On Sun, 2010-09-05 at 19:09 +0200, Guennadi Liakhovetski wrote: > In a currently running mt9m111 thread we're discussing ways to activate > one of camera's (sensor's) test patterns. A module parameter has been > proposed, earlier this has been done by just using the infamous > VIDIOC_DBG_S_REGISTER. But then it occurred to me, that there has been > previously such a discussion and it has been proposed to assign > alternative inputs to various test patterns. So, you just issue a > VIDIOC_S_INPUT to switch between the actual video input and one of test > patterns. Can anyone else remember such a discussion or maybe just knows > examples of such drivers? The SAA7127 Video Encoder has a test pattern generator. The saa7127.c file uses a module option to enable it a module probe time. It also appears the v4l2_subdev.s_routing method of the saa7127 module can also be used to switch to the test signal generator as input (So VIDIOC_S_INPUT looks like it should work, maybe?). There's your precedent. Also using VIDIOC_S_INPUT also makes a lot of sense to me. A test pattern is an input; just an internal one as opposed to an external one. > A couple of grep attempts haven't revealed > anything. Is this a good idea? I don't think it's bad. Working through implementation details might show you if anything is really bad (VIDIOC_ENUMINPUT, etc.). Regards, Andy > Thanks > Guennadi -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
