Re: [LAU] Jack, HDA and mic input

On Thu, Apr 29, 2010 at 4:31 PM, Alexandros Diamantidis <adia@email-addr-hiddenwrote:

> Hello all,
>
> I got a new computer recently, with onboard audio (ATI Technologies
> Inc SBx00 Azalia (Intel HDA) according to ALSA). I discovered that if
> there's no microphone connected, jack (jackdmp 1.9.5) doesn't run and
> outputs a continuous stream of "alsa_driver_xrun_recovery
> JackAudioDriver::ProcessAsync: read error, skip cycle". As soon as I
> connect a mic, it works normally.
>
> When starting it with the -P option (playback only), mic presence
> doesn't affect jack operation, but of course there are no capture ports
> available.
>
> It doesn't make much of a difference for me right now, but just for
> curiosity's sake, I'm wondering if it's possible to start jack without a
> mic and have capture ports appear automatically when one is connected.
>

you appear to have an HDA chipset with "jack detection" (it detects when a
jack is inserted). you can't do what you asked about, but you can get close
to it.
use a h/w mixer control application (e.g. the ugly and terminal-based
but-so-far-unmatched alsamixer) to set the capture source of the device back
to, perhaps, "line in". then later, switch it to the "mic". JACK pays
(almost) no attention to the state/settings of the h/w mixer, so it has no
clue what you're recording from or whether or not a mic is plugged in.

--p

_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-user
Received on Fri Apr 30 00:15:07 2010