Le vendredi 15 juin 2007 à 23:08 +0200, Jiri Slaby a écrit : > Mauro Carvalho Chehab wrote: > > Em Sáb, 2007-06-02 à s 11:00 +0200, Thierry Merle escreveu: > > > > > > Mauro Carvalho Chehab a écrit : > > > >>> This seems to be an interesting approach. > > > >>> > > > >>> > > > >>> > > > >> Interesting but impossible to do for ioctl calls. > > > >> When the application does a > ioctl(fd_of_mnt_video0,VIDIOC_G_FMT,&arg) > > > >> for example, there is no way for the userspace helper to catch > this ioctl. > > > >> The application could only open/read from the userspace > helper's file > > > >> /mnt/video0. > > > >> ioctl would still have to be done on the kernel device driver. > > > >> I thought also about a /proc interface for decompression > algorithms (a > > > >> helper would listen on a /proc file and write on another /proc > file) but > > > >> /proc is not designed for that kind of thing. > > > >> A separate library seems to be the simplest solution. > > > >> > > > > > > > > There are some ways for this to work. For example, you may > create a > > > > helper device for the daemon driver to bind, even requiring it > to have > > > > root permission. > > > > > > > > > > > Right, but I am afraid that complex userspace/kernelspace context > > > changes breaks performance. > > Yes, there's a risk. > > > > > Nevertheless, I will start to specify the framework. > > > The helper daemon would link to the v4l2-apps/lib. > > > > Ok, thanks! > > Ok, here comes updated version of stk11xx driver. Note that it's not > still > separated into more files (I'll do this as the last step) and also > resize > and bayer->rgb conversion remains. This is what I'm interested in -- > is > there some embryo of library with resize and conversion? Or what was > the > decision to create?
Hi Jiri, sorry I started the specification but nothing finalized (and consequently no code). Here is the start of my idea for a v4l2_extension: http://thierry.merle.free.fr/v4l2_extension/general.html My new USB tuner took me all my little time and I did not get into details (the spec is incomplete). Well, as you insist I will explain a bit more :) Please comment, tell me what you don't understand I will try to update during this week-end... Thierry - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
