fixed random WdmSyncloctl error in nats server (windows)

When starting a Nats Server on Windows, enabling the ScWriter during
startup caused the following portaudio error:
'WdmSyncIoctl: DeviceIoControl GLE = 0x00000490
(prop_set = {8C134960-51AD-11CF-878A-94F801C10000}, prop_id = 10)'
For unknown reasons, this error is thrown if the stream is started
immediately.

audio/sinks/scWriter/scWriter.go

@@ -39,10 +39,6 @@ type src struct {
 // device. This is typically a speaker or a pair of headphones.
 func NewScWriter(opts ...Option) (*ScWriter, error) {
 
-	if err := pa.Initialize(); err != nil {
-		return