# Ubuntu Linux + Octave **URL:** \ **Category:** Uncategorized\ **Created:** [February 27, 2007, 11:54am UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781 "2007-02-27T11:54:26Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![sheitmann](https://avatars.discourse-cdn.com/v4/letter/s/8c91f0/32.png) [@sheitmann](https://psychtoolbox.discourse.group/u/sheitmann)\ **Post date:** [February 27, 2007, 11:54am UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781/1 "2007-02-27T11:54:26Z")
Hi, I'm trying to get Psychtoolbox running under Ubuntu Linux and octave. I am nearly there, but not quite. I seem to be missing some X11 configuration, as shown here. octave:2\> DrawSomeTextDemo PTB-WARNING: Couldn't enable AUX buffers on onscreen window due to limitations of your gfx-hardware or driver. Some features may be disabled or limited... PTB-ERROR[glXChooseVisual() failed]: Couldn't get any suitable visual from X-Server. PTB-ERROR[Low-Level setup of window failed]:The specified display may not support double buffering and/or stereo output. There could be insufficient video memory Does anybody happen to know what I'm missing? I'm loading the following X11 modules in /etc/X11/xorg.conf Section "Module" Load "i2c" Load "bitmap" Load "ddc" Load "dri" Load "extmod" Load "freetype" Load "int10" Load "type1" Load "vbe" Load "dbe" # Double-buffering extension Load "glx" # 3D layer Load "dri" # Direct Rendering Support EndSection Section "DRI" Mode 0666 EndSection Apart from the standard Ubuntu (6.06 LTS) packages, I am using octave-2.1.73, libdc1394-2.0.0-pre7, libraw1394-1.2.0 and the psychtoolbox source code from the head of the beta tree svn://svn.berlios.de/osxptb/beta ---
**Author:** ![kjmacken](https://avatars.discourse-cdn.com/v4/letter/k/839c29/32.png) [@kjmacken](https://psychtoolbox.discourse.group/u/kjmacken)\ **Post date:** [February 27, 2007, 6:08pm UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781/2 "2007-02-27T18:08:39Z")
Which driver are you using for the video card? If you are using the "vesa" driver - you will not have buffering enabled. Also, if using an nvidia card, make sure you have the proprietary nvidia kernel modules installed instead of the "nv" driver. Could you forward your entire xorg.conf file? Kevin Stewart Heitmann wrote: > \> > \> Hi, > \> I'm trying to get Psychtoolbox running under Ubuntu Linux and octave. > \> I am nearly there, but not quite. I seem to be missing some X11 > \> configuration, as shown here. > \> > \> octave:2\> DrawSomeTextDemo > \> PTB-WARNING: Couldn't enable AUX buffers on onscreen window > \> due to limitations of your gfx-hardware or driver. Some > \> features may be disabled or limited... > \> > \> PTB-ERROR[glXChooseVisual() failed]: Couldn't get any suitable > \> visual from X-Server. > \> > \> PTB-ERROR[Low-Level setup of window failed]:The specified > \> display may not support double buffering and/or stereo output. > \> There could be insufficient video memory > \> > \> Does anybody happen to know what I'm missing? > \> > \> I'm loading the following X11 modules in /etc/X11/xorg.conf > \> Section "Module" > \> Load "i2c" > \> Load "bitmap" > \> Load "ddc" > \> Load "dri" > \> Load "extmod" > \> Load "freetype" > \> Load "int10" > \> Load "type1" > \> Load "vbe" > \> Load "dbe" # Double-buffering extension > \> Load "glx" # 3D layer > \> Load "dri" # Direct Rendering Support > \> EndSection > \> > \> Section "DRI" > \> Mode 0666 > \> EndSection > \> > \> Apart from the standard Ubuntu (6.06 LTS) packages, I am using > \> octave-2.1.73, libdc1394-2.0.0-pre7, libraw1394-1.2.0 and the > \> psychtoolbox source code from the head of the beta tree > \> svn://svn.berlios.de/osxptb/beta \ > \> > \> ---
