Public bug reported: Hi,
it isn't easy to describe but i will try and give you all information which seem to interfer with the bug .. Sorry, my system is running with german language output. First my environment : Description: Ubuntu 18.04.5 LTS Release: 18.04 Kernel: 5.4.0-54-generic #60~18.04.1-Ubuntu SMP Fri Nov 6 17:25:16 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux alsa: $ apt list --installed|grep -i alsa alsa-base/bionic,bionic,now 1.0.25+dfsg-0ubuntu5 all [installiert] alsa-utils/bionic,now 1.1.3-1ubuntu1 amd64 [installiert] libsox-fmt-alsa/bionic-updates,bionic-security,now 14.4.2-3ubuntu0.18.04.1 amd64 [Installiert,automatisch] libzita-alsa-pcmi0/bionic,now 0.2.0-4ubuntu2 amd64 [Installiert,automatisch] jackd: apt list --installed|grep -i jackd jackd/bionic,bionic,now 5 all [Installiert,automatisch] jackd2/bionic,now 1.9.12~dfsg-2 amd64 [Installiert,automatisch] libjack-jackd2-0/bionic,now 1.9.12~dfsg-2 amd64 [Installiert,automatisch] libjack-jackd2-dev/bionic,now 1.9.12~dfsg-2 amd64 [installiert] My interface (Omega) : $ aplay -l **** Liste der Hardware-Geräte (PLAYBACK) **** Karte 0: PCH [HDA Intel PCH], Gerät 0: ALC887-VD Analog [ALC887-VD Analog] Sub-Geräte: 1/1 Sub-Gerät #0: subdevice #0 Karte 0: PCH [HDA Intel PCH], Gerät 1: ALC887-VD Digital [ALC887-VD Digital] Sub-Geräte: 1/1 Sub-Gerät #0: subdevice #0 Karte 0: PCH [HDA Intel PCH], Gerät 3: HDMI 0 [HDMI 0] Sub-Geräte: 1/1 Sub-Gerät #0: subdevice #0 Karte 0: PCH [HDA Intel PCH], Gerät 7: HDMI 1 [HDMI 1] Sub-Geräte: 1/1 Sub-Gerät #0: subdevice #0 Karte 1: Omega [Lexicon Omega], Gerät 0: USB Audio [USB Audio] Sub-Geräte: 1/1 Sub-Gerät #0: subdevice #0 Karte 1: Omega [Lexicon Omega], Gerät 1: USB Audio [USB Audio #1] Sub-Geräte: 1/1 Sub-Gerät #0: subdevice #0 The problem: I try to record some audio, using the usb-audio-interface Lexicon Omega. This interface has 4 capture channels, but all efforts to get them working/configured failed. Here is the commandline wich is working (but only two capture-channels !) $ /usr/bin/jackd -T -ndefault -dalsa -r4800 -p256 -n3 H -D -d hw:Omega -i2 -o2 jackdmp 1.9.12 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2016 Grame. Copyright 2016-2017 Filipe Coelho. 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 10 self-connect-mode is "Don't restrict self connect requests" audio_reservation_init Acquire audio card Audio1 creating alsa driver ... hw:Omega|hw:Omega|256|3|4800|2|2|nomon|swmeter|-|32bit configuring for 4800Hz, period = 256 frames (53.3 ms), buffer = 3 periods ALSA: final selected sample format for capture: 24bit little-endian in 3bytes format ALSA: use 3 periods for capture ALSA: final selected sample format for playback: 24bit little-endian in 3bytes format ALSA: use 3 periods for playback The same with 4 capture-channels fails: $ /usr/bin/jackd -T -ndefault -dalsa -r4800 -p256 -n3 H -D -d hw:Omega -i4 -o2 jackdmp 1.9.12 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2016 Grame. Copyright 2016-2017 Filipe Coelho. 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 10 self-connect-mode is "Don't restrict self connect requests" audio_reservation_init Acquire audio card Audio1 creating alsa driver ... hw:Omega|hw:Omega|256|3|4800|4|2|nomon|swmeter|-|32bit configuring for 4800Hz, period = 256 frames (53.3 ms), buffer = 3 periods ALSA: final selected sample format for capture: 24bit little-endian in 3bytes format ALSA: cannot set channel count to 4 for capture ALSA: cannot configure capture channel JackTemporaryException : now quits... Released audio card Audio1 audio_reservation_finish Cannot initialize driver JackServer::Open failed with -1 Failed to open server So, one could say the interface is broken, but i tested on an older system (Ubuntustudio 16.04): $ uname -a 4.10.0-42-lowlatency #46~16.04.1-Ubuntu SMP PREEMPT Mon Dec 4 17:13:40 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux $ apt list --installed|grep -i alsa alsa-base/bionic,bionic,now 1.0.25+dfsg-0ubuntu5 