Hi Stefan, On Monday 28 September 2009 16:04:58 Stefan.Kost@xxxxxxxxx wrote: > hi, > > >-----Original Message----- > >From: ext Laurent Pinchart [mailto:laurent.pinchart@xxxxxxxxxxxxxxxx] > >Sent: 16 September, 2009 18:47 > >To: linux-media@xxxxxxxxxxxxxxx; Hans Verkuil; Sakari Ailus; > >Cohen David.A (Nokia-D/Helsinki); Koskipaa Antti > >(Nokia-D/Helsinki); Zutshi Vimarsh (Nokia-D/Helsinki); Kost > >Stefan (Nokia-D/Helsinki) > >Subject: [RFC] Global video buffers pool > > > > Hi everybody, > > > > I didn't want to miss this year's pretty flourishing RFC > > season, so here's another one about a global video buffers pool. > > Sorry for ther very late reply. No worries, better late than never. > I have been thinking about the problem on a bit broader scale and see the > need for something more kernel wide. E.g. there is some work done from intel > for graphics: > http://keithp.com/blogs/gem_update/ > > and this is not so much embedded even. If there buffer pools are > v4l2specific then we need to make all those other subsystems like xvideo, > opengl, dsp-bridges become v4l2 media controllers. The global video buffers pool topic has been discussed during the v4l2 mini- summit at Portland last week, and we all agreed that it needs more research. The idea of having pools at the media controller level has been dropped in favor of a kernel-wide video buffers pool. Whether we can make the buffers pool not v4l2-specific still needs to be tested. As you have pointed out, we currently have a GPU memory manager in the kernel, and being able to interact with it would be very interesting if we want to DMA video data to OpenGL texture buffers for instance. I'm not sure if that would be possible though, as the GPU and the video acquisition hardware might have different memory requirements, at least in the general case. I will contact the GEM guys at Intel to discuss the topic. If we can't share the buffers between the GPU and the rest of the system, we could at least create a V4L2 wrapper on top of the DSP bridge core (which will require a major cleanup/restructuring), making it possible to share video buffers between the ISP and the DSP. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
