mu-law

pi/bin/video-publisher.sh

@@ -29,10 +29,10 @@ VIDEO_HEIGHT="${VIDEO_HEIGHT:-1080}"
 VIDEO_FPS="${VIDEO_FPS:-30}"
 VIDEO_BITRATE="${VIDEO_BITRATE:-3000000}"
 AUDIO_ENABLE="${AUDIO_ENABLE:-0}"
-AUDIO_DEVICE="${AUDIO_DEVICE:-plughw:0,0}"
-AUDIO_CODEC="pcm_s16le"
-# Keep the audio path simple for the Pi Zero; default to PCM, and honor any rate/channels provided.
-AUDIO_RATE="${AUDIO_RATE:-48000}"
+AUDIO_DEVICE="${AUDIO_DEVICE:-hw:0,0}"
+AUDIO_CODEC="${AUDIO_CODEC:-pcm_mulaw}"
+# Keep the audio path simple for the Pi Zero; default to G.711 mu-law (very light) and honor overrides.
+AUDIO_RATE="${AUDIO_RATE:-8000}"
 AUDIO_CHANNELS="${AUDIO_CHANNELS:-1}"
 AUDIO_DEVICE="${AUDIO_DEVICE:-plughw:0,0}"
 # Flip the camera 180deg (supported by rpicam-vid/libcamera-vid)

pi/install_roverd.sh

@@ -208,7 +208,7 @@ VIDEO_FPS=30
 VIDEO_BITRATE=2000000
 AUDIO_ENABLE=0
 AUDIO_DEVICE=hw:0,0
-AUDIO_RATE=48000
+AUDIO_RATE=8000
 AUDIO_CHANNELS=1
 ENV
 chown roverd:roverd /var/lib/roverd/video.env

pi/roverd/config.go

@@ -143,7 +143,7 @@ func LoadConfig(path string) (*Config, error) {
 		Audio: AudioConfig{
 			CaptureEnabled: false,
 			CaptureDevice:  "hw:0,0",
-			SampleRate:     48000,
+			SampleRate:     8000,
 			Channels:       1,
 			Bitrate:        24000,
 			TTSEnabled:     false,
@@ -249,7 +249,7 @@ func validateAudioConfig(cfg *AudioConfig) {
 		cfg.CaptureDevice = "hw:0,0"
 	}
 	if cfg.SampleRate <= 0 {
-		cfg.SampleRate = 48000
+		cfg.SampleRate = 8000
 	}
 	if cfg.Channels <= 0 {
 		cfg.Channels = 1

pi/roverd/media_env.go

@@ -30,7 +30,7 @@ func UpdatePublisherEnv(media MediaConfig, audio AudioConfig) error {
 		audioDevice = "hw:0,0"
 	}
 	if audio.SampleRate <= 0 {
-		audio.SampleRate = 48000
+		audio.SampleRate = 8000
 	}
 	if audio.Channels <= 0 {
 		audio.Channels = 1

pi/roverd/roverd.sample.yaml

@@ -40,7 +40,7 @@ cameraServo:
 audio:
   captureEnabled: false
   captureDevice: hw:0,0
-  sampleRate: 48000
+  sampleRate: 8000
   channels: 1
   bitrate: 24000
   ttsEnabled: false