ALSA: properly setup for onboard & USB audio devices

[sbbg]

Hi,
I know it sounds too familiar for many of you. But allow me to explain my self:
I googled around and read the following very carefully. But all these guide does not help me resolve my problem.
dmix - ALSA wiki
.asoundrc - ALSA wiki
Gentoo Linux ALSA Guide
Multiple discussion on Arch Linux.

All I want to do is: (1)Make USB DAC default output, (2)Make dmix works for default device.


I tried suggestion in .asoundrc, the USB DAC became the default output ... for 1 stream only. The USB DAC is blocked when it's playing, and 2nd file played will go to onboard device. That's definitely NOT what I want. ( Didn't ALSA wiki promise me that dmix will work as default? lol )

I tried dmix guide suggestion. But I try very hard. I just could NOT make dmix to fall back to onboard device if USB DAC is not connected.

May somebody shed some light into this helpless lamb? Please.

[BoDiddley]

Hi, I am Debian - but I have insight regarding ALSA. Did you run "alsactl init", accept the defaults and reboot system after.

I also continued to have insufficiencies which were rectified by installing "esound"; "esound-clients", and "alsamixergui". (all package names).

[sbbg]

Hi, I am Debian - but I have insight regarding ALSA. Did you run "alsactl init", accept the defaults and reboot system after.

I also continued to have insufficiencies which were rectified by installing "esound"; "esound-clients", and "alsamixergui". (all package names).

Thanks for replying.

Shall I run #alsactl with my USBDAC connected or not?

[BoDiddley]

"alsactl init" is to properly initialize your specific system sound driver within Linux. This would be phase one. After that, "esound", and "alsamixergui" is what I used to correct remaining deficiencies.

Again, this is basic stuff. I always work from the bottom-up. Some people seem to try to work from the top-down. Once you have the basic sound installed properly, then you should sort out the rest. "alsamixergui" has sound levels, by device - which can be enabled or disabled.

[sbbg]

Hi,
This is solved after I read over and over and fiddled with mplayer for a long while. I'm replying for "Who happened to look for answer here."
It turns out that I have to work around between 2 alsa device co-existing at the same time. Better not go windy by removing another device when my USB DAC plugged in.
So here is my way:

in .asoundrc

pcm.!default{
        type plug
        slave.pcm "usbdac_dmix"
}

pcm.usbdac {
           type hw # USB DAC device
           card 2     # check these value by "aplay -l" output!! something like "card 2: Device [USB PnP Sound Device], device 0"
           device 0  # check these value by "aplay -l" output!!
}
pcm.onboard {
            type hw
            card 0     # check these value by "aplay -l" output!! card 0: SB [HDA ATI SB], device 0: CONEXANT Analog [CONEXANT Analog]
            device 0  # check these value by "aplay -l" output!!
}
pcm.usbdac_dmix {
                type dmix
                ipc_key 1026 # must be unique!
                slave {
                        pcm "usbdac"  
 ## all following in this dmix section should be set according to your hardware. If you're not sure, don't try to add them!
                        period_time 0
                        period_size 1024
                        buffer_size 8192
                        rate 48000  # Fireye 2 support up to 48000Hz, please refer to your hardware spec.
                      }
}
pcm.onboard_dmix {
type dmix
ipc_key 1025 # must be unique!
slave {
        pcm "onboard"
 ## all following in this dmix section should be set according to your hardware. If you're not sure, don't try to add them!
        period_time 0
        period_size 1024
        buffer_size 8192
        rate 44100
      }
}

This will make 2 dmix output for each devices. Fortunately, mplayer support some advance argument to alsa control.

Here is my "-ao" argument of mplayer:

alsa:device=plug=usbdac_dmix,alsa:device=plug=onboard_dmix

you can put them into a line of ~/.mplayer/config like

ao=alsa:device=plug=usbdac_dmix,alsa:device=plug=onboard_dmix

It now can play by USBDAC by default, and fallback to onboard if it's not available & with dmix working for both.

Finally, you can tune all the apps to use mplayer to output. (for kde user, try phonon-mplayer)Then the problem is solved.