audio

pi/asound.conf

@@ -1,10 +1,26 @@
 # Use the Google Voice HAT soundcard as the primary device by name (card id is "sndrpigooglevoi")
 options snd_rpi_googlevoicehat_soundcard index=0
 
+# Mix multiple playback clients in software with a fixed low-cost format.
+pcm.dmixer {
+    type dmix
+    ipc_key 1024
+    ipc_perm 0666
+    slave {
+        pcm "hw:0,0"
+        format S16_LE
+        rate 16000
+        channels 1
+        period_time 0
+        period_size 1024
+        buffer_size 4096
+    }
+}
+
 # Software playback volume (adjust with: amixer -c0 sset 'SoftMaster' 70%)
 pcm.softvol {
     type softvol
-    slave.pcm "plughw:0,0"
+    slave.pcm "dmixer"
     control {
         name "SoftMaster"
         card 0
@@ -13,10 +29,16 @@ pcm.softvol {
     max_dB 0.0
 }
 
-# Defaults: playback through softvol, capture raw on the HAT
+# Allow clients with mismatched sample formats/rates to use the mixer.
+pcm.playback {
+    type plug
+    slave.pcm "softvol"
+}
+
+# Defaults: playback through shared mixer + softvol, capture raw on the HAT
 pcm.!default {
     type asym
-    playback.pcm "softvol"
+    playback.pcm "playback"
     capture.pcm "hw:0,0"
 }