**Author:** ![simon.barthelme](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@simon.barthelme](https://psychtoolbox.discourse.group/u/simon.barthelme)\ **Post date:** [February 28, 2007, 9:50am UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781/3 "2007-02-28T09:50:18Z")
Hi, Could you please post the output of the "glxinfo" command ? There could be a hint in there. Thanks, Simon Barthelmé Stewart Heitmann a écrit : > \> > \> Hi, > \> I'm trying to get Psychtoolbox running under Ubuntu Linux and octave. > \> I am nearly there, but not quite. I seem to be missing some X11 > \> configuration, as shown here. > \> > \> octave:2\> DrawSomeTextDemo > \> PTB-WARNING: Couldn't enable AUX buffers on onscreen window > \> due to limitations of your gfx-hardware or driver. Some > \> features may be disabled or limited... > \> > \> PTB-ERROR[glXChooseVisual() failed]: Couldn't get any suitable > \> visual from X-Server. > \> > \> PTB-ERROR[Low-Level setup of window failed]:The specified > \> display may not support double buffering and/or stereo output. > \> There could be insufficient video memory > \> > \> Does anybody happen to know what I'm missing? > \> > \> I'm loading the following X11 modules in /etc/X11/xorg.conf > \> Section "Module" > \> Load "i2c" > \> Load "bitmap" > \> Load "ddc" > \> Load "dri" > \> Load "extmod" > \> Load "freetype" > \> Load "int10" > \> Load "type1" > \> Load "vbe" > \> Load "dbe" # Double-buffering extension > \> Load "glx" # 3D layer > \> Load "dri" # Direct Rendering Support > \> EndSection > \> > \> Section "DRI" > \> Mode 0666 > \> EndSection > \> > \> Apart from the standard Ubuntu (6.06 LTS) packages, I am using > \> octave-2.1.73, libdc1394-2.0.0-pre7, libraw1394-1.2.0 and the > \> psychtoolbox source code from the head of the beta tree > \> svn://svn.berlios.de/osxptb/beta \ > \> > \> ---
**Author:** ![sheitmann](https://avatars.discourse-cdn.com/v4/letter/s/8c91f0/32.png) [@sheitmann](https://psychtoolbox.discourse.group/u/sheitmann)\ **Post date:** [February 28, 2007, 10:09am UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781/4 "2007-02-28T10:09:00Z")
Simon Barthelmé wrote: > \> Could you please post the output of the "glxinfo" command ? There could > \> be a hint in there. Sure, here it is: name of display: :0.0 display: :0 screen: 0 direct rendering: Yes server glx vendor string: SGI server glx version string: 1.2 server glx extensions: GLX\_ARB\_multisample, GLX\_EXT\_visual\_info, GLX\_EXT\_visual\_rating, GLX\_EXT\_import\_context, GLX\_OML\_swap\_method, GLX\_SGI\_make\_current\_read, GLX\_SGIS\_multisample, GLX\_SGIX\_hyperpipe, GLX\_SGIX\_swap\_barrier, GLX\_SGIX\_fbconfig client glx vendor string: SGI client glx version string: 1.4 client glx extensions: GLX\_ARB\_get\_proc\_address, GLX\_ARB\_multisample, GLX\_EXT\_import\_context, GLX\_EXT\_visual\_info, GLX\_EXT\_visual\_rating, GLX\_MESA\_allocate\_memory, GLX\_MESA\_swap\_control, GLX\_MESA\_swap\_frame\_usage, GLX\_OML\_swap\_method, GLX\_OML\_sync\_control, GLX\_SGI\_make\_current\_read, GLX\_SGI\_swap\_control, GLX\_SGI\_video\_sync, GLX\_SGIS\_multisample, GLX\_SGIX\_fbconfig, GLX\_SGIX\_pbuffer, GLX\_SGIX\_visual\_select\_group, GLX\_EXT\_texture\_from\_pixmap GLX version: 1.2 GLX extensions: GLX\_ARB\_get\_proc\_address, GLX\_ARB\_multisample, GLX\_EXT\_import\_context, GLX\_EXT\_visual\_info, GLX\_EXT\_visual\_rating, GLX\_MESA\_swap\_control, GLX\_MESA\_swap\_frame\_usage, GLX\_OML\_swap\_method, GLX\_SGI\_make\_current\_read, GLX\_SGI\_video\_sync, GLX\_SGIS\_multisample, GLX\_SGIX\_fbconfig OpenGL vendor string: VA Linux Systems Inc. OpenGL renderer string: Mesa DRI G400 20050609 AGP 4x OpenGL version string: 1.2 Mesa 6.4.1 OpenGL extensions: