From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Wed, 26 Apr 2017 12:53:56 +0200 Subject: support autofocus / autogain in libv4l2 In-Reply-To: <1493139207.19105.16.camel@ndufresne.ca> References: <1487074823-28274-2-git-send-email-sakari.ailus@linux.intel.com> <20170414232332.63850d7b@vento.lan> <20170416091209.GB7456@valkosipuli.retiisi.org.uk> <20170419105118.72b8e284@vento.lan> <20170424093059.GA20427@amd> <20170424103802.00d3b554@vento.lan> <20170424212914.GA20780@amd> <20170424224724.5bb52382@vento.lan> <20170425080538.GA30380@amd> <1493139207.19105.16.camel@ndufresne.ca> Message-ID: <20170426105356.GB857@amd> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue 2017-04-25 12:53:27, Nicolas Dufresne wrote: > Le mardi 25 avril 2017 ? 10:05 +0200, Pavel Machek a ?crit?: > > Well, fd's are hard, because application can do fork() and now > > interesting stuff happens. Threads are tricky, because now you have > > locking etc. > > > > libv4l2 is designed to be LD_PRELOADED. That is not really feasible > > with "complex" library. > > That is incorrect. The library propose an API where you simply replace > certain low level calls, like ioctl -> v4l2_ioctl, open -> v4l2_open(). > You have to do that explicitly in your existing code. It does not > abstract the API itself unlike libdrm. You are right, no LD_PRELOAD. But same API as kernel, which is really limiting -- see my other mail. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: