my overscan so that playback
looks just like my real TV, items down the left side can get obscured as
well. I actually noticed just last night that the right hand side of
the mythcenter UI as well as the OSDs tend to run off the edge into the
overscan as well.

> I'd guess it's a theme issue and maybe there are some themes that
> allow for overscan properly.

I doubt it. It's a UI-toolkit design problem. All of the themes use
the same tools where I suspect placement on the canvas is absolute with
the idea of scaling the canvas rather than making the placement of
widget relative to each other and allowing the "origin" (i.e. one single
static placement on the canvas) to be adjusted.

b.

Attachments:

signature.asc (0.19 KB)

brian at interlinx

Nov 12, 2009, 6:28 AM

Post #19 of 25 (1899 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Thu, 2009-11-12 at 11:46 +0100, Terjesen Jens Peder wrote:
>
> I think perhaps you should have a look at the TVs menus again.

I've already been through them a zillion times, toggling everything
that's available.

> According to this site: http://www.toshiba.ca/web/product.grp?lg=en&section=2&group=521&product=8013
> the TV has Native Mode (HDMI), look at the Features tab.
> And according to this site: http://www.toshiba.ca/web/product.grp?lg=en&section=2&group=521&product=8751&category=
> this means no overscan, again look at the Features tab.
> So unless Toshiba has decided to use the term Native Mode for different things on different models then you should be able to turn off overscan.

What can I tell you? The term "Native Mode" doesn't even exist in the
menus, anywhere, on any input.

b.

Attachments:

signature.asc (0.19 KB)

Jens.Peder.Terjesen at devoteam

Nov 12, 2009, 7:01 AM

Post #20 of 25 (1900 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

Brian J. Murrell wrote:

On Thu, 2009-11-12 at 11:46 +0100, Terjesen Jens Peder wrote:
>
> I think perhaps you should have a look at the TVs menus again.

I've already been through them a zillion times, toggling everything
that's available.

> According to this site: http://www.toshiba.ca/web/product.grp?lg=en&section=2&group=521&product=8013
> the TV has Native Mode (HDMI), look at the Features tab.
> And according to this site: http://www.toshiba.ca/web/product.grp?lg=en&section=2&group=521&product=8751&category=
> this means no overscan, again look at the Features tab.
> So unless Toshiba has decided to use the term Native Mode for different things on different models then you should be able to turn off overscan.

What can I tell you? The term "Native Mode" doesn't even exist in the
menus, anywhere, on any input.

b.
________________________________________

I found an online manual for this TV here: http://support.toshiba.ca/support/ceg/manuals/

And on page 16 I found this:
Note:
� The edges of the images may be hidden.
� If receiving a 720p, 1080i, or 1080p signal program, Native
mode scales the video to display the entire picture within the
borders of the screen (i.e. no overscanning).

So this seems to only work on these resolutions and not on the TVs native resolution.
A bit misleading then I would say.

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

brian at interlinx

Nov 12, 2009, 7:26 AM

Post #21 of 25 (1913 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

To add just a bit more info to this thread for anyone who might benefit
from it in the future, on a gnome desktop with panel(s), unless you can
make your GUI window the same size as the screen, your myth window will
sit "under" the panels. I guess a window being the same dimensions as
the screen is gnome's hint to "get out of the way".

The implication of this is of course, if your screen has overscan you
can't make the UI window the same size as the screen or you lose parts
of it into the overscan and then of course the fallout is that the myth
window sits under the panels.

Despite the myth UI window sitting under the panels, playback still uses
a full screen window and successfully hints to gnome to "get out of the
way". So this is not terrible. Panels while you are at the UI but no
panels while playing back.

Unless!! You use compiz. If you use compiz, the panels continue to sit
on top of even playback, even with the "legacy full screen" compiz
workaround enabled. Sadly.

For non shared desktop/mythfe machines, no biggie. Who needs compiz
there anyway. But for shared machines, not so great.

b.

