<div dir="ltr">Hi LADs<div><br></div><div>We are working on an ARM based MOD device and while fiddling with JACK some questions appeared.</div><div><br></div><div>I didn't know whether to post on the ALSA os JACK lists, so I decided to post here :-) </div>
<div><br></div><div>When I start Jack in my PC I get the well know message:</div><div><br></div><div>
<p style="margin:0px"><span style="color:rgb(153,0,153)">/usr/bin/jackd -P80 -dalsa -r48000 -p128 -n2 -D -Chw:0 -Phw:0</span></p></div><div><br></div><div>
<p style="margin:0px">creating alsa driver ... hw:0|hw:0|128|2|48000|0|0|nomon|swmeter|-|32bit</p>
<p style="margin:0px">configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 2 periods</p>
<p style="margin:0px">ALSA: final selected sample format for capture: 32bit integer little-endian</p>
<p style="margin:0px">ALSA: use 2 periods for capture</p>
<p style="margin:0px">ALSA: final selected sample format for playback: 32bit integer little-endian</p>
<p style="margin:0px">ALSA: use 2 periods for playback</p></div><p style="margin:0px"></p><p style="margin:0px"><br></p><p style="margin:0px">When starting it on the Beaglebone Black I get:</p><p style="margin:0px"><br></p>
<p style="margin:0px">/usr/bin/jackd --realtime -P80 -dalsa -r48000 -p128 -n2 -Xraw<br></p><p style="margin:0px"><br></p><p style="margin:0px">creating alsa driver ... hw:0|hw:0|128|2|48000|0|0|nomon|swmeter|-|32bit</p><p style="margin:0px">
configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 2 periods</p><p style="margin:0px">ALSA: final selected sample format for capture: 32bit integer little-endian</p><p style="margin:0px">ALSA: use 16 periods for capture</p>
<p style="margin:0px">ALSA: final selected sample format for playback: 32bit integer little-endian</p><p style="margin:0px">ALSA: use 16 periods for playback</p><div><br></div><div><br></div><div>- what are those "periods" in the ALSA lines? (2 for the PC and 16 for the BBB) ? I read a post by Jeremy Jongepier about the Cubieboard2 stating that the hardcoded values for the Cubie (<span style="font-family:'Lucida Grande','Lucida Sans Unicode',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">Minimum number of periods was 4 and minimum buffer size was 1024) where unfit for realtime operation. Why is that so?</span></div>
<div><span style="font-family:'Lucida Grande','Lucida Sans Unicode',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px"><br></span></div><div><span style="font-family:'Lucida Grande','Lucida Sans Unicode',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">- on the ArchWiki page on Jack there is a D-bus call</span></div>
<div><pre style="padding:1em;border:1px solid rgb(187,204,221);background-color:rgb(235,241,245);line-height:1.1em;overflow:auto">jack_control eps realtime true</pre></div><div>stating that it "<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19.049999237060547px">Sets JACK to realtime mode in its own internal setup."</span></div>
<div><span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19.049999237060547px">What is this internal setup? How do I address this when not using D-Bus?</span></div><div><span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19.049999237060547px"><br>
</span></div><div><font color="#000000" face="sans-serif"><span style="line-height:19.049999237060547px">King regards all</span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19.049999237060547px"><br>
</span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19.049999237060547px">Gianfranco Ceccolini</span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19.049999237060547px">The MOD Team</span></font></div>
<div><font color="#000000" face="sans-serif"><span style="line-height:19.049999237060547px"><br></span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19.049999237060547px">PS: We will be at LAC againd this year. I'm very eager to meet most of this distinguished community members there. We have lots of good new for the MOD in 2014.</span></font></div>
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