Inhaltsverzeichnis

Audio unter Linux

sx Audio Debugging für OpenSUSE: https://en.opensuse.org/SDB:Audio_troubleshooting

Das Basis-Framework für Sound ist ALSA mit dem für die Soundkarte passenden Treiber. Moderne Linux Distros transportieren alle Audiodaten über den Pulseaudio Daemon als netzwerk-transparenten Datenstream. Daher kann der Pluseaudio Daemon auch auf entfernte Sound-Hardware im Netz zugreifen. Entsprechend kann man Audiodaten über ALSA oder Pulseaudio abgreifen und weiter verarbeiten. Pulseaudio abstrahiert die Audiodaten vollständig von der darunter liegenden Hardware:

Soundquelle oder -Ziel → PulseAudio → ALSA-Treiber → Soundkarte

Jedes Soundgerät ist entweder Quelle (Source) oder Senke (Sink) für Audiodaten.

Aufnehmen auf der Kommandozeile

Mit arecord/aplay

Auflisten aller Mikrofone 

arecord -l

**** Liste der Hardware-Geräte (CAPTURE) ****
Karte 1: PCH [HDA Intel PCH], Gerät 0: ALC1150 Analog [ALC1150 Analog]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 1: PCH [HDA Intel PCH], Gerät 2: ALC1150 Alt Analog [ALC1150 Alt Analog]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 3: CinemaTM [Microsoft® LifeCam Cinema(TM)], Gerät 0: USB Audio [USB Audio]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 4: MS [Sennheiser USB-ED CC 01 for MS], Gerät 0: USB Audio [USB Audio]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0

Aufnahme im Sample Format S16_LE (16 bit little endian, 44100, stereo) in zwei Kanälen (-c) mit Rate 48000 Hertz (-r) für 20 Sekunden (-d) von einem bestimmten Mikrofon (–device) 

arecord -f S16_LE -c 2 -r 48000 -d 20 --device="hw:4,0" tmp/test.wav

Mit Pulseaudio

pactl: Control a running PulseAudio sound server

list [short] [TYPE] 

            Dump all currently loaded modules, available sinks, sources, streams, etc. TYPE must be one of: modules,
            sinks,  sources,  sink-inputs,  source-outputs,  clients,  samples, cards. If not specified, all info is
            listed. If short is given, output is in a tabular format, for easy parsing by scripts.

Oder über pacmd, Auflisten der Devices 

thommie@locutus:~> pacmd list-sources | egrep '^\s+name:.*\.monitor'
        name: <alsa_output.usb-Sennheiser_Sennheiser_USB-ED_CC_01_for_MS_A001010202601978-00.analog-stereo.monitor>
        name: <alsa_output.pci-0000_00_1b.0.analog-stereo.monitor>
        name: <combined.monitor>
        name: <ladspa_output.mbeq_1197.mbeq.monitor>

Aufnehmen 

parecord --channels=1 -d STREAM_NAME filename.wav

Aufnehmen aus einer bestimmten Applikation

(ohne Störung durch Notification aus Plasma/KDE usw.)

Auflisten der Quellen 

pacmd list-sinks | egrep '^\s+name: .*alsa_output'

At a high level, here is what you are going to do:

  1. Create a “null” sink that you will be recording. Let’s call it recording.
  2. Create a combined sink that will send its input to both headphones and the recording sink. Otherwise, you will be able to record a stream but not hear it yourself. So, let’s call this sink combined.
  3. Direct the sound from the specific applications you want to record into the combined sink.
  4. Record the monitor of the recording sink to a file.

Find out the name of your output device by running 

''pacmd list-sinks | egrep '^\s+name: .*alsa_output'''

In my case, it says 

''name: <alsa_output.pci-0000_00_1f.3.analog-stereo>''

To create the two sinks, run these commands (you need to substitute the name of the output device that you learned on the previous step): 

''pacmd load-module module-null-sink sink_name=recording sink_properties=device.description=recording
pacmd load-module module-combine-sink sink_name=combined sink_properties=device.description=combined \
  slaves=recording,alsa_output.pci-0000_00_1f.3.analog-stereo''

If you do this often, make it a permanent setup by creating the file ~/.config/pulse/default.pa with this contents (note that the long load-module command should be on a single line, don’t wrap it): 

''.include /etc/pulse/default.pa
load-module module-null-sink sink_name=recording sink_properties=device.description=recording
load-module module-combine-sink sink_name=combined sink_properties=device.description=combined slaves=recording,alsa_output.pci-0000_00_1f.3.analog-stereo''

Now, redirect the sound to the combined sink:

  1. Run the pavucontrol command (a graphical window will appear) and go to the “Playback” tab.
  2. Start the application you’d like to record.
  3. The application should appear in pavucontrol. If it doesn’t, make sure the application produces some sound. Unfortunately, until the application tries to play something, PulseAudio cannot “see” it.

Quelle: https://ro-che.info/articles/2017-07-21-record-audio-linux

pipewire als pulseaudio Ersatz

https://cubiclenate.com/2021/07/17/pipewire-audio-server-on-opensuse-tumbleweed/

Pakete nachinstallieren 

sudo zypper in pipewire pipewire-pulseaudio pipewire-alsa''

Konflikt 

Problem: the installed pulseaudio-15.0-6.1.x86_64 conflicts with 'pulseaudio-daemon' provided by the to be installed pipewire-pulseaudio-0.3.42-1.1.x86_64
 Solution 1: Following actions will be done:
  deinstallation of pulseaudio-15.0-6.1.x86_64
  deinstallation of pulseaudio-module-bluetooth-15.0-6.1.x86_64
  deinstallation of pulseaudio-module-gsettings-15.0-6.1.x86_64
  deinstallation of pulseaudio-module-x11-15.0-6.1.x86_64
  deinstallation of pulseaudio-module-zeroconf-15.0-6.1.x86_64
  deinstallation of pulseaudio-lang-15.0-6.1.noarch
 Solution 2: do not install pipewire-pulseaudio-0.3.42-1.1.x86_64

Diese Pakete werden deinstalliert 

The following 7 packages are going to be REMOVED:
  alsa-plugins-pulse pulseaudio pulseaudio-lang pulseaudio-module-bluetooth pulseaudio-module-gsettings
  pulseaudio-module-x11 pulseaudio-module-zeroconf

Tuning: https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Migrate-PulseAudio

Crackling/Popping issues on intel-hda soundcard https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/1569

Neustart Audio-System (z.B: bei Erkennungsproblem Bluetooth Audio): 

systemctl restart sound.target

Audio Cleanup