[Libva] Running libva applications without X

[Mark Phelan]

Gwenole Beauchesne <gb.devel at ...> writes:
> 
> Hi,
> 
> 2013/4/13 Jonathan Haws <Jonathan.Haws at ...>:
> 
> > However, I don't have X setup or configured since I don't need it or 
want it.  Is there a way around this?  Is
> there a way I can get X configured solely to provide me with this?  Can I 
simply pass a NULL pointer to this (I
> would doubt it)? I don't want to do any sort of displaying of the video - 
just decoding.
> >
> > Are there better ways to do this?  Am I on the right track?  How can I 
get my headless system ready to use VAAPI
> without a full blown window manager?
> 
> You need to look into the VA/DRM API. I think I had sample code set in
> place in hwdecode-demos (vo_drm.c). This will work as long as you
> don't have an X server running and that you don't expect several users
> to do the same thing at the same time, i.e. access to the HW.
> 
> It's very simple, you just need to create a VA display with
> vaGetDisplayDRM() instead of vaGetDisplay() used for X11. In the
> former case, you pass on a file descriptor to an open GPU device.
> Either you use libudev to determine the correct device path, or you
> have a consistent system and you could just open /dev/dri/card0
> instead.
> 
> Regards,
> Gwenole.
> 

Sorry to highjack this thread, but I'm trying to do the same thing and since 
there aren't many of us out there, I figured this would be as good a place 
as any to ask. I'm fairly new to all this, but have spent the last month 
reading up extensively.  Hopefully someone can help me.

I got vaGetDisplayDRM() to work and the returned display is passed into 
vaInitialize().  However, I want 4 of the same application running, and 
vaInitialize() fails on the 2-4 instances.  I had the 4 instances all 
running well using X11 and vaGetDisplay, so I'm very confident this has 
something to do with the switch to not using X11.

a section of the code: 
#ifdef HEADLESS_MODE
   //for headless (no X11)
   int drm_device = -1;
   drm_device = open(DRM_DEVICE_PATH, O_RDWR|O_CLOEXEC);
   std::cout << "mtp:: drm_device= " << drm_device << std::endl;
   if(drm_device < 0)
   {
       std::cout << "mtp:: GPU device not found...Exiting" << std::endl;
       exit(-1);
   }
   mVADisplay = vaGetDisplayDRM(drm_device);
   if(!mVADisplay)
       std::cout << "mtp:: Not a valid display" << std::endl;
   close(drm_device);
   if(!mVADisplay)
       std::cout << "mtp:: Not a valid display::2nd" << std::endl;
#else
   //for X11 use
   mX11Display = XOpenDisplay(":0.0");
   assert(mX11Display);
   mVADisplay = vaGetDisplay(mX11Display);
#endif


   mVAStatus = vaInitialize(mVADisplay, &maj, &min);
   checkVAStatus("vaInitialize");

Thanks for any help anyone can provide!