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

Holger Marzen holger at marzen.de
Sat Sep 29 10:19:44 CEST 2018

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.

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
self-connect-mode is "Don't restrict self connect requests"
Acquire audio card Audio1
creating alsa driver ... hw:1|hw:1|128|3|48000|0|0|nomon|swmeter|-|32bit
configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 3 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 3 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 3 periods for playback
port created: Midi-Through:midi/playback_1
port created: Midi-Through:midi/capture_1
port created: Scarlett-2i4-USB:midi/playback_1
port created: Scarlett-2i4-USB:midi/capture_1
Fixed ringbuffer size = 1024 frames
Audio Interface Description :
Sampling Frequency : 48000, Sample Format : S32_LE, buffering : 256, nperiod : 3
Software inputs :  2, Software outputs :  2
Hardware inputs :  2, Hardware outputs :  2
Card info (address : 0x7fd536e242f0)
	ID         = USB_1
	Driver     = USB-Audio
	Name       = Scarlett 2i2 USB
	LongName   = Focusrite Scarlett 2i2 USB at usb-0000:00:14.0-1.4.3, high speed
	MixerName  = USB Mixer
	Components = USB1235:8006
HW Params info (address : 0x7fd52c0bf6e0)

HW Params info (address : 0x7fd52c0bf950)


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