On Tuesday, November 16, 2010 23:18:02 Jonathan Corbet wrote: > I've just spent a fair while looking through the September posting of > the media controller code (is there a more recent version?). The > result is a high-level review which interested people can read here: > > http://lwn.net/SubscriberLink/415714/1e837f01b8579eb7/ > > Most people will not see it for another 24 hours or so; if there's > something I got radically wrong, I'd appreciate hearing about it. Just two points, really: we do not expect generic applications to use this API other than for determining the default device nodes. E.g. if a device has 5 video nodes and two alsa nodes, then one video and one alsa node will be marked as the default and applications are supposed to open those. This will allow apps to find the right device nodes for capturing. The more advanced functionality is expected to be used by custom applications specific to that hardware. I also expect to see either libv4l2 or gstreamer plugins or libraries created for specific SoCs that use this API. The hardware that the MC describes is simply too varied and unpredictable to ever be able to use it with just the MC data. The main purpose is to at least be able to expose the full functionality to userspace. The other point is the same that Andy made: we expect that the API will change a bit allowing for atomically changing multiple links at the same time. Not something that sysfs can handle (not without some horrible hacks at least). I also think sysfs is a mess and horrible to use, but that's just my opinion. > The executive summary is that I think this code really needs some > exposure outside of the V4L2 list; I'd encourage posting it to > linux-kernel. That could be hard on plans for a 2.6.38 merge (or, at > least, plans for any spare time between now and then), but the end > result might be better for everybody. I agree with that. It was always designed for generic use, but on the other hand we can't postpone it for too long since V4L really needs this. Thanks for the article! Regards, Hans > I have some low-level comments too which were not suitable for the > article. I'll be posting them here, but I have to get some other > things done first. > > Thanks, > > jon > -- > 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 > > -- Hans Verkuil - video4linux developer - sponsored by Cisco -- 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
