separate audio stream

pi/bin/audio-only-publisher.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+set -euo pipefail
+set +H
+
+ENV_FILE="${VIDEO_ENV_FILE:-/var/lib/roverd/video.env}"
+
+if [[ ! -f "$ENV_FILE" ]]; then
+	echo "Environment file ${ENV_FILE} missing; cannot publish audio" >&2
+	exit 1
+fi
+
+# shellcheck disable=SC1090
+source "$ENV_FILE"
+: "${AUDIO_PUBLISH_URL:?AUDIO_PUBLISH_URL not set in ${ENV_FILE}}"
+
+AUDIO_DEVICE="${AUDIO_DEVICE:-hw:0,0}"
+AUDIO_RATE="${AUDIO_RATE:-48000}"
+AUDIO_CHANNELS="${AUDIO_CHANNELS:-2}"
+
+if [[ -n "${FFMPEG_BIN:-}" ]]; then
+	FFMPEG_BIN_PATH="$FFMPEG_BIN"
+elif command -v ffmpeg >/dev/null 2>&1; then
+	FFMPEG_BIN_PATH="$(command -v ffmpeg)"
+else
+	echo "ffmpeg not found; install it via apt install ffmpeg." >&2
+	exit 1
+fi
+
+run_pipeline() {
+	"${FFMPEG_BIN_PATH}" \
+		-hide_banner \
+		-loglevel warning \
+		-fflags nobuffer \
+		-rtbufsize 0 \
+		-thread_queue_size 4096 \
+		-f s32le \
+		-ar "${AUDIO_RATE}" \
+		-ac "${AUDIO_CHANNELS}" \
+		-i <(arecord -D "${AUDIO_DEVICE}" -f S32_LE -c "${AUDIO_CHANNELS}" -r "${AUDIO_RATE}" -B 65536 -F 2048 -q -t raw) \
+		-af "aresample=16000,pan=mono|c0=0.5*FL+0.5*FR" \
+		-c:a libopus \
+		-b:a 24000 \
+		-ar:a 16000 \
+		-ac:a 1 \
+		-application lowdelay \
+		-frame_duration 20 \
+		-compression_level 0 \
+		-f mpegts \
+		"${AUDIO_PUBLISH_URL}"
+}
+
+while true; do
+	if run_pipeline; then
+		exit 0
+	fi
+	echo "Audio-only publisher exited, restarting in 2s..." >&2
+	sleep 2
+done

pi/install_roverd.sh

@@ -206,6 +206,10 @@ install -D -o root -g root -m 0755 pi/bin/video-publisher.sh /usr/local/bin/vide
 log "Installed video-publisher helper"
 install -m 0644 pi/systemd/video-publisher.service /etc/systemd/system/video-publisher.service
 log "Installed video-publisher systemd unit"
+# Install audio-only publisher assets
+install -D -o root -g root -m 0755 pi/bin/audio-only-publisher.sh /usr/local/bin/audio-only-publisher
+install -m 0644 pi/systemd/audio-only-publisher.service /etc/systemd/system/audio-only-publisher.service
+log "Installed audio-only publisher helper + systemd unit"
 # Install audio capture assets (arecord -> FIFO) [optional, not enabled by default]
 install -D -o root -g root -m 0755 pi/bin/audio-capture.sh /usr/local/bin/audio-capture
 install -m 0644 pi/systemd/audio-capture.service /etc/systemd/system/audio-capture.service
@@ -214,6 +218,7 @@ install -d -o roverd -g roverd /var/lib/roverd
 cat > /var/lib/roverd/video.env <<'ENV'
 # Managed by roverd; placeholder values will be overwritten at runtime.
 PUBLISH_URL=srt://192.168.0.86:9000?streamid=#!::r=CHANGE_ME,m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316
+AUDIO_PUBLISH_URL=srt://192.168.0.86:9000?streamid=#!::r=CHANGE_ME-audio,m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316
 VIDEO_WIDTH=1280
 VIDEO_HEIGHT=720
 VIDEO_FPS=30
@@ -245,12 +250,14 @@ install_audio_support
 systemctl daemon-reload
 systemctl enable roverd.service
 systemctl enable video-publisher.service
+systemctl enable audio-only-publisher.service
 if [[ $CONFIG_EXISTS -eq 1 ]]; then
 	systemctl restart roverd.service
 	systemctl restart video-publisher.service
-	log "Restarted roverd + video publisher"
+	systemctl restart audio-only-publisher.service
+	log "Restarted roverd + video/audio publishers"
 else
-	log "Skipped auto-start because config is the sample; edit $CONFIG_DEST then run: sudo systemctl restart roverd video-publisher"
+	log "Skipped auto-start because config is the sample; edit $CONFIG_DEST then run: sudo systemctl restart roverd video-publisher audio-only-publisher"
 fi
 
 log "Install complete"

