[vlc] Trying to use AssignNVidiaAffinity to assign OpenGL a specific graphics card

[David R Robison]

I've come close. Here is the code I used to assign the nVidia affinity

#undef wglEnumGpusNV
#undef wglCreateAffinityDCNV
static PFNWGLENUMGPUSNVPROC wglEnumGpusNV;
static PFNWGLCREATEAFFINITYDCNVPROC wglCreateAffinityDCNV;

static void AssignNVidiaAffinity(vout_display_t *vd, UINT nVidiaAffinity) {

     // initialize the wgl context
     if (wglEnumGpusNV == NULL) {
         msg_Dbg(vd, "Initialize wgl context" );
         HDC winDC = GetDC(vd->sys->hvideownd);
         PIXELFORMATDESCRIPTOR pfd;
         memset(&pfd, 0, sizeof(pfd));
         pfd.nSize = sizeof(pfd);
         pfd.nVersion = 1;
         pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | 
PFD_DOUBLEBUFFER;
         pfd.iPixelType = PFD_TYPE_RGBA;
         pfd.cColorBits = 24;
         pfd.cDepthBits = 16;
         pfd.iLayerType = PFD_MAIN_PLANE;
         SetPixelFormat(winDC, ChoosePixelFormat(winDC, &pfd), &pfd);
         HGLRC hGLRC = wglCreateContext(winDC);
         wglMakeCurrent(winDC, hGLRC);
         wglEnumGpusNV = 
(PFNWGLENUMGPUSNVPROC)wglGetProcAddress("wglEnumGpusNV");
         wglCreateAffinityDCNV = 
(PFNWGLCREATEAFFINITYDCNVPROC)wglGetProcAddress("wglCreateAffinityDCNV");
         wglDeleteContext(hGLRC);
     }

     // see if we have the extensions
     if (!wglEnumGpusNV || !wglCreateAffinityDCNV) {
         msg_Dbg(vd, "OpenGL nVidia extensions do not seem to be present" );
         return;
     }

     // find the graphics card
     HGPUNV GpuMask[2];
     GpuMask[0] = NULL;
     GpuMask[1] = NULL;
     HGPUNV hGPU;
     if (!wglEnumGpusNV(nVidiaAffinity, &hGPU)) {
         msg_Warn(vd, "Could not enumerate nVidia adapter %d", 
nVidiaAffinity );
      return;
     }

     // make the new context
     GpuMask[0] = hGPU;
     vd->sys->hGLDC = wglCreateAffinityDCNV(GpuMask);
}

This is called in the glwin32.c program as

     // process card specific affinities
     int nVidiaAffinity = var_InheritInteger(vd, "nvidia-affinity");
     if (nVidiaAffinity >= 0) {
         msg_Dbg(vd, "nVidia affinity using adapter %d", nVidiaAffinity );
         AssignNVidiaAffinity(vd, nVidiaAffinity);
     }

     /*
      * use default card affinity
      */
     if (sys->hGLDC == NULL) sys->hGLDC = GetDC(sys->hvideownd);

It works, in the since that I can select the card and see the card's 
memory and activity increase, but it plays no video. I'm not sure what 
I'm doing wrong, but I guess there is more investigation on my part that 
is needed. Any thoughts?
David

David R Robison
Open Roads Consulting, Inc.
103 Watson Road, Chesapeake, VA 23320
phone: (757) 546-3401
e-mail: drrobison at openroadsconsulting.com
web: http://openroadsconsulting.com
blog: http://therobe.blogspot.com
book: http://www.xulonpress.com/bookstore/bookdetail.php?PB_ISBN=9781597816526

On 8/21/2013 4:51 AM, Jean-Baptiste Kempf wrote:
> On 13 Aug, David R Robison wrote :
>> Has anyone attempted this before? Any thoughts on what I may be doing
>> wrong? We are running under Windows 7.
> Did you fix it, in the end?
>
> Best regards,
>



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