Hi I am building a small form factor PC communication device for a communication system. The PC is running Ubuntu 12.04 (using a small set of installed packages). We use a number of USB audio devices attached to the PC to perform the actual audio input and output. In this case a PC might have 3 devices connected simultaneously: a handset, a headset and a speaker. For each of these devices I would like to be able to set a reference volume (a volume that we set from the system to a configured value) and provide a volume control that the user is able to control - but control relative to the reference value.
For some devices we are able to do this using the Master volume control (as reference) and the PCM volume control for the user. We control the UI for changing the volume so the name of the control is not important. My problem is that not all of the devices we have provide a Master volume control, so my goal is to provide this "Master" control as a softvol control either for devices that does not have them, or create an entirely different control, perhaps "Reference" and use that. I have followed http://alsa.opensrc.org/How_to_use_softvol_to_control_the_master_volume and configured individual devices to add this control and doing it this way works quite well. The only problem is that I have to do this for each device individually and I would rather if I could define this once and have it created for all USB audio devices. I have tried to create an /etc/asound.conf to see if I could do this but unfortunately I am not very strong in writing these configuration files so I have been unable to write something that actually works. I there anyone who can help me shed some light on whether it is possible to do it generally and if so, how to do it? The audio configuration is based on the scripts that are part of the Ubuntu 12.04 (LTS) distribution and has not been modified. One of my tries has looked like the following, but I am definitely missing something: pcm.reference { @args [ CARD ] @args.CARD { type string } type softvol slave.pcm { type hw card $CARD subdevice 0 } control { name "Reference" card $CARD } } pcm.!default { type plug slave.pcm "reference" } Med venlig hilsen/ Best Regards Lau Bakman Systems Engineer Business Area Security & Defence Solutions Direct: + 45 36 38 30 23 Mobile: + 45 41 87 60 23 E-mail: lau.bak...@dk.saabgroup.com Saab Danmark A/S Alsion 2 DK - 6400 Sonderborg www.saabgroup.com This e-mail is private and confidential between the sender and the addressee. In the event of misdirection, the recipient is prohibited from using, copying or disseminating it or information in it. Please notify the above if any misdirection. ------------------------------------------------------------------------------ Shape the Mobile Experience: Free Subscription Software experts and developers: Be at the forefront of tech innovation. Intel(R) Software Adrenaline delivers strategic insight and game-changing conversations that shape the rapidly evolving mobile landscape. Sign up now. http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