all [installiert] alsa-tools/bionic,now 1.1.3-1 amd64 [installiert] alsa-tools-gui/bionic,now 1.1.3-1 amd64 [installiert] alsa-utils/bionic,now 1.1.3-1ubuntu1 amd64 [installiert] gstreamer1.0-alsa/bionic-updates,now 1.14.5-0ubuntu1~18.04.1 amd64 [installiert] libsox-fmt-alsa/bionic-updates,bionic-security,now 14.4.2-3ubuntu0.18.04.1 amd64 [installiert] libzita-alsa-pcmi0/bionic,now 0.2.0-4ubuntu2 amd64 [installiert] $ apt list --installed|grep -i jackd jackd/bionic,bionic,now 5 all [installiert] jackd2/bionic,now 1.9.12~dfsg-2 amd64 [installiert] jackd2-firewire/bionic,now 1.9.12~dfsg-2 amd64 [installiert] libjack-jackd2-0/bionic,now 1.9.12~dfsg-2 amd64 [installiert] libjack-jackd2-dev/bionic,now 1.9.12~dfsg-2 amd64 [installiert] jackd is configure via qjackctl, no specification of channelcount (only default-value:0 ). Here's the output of jackd starting (finding 4 capture channels + 2 playback channels) --- snip--- Tue Nov 17 12:23:43 2020: Starting jack server... Tue Nov 17 12:23:43 2020: JACK server starting in realtime mode with priority 10 Tue Nov 17 12:23:43 2020: self-connect-mode is "Don't restrict self connect requests" Tue Nov 17 12:23:43 2020: Jack: JackPosixThread::StartImp : create non RT thread Tue Nov 17 12:23:43 2020: Jack: JackPosixThread::ThreadHandler : start Tue Nov 17 12:23:43 2020: Jack: capture device hw:Omega Tue Nov 17 12:23:43 2020: Jack: playback device hw:Omega Tue Nov 17 12:23:43 2020: Jack: apparent rate = 44100 Tue Nov 17 12:23:43 2020: Jack: frames per period = 256 Tue Nov 17 12:23:43 2020: Jack: JackDriver::Open capture_driver_name = hw:Omega Tue Nov 17 12:23:43 2020: Jack: JackDriver::Open playback_driver_name = hw:Omega Tue Nov 17 12:23:43 2020: Jack: Check protocol client = 8 server = 8 Tue Nov 17 12:23:43 2020: Jack: JackEngine::ClientInternalOpen: name = system Tue Nov 17 12:23:43 2020: Jack: JackEngine::AllocateRefNum ref = 0 Tue Nov 17 12:23:43 2020: Jack: JackLinuxFutex::Allocate name = jack_sem.505_default_system val = 0 Tue Nov 17 12:23:43 2020: Jack: JackEngine::NotifyAddClient: name = system Tue Nov 17 12:23:43 2020: Jack: JackGraphManager::SetBufferSize size = 256 Tue Nov 17 12:23:43 2020: Jack: JackConnectionManager::DirectConnect first: ref1 = 0 ref2 = 0 Tue Nov 17 12:23:43 2020: Jack: JackGraphManager::ConnectRefNum cur_index = 0 ref1 = 0 ref2 = 0 Tue Nov 17 12:23:43 2020: Jack: JackDriver::SetupDriverSync driver sem in flush mode Tue Nov 17 12:23:43 2020: Acquired audio card Audio1 Tue Nov 17 12:23:43 2020: creating alsa driver ... hw:Omega|hw:Omega|256|2|44100|0|0|hwmon|swmeter|-|32bit Tue Nov 17 12:23:43 2020: configuring for 44100Hz, period = 256 frames (5.8 ms), buffer = 2 periods Tue Nov 17 12:23:43 2020: ALSA: final selected sample format for capture: 24bit little-endian in 3bytes format Tue Nov 17 12:23:43 2020: ALSA: use 2 periods for capture Tue Nov 17 12:23:43 2020: ALSA: final selected sample format for playback: 24bit little-endian in 3bytes format Tue Nov 17 12:23:43 2020: ALSA: use 2 periods for playback --- snip-- The attachment shows you there are 4 capture-channels. The bug is described here by another person too: https://linuxmusicians.com/viewtopic.php?f=64&t=21380 My opinion is that somewhere in development of kernel alsa has lost it's capability to configure more than 2 capture-channels. I wonder why nobody else is complaining, maybe because it's an usb-device ? If you need more information, please tell me which, i will provide them. best regards Harry ** Affects: ubuntu Importance: Undecided Status: New ** Attachment added: "Screenshot showing 4 capture-channels" https://bugs.launchpad.net/bugs/1904566/+attachment/5435139/+files/4-Channels.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1904566 Title: jackd/alsa: only 2 channels of 4 found on usb-interface Lexicon Omega (ALSA: cannot set channel count to 4 for capture) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1904566/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs