[directfb-users] Re: YUY2 video + RGBA osd alpha blending

[Claudio \"KLaN\" Ciccani]

Stefan Lucke wrote:

Hi,

I'm trying to blend and osd with alpha over an yuy2 video source.
Drawing is done with this:
     fprintf (stderr, "now stretch\n");
     //screen->Clear(0,0,0,0xff);
     //screen->SetBlittingFlags(DSBLIT_BLEND_ALPHACHANNEL);
     screen->SetBlittingFlags(DSBLIT_NOFX);
     screen->StretchBlit(videoSurface, &src, &dst);

//      if (osdActive)
     {
       fprintf (stderr, "now osd blit\n");
       //screen->SetBlittingFlags(DSBLIT_NOFX);
       screen->SetBlittingFlags(DSBLIT_BLEND_ALPHACHANNEL);
       //screen->SetBlittingFlags(DSBLIT_BLEND_COLORALPHA);
       screen->Blit(osdSurface, NULL, 0, 0);//&src, &dst);
     }

     fprintf (stderr, "now flip\n");
     screen->Flip();
     fprintf (stderr, "now done\n");

Surfaces are allocated by:
 dsc.flags = (DFBSurfaceDescriptionFlags) (DSDESC_CAPS |
                                           DSDESC_PIXELFORMAT);
 dsc.caps = DSCAPS_NONE;
 DFB_ADD_SURFACE_CAPS(dsc.caps, DSCAPS_FLIPPING);
 DFB_ADD_SURFACE_CAPS(dsc.caps, DSCAPS_PRIMARY);
 DFB_ADD_SURFACE_CAPS(dsc.caps, DSCAPS_VIDEOONLY);
 dsc.pixelformat = DSPF_ARGB;

 osdSurface   = dfb->CreateSurface (dsc);
 screen       = dfb->CreateSurface (dsc);

The problem is that the screen gets only updated once for a while when the osd is 
refreshed,
and only the area that is half transpararent is redrawn.
Graphic card is G550. DirectFB is v0.9.21.

--
Stefan Lucke

I assume that your program is written in C++ and you are using DFB++.

Do you flip the osd surface after drawing to it ?
Have you tried using C and DirectFB ?

Regards,
Claudio