>Guennadi Liakhovetski <g.liakhovetski@xxxxxx> wrote: >On Thu, 27 May 2010, Pawel Osciak wrote: > >> Hi, >> >> >Guennadi Liakhovetski wrote: >> > >> >No idea whether this is a worthy and suitable topic for this meeting, but: >> > >> >V4L(2) video output vs. framebuffer. >> > >> >How about a v4l2-output - fbdev translation layer? You write a v4l2-output >> >driver and get a framebuffer device free of charge... TBH, I haven't given >> >this too much of a thought, but so far I don't see anything that would >> >make this impossible in principle. The video buffer management is quite >> >different between the two systems, but maybe we can teach video-output >> >drivers to work with just one buffer too? Anyway, feel free to tell me why >> >this is an absolutely impossible / impractical idea;) >> >> We also use v4l2-outputs for our display interfaces and for that we have >> v4l2-subdevices in a framebuffer driver. Although we have had no need for >> such a translation layer per se up to now, the idea seems interesting. > >Interesting, but sorry, don't quite understand "we use v4l2-outputs" and >"in a framebuffer driver" - so, is it a framebuffer (/dev/fbX) or a v4l2 >output device driver or both? Which driver is this? Is it already in the >mainline? > It's the (mostly) standard s3c-fb driver with a v4l2-subdev video interface added. A separate v4l2 output device driver uses that interface to communicate with the framebuffer driver, as some setup is required on both parts. Those operations cannot be performed from userspace as they have to be synchronized in interrupts. Best regards -- Pawel Osciak Linux Platform Group Samsung Poland R&D Center -- 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
