[Jack-Devel] audioadapter: quality setting important when not changing sampling frequency?

[Holger Marzen]

On Sat, 29 Sep 2018, David Kastrup wrote:

> Holger Marzen <holger at marzen.de> writes:
> 
> > On Fri, 28 Sep 2018, Holger Marzen wrote:
> >
> >> On Fri, 28 Sep 2018, Holger Marzen wrote:
> >> 
> >> > q2 (SRC_SINC_FASTEST) showed the desired flat envelope and seems to be
> >> > the best compromise between CPU load and quality.
> >> > 
> >> > -> That's the setting I'll use from now on.
> >> 
> >> Unfortunately this leads to errors once in a while (although my Core i7
> >> has no big CPU load), the ringbuffer increases up to 64k. So it's no
> >> stable solution for me.
> >
> > It seems that playing with jackd's priority can cure the problem. I'll
> > play around with the parms but this seems to be a good start. Maybe
> > squeezelite, an audioplayer, was the cause because it was running at a
> > higher priority than jackd.
> 
> Wouldn't jackd be running at realtime priority usually?
> 
> > jackdmp 1.9.11
> > Copyright 2001-2005 Paul Davis and others.
> > Copyright 2004-2014 Grame.
> > jackdmp comes with ABSOLUTELY NO WARRANTY
> > This is free software, and you are welcome to redistribute it
> > under certain conditions; see the file COPYING for details
> > JACK server starting in realtime mode with priority
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> Yup.  Is squeezelite also running with realtime priority?  That would
> seem weird.  I mean, running an audioplayer while in a recording session
> seems weird anyway.

I was surprised, too, that squeezelite runs in realtime:

RTPRIO   TID   PID CMD
     1   262   262 [i915/signal:0]
     1   263   263 [i915/signal:1]
     1   264   264 [i915/signal:2]
     1   265   265 [i915/signal:4]
     5 10207 10194 pulseaudio --exit-idle-time=-1
     5 10218 10194 pulseaudio --exit-idle-time=-1
     9 10200 10194 pulseaudio --exit-idle-time=-1
     9 10202 10194 pulseaudio --exit-idle-time=-1
     9 10208 10194 pulseaudio --exit-idle-time=-1
     9 10215 10194 pulseaudio --exit-idle-time=-1
     9 10219 10194 pulseaudio --exit-idle-time=-1
    45 13118 13115 squeezelite -z -n squeezelite-bubu -s mortimer
    45 13119 13115 squeezelite -z -n squeezelite-bubu -s mortimer
    50  1123  1123 [irq/133-enp5s0]
    50   129   129 [irq/122-xhci_hc]
    50   130   130 [irq/123-xhci_hc]
    50   131   131 [irq/124-xhci_hc]
    50   132   132 [irq/125-xhci_hc]
    50   133   133 [irq/126-xhci_hc]
    50   134   134 [irq/127-xhci_hc]
    50   135   135 [irq/128-xhci_hc]
    50   136   136 [irq/129-xhci_hc]
    50   137   137 [irq/130-xhci_hc]
    50   138   138 [irq/12-i8042]
    50   139   139 [irq/1-i8042]
    50   140   140 [irq/8-rtc0]
    50   215   215 [irq/131-rtsx_pc]
    50   220   220 [irq/132-ahci[00]
    50   260   260 [irq/134-i915]
    50   627   627 [irq/135-mei_me]
    50    70    70 [irq/9-acpi]
    50   746   746 [irq/136-snd_hda]
    85 10189 10172 /usr/bin/jackd -P90 -p512 -t2000 -dalsa -r48000 -p128 -n3 -Xseq -dhw:1
    85 10190 10172 /usr/bin/jackd -P90 -p512 -t2000 -dalsa -r48000 -p128 -n3 -Xseq -dhw:1
    85 10216 10196 calfjackhost --load /home/hm/scripts/calf.d/main
    85 10217 10195 /usr/bin/python /usr/bin/jack_mixer -c /home/hm/.jack_mixer
    90 10179 10172 /usr/bin/jackd -P90 -p512 -t2000 -dalsa -r48000 -p128 -n3 -Xseq -dhw:1
    99    11    11 [migration/0]
    99    12    12 [watchdog/0]
    99    15    15 [watchdog/1]
    99    16    16 [migration/1]
    99    21    21 [watchdog/2]
    99    22    22 [migration/2]
    99  2341  2339 /usr/lib/rtkit/rtkit-daemon
    99    27    27 [watchdog/3]
    99    28    28 [migration/3]
    99    33    33 [watchdog/4]
    99    34    34 [migration/4]
    99    39    39 [watchdog/5]
    99    40    40 [migration/5]
    99    45    45 [watchdog/6]
    99    46    46 [migration/6]
    99    51    51 [watchdog/7]
    99    52    52 [migration/7]