On Sat, Oct 25, 2014 at 03:08:10PM +0200, wm4 wrote: > On Sat, 25 Oct 2014 14:43:39 +0200 > Nicolas George <geo...@nsup.org> wrote: > > That would not be heavy-weight, that would be outright irresponsible: > > ioctl() opcodes are not globally unique. An opcode that maps to a harmless > > probe on v4l devices can trigger catastrophic consequences on other devices. > > > > (Remember 2003, when installing Mandrake 9.2 would brick LG CD drives? That > > was the same issue, but our case is worse because what Mandrake did was > > actually supposed to work reliably if LG had not messed their firmware.) > > > > (If your conclusion is that the ioctl() interface is braindead, I am right > > there with you, but that is something we have to live with.) > > Then there's no sane way to handle this. Basically, you need to know: > yes, this is a video device.
I think this might be the whole reason for the disagreement. Me and Nicolas don't think there is any reason at all for you to _know_ it is a video device. That's why we have probe scores. We just make the best guess we find reasonable and then assign a score corresponding to the confidence we have in that. So I actually don't see much of an issue with the patch except the question which confidence we should assign to a test that just checks for /dev/video. Anything I miss? > > > I admittedly just assumed that v4l2:///dev/video/... would work > > > currently. If not, that sounds like something that can and should > > > be fixed. > > > > Well, "foo:" prefixes are normally reserved for protocols. We could add to > > that "or formats with the NOFILE flag", that would probably make things > > better. Or if we are afraid to trigger untested corner cases, have a > > dedicated new flag AVFMT_PROTO_PREFIX or something. > > Such a flag might probably work... I think this is too complex and not directly related to this. Maybe we should move it to a different thread if someone wants to work on it? _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel