On 2011-08-03 15:05, Himanshu Chug wrote: > Hi Colin, David > > I can see David posts on the group recently and assuming David is back > from vacations :) Your assumption is correct :-) Btw I don't mind being cc:ed if you need to reach me in person as I don't read all of pulseaudio-discuss normally. > unfortunately we don't access to IRC chat due to some security > restriction (thou we are working to get this sorted, if possible) so > currently I can discuss only over group emails. > > On Fri, Jul 22, 2011 at 1:42 AM, Colin Guthrie <gmane at colin.guthr.ie > <mailto:gmane at colin.guthr.ie>> wrote: > > 'Twas brillig, and Himanshu Chug at 21/07/11 08:24 did gyre and gimble: > > Thanks Colin and Spidey for making this clarification. > > > > So regarding JACK detection and routing: > > > > 1. module-udev-detect currently can detect JACK physical hot-plugging > > but it can't decode the information about what type of JACK device ( > > input or output ) is connected to the sound-card, and for that > one need > > to write an JACK detection module to handle that. > > is my understanding correct ? > > Not quite. Udev detect does absolutely nothing with JACKs. It detects > totally new devices in a hotplug way. These devices are e.g. USB > speakers or headsets. Although as of now, and the preliminary implementation the UCM folks did, the jack input devices are being detected by udev. > one colleague of mine from ALSA /kernel team have wrote the Jack > detection app using udev API from libudev, > so the Jack plug in/plug Out state can be read at > sys/devices/virtual/switch/h2w/state > State Meaning > 0 No Headset Connected > 1 Headset with MIC connected > 2 Headset without MIC connected This is a non-standard way of doing it, so once we have the infrastructure in place you'd still have to write your own module for that. > here we are monitoring in a loop using udev monitor fd and based on the > "state" we are calling kcontrols for loudspeaker and headset > something like here... > > fd = udev_monitor_get_fd(mon); > > while (1) { > ............ > r = select(fd, ...); > > dev = udev_monitor_receive_device(mon); > if (dev) { > // Jack Inserted/Removed > Jack_Report(state); // this function will call kcontrols for > headset/loudspeaker based on "state" > } > ............ > } > > I am trying to understand if this approach of Jack detection is fine? > at-least I need to know if I am going in right direction? If you do your own program as listed above and nothing inside PulseAudio, Jack_Report could call "pacmd set-sink-port", at least if you got your PulseAudio profiles and paths set up correctly (see WritingProfiles on the wiki). > The actual HP Jack detection stuff is not present at all in PA as the > underlying layers in ALSA are in flux. These need to settle before we > can write anything to deal with them. > > > As Colin comments about ALSA layers are in flux, I need to understand > this bit more some brief information about this problem with ALSA ? > if you can point to some link or so is also fine :) http://comments.gmane.org/gmane.linux.alsa.devel/86315 > There are active discussions on this topic just now on the alsa-devel > mailing list. None that I have missed I hope? :-) > > 2 Currently our Kernel/ALSA team support for providing seperate > kcontrol > > (amixer scripts) for enabling/disabling loudspeaker and headset > to PA, > > so it might be an good idea to handle Jack detection and routing > in one > > of the existing module or write up an new jack detection module for > > this, as Colin suggested, provided that we are able to recognize Jack > > device type (input/mic or output/headset or both) from point 1, ( i > > will take further help from kernel team here about detecting jack > device > > type, but any suggestions are welcome :-) ) > > Kinda. PA should be able to display to you the different "ports" for > each sink. These ports represent the Speakers or the Headphones > kcontrols that are on your device and you can change ports at runtime > (just run pavucontrol and if your sinks actually have ports, there will > be a drop downo n the "Output Devices" pane). > > > I am not able to get pavucontrol installed and working on my rootstrap, > due to some other issues, but I need to test this out also soon. "pacmd list" should - among many other things - give you a list of ports and profiles for a card. > but I tried on UBUNTU 10.10 desktop, pavucontrol app showing me the > dropdown for Output Devices, > > At present you have to > change ports manually but the plan is to hook this up to jack detection, > such that the port is simply flipped accordingly. > > > I need to know where (or how) in code we can do "flipping of ports from > headphones to loudspeaker" > if I use our udev API for jack detection from above ? > > > Multifunction jacks (i.e. those that can be input or output, analog or > digital) are even more interesting :) > > > I very strongly suggest you discuss this with David Henningsson. He's on > this list but is away on vacation for (I think) another week. He's is > actively working on JACK support for ALSA and PA layers so it will > likely be the most productive for you if you wait and speak with him. > He's employed by Canonical and is diwic on IRC. Nitpick: JACK with all caps usually refers to "Jack Audio Connection Kit", which is a low-latency (rather than low-power) sound server, i e something completely different. -- David Henningsson, Canonical Ltd. http://launchpad.net/~diwic
