<br><br><div class="gmail_quote">On Thu, Apr 29, 2010 at 4:31 PM, Alexandros Diamantidis <span dir="ltr"><<a href="mailto:adia@hellug.gr">adia@hellug.gr</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hello all,<br>
<br>
I got a new computer recently, with onboard audio (ATI Technologies<br>
Inc SBx00 Azalia (Intel HDA) according to ALSA). I discovered that if<br>
there's no microphone connected, jack (jackdmp 1.9.5) doesn't run and<br>
outputs a continuous stream of "alsa_driver_xrun_recovery<br>
JackAudioDriver::ProcessAsync: read error, skip cycle". As soon as I<br>
connect a mic, it works normally.<br>
<br>
When starting it with the -P option (playback only), mic presence<br>
doesn't affect jack operation, but of course there are no capture ports<br>
available.<br>
<br>
It doesn't make much of a difference for me right now, but just for<br>
curiosity's sake, I'm wondering if it's possible to start jack without a<br>
mic and have capture ports appear automatically when one is connected.<br></blockquote><div><br>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.<br>
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.<br>
<br>--p<br><br></div></div>