GL\_ARB\_multisample, GL\_ARB\_multitexture, GL\_ARB\_texture\_compression, GL\_ARB\_texture\_env\_add, GL\_ARB\_texture\_env\_combine, GL\_ARB\_texture\_env\_crossbar, GL\_ARB\_texture\_rectangle, GL\_ARB\_transpose\_matrix, GL\_ARB\_vertex\_program, GL\_ARB\_window\_pos, GL\_EXT\_abgr, GL\_EXT\_bgra, GL\_EXT\_blend\_logic\_op, GL\_EXT\_clip\_volume\_hint, GL\_EXT\_compiled\_vertex\_array, GL\_EXT\_copy\_texture, GL\_EXT\_draw\_range\_elements, GL\_EXT\_fog\_coord, GL\_EXT\_multi\_draw\_arrays, GL\_EXT\_packed\_pixels, GL\_EXT\_polygon\_offset, GL\_EXT\_rescale\_normal, GL\_EXT\_secondary\_color, GL\_EXT\_separate\_specular\_color, GL\_EXT\_stencil\_wrap, GL\_EXT\_subtexture, GL\_EXT\_texture, GL\_EXT\_texture3D, GL\_EXT\_texture\_edge\_clamp, GL\_EXT\_texture\_env\_add, GL\_EXT\_texture\_env\_combine, GL\_EXT\_texture\_object, GL\_EXT\_texture\_rectangle, GL\_EXT\_vertex\_array, GL\_APPLE\_packed\_pixels, GL\_ATI\_texture\_env\_combine3, GL\_IBM\_rasterpos\_clip, GL\_MESA\_ycbcr\_texture, GL\_MESA\_window\_pos, GL\_NV\_light\_max\_exponent, GL\_NV\_texture\_rectangle, GL\_NV\_texgen\_reflection, GL\_NV\_vertex\_program, GL\_NV\_vertex\_program1\_1, GL\_OES\_read\_format, GL\_SGIS\_generate\_mipmap, GL\_SGIS\_texture\_edge\_clamp, GL\_SGIS\_texture\_lod, GL\_SUN\_multi\_draw\_arrays glu version: 1.3 glu extensions: GLU\_EXT\_nurbs\_tessellator, GLU\_EXT\_object\_space\_tess visual x bf lv rg d st colorbuffer ax dp st accumbuffer ms cav id dep cl sp sz l ci b ro r g b a bf th cl r g b a ns b eat ---------------------------------------------------------------------- 0x23 24 tc 0 24 0 r y . 8 8 8 0 0 0 0 0 0 0 0 0 0 None 0x24 24 tc 0 24 0 r . . 8 8 8 0 0 0 0 0 0 0 0 0 0 None 0x25 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x26 24 tc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x27 24 tc 0 24 0 r y . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow 0x28 24 tc 0 24 0 r . . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow 0x29 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x2a 24 tc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x2b 24 dc 0 24 0 r y . 8 8 8 0 0 0 0 0 0 0 0 0 0 None 0x2c 24 dc 0 24 0 r . . 8 8 8 0 0 0 0 0 0 0 0 0 0 None 0x2d 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x2e 24 dc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x2f 24 dc 0 24 0 r y . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow 0x30 24 dc 0 24 0 r . . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow 0x31 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x32 24 dc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow -- Stewart Heitmann ---
**Author:** ![mariokleiner](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@mariokleiner](https://psychtoolbox.discourse.group/u/mariokleiner)\ **Post date:** [March 4, 2007, 6:43pm UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781/5 "2007-03-04T18:43:16Z")
Just set the pixelSize argument in Screen('OpenWindow',...) to 16 and you should be done. PTB requests an 8 bit alpha channel, which your gfx-card doesn't provide, that's why it fails. If you set pixelSize to 16, PTB will do without an alpha channel, but still use the RGB8 24 bpp color buffer. As long as you don't need complex alpha blending (e.g., like in gaze contingent displays) it should be fine. The gfx-performance of the G450 is about one third of the Geforce-2, roughly the state of the art from 8 years ago. But for the stimuli you describe it should do. -mario > --- In [psychtoolbox@yahoogroups.com](mailto:psychtoolbox@yahoogroups.com), Stewart Heitmann \ wrote: > \> > \> Well I'm getting nowhere with my matrox driver. > \> I have it configured for a 32bpp framebuffer... > \> > \> (--) MGA(0): Chipset: "mgag400" (G450) > \> (II) MGA(0): Creating default Display subsection in Screen section > \> "Screen1" for depth/fbbpp 24/32 > \> (--) MGA(0): Depth 24, (\*\*) framebuffer bpp 32 > \> (==) MGA(0): RGB weight 888 > \> (\*\*) MGA(0): Option "AGPMode" "4" > \> (\*\*) MGA(0): Using AGP 4x mode > \> > \> ...but Screen('OpenWindow',0) still fails to get any suitable visual > \> from the X-Server. > \> > \> PTB-WARNING: Couldn't enable AUX buffers on onscreen window due > \> to limitations of your gfx-hardware or driver. Some features may > \> be