pi/roverd/config.go

@@ -66,16 +66,19 @@ type AudioConfig struct {
 }
 
 type MediaConfig struct {
-	PublishURL     string   `yaml:"publishUrl" json:"publishUrl,omitempty"`
+	PublishURL      string   `yaml:"publishUrl" json:"publishUrl,omitempty"`
-	PublishPort    int      `yaml:"publishPort" json:"-"`
+	AudioPublishURL string   `yaml:"audioPublishUrl" json:"audioPublishUrl,omitempty"`
-	Manage         bool     `yaml:"manage"`
+	PublishPort     int      `yaml:"publishPort" json:"-"`
-	Service        string   `yaml:"service"`
+	Manage          bool     `yaml:"manage"`
-	HealthURL      string   `yaml:"healthUrl"`
+	ManageAudio     bool     `yaml:"manageAudio"`
-	HealthInterval Duration `yaml:"healthInterval"`
+	Service         string   `yaml:"service"`
-	VideoWidth     int      `yaml:"videoWidth" json:"-"`
+	AudioService    string   `yaml:"audioService"`
-	VideoHeight    int      `yaml:"videoHeight" json:"-"`
+	HealthURL       string   `yaml:"healthUrl"`
-	VideoFPS       int      `yaml:"videoFps" json:"-"`
+	HealthInterval  Duration `yaml:"healthInterval"`
-	VideoBitrate   int      `yaml:"videoBitrate" json:"-"`
+	VideoWidth      int      `yaml:"videoWidth" json:"-"`
+	VideoHeight     int      `yaml:"videoHeight" json:"-"`
+	VideoFPS        int      `yaml:"videoFps" json:"-"`
+	VideoBitrate    int      `yaml:"videoBitrate" json:"-"`
 }
 
 type CameraServoConfig struct {
@@ -201,6 +204,13 @@ func LoadConfig(path string) (*Config, error) {
 		}
 		cfg.Media.PublishURL = derived
 	}
+	if cfg.Media.AudioPublishURL == "" {
+		derived, err := derivePublishURL(cfg.ServerURL, cfg.Name+"-audio", cfg.Media.PublishPort)
+		if err != nil {
+			return nil, fmt.Errorf("derive audioPublishUrl: %w", err)
+		}
+		cfg.Media.AudioPublishURL = derived
+	}
 	if err := validateServoConfig(&cfg.CameraServo); err != nil {
 		return nil, fmt.Errorf("cameraServo: %w", err)
 	}
@@ -268,9 +278,9 @@ func validateAudioConfig(cfg *AudioConfig) {
 	}
 }
 
-func derivePublishURL(serverURL, roverName string, port int) (string, error) {
+func derivePublishURL(serverURL, streamName string, port int) (string, error) {
-	if roverName == "" {
+	if streamName == "" {
-		return "", errors.New("missing rover name for publishUrl")
+		return "", errors.New("missing stream name for publishUrl")
 	}
 	parsed, err := url.Parse(serverURL)
 	if err != nil {
@@ -283,6 +293,6 @@ func derivePublishURL(serverURL, roverName string, port int) (string, error) {
 	if port <= 0 {
 		port = 9000
 	}
-	streamName := url.PathEscape(roverName)
+	escaped := url.PathEscape(streamName)
-	return fmt.Sprintf("srt://%s:%d?streamid=#!::r=%s,m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316", host, port, streamName), nil
+	return fmt.Sprintf("srt://%s:%d?streamid=#!::r=%s,m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316", host, port, escaped), nil
 }

pi/roverd/media_env.go

@@ -13,6 +13,9 @@ func UpdatePublisherEnv(media MediaConfig, audio AudioConfig) error {
 	if media.PublishURL == "" {
 		return fmt.Errorf("media publishUrl missing")
 	}
+	if media.AudioPublishURL == "" && audio.CaptureEnabled {
+		return fmt.Errorf("audio publishUrl missing")
+	}
 	if media.VideoWidth <= 0 || media.VideoHeight <= 0 || media.VideoFPS <= 0 || media.VideoBitrate <= 0 {
 		return fmt.Errorf("invalid media dimensions/bitrate")
 	}
@@ -21,6 +24,9 @@ func UpdatePublisherEnv(media MediaConfig, audio AudioConfig) error {
 	}
 	var buf bytes.Buffer
 	fmt.Fprintf(&buf, "PUBLISH_URL=%s\n", media.PublishURL)
+	if audio.CaptureEnabled && media.AudioPublishURL != "" {
+		fmt.Fprintf(&buf, "AUDIO_PUBLISH_URL=%s\n", media.AudioPublishURL)
+	}
 	fmt.Fprintf(&buf, "VIDEO_WIDTH=%d\n", media.VideoWidth)
 	fmt.Fprintf(&buf, "VIDEO_HEIGHT=%d\n", media.VideoHeight)
 	fmt.Fprintf(&buf, "VIDEO_FPS=%d\n", media.VideoFPS)

pi/systemd/audio-only-publisher.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=Rover Audio Publisher (ALSA -> SRT)
+After=network-online.target roverd.service
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=roverd
+Group=roverd
+EnvironmentFile=/var/lib/roverd/video.env
+ExecStart=/usr/local/bin/audio-only-publisher
+Restart=always
+RestartSec=2
+
+[Install]
+WantedBy=multi-user.target