music/bitvis: Add a gain filter

roles/music/tasks/bitvis.yaml

@@ -47,4 +47,13 @@
     - bitvis
     - bitvis-tee
 
+- name: Install bitvis gain filter
+  ansible.builtin.template:
+    src: pw-bitvis-mixer.conf
+    dest: /etc/pipewire/filter-chain.conf.d/bitvis-mixer.conf
+    owner: root
+    group: root
+    mode: 0644
+  notify: restart bitvis
+
 - meta: flush_handlers

roles/music/templates/bitvis.service

@@ -8,7 +8,10 @@ Restart=always
 RestartSec=10s
 ExecStart=/usr/bin/pw-jack bitvis -a localhost -p 1337 -m localhost -o 6600
 ExecStartPost=/usr/bin/sleep 4
-ExecStartPost=/usr/bin/pw-link alsa_output.usb-ASUS_Xonar_U7_MKII-00.analog-stereo:monitor_FR bitvis:input
+ExecStartPost=-/usr/bin/pw-link bitvis-mixer:output_FL bitvis:input
+ExecStartPost=-/usr/bin/pw-link alsa_output.usb-ASUS_Xonar_U7_MKII-00.analog-stereo:monitor_FL bitvis-mixer:playback_FL
+ExecStartPost=-/usr/bin/pw-link alsa_output.usb-ASUS_Xonar_U7_MKII-00.analog-stereo:monitor_FR bitvis-mixer:playback_FR
+
 User={{ music_audio_user }}
 Environment="XDG_RUNTIME_DIR=/run/user/{{ music_audio_user_id }}"
 

roles/music/templates/pw-bitvis-mixer.conf

@@ -0,0 +1,38 @@
+# {{ ansible_managed }}
+
+context.modules = [
+    {
+        name = libpipewire-module-filter-chain
+        args = {
+            node.description = "bitvis-mixer"
+            media.name       = "bitvis-mixer"
+            filter.graph = {
+                nodes = [
+                    {
+                        name   = mix
+                        type   = builtin
+                        label  = mixer
+                        control = {
+                          "Gain 1" = 10
+                          "Gain 2" = 10
+                        }
+                    }
+                ]
+                inputs  = [ "mix:In 1" "mix:In 2" ]
+                outputs = [ "mix:Out" ]
+            }
+            capture.props = {
+                node.name         = "mix_input.bitvis"
+                audio.position    = [ FL FR ]
+                media.class       = "Audio/Sink"
+            }
+            playback.props = {
+                node.name         = "mix_output.bitvis"
+                audio.position    = [ FL ]
+                stream.dont-remix = true
+                node.passive      = true
+                node.autoconnect  = false
+            }
+        }
+    }
+]