On Saturday, September 11, 2010 16:10:52 Andy Walls wrote: > On Sat, 2010-09-11 at 15:49 +0200, Hans Verkuil wrote: > > I'm working on the V4L2 DocBook spec and when reading through the "Device Naming" > > subsection of the "Opening and Closing Devices" section in the first chapter I > > realized that it is really out of date. The text is in this file: > > > > Documentation/DocBook/v4l/common.xml > > > > With udev pretty much everything in that section is useless (and probably confusing > > for first-time readers). > > > > I propose that we replace it with something short like this: > > > > ----------------------------------------------------- > > Device Naming > > > > V4L2 drivers create one or more device nodes with major number 81 and a minor number > > between 0 and 255. Three types of devices can be created: > > > > /dev/videoX Used for video capture/output/overlay. > > PCM audio capture I don't really dare mention this :-) This really should have been an alsa device. PCM audio capture is really a big hack. This is a topic for a v4l summit to decide what to do with this. And I guess it depends on whether alsa can be extended with proper time stamping. > MPEG index (metadata) I think is a bit too detailed for an overview section. > > > /dev/radioX Used for radio and RDS tuning/modulating. > > /dev/vbiX Used for VBI capture and output. > > ----------------------------------------------------- > > > > Is there anything else that should be in here? > > You may want to mention, without fully specifying, that V4L2 drivers can > present ALSA device nodes as well. This is covered in the 'Related Devices' section. > I don't think the V4L2 drivers have a really uniform convention for > their "card" name exported to ALSA nor the ALSA mixer control names. > > To document the Media Controller, the document will eventually have to > mention ALSA, framebuffer, LED, etc. APIs anyway. Of course. Regards, Hans > > > > BTW, I'm working on editing the 'Related Devices', 'Multiple Opens' and > > 'Shared Data Streams' as well. > > > > Regards, > > > > Hans > > Regards, > Andy > > > -- Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of 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
