Hi Mauro, On Friday 17 August 2012 19:03:47 Mauro Carvalho Chehab wrote: > Em 17-08-2012 18:01, Sylwester Nawrocki escreveu: > > On 08/15/2012 11:09 PM, Laurent Pinchart wrote: > >> On Wednesday 15 August 2012 18:13:19 Sylwester Nawrocki wrote: > >>> On 08/15/2012 12:06 AM, Laurent Pinchart wrote: > >>>> On Tuesday 14 August 2012 18:37:23 Sylwester Nawrocki wrote: > >>>>> On 08/14/2012 03:04 PM, Mauro Carvalho Chehab wrote: > >>>>>> This one requires more testing: > >>>>>> > >>>>>> May,15 2012: [GIT,PULL,FOR,3.5] DMABUF importer feature in V4L2 API > >>>>>> > >>>>>> http://patchwork.linuxtv.org/patch/11268 Sylwester > >>>>>> Nawrocki > >>>>>> > >>>>>> <s.nawrocki@xxxxxxxxxxx> > >>>>> > >>>>> Hmm, this is not valid any more. Tomasz just posted a new patch series > >>>>> that adds DMABUF importer and exporter feature altogether. > >>>>> > >>>>> [PATCHv8 00/26] Integration of videobuf2 with DMABUF > >>>>> > >>>>> I guess we need someone else to submit test patches for other H/W than > >>>>> just Samsung SoCs. I'm not sure if we've got enough resources to port > >>>>> this to other hardware. We have been using these features internally > >>>>> for some time already. It's been 2 kernel releases and I can see only > >>>>> Ack tags from Laurent on Tomasz's patch series, hence it seems there > >>>>> is no wide interest in DMABUF support in V4L2 and this patch series is > >>>>> probably going to stay in a fridge for another few kernel releases. > >>>> > >>>> What would be required to push it to v3.7 ? > >>> > >>> Mauro requested more test coverage on that, which is understood since > >>> this is a fairly important API enhancement and the V4L2 video overlay > >>> API replacement. > >>> > >>> We need DMABUF support added at some webcam driver and a DRM driver with > >>> prime support (or some V4L2 output driver), I guess it would be best to > >>> have that in a PC environment. It looks like i915/radeon/nouveau drivers > >>> already have prime support. > >> > >> uvcvideo has recently been moved to videobuf2, using vb2_vmalloc. I can > >> easily test that, except that I have no idea how to export buffers on > >> the i915 side when X is running. Have you looked into that ? > > > > All right. Yes, I'm also not sure yet how to do it. I tried it on a laptop > > with i915 driver, but in the running system drmModeGetResources() just > > fails with EPERM. I've CCed dri-devel, so hopefully someone can shed some > > light on this. > > Likely, you need to run with root permission to use it, or to write an Xorg > driver. > > It is probably easier to get the V4L driver there, that uses the > VIDIOC_OVERLAY stuff, and make it work via DMABUF: > http://cgit.freedesktop.org/xorg/driver/xf86-video-v4l/ That won't really help for our test cases. I want to capture from a UVC device using DMABUF import directly to the i915 DRM device using DRM export. In order to do so I will need to get hold of GEM objects that I can use to display the data, possibly through the OpenGL API. I'm looking for help on that last point, I can easily handle the UVC capture code myself. > In order to test it, xawtv has already the code needed to talk with the v4l > plugin. > > What the plugin does is to export the video board as a XV extension, > accessible via xawtv. It currently talks with the display card also via XV, > but I believe it won't be hard to port it to work with DMABUF. > > As the interface between xawtv and the v4l plugin is just Xv, changing the > code there from VIDIOC_OVERLAY to DMABUF should be trivial. -- 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
