On Thu, 2002-03-21 at 14:10, Joe Burks wrote: > There are a lot of good reasons for a camera *NOT* to do all the filtering in > firmware. And for exactly that reason, you shouldn't do it in a base lib as well, but let the application find a suitable way of doing it, as it feels like doing itself. See Alan's response. > How is it done now? The reccomendation I saw was "we could just let xv do > it". How many apps are perfectly happy to let xv manipulate their images for > display? How many people don't have Xv? I don't (nvidia's XFree driver doesn't do Xv and I don't want to run nvidia.com's driver). Other people feel fine with it. Hence my point, everyone's needs are different! > How many current v4l applications support gamma correction? How do I express > the need for this sort of post processing to the v4l application? Why aren't > the application developers pumping out more v4l apps with advanced post > processing capabilities? How about obvious postprocessing tasks like > rotation? It's pretty easy to rotate a camera 90 degrees to get better scene > composition, few v4l apps have that feature. Heck my live webcam is > mounted to a bracket on the ceiling, that image needs 180 degrees of > rotation. If I wanted to stream live video from that camera, it'd look > horrible. So, if it isn't there, hack it in the applications. But don't let the driver or quasi-driver (libv4l) do it. What about closedsource apps (not that we care) that have terribly fast asm/mmx/sse-algorithms (but proprietary). Should we just make their live impossible? > If we would want the application to have the option of saying "give me an > unfiltered video stream", I have no problem with that. Then they could use > their own gamma, rescaling, contrast, whatever. But I'm going to bet > that few applications are going to make use of it. I base this on the fact > that the apps available now could do this and generally don't. Generally because they're all 1-man projects (or so). If there was one bigger project, I bet it'd be interested in doing their own post-capture filtering. So this is a pretty good idea (tm), imho. Ronald -- - .-. - /V\ | Ronald Bultje <rbultje@xxxxxxxxxxxxxxxxxxx> - // \\ | Running: Linux 2.4.18-XFS and OpenBSD 3.0 - /( )\ | http://ronald.bitfreak.net/ - ^^-^^
