Le Sat, 19 May 2012 06:25:26 +0200, Dieter Knopf <dieterknopf@xxxxxxxxxxxxxx> a écrit : > Hello, > > i'm searching for a way to create a permanent audio device with the > snd-usb-audio and a USB microphone. If you have only one USB sound device, to modify the alsa configuration in /etc/modprobe.d should be enough. It is some examples of multi sound card configuration on the alsa wiki. If you have more than one USB sound device, you should modify the alsa configuration and write some custom udev rules in /etc/udev/rules.d. lsusb It is zdev that will assign permanent device nodes (or permanent symlinks to the real device nodes). > > The device should be already there and working and after plugging in > the USB device it should be avaialble through that device. > > Example: /dev/pcm is already there and i can stream from it and after > i plugged in the USB device this should be available through that > device. After unplugging it it should be still there. Like a mixer. Short answer: you can't. Long answer: if a device node is already in /dev, you will have to write some custom script that will unload alsa, remove /dev/pcm, recreate it for the USB device, modify the alsa configuration and reload alsa when the usb device is plugged in. Of course, that script should be launched by some udev rule. Another udev rule and another script will do the same work for the other sound card when the usb device is plugged out. I never experimented with udev that way (I mean with external script to create the device nodes), and I don't know if or how it is possible. Another solution would be to write a correct alsa sound for 2 or more sound cards and make a ~/.asoundrc to make a virtual sound card with the output of the 2 cards. But I don't know if it will work if you start alsa and plug in the USB card later. The last solution I can see is with JACK and alsa_out. From 'man alsa_out': A JACK client that opens a specified audio interface (different to the one used by the JACK server, if any) and moves audio data between its JACK ports and the interface. alsa_in will provide data from the interface (potentially for capture); alsa_out will deliver data to it (for playback). Ciao, Dominique > > Thanks > > Dieter > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. > Discussions will include endpoint security, mobile security and the > latest in malware threats. > http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ Alsa-user mailing list > Alsa-user@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/alsa-user -- "We have the heroes we deserve." ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
