PulseAudio: Difference between revisions

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</syntaxHighlight>

==Troubleshooting ~~PulseAudio~~==

==Explicit PulseAudio support in applications==

Normally, the system-wide ALSA configuration (<tt>/etc/asound.conf</tt>) redirects the audio of applications which use the ALSA API through PulseAudio. For this reason, most applications do not need to be PulseAudio-aware. Some NixOS packages can be built with explicit PulseAudio support which is disabled by default. This support can be enabled in all applicable packages by setting:

nixpkgs.config.pulseaudio = true;

</syntaxHighlight>

== Using Pulseaudio Equalizer ==

Currently (2017-11-29 {{issue|8384}}) the <code>qpaeq</code> command does not work out of the box, use the following commands to get it running:

$ pactl load-module module-equalizer-sink

$ pactl load-module module-dbus-protocol

$ nix-shell -p python27Full python27Packages.pyqt4 python27Packages.dbus-python --command qpaeq

</syntaxHighlight>

== Troubleshooting ==

=== General troubleshooting ===

Before troubleshooting PulseAudio, determine that the kernel-level sound APIs (ALSA) are functional; see [[ALSA]].

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(The problem is that also also tries to connect to the card that is already used by pulseaudio, so we need a module pulseaudio-alsa on pulseaudio to redirect also calls to pulseaudio)

==~~Explicit PulseAudio support in applications~~==

=== Clicking and Garbled Audio ===

~~Normally,~~ the ~~system~~-~~wide ALSA configuration (<tt>/etc/asound.conf</tt>) redirects the~~ audio of ~~applications which use~~ the ~~ALSA API through PulseAudio. For this reason~~, ~~most applications do not need to be PulseAudio~~-~~aware~~. ~~Some NixOS packages can be built with explicit PulseAudio support which is disabled by default. This support can be enabled in all applicable packages by setting:~~

The newer implementation of the PulseAudio sound server uses timer-based audio scheduling instead of the traditional, interrupt-driven approach.

~~<syntaxHighlight lang="nix">~~

~~nixpkgs.config.pulseaudio = true;~~

~~</syntaxHighlight>~~

~~== Using Pulseaudio Equalizer ==~~

Timer-based scheduling may expose issues in some ALSA drivers. On the other hand, other drivers might be glitchy without it on, so check to see what works on your system.

~~Currently (2017~~-~~11-29 {{issue|8384}})~~ the ~~<code>qpaeq</code> command does not work out of the box~~, ~~use the following commands~~ to ~~get it running:~~

~~<syntaxHighlight lang=console>~~

~~$ pactl load-module module-equalizer-sink~~

~~$ pactl load-module module-dbus-protocol~~

~~$ nix-shell -p python27Full python27Packages~~.~~pyqt4 python27Packages.dbus-python --command qpaeq~~

~~</syntaxHighlight>~~

~~== Clicking and Garbled Audio for Creative Sound Cards ==~~

To turn timer-based scheduling off add this to your configuration:

~~If you own a sound card from Creative like X~~-~~Fi and you notice random clicks during audio playback, then~~ add ~~following~~ to your configuration ~~[https://github.com/NixOS/nixpkgs/issues/788#issuecomment-21707426]~~:

hardware.pulseaudio.configFile = pkgs.runCommand "default.pa" {} ''

sed 's/module-udev-detect$/module-udev-detect tsched=0/' \

${pkgs.pulseaudio}/etc/pulse/default.pa > $out

'';

</syntaxHighlight>

Then perform <code># nixos-rebuild switch</code>, followed by <code>$ pulseaudio -k</code>.

The difference should be directly noticeable. This is a known issue related to quality of Creative driver [https://guh.me/solving-creative-sound-blaster-x-fi-titanium-crackling-slash-distortion-on-linux].

The difference should be directly noticeable. This is a known issue related to quality of Creative driver [https://guh.me/solving-creative-sound-blaster-x-fi-titanium-crackling-slash-distortion-on-linux], but it can also happen with other sound cards.

