On Friday 16 July 2010 01:55:01 P F wrote: > Hi, > > --- On Fri, 7/9/10, P F <public_fil...@yahoo.com> wrote: > > I have ordered a camera which uses the gspca driver (Logitech QuickCam > > Communicate STX), so hopefully that should give me something to compare > > against. The gscpa maintainer long ago noted memory corruption on ARM > > platforms > > (http://sourceforge.net/mailarchive/forum.php?thread_name=200512301104.1 > > 3088.mxhaard%40magic.fr&forum_name=spca50x-devs), so maybe he will have > > some insight. > > I received the non-UVC Logitech camera (it uses gspca_zc3xx) and re-ran my > tests. It experiences corruption identical to the two UVC cameras. > > In trying to better understand the corruption, I split a corrupted JPEG > into 3 grayscale PNMs consisting of its 3-components (Y, Cb, Cr). > Interestingly, each component shows corruption, they all start at the same > macroblock, and the corruption manifestation is slightly different in each > component. To me it seems there is a pattern.
Could you try to modify the userspace application to mmap buffers only right before reading from them (after VIDIOC_DQBUF) and unmap them when you're done (before requeuing the buffer with VIDIOC_QBUF) ? -- Regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
