[mythtv-users] VGA -> RGB-SCART (PAL, 720x576i50) on Intel HD video possible?

Hika van den Hoven hikavdh at gmail.com
Wed Jun 1 20:08:46 UTC 2016

Hoi Hika,

Wednesday, June 1, 2016, 9:55:08 PM, you wrote:

> Hoi Nick,

> Wednesday, June 1, 2016, 9:39:36 PM, you wrote:

>> On 1 June 2016 at 13:09, Hika van den Hoven <hikavdh at gmail.com> wrote:
>>> Hoi Nick,
>>> Wednesday, June 1, 2016, 10:04:27 AM, you wrote:
>>>> I'm curious to know if it's possible to use (and thus if anyone is
>>> using) a VGA->>RGB SCART output path on recent Intel Core-based systems
>>>> with Intel HD (i915) video?
>>>> Does the Intel HD video platform support outputting PAL-compatible
>>>> 720x576i50 signals at 15kHz?

>>> If the card supports interlacing, it's a simple scheme to convert vga
>>> to scart. All it has to do is combine hsync and vsync. I use it with
>>> an nvidea card. If you are interested I can lookup the scheme. I also
>>> have created my own modeline to optimize for my TV and to remove
>>> overscan.

>> It's not as simple as that. The VGA output needs to be able to display
>> a PAL-compatible modeline directly to be able to use one of these
"simple" VGA->>>RGB SCART cables.

>> As I mentioned, I already use a VGA->RGB SCART cable with an ATI
>> Radeon card (the sync circuit for Radeons is even simpler than for
>> NVidia cards, as the ATI Radeon outputs composite sync).

>> What I want to know is whether current Intel HD video natively
>> supports a low enough dot clock (14MHz) to output the necessary
>> 15.625kHz horizontal frequency PAL signal directly through the VGA
>> output, or whether a "VGA -> PAL" converter would be required.

>> Cheers,
>> Nick
>> _______________________________________________

> As far as I know Intel does not do interlaced, so the only option then
> is Nvidia (nouveau also doesn't do interlaced). And I don't know about
> those adapters you can buy, but for a few euro in electronics you can
> solder one and all it needs is a card that does interlaced. The
> modelines you can create/ supply yourself.
> At the time I was building testing my solution, there where cards that
> should do it, but the drivers'(a.o Nouveau, Intel) didn't do the
> interlacing correct, giving f.i. two half pictures above each other.
> The build-in Intel card I couldn't get working so I ended up added an
> Nvidia with their driver.

Common modelines for PAL is:
Modeline "720x576pali"  13.88  720 742 808 888  576 578 581 625 -hsync -vsync interlace

I adapted it to optimize for my TV removing overscan to:
modeline "720x545_50i"  14.80  720 752 841 945  545 565 597 620 -hsync -vsync interlace

You can use this site for modeline calculations:

Tot mails,
  Hika                            mailto:hikavdh at gmail.com

"Zonder hoop kun je niet leven
Zonder leven is er geen hoop
Het eeuwige dilemma
Zeker als je hoop moet vernietigen om te kunnen overleven!"

De lerende Mens

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