==See also==

@@ Line 15: / Line 15: @@
 </syntaxHighlight>
-==Troubleshooting PulseAudio==
+==Explicit PulseAudio support in applications==
+Normally, the system-wide ALSA configuration (<tt>/etc/asound.conf</tt>) redirects the audio of applications which use the ALSA API through PulseAudio. For this reason, most applications do not need to be PulseAudio-aware. Some NixOS packages can be built with explicit PulseAudio support which is disabled by default. This support can be enabled in all applicable packages by setting:
+<syntaxHighlight lang="nix">
+nixpkgs.config.pulseaudio = true;
+</syntaxHighlight>
+== Using Pulseaudio Equalizer ==
+Currently (2017-11-29 {{issue|8384}}) the <code>qpaeq</code> command does not work out of the box, use the following commands to get it running:
+<syntaxHighlight lang=console>
+$ pactl load-module module-equalizer-sink
+$ pactl load-module module-dbus-protocol
+$ nix-shell -p python27Full python27Packages.pyqt4 python27Packages.dbus-python --command qpaeq
+</syntaxHighlight>
+== Troubleshooting ==
+=== General troubleshooting ===
 Before troubleshooting PulseAudio, determine that the kernel-level sound APIs (ALSA) are functional; see [[ALSA]].
@@ Line 47: / Line 64: @@
 (The problem is that also also tries to connect to the card that is already used by pulseaudio, so we need a module pulseaudio-alsa on pulseaudio to redirect also calls to pulseaudio)
-==Explicit PulseAudio support in applications==
+=== Clicking and Garbled Audio ===
-Normally, the system-wide ALSA configuration (<tt>/etc/asound.conf</tt>) redirects the audio of applications which use the ALSA API through PulseAudio. For this reason, most applications do not need to be PulseAudio-aware. Some NixOS packages can be built with explicit PulseAudio support which is disabled by default. This support can be enabled in all applicable packages by setting:
+The newer implementation of the PulseAudio sound server uses timer-based audio scheduling instead of the traditional, interrupt-driven approach.
-<syntaxHighlight lang="nix">
-nixpkgs.config.pulseaudio = true;
-</syntaxHighlight>
-== Using Pulseaudio Equalizer ==
+Timer-based scheduling may expose issues in some ALSA drivers. On the other hand, other drivers might be glitchy without it on, so check to see what works on your system.
-Currently (2017-11-29 {{issue|8384}}) the <code>qpaeq</code> command does not work out of the box, use the following commands to get it running:
-<syntaxHighlight lang=console>
-$ pactl load-module module-equalizer-sink
-$ pactl load-module module-dbus-protocol
-$ nix-shell -p python27Full python27Packages.pyqt4 python27Packages.dbus-python --command qpaeq
-</syntaxHighlight>
-== Clicking and Garbled Audio for Creative Sound Cards ==
+To turn timer-based scheduling off add this to your configuration:
-If you own a sound card from Creative like X-Fi and you notice random clicks during audio playback, then add following to your configuration [https://github.com/NixOS/nixpkgs/issues/788#issuecomment-21707426]:
 <syntaxHighlight lang="nix">
-  hardware.pulseaudio.configFile = pkgs.runCommand "default.pa" {} ''
+hardware.pulseaudio.configFile = pkgs.runCommand "default.pa" {} ''
-    sed 's/module-udev-detect$/module-udev-detect tsched=0/' \
+  sed 's/module-udev-detect$/module-udev-detect tsched=0/' \
-      ${pkgs.pulseaudio}/etc/pulse/default.pa > $out
+    ${pkgs.pulseaudio}/etc/pulse/default.pa > $out
-  '';
+'';
 </syntaxHighlight>
 Then perform <code># nixos-rebuild switch</code>, followed by <code>$ pulseaudio -k</code>.
-The difference should be directly noticeable. This is a known issue related to quality of Creative driver [https://guh.me/solving-creative-sound-blaster-x-fi-titanium-crackling-slash-distortion-on-linux].
+The difference should be directly noticeable. This is a known issue related to quality of Creative driver [https://guh.me/solving-creative-sound-blaster-x-fi-titanium-crackling-slash-distortion-on-linux], but it can also happen with other sound cards.
 ==See also==