Hi! > > On Nokia N900, I have similar problems as Intel IPU3 hardware. > > > > Meeting notes say that pure software implementation is not fast > > enough, but that it may be useful for debugging. It would be also > > useful for me on N900, and probably useful for processing "raw" images > > from digital cameras. > > > > There is sensor part, and memory-to-memory part, right? What is > > the format of data from the sensor part? What operations would be > > expensive on the CPU? If we did everthing on the CPU, what would be > > maximum resolution where we could still manage it in real time? > > We can still use the memory-to-memory part (IMGU), even without 3A. It > would just do demosaicing at default parameters and give us a YUV > (NV12) frame. We could use some software component to analyze the YUV > output and adjust sensor parameters accordingly. Possibly the part we > already have in libv4l2 could just work? As soon as you get YUV, yes, libv4l2 should be able to work with that. OTOH using the memory-to-memory part is going to be tricky. What format is the data before demosaicing? Something common like BGGR10? > The expensive operation would be analyzing the frame itself. I suppose > you need to build some histogram representing brightness and white > balance of the frame and then infer necessary sensor adjustments from > that. That does not really have to be expensive. You can sample ... say 10000 pixels from the image, and get good-enough data for 3A. > > Would it be possible to get access to machine with IPU3, or would > > there be someone willing to test libv4l2 patches? > > I should be able to help with some basic testing, preferably limited > to command line tools (but I might be able to create a test > environment for X11 tools if really necessary). Could you just compile libv4l2 with sdlcam demo on the target, and then ssh -X there from some sort of reasonable system? Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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