🎉 live server seems to be working now

internal/pipewire/nodes.go

@@ -0,0 +1,155 @@
+package pipewire
+
+import (
+	"encoding/json"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+type Node struct {
+	ID          int
+	Name        string
+	Description string
+	MediaClass  string
+}
+
+func (n Node) String() string {
+	if n.Description != "" && n.Description != n.Name {
+		return fmt.Sprintf("%s  [%s]", n.Description, n.Name)
+	}
+	return n.Name
+}
+
+type pwObject struct {
+	ID   int    `json:"id"`
+	Type string `json:"type"`
+	Info struct {
+		Props struct {
+			MediaClass  string `json:"media.class"`
+			NodeName    string `json:"node.name"`
+			NodeDesc    string `json:"node.description"`
+		} `json:"props"`
+	} `json:"info"`
+}
+
+func listAllNodes() ([]Node, error) {
+	out, err := exec.Command("pw-dump").Output()
+	if err != nil {
+		return nil, fmt.Errorf("pw-dump: %w", err)
+	}
+
+	var objects []pwObject
+	if err := json.Unmarshal(out, &objects); err != nil {
+		return nil, fmt.Errorf("parse pw-dump: %w", err)
+	}
+
+	var nodes []Node
+	for _, o := range objects {
+		if o.Type != "PipeWire:Interface:Node" {
+			continue
+		}
+		if !strings.HasPrefix(o.Info.Props.MediaClass, "Audio/") || o.Info.Props.NodeName == "" {
+			continue
+		}
+		nodes = append(nodes, Node{
+			ID:          o.ID,
+			Name:        o.Info.Props.NodeName,
+			Description: o.Info.Props.NodeDesc,
+			MediaClass:  o.Info.Props.MediaClass,
+		})
+	}
+	return nodes, nil
+}
+
+func ListSinks() ([]Node, error) {
+	all, err := listAllNodes()
+	if err != nil {
+		return nil, err
+	}
+	var out []Node
+	for _, n := range all {
+		if n.MediaClass == "Audio/Sink" {
+			out = append(out, n)
+		}
+	}
+	return out, nil
+}
+
+func ListSources() ([]Node, error) {
+	all, err := listAllNodes()
+	if err != nil {
+		return nil, err
+	}
+	var out []Node
+	for _, n := range all {
+		switch n.MediaClass {
+		case "Audio/Source", "Audio/Source.Virtual":
+			out = append(out, n)
+		}
+	}
+	return out, nil
+}
+
+// CaptureTarget is a node that can be fed to `pw-cat --capture --target`.
+// Real microphones / line-ins / virtual sources have IsMonitor=false.
+// Audio sinks are surfaced with IsMonitor=true: pw-cat reads the monitor
+// port when given a sink as --target, so the live server can stream
+// whatever audio the host is currently playing.
+type CaptureTarget struct {
+	Name        string
+	Description string
+	IsMonitor   bool
+}
+
+// ListCaptureTargets returns every PipeWire node usable as audio input
+// for the live server. Sinks are surfaced as monitor capture targets
+// (pw-cat captures the monitor port when given a sink as --target);
+// `.monitor` pseudo-sources exposed by the PulseAudio compatibility
+// layer are also included since `pw-cat --target <name>.monitor` is
+// the canonical way to capture playback on many setups.
+//
+// Order: real microphones / line-ins first, then monitors (the things
+// most users actually want for "stream what's playing").
+func ListCaptureTargets() ([]CaptureTarget, error) {
+	all, err := listAllNodes()
+	if err != nil {
+		return nil, err
+	}
+
+	var realSources, monitorSources, sinkMonitors []CaptureTarget
+	monitorNames := map[string]bool{}
+
+	for _, n := range all {
+		switch n.MediaClass {
+		case "Audio/Source", "Audio/Source.Virtual":
+			if strings.HasSuffix(n.Name, ".monitor") {
+				monitorSources = append(monitorSources, CaptureTarget{
+					Name: n.Name, Description: n.Description, IsMonitor: true,
+				})
+				monitorNames[n.Name] = true
+			} else {
+				realSources = append(realSources, CaptureTarget{
+					Name: n.Name, Description: n.Description,
+				})
+			}
+		case "Audio/Sink":
+			// Skip the sink itself when its corresponding ".monitor"
+			// source already covers the same capture path — pick one
+			// canonical name (the source) to avoid two indistinguishable
+			// dropdown entries.
+			if monitorNames[n.Name+".monitor"] {
+				continue
+			}
+			sinkMonitors = append(sinkMonitors, CaptureTarget{
+				Name: n.Name, Description: n.Description, IsMonitor: true,
+			})
+		}
+	}
+
+	out := make([]CaptureTarget, 0, len(realSources)+len(monitorSources)+len(sinkMonitors))
+	out = append(out, realSources...)
+	out = append(out, monitorSources...)
+	out = append(out, sinkMonitors...)
+	return out, nil
+}