Hi Guennadi, Thanks for your quick response. > ./capture-example -u -f -d /dev/video0 > mx3-camera mx3-camera.0: MX3 Camera driver attached to camera 0 > Failed acquiring VMA for vaddr 0x76cd9008 > VIDIOC_QBUF error 22, Invalid arg >> It doesn't surprise me, that this doesn't work. capture-example allocates >> absolutely normal user-space buffers, when called with USERPTR, and those >> buffers are very likely discontiguous. Whereas mx3-camera needs physically >> contiguous buffers, so, this can only fail. This means, you either have to >> use MMAP or you need to allocate USERPTR buffers in a special way to >> guarantee their contiguity. I have a little progress:-) In thread "i.mx35 live video" you and Sylvester gave me advice on how to get the live video with using the display panning method ... thanks for this invaluable support :-) I took note of this and I'm currently trying to implement this. Instead of discontiguous memory allocation I use framebuffer memory allocation to userspace and this solves the problem. Now I'm starting to see a live video for 3 seconds, after this video freezes (it looks like a flickering pause), but the application continues to run without errors. can see bellow my strace diagnostic: ioctl(3, VIDIOC_STREAMON, 0x7ece99f0) = 0 select(4, [3], NULL, NULL, {2, 0}) = 1 (in [3], left {1, 884508}) ioctl(3, VIDIOC_DQBUF, 0x7ece990c) = 0 ioctl(4, FBIOPAN_DISPLAY, 0x7ece9854) = 0 ioctl(3, VIDIOC_QBUF or VT_SETACTIVATE, 0x7ece990c) = 0 select(4, [3], NULL, NULL, {2, 0}) = 1 (in [3], left {1, 919066}) ioctl(3, VIDIOC_DQBUF, 0x7ece990c) = 0 ioctl(4, FBIOPAN_DISPLAY, 0x7ece9854) = 0 ioctl(3, VIDIOC_QBUF or VT_SETACTIVATE, 0x7ece990c) = 0 select(4, [3], NULL, NULL, {2, 0}) = 1 (in [3], left {1, 918928}) ioctl(3, VIDIOC_DQBUF, 0x7ece990c) = 0 ioctl(4, FBIOPAN_DISPLAY, 0x7ece9854) = 0 [snip] ioctl(3, VIDIOC_QBUF or VT_SETACTIVATE, 0x7ece990c) = 0 select(4, [3], NULL, NULL, {2, 0}) = 1 (in [3], left {1, 999987}) ioctl(3, VIDIOC_DQBUF, 0x7ece990c) = 0 ioctl(4, FBIOPAN_DISPLAY, 0x7ece9854) = 0 ioctl(3, VIDIOC_QBUF or VT_SETACTIVATE, 0x7ece990c) = 0 select(4, [3], NULL, NULL, {2, 0}) = 1 (in [3], left {1, 999988}) ioctl(3, VIDIOC_DQBUF, 0x7ece990c) = 0 ioctl(4, FBIOPAN_DISPLAY, 0x7ece9854) = 0 ioctl(3, VIDIOC_QBUF or VT_SETACTIVATE, 0x7ece990c) = 0 I do not understand what's the problem, maybe need to implement FBIO_WAITFORVSYNC ioctl for mx3fb ? Thanks, Alex -- 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