disabled or limited... > \> > \> PTB-ERROR[glXChooseVisual() failed]: Couldn't get any suitable > \> visual from X-Server. > \> > \> PTB-ERROR[Low-Level setup of window failed]:The specified display > \> may not support double buffering and/or stereo output. There could > \> be insufficient video memory > \> > \> I also get the same problem at lower screen resolutions, so I dont think > \> its just a matter of insufficient memory. > \> > \> As for the Matrix driver configuration, the mga driver will not accept > \> a colour depth greater than 24. > \> The driver manual is adamant that a colour depth of 32 is meaningless > \> although it does permit a 32bpp framebuffer depth, wherein (I presume) > \> that it regards the fourth byte of each pixel as unused padding. > \> > \> I presume this depth/fbbpp 24/32 setup is what PTB requires (correct?). > \> > \> Even with a 32bpp framebuffer, glxinfo reports only 24 bit depth. > \> > \> visual x bf lv rg d st colorbuffer ax dp st accumbuffer ms cav > \> id dep cl sp sz l ci b ro r g b a bf th cl r g b a ns b eat > \> ---------------------------------------------------------------------- > \> 0x23 24 tc 0 24 0 r y . 8 8 8 0 0 0 0 0 0 0 0 0 0 None > \> 0x24 24 tc 0 24 0 r . . 8 8 8 0 0 0 0 0 0 0 0 0 0 None > \> 0x25 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None > \> 0x26 24 tc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None > \> 0x27 24 tc 0 24 0 r y . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow > \> 0x28 24 tc 0 24 0 r . . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow > \> 0x29 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow > \> 0x2a 24 tc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow > \> 0x2b 24 dc 0 24 0 r y . 8 8 8 0 0 0 0 0 0 0 0 0 0 None > \> 0x2c 24 dc 0 24 0 r . . 8 8 8 0 0 0 0 0 0 0 0 0 0 None > \> 0x2d 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None > \> 0x2e 24 dc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None > \> 0x2f 24 dc 0 24 0 r y . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow > \> 0x30 24 dc 0 24 0 r . . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow > \> 0x31 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow > \> 0x32 24 dc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow > \> > \> I am new to Matlab, Octave, and PTB, so I'm uncertain as to what PTB > \> is needing from my driver config that I'm not giving it. > \> > \> Is there anything obvious wrong with my configuration? > \> If not then I'll try it with an NVidia card. > \> > \> My stimuli will be 2D dot fields, oscillating back and forth every > \> second. Nothing 3D. I dont imagine it would require a whizz-bang > \> graphics card. > \> -- > \> Stewart Heitmann > \> > \> > \> But > \> \> spending 100-150$ on a up to date NVidia card will be worth the money if you do > more > \> \> complex stims. > \> \> > \> \> What kind of stimuli do you use? > \> \> > \> \> -mario > \> ---
**Author:** ![sheitmann](https://avatars.discourse-cdn.com/v4/letter/s/8c91f0/32.png) [@sheitmann](https://psychtoolbox.discourse.group/u/sheitmann)\ **Post date:** [March 4, 2007, 11:04pm UTC](https://psychtoolbox.discourse.group/t/ubuntu-linux-octave/1781/6 "2007-03-04T23:04:05Z")
Got it, thanks! -- Stewart Heitmann Mario Kleiner wrote: > \> Just set the pixelSize argument in Screen('OpenWindow',...) to 16 and you should be done. > \> PTB requests an 8 bit alpha channel, which your gfx-card doesn't provide, that's why it > \> fails. If you set pixelSize to 16, PTB will do without an alpha channel, but still use the RGB8 > \> 24 bpp color buffer. As long as you don't need complex alpha blending (e.g., like in gaze > \> contingent displays) it should be fine. > \> > \> The gfx-performance of the G450 is about one third of the Geforce-2, roughly the state of > \> the art from 8 years ago. But for the stimuli you describe it should do. > \> > \> -mario