Hi; I've gotten a little positive and no negative feedback on the changes I made to PWC (posted a couple weeks ago). I'd like to submit my changes to the code base. Would this be the forum for doing so?
To recapitulate, my goal was to reduce the latency which occurs when snapshots are taken. Prior to my modification, the oldest frame in the buffer list would be returned. I have added an ioctl mode which causes the youngest frame to be returned instead, and the older frames to be discarded. I also implemented another ioctl mode which waits until a frame is finished being captured before returning, allowing one to sync to the camera's clock, rather than trying to work the other way around. This is independent of the existing sync ioctl used in mmap operations and can be used whether actually reading a frame or not. In the process of implementing these changes, I believe I significantly improved the frame buffer handling. both by simplifying it and thus making it possible to run faster on slower hardware. I have tested these changes on Intel PC's (both AMD and an Intel mini-ITX), and on an ARM-9 sbc. I have only tested them with a Philips 900NC camera, but nothing I did should affect other devices so far as I can see. I modified three files: pwc.h, pwc-if.c and pwc-v4l.c. A tarball of the modified code set can be obtained from: http://cunningham.homeip.net/code.html Regards, --Jeff Cunningham > > _______________________________________________ pwc mailing list [email protected] http://lists.saillard.org/mailman/listinfo/pwc