Attachments:

signature.asc (0.19 KB)

jarpublic at gmail

Nov 12, 2009, 7:39 AM

Post #22 of 25 (1901 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

> To add just a bit more info to this thread for anyone who might benefit
> from it in the future, on a gnome desktop with panel(s), unless you can
> make your GUI window the same size as the screen, your myth window will
> sit "under" the panels. �I guess a window being the same dimensions as
> the screen is gnome's hint to "get out of the way".

You can also just set your panels to auto-hide. This is what I do.
Then you don't see them on the gui or playback. and occasionally when
I need them I just roll the mouse over. This would be more problematic
on a desktop machine, but it works great for myth.
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

Jens.Peder.Terjesen at devoteam

Nov 12, 2009, 4:33 PM

Post #23 of 25 (1868 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

________________________________________
Fra: mythtv-users-bounces [at] mythtv [mythtv-users-bounces [at] mythtv] på vegne av Brian J. Murrell [brian [at] interlinx]
Sendt: 12. november 2009 16:26
Til: Discussion about mythtv
Emne: Re: [mythtv-users] LCD and traditional CRT TVs, overscan and UI size and widget placement

To add just a bit more info to this thread for anyone who might benefit
from it in the future, on a gnome desktop with panel(s), unless you can
make your GUI window the same size as the screen, your myth window will
sit "under" the panels. I guess a window being the same dimensions as
the screen is gnome's hint to "get out of the way".

The implication of this is of course, if your screen has overscan you
can't make the UI window the same size as the screen or you lose parts
of it into the overscan and then of course the fallout is that the myth
window sits under the panels.

Despite the myth UI window sitting under the panels, playback still uses
a full screen window and successfully hints to gnome to "get out of the
way". So this is not terrible. Panels while you are at the UI but no
panels while playing back.

Unless!! You use compiz. If you use compiz, the panels continue to sit
on top of even playback, even with the "legacy full screen" compiz
workaround enabled. Sadly.

For non shared desktop/mythfe machines, no biggie. Who needs compiz
there anyway. But for shared machines, not so great.

b.

http://lmgtfy.com/?q=gnome+mythtv+panel
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

brian at interlinx

Nov 12, 2009, 8:20 PM

Post #24 of 25 (1861 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Fri, 2009-11-13 at 01:33 +0100, Terjesen Jens Peder wrote:
>
> http://lmgtfy.com/?q=gnome+mythtv+panel

First of all, I really wish you'd quote the e-mails you are replying to
more properly so that trying to find what you are adding is not so
difficult.

Second of all... trim please. Please don't quote entire e-mails to add
just a single line of text.

Third, why do I need this silly "lmgtfy.com" animated site to show me
how to type into google and hit the search button? Would a regular
google link not have sufficed?

Forth, do you think I have not already googled for all that information?
How do you think I came across the compiz "legacy full-screen"
work-around. None of what your suggested search yields provides any
more information than I have already provided.

b.

Attachments:

signature.asc (0.19 KB)

brian at interlinx

Nov 12, 2009, 8:28 PM

Post #25 of 25 (1868 views)
Permalink

Re: LCD and traditional CRT TVs, overscan and UI size and widget placement [In reply to]

On Thu, 2009-11-12 at 16:01 +0100, Terjesen Jens Peder wrote:
>
> I found an online manual for this TV here: http://support.toshiba.ca/support/ceg/manuals/

Ahhh. Awesome.

> And on page 16 I found this:
> Note:
> • The edges of the images may be hidden.

That's my experience with DVI->HDMI on the TV and a 1280x720 video
resolution.

> • If receiving a 720p, 1080i, or 1080p signal program, Native
> mode scales the video to display the entire picture within the
> borders of the screen (i.e. no overscanning).

But this bullet seems to contradict the previous bullet. Strange
documentation.

> So this seems to only work on these resolutions and not on the TVs native resolution.
> A bit misleading then I would say.

'Specially considering I am using 1280x720 and I don't get his supposed
"Native mode". Now, I will say that the amount of overscan is quite a
bit less than a CRT. So maybe this little bit of overscan that I do
have is what they consider "entire picture [being] within the borders of
the screen".

I should just phone them.

b.

Attachments:

signature.asc (0.19 KB)

Index | Next | Previous | View Threaded

Interested in having your list archived? Contact Gossamer Threads