Two video cards

SDL Development
1

Hi All,
i have a PC with two video cards, one AGP and one PCI.
May i run two different SDL applications on each videocard’s frame buffer ?
Thanks a lot in advantage.

2

Hi All,
i have a PC with two video cards, one AGP and one PCI.
May i run two different SDL applications on each videocard’s frame buffer ?
Thanks a lot in advantage.

Did you try setting the environment variable SDL_FBDEV to two different values, like
export SDL_FBDEV=/dev/fb0
/usr/bin/program1

export SDL_FBDEV=/dev/fb1
/usr/bin/program2

Stephane

3

Il Tue, 18 May 2004 11:59:03 +0200 (CEST)
Stephane Marchesin <stephane.marchesin at wanadoo.fr> scrisse:

Hi All,
i have a PC with two video cards, one AGP and one PCI.
May i run two different SDL applications on each videocard’s frame buffer ?
Thanks a lot in advantage.

Did you try setting the environment variable SDL_FBDEV to two different values, like
export SDL_FBDEV=/dev/fb0
/usr/bin/program1
OK all work fine…

export SDL_FBDEV=/dev/fb1
/usr/bin/program2
My app receive an:
Received SIGSEGV quitting !! Core: Invalid memory reference
The SIGSEV is received when i try to use :
elem.overlay->pixels[0]
of overlay created with:
elem[j].overlay = SDL_CreateYUVOverlay(DIM_WIDTH, DIM_HEIGHT, SDL_IYUV_OVERLAY, screen);

no problem with SDL_FBDEV=/dev/fb0
maybe this is the right way, some suggest.
Thnks> Stephane

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4

The SIGSEV is received when i try to use :
elem.overlay->pixels[0]
of overlay created with:
elem[j].overlay = SDL_CreateYUVOverlay(DIM_WIDTH,
DIM_HEIGHT, SDL_IYUV_OVERLAY, screen);

Did you check to make sure the overlay was
successfully created? Perhaps overlays aren’t
supported on that display…__________________________________
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5

Il Tue, 18 May 2004 04:44:02 -0700 (PDT)
Donny Viszneki scrisse:

The SIGSEV is received when i try to use :
elem.overlay->pixels[0]
of overlay created with:
elem[j].overlay = SDL_CreateYUVOverlay(DIM_WIDTH,
DIM_HEIGHT, SDL_IYUV_OVERLAY, screen);

Did you check to make sure the overlay was
successfully created? Perhaps overlays aren’t
supported on that display…

You are on right!
SDL_CreateYUVOverlay() return (nil).

lspci return:
00:09.0 VGA compatible controller: S3 Inc. 86c775/86c785 [Trio 64V2/DX or /GX] (rev 14)

So overlay aren’t supported by all videocard! (i’m a poor sdl programmer :-))
How i can test the capability of my video card?

thnks a lot!!

6

I have tried with testbitmap.c from SDL source package but use always the same video card both with

export SDL_FBDEV=/dev/fb0 and
export SDL_FBDEV=/dev/fb1

Il Tue, 18 May 2004 04:44:02 -0700 (PDT)
Donny Viszneki scrisse:>

The SIGSEV is received when i try to use :
elem.overlay->pixels[0]
of overlay created with:
elem[j].overlay = SDL_CreateYUVOverlay(DIM_WIDTH,
DIM_HEIGHT, SDL_IYUV_OVERLAY, screen);

Did you check to make sure the overlay was
successfully created? Perhaps overlays aren’t
supported on that display…

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http://promo.yahoo.com/sbc/

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http://www.libsdl.org/mailman/listinfo/sdl

7

— Devel wrote:

Il Tue, 18 May 2004 04:44:02 -0700 (PDT)
Donny Viszneki scrisse:

The SIGSEV is received when i try to use :
elem.overlay->pixels[0]
of overlay created with:
elem[j].overlay =
SDL_CreateYUVOverlay(DIM_WIDTH,

DIM_HEIGHT, SDL_IYUV_OVERLAY, screen);

Did you check to make sure the overlay was
successfully created? Perhaps overlays aren’t
supported on that display…

You are on right!
SDL_CreateYUVOverlay() return (nil).

lspci return:
00:09.0 VGA compatible controller: S3 Inc.
86c775/86c785 [Trio 64V2/DX or /GX] (rev 14)

So overlay aren’t supported by all videocard! (i’m a
poor sdl programmer :-))
How i can test the capability of my video card?

I don’t know about testing video card capabilities,
perhaps someone else can field that question.

For now, if you have enough CPU to spare, perhaps you
could try software rendering? Use SWSURFACE when
creating your screen in SDL instead of HWSURFACE.

I have been told that some video card features are
handled by SDL if not available on your video card,
perhaps overlays are not one of them? Or maybe it will
only work with software rendering. I know that DirectX
uses its own software rendering to make up for
features missing on the video card. You can even tell
DirectX when to substitute software rendering where
your video card’s implementation of a certain feature
causes undesired operation. AFAIK, most video cards
are pretty conformant nowadays.

thnks a lot!!

No problem, glad to help.>

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8

I have tried with testbitmap.c from SDL source package but use always the same video card both with

export SDL_FBDEV=/dev/fb0 and
export SDL_FBDEV=/dev/fb1

Try to do the following before launching it :
export SDL_VIDEODRIVER=fbcon
That’ll force the usage of the fbcon backend. My guess is that you’ll get a message like “unable to set video mode” or similar (that would be the sign of a problem in your framebuffer setup).

Stephane

9

I also set SDL_VIDEODRIVER=fbcon but the result is the same. One difference is that when i set SDL_FBDEV=/dev/fb1 the image of video card on AGP(fb2) is noised but nothing is on the video card PCI (fb2).
Maybe someone has resolved a problem like this?

thnks
Il Tue, 18 May 2004 17:09:58 +0200 (CEST)
Stephane Marchesin <stephane.marchesin at wanadoo.fr> scrisse:> > I have tried with testbitmap.c from SDL source package but use always the same video card both with

export SDL_FBDEV=/dev/fb0 and
export SDL_FBDEV=/dev/fb1

Try to do the following before launching it :
export SDL_VIDEODRIVER=fbcon
That’ll force the usage of the fbcon backend. My guess is that you’ll get a message like “unable to set video mode” or similar (that would be the sign of a problem in your framebuffer setup).

Stephane

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10

Devel wrote:

I also set SDL_VIDEODRIVER=fbcon but the result is the same. One difference is that when i set SDL_FBDEV=/dev/fb1 the image of video card on AGP(fb2) is noised but nothing is on the video card PCI (fb2).
Maybe someone has resolved a problem like this?

Hmm, if your video cards are fb1 and fb2, you should set SDL_FBDEV to
/dev/fb1 and /dev/fb2…
Are you able to use your video cards separately or at the same time
using the fb tools ?

Stephane

11

Il Wed, 19 May 2004 13:27:05 +0200
Stephane Marchesin <stephane.marchesin at wanadoo.fr> scrisse:

Devel wrote:

I also set SDL_VIDEODRIVER=fbcon but the result is the same. One difference is that when i set SDL_FBDEV=/dev/fb1 the image of video card on AGP(fb2) is noised but nothing is on the video card PCI (fb2).
Maybe someone has resolved a problem like this?

Hmm, if your video cards are fb1 and fb2, you should set SDL_FBDEV to
/dev/fb1 and /dev/fb2…
Are you able to use your video cards separately or at the same time
using the fb tools ?
No. On the second fb i see nothing!
Maybe the fb tools can help me?>

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12

Devel wrote:

Il Wed, 19 May 2004 13:27:05 +0200
Stephane Marchesin <@Stephane_Marchesin> scrisse:

Devel wrote:

I also set SDL_VIDEODRIVER=fbcon but the result is the same. One difference is that when i set SDL_FBDEV=/dev/fb1 the image of video card on AGP(fb2) is noised but nothing is on the video card PCI (fb2).
Maybe someone has resolved a problem like this?

Hmm, if your video cards are fb1 and fb2, you should set SDL_FBDEV to
/dev/fb1 and /dev/fb2…
Are you able to use your video cards separately or at the same time
using the fb tools ?

No. On the second fb i see nothing!
Maybe the fb tools can help me?

Do you mean that’s an fb configuration problem ?

If so, well, fb is complex to set up on two screens. There are some
guidelines to follow :

  • load the *fb.o modules in the correct order. That means first load the
    module for the first card (the one used for boot), then the module for
    the second
  • IIRC, nvidia cards have to be loaded first (that means you also have
    to use the nvidia card to boot)

Plus there can be a ton of reasons it wouldn’t work even on a single
screen setup : you might want to experiment using the simple fbset
command (man fbset for more info). I also sometimes experiment with
fbview (image viewer for the framebuffer).

Anyway, fb questions would better be asked on an fb mailing list, as
you’re likely to get more answers there.

Stephane