[gentoo-user] Outputing 15.9kHz?

[gentoo-user] Outputing 15.9kHz?

[Grant]

I'm trying to figure out if a device that converts a VGA output to a
component output for HDTV connection will work with a standard TV that
has component inputs.

I've been corresponding with an A/V guy who thinks the key will be
getting the computer to output at 15.9kHz as opposed to the 31-33kHz
of HDTV.  I know I can specify specific HorizSync values in xorg.conf.
 Can I expect my on-board video card to be capable of 15.9kHz?  It's
in a Dell desktop that's a few years old.

- Grant
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gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Hans-Werner Hilse]

Hi,

On Tue, 5 Sep 2006 17:13:55 -0700 Grant <emailgrant@gmail.com> wrote:

> I'm trying to figure out if a device that converts a VGA output to a
> component output for HDTV connection will work with a standard TV that
> has component inputs.

Your VGA card can probably generate that signal itself. You'll only
need an adapter for having the correct plugs. See

http://www.sput.nl/hardware/tv-x.html

In short: Besides proper frequencies, you need interlacing.

-hwh
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gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Grant]

> > I'm trying to figure out if a device that converts a VGA output to a
> > component output for HDTV connection will work with a standard TV that
> > has component inputs.
>
> Your VGA card can probably generate that signal itself. You'll only
> need an adapter for having the correct plugs. See
>
> http://www.sput.nl/hardware/tv-x.html
>
> In short: Besides proper frequencies, you need interlacing.

I just spoke to someone from Audio Authority which is the company that
makes the device I linked to:

http://www.digitalconnection.com/Products/Video/9a60.asp

The guy there says it won't work because a computer outputs a
non-interlaced signal and a standard TV uses interlaced.  Basically,
exactly what you said.  From your link, it looks like an interlaced
signal can be specifiec in xorg.conf which should solve that problem.
Is that right?

- Grant
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gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Hans-Werner Hilse]

Hi,

On Wed, 6 Sep 2006 08:03:48 -0700
Grant <emailgrant@gmail.com> wrote:

> The guy there says it won't work because a computer outputs a
> non-interlaced signal and a standard TV uses interlaced.  Basically,
> exactly what you said.  From your link, it looks like an interlaced
> signal can be specifiec in xorg.conf which should solve that problem.
> Is that right?

There might be some vga cards that can't output an interlaced signal.
But most should do pretty well. And I'm relatively sure you can't break
anything by trying it out. Take the modelines from the link I've given
and just try it out. And I did not talk about the different
synchronization behaviour (mentioned in the site I've linked, too), but
that's probably what your adapter does. So I would just give it a try.
I would do a "hot" plugin and not wait too long if there's no picture
appearing. No guarantees, though, but at that signal levels it
shouldn't hurt. People did that before...

-hwh
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Grant]

> > The guy there says it won't work because a computer outputs a
> > non-interlaced signal and a standard TV uses interlaced.  Basically,
> > exactly what you said.  From your link, it looks like an interlaced
> > signal can be specifiec in xorg.conf which should solve that problem.
> > Is that right?
>
> There might be some vga cards that can't output an interlaced signal.
> But most should do pretty well. And I'm relatively sure you can't break
> anything by trying it out. Take the modelines from the link I've given
> and just try it out. And I did not talk about the different
> synchronization behaviour (mentioned in the site I've linked, too), but
> that's probably what your adapter does. So I would just give it a try.
> I would do a "hot" plugin and not wait too long if there's no picture
> appearing. No guarantees, though, but at that signal levels it
> shouldn't hurt. People did that before...

Ok I finally got this device today:

http://mythic.tv/product_info.php?products_id=30

I'm using the modeline from this link:

http://www.sput.nl/hardware/tv-x.html

and my xorg.conf looks like this:

Section "Monitor"
        Identifier "monitor1"
        Modeline "736x485i" 14.16 736 760 824 904 485 491 496 525
interlace -hsync -vsync
EndSection

Section "Device"
        Identifier "device1"
        Driver "i810"
        VideoRam 4096
EndSection

Section "Screen"
        Identifier "screen1"
        Device "device1"
        Monitor "monitor1"
EndSection

Section "ServerLayout"
        Identifier "layout1"
        Screen "screen1"
        InputDevice "mouse1" "CorePointer"
        InputDevice "keyboard1" "CoreKeyboard"
EndSection

When I try to open an xfce4 desktop like this, the image is somewhat
scrambled and constantly rolls on the TV.  It looks normal on a
monitor with the same settings.

/var/log/Xorg.0.log reports this:

(II) I810(0): monitor1: Using default hsync range of 28.00-33.00 kHz
(II) I810(0): monitor1: Using default vrefresh range of 43.00-72.00 Hz
(II) I810(0): Clock range:   9.50 to 163.00 MHz
(II) I810(0): Not using mode "736x485i" (unknown reason)
(II) I810(0): Not using default mode "640x350" (hsync out of range)
(II) I810(0): Not using default mode "320x175" (bad mode
clock/interlace/doublescan)

It continues through a long list of "Not using" resolutions, and then:

(--) I810(0): Virtual size is 640x480 (pitch 640)
(**) I810(0): *Default mode "640x480": 25.2 MHz, 31.5 kHz, 60.0 Hz
(II) I810(0): Modeline "640x480"   25.20  640 656 752 800  480 490 492
525 -hsync -vsync

I've tried the 640x480i modeline from the above link with the same results.

