Hi Adrian, On Thursday 18 December 2008, Adrian Sergiu DARABANT wrote: > Hi Laurent, hi all > 1) In fact I would be interested in a MJPEG camera with more than 1600x1200 > resolution. Even if a bit more expensive than usual consumer cameras. The > problem I guess is that econding in jpeg requires processing power which is > not availble on the low end hardware.
I haven't come across such a camera yet, which of course doesn't mean one doesn't exist. Please keep me informed if you find such a camera. > 2) Regarding the flip there are a few things to notice > a) I implemented mine in the video window just before display (display > using SDL) > b) I am using a software buffer which is directly given to the driver. The > horiz flip is done without copy - in place (in place 4 bytes on each swap > operation for yuv422 - byte by byte) which yields something around > 800x600x2 bytes swapped. > c) I am not using hardware buffers (video memory) as that one is slow > reading. > > Given this when streaming at 800x600 (aprox 10-15 grames/sec never measured > it exactly) I get 95% idle processor time and around 93%-94% (with flip > activated) on a pentium IV celeron at 2.4Ghz ( a low end machine). The > figures don't change when streaming at 1600x1200 as I get half only the > frames count/sec anyway which is just about the sama data quantity. Thanks for the information. Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
