<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1444538095346_3237">Many thanks for taking the time to write this very clear explaination Len :)</div><div id="yui_3_16_0_1_1444538095346_3212"><span id="yui_3_16_0_1_1444538095346_3484">Maybe you have a site/blog/else where you share your knowledge?</span></div><br> <blockquote id="yui_3_16_0_1_1444538095346_3189" style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; margin-top: 5px; padding-left: 5px;"> <div id="yui_3_16_0_1_1444538095346_3188" style="font-family: HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1444538095346_3187" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1444538095346_3186" dir="ltr"> <hr id="yui_3_16_0_1_1444538095346_3280" size="1"> <font id="yui_3_16_0_1_1444538095346_3190" face="Arial" size="2"> <b id="yui_3_16_0_1_1444538095346_3211"><span id="yui_3_16_0_1_1444538095346_3210" style="font-weight:bold;">De :</span></b> Len Ovens <len@ovenwerks.net><br> <b id="yui_3_16_0_1_1444538095346_3209"><span id="yui_3_16_0_1_1444538095346_3208" style="font-weight: bold;">À :</span></b> fred <f.rech@yahoo.fr> <br><b id="yui_3_16_0_1_1444538095346_3466"><span id="yui_3_16_0_1_1444538095346_3465" style="font-weight: bold;">Cc :</span></b> "linux-audio-user@lists.linuxaudio.org" <linux-audio-user@lists.linuxaudio.org> <br> <b id="yui_3_16_0_1_1444538095346_3268"><span id="yui_3_16_0_1_1444538095346_3267" style="font-weight: bold;">Envoyé le :</span></b> Samedi 10 octobre 2015 16h19<br> <b id="yui_3_16_0_1_1444538095346_3449"><span id="yui_3_16_0_1_1444538095346_3448" style="font-weight: bold;">Objet :</span></b> Re: [LAU] What happens (or not) if one use the active d-bus interface option in QjackCtl ?<br> </font> </div> <div id="yui_3_16_0_1_1444538095346_3191" class="y_msg_container"><br>On Sat, 10 Oct 2015, fred wrote:<br><br>> What happens (or not) if one use the active d-bus interface option in QjackCtl ?<br>> <br>> Maybe, with a good luck, someone in the list will invest some time to explain,<br>> or point to a link that explains,<br>> all those options in QjackCtl that most of us leaves alone since years,<br>> just because doesn't know what is all about, or pass hours to test???<br><br>dbus options with jack are to do with jack2. There is a patch to allow <br>jack1 to be dbus controllable as well, but I don't know that any distos <br>ship it and Qjackctl is not designed for it.<br><br>jackdbus is the same jackd with the ability to use dbus to control it's <br>operation. The advantage of this is that more than one program can <br>interact with jackdbus. With jackd, only the program that starts it can <br>stop it and the parameters can only be set at start time (with the <br>exception of buffers which can be changed during run). With jackdbus, all <br>parameters can be changed including audio device during runtime and can be <br>changed by any program that can find the same dbus server (anything <br>started since session startup). This means Qjackctl can be used to start <br>jackdbus and then jack_control can be used to stop or maodify parameters.<br><br>I think what stops people from making more use of jackdbus is that all the <br>documentation and help for jack is with jackd command lines. So the new <br>comer will be flooded with advice that shows how to use jackd and not <br>jackdbus.<br><br>To start jackd with default parameters (whatever was used last time) on <br>the command line:<br>jackd<br>or:<br>jackd &<br><br>to start jackdbus:<br>jack_control start<br><br>To stop jackd the controlling terminal can use control c or if it was <br>started with the & then you have to:<br>killall -9 jackd<br>With jackdbus:<br>jack_control stop<br><br>A typical jackd start line with parameters would be:<br>/usr/bin/jackd -p1024 -dalsa -dhw:M66 -r48000 -p1024 -n2<br><br>The same thing in jackdbus might be:<br>jack_control ds alsa dps device hw:M66 dps rate 48000 dps period 1024 \<br> dps nperiods 2 start<br><br>or (if it is easier in a script):<br>jack_control ds alsa<br>jack_control dps device hw:M66<br>jack_control dps rate 48000<br>jack_control dps period 1024<br>jack_control dps nperiods 2<br>jack_control start<br><br>Now to change the device without stopping jackdbus:<br>jack_control dps device hw:AudioPCI sm<br><br>An interesting side note:<br>I have the AudioPCI installed only so I can use its MIDI port. The MIDI <br>port is available no matter which device is set with jackd/bus. I use <br>a2j_control to bridge alsa MIDI to jack MIDI (a2j_control ehw start).<br><br>Documentation:<br>Very little. man jack_control gives nothing, but jack_control on it's own <br>with give a usage message (or jack_control help). I went through using the <br>"get" commands to find out more. Jack_control is written in python and so:<br>less /usr/bin/jack_control<br>will allow one to see what dbus commands jack_control is sending to dbus <br>to control jackdbus.<br><br>Qjackctl does not at this time (maybe never) allow changing the jack <br>server parameters on the fly. However, a jackdbus server started with <br>qjackctl can be changed from command line with jack_control.<br><br>Jackdbus works much more smoothly and automatically with Pulseaudio and <br>the pulse-jack bridge. Pulse can be bridged to jackd (1 or 2) manually as <br>well, but it requires an extra script to be run each time jackd is <br>started.<br><br>Depending which version of qjackctl you have (mine is older), it sets <br>port-max lower (1024) than default (2048) and can not be set higher. Most <br>desktops have no reason to run any lower than default. Embedded systems <br>with limited memory might need something smaller... but probably also <br>won't run qjackctl :)<br><br>I know this is much more than the qjackctl side of jackdbus, but it does <br>give some of the why too.<br><br>--<br>Len Ovens<br>www.ovenwerks.net<br><br><br><br></div> </div> </div> </blockquote> </div></body></html>