What do you guys think?

- Grant
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gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Hans-Werner Hilse]

Hi,

On Tue, 12 Sep 2006 18:21:44 -0700 Grant <emailgrant@gmail.com> wrote:

> I'm using the modeline from this link:
> 
> http://www.sput.nl/hardware/tv-x.html
> 
> and my xorg.conf looks like this:
> 
> Section "Monitor"
>         Identifier "monitor1"
>         Modeline "736x485i" 14.16 736 760 824 904 485 491 496 525
> interlace -hsync -vsync
> EndSection
> [...]
> 
> When I try to open an xfce4 desktop like this, the image is somewhat
> scrambled and constantly rolls on the TV.  It looks normal on a
> monitor with the same settings.

OK, that "rolling" is bad sync.

> /var/log/Xorg.0.log reports this:
> 
> (II) I810(0): monitor1: Using default hsync range of 28.00-33.00 kHz

That's the culprit. You need to override defaults (TVs don't usually
have DDC, such no automatic detection) for hsync/vsync. Add a
"HorizSync" line to your xorg.conf:

Section "Monitor"
	...
	HorizSync 19.00-20.00
	...
EndSection

Note that "VertRefresh" probably hasn't to be set, since its default is
sufficient.

> (II) I810(0): Not using mode "736x485i" (unknown reason)

Hm, I can not explain why this would be "unknown", though. For me, this
seems like another case of "hsync out of range"...

-hwh
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Grant]

> > I'm using the modeline from this link:
> >
> > http://www.sput.nl/hardware/tv-x.html
> >
> > and my xorg.conf looks like this:
> >
> > Section "Monitor"
> >         Identifier "monitor1"
> >         Modeline "736x485i" 14.16 736 760 824 904 485 491 496 525
> > interlace -hsync -vsync
> > EndSection
> > [...]
> >
> > When I try to open an xfce4 desktop like this, the image is somewhat
> > scrambled and constantly rolls on the TV.  It looks normal on a
> > monitor with the same settings.
>
> OK, that "rolling" is bad sync.
>
> > /var/log/Xorg.0.log reports this:
> >
> > (II) I810(0): monitor1: Using default hsync range of 28.00-33.00 kHz
>
> That's the culprit. You need to override defaults (TVs don't usually
> have DDC, such no automatic detection) for hsync/vsync. Add a
> "HorizSync" line to your xorg.conf:
>
> Section "Monitor"
>         ...
>         HorizSync 19.00-20.00
>         ...
> EndSection

I always seem to get hsync out of range errors trying to go this low.
I guess my card can't go as low as necessary.

- Grant
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Hans-Werner Hilse]

Hi,

(sorry, must have overlooked your last answer...)

On Thu, 14 Sep 2006 01:32:36 -0700 Grant <emailgrant@gmail.com> wrote:

> I always seem to get hsync out of range errors trying to go this low.
> I guess my card can't go as low as necessary.

Argh, my failure. I must have read "19.5 kHz" instead of 15.9 kHz, so
try a HorizSync of 15-16.

The exact frequency can probably be calculated from the modeline:

Modeline "736x485i" 14.16 736 760 824 904 485 491 496 525 interlace -hsync -vsync

would be

14.16MHz / 904 "virtual line lenght" = 15,66 kHz

I've also read values like 14.35 MHz for the pixel clock.

The i810 should work for pixel clock frequencies >= 9,5 MHz (the driver
sources tell that), so it *should* work.

-hwh
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Outputing 15.9kHz?

[Grant]

> (sorry, must have overlooked your last answer...)
>
> On Thu, 14 Sep 2006 01:32:36 -0700 Grant <emailgrant@gmail.com> wrote:
>
> > I always seem to get hsync out of range errors trying to go this low.
> > I guess my card can't go as low as necessary.
>
> Argh, my failure. I must have read "19.5 kHz" instead of 15.9 kHz, so
> try a HorizSync of 15-16.
>
> The exact frequency can probably be calculated from the modeline:
>
> Modeline "736x485i" 14.16 736 760 824 904 485 491 496 525 interlace -hsync -vsync
>
> would be
>
> 14.16MHz / 904 "virtual line lenght" = 15,66 kHz
>
> I've also read values like 14.35 MHz for the pixel clock.
>
> The i810 should work for pixel clock frequencies >= 9,5 MHz (the driver
> sources tell that), so it *should* work.

It doesn't seem to want to go below 26, plus the source specifically
says interlacing is not supported.  I tried it with a couple other
video cards I have with the same results as far as the sync.

I really appreciate your help, but I'm going to go ahead return the
9a60 and get an HDTV.

- Grant
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gentoo-user@gentoo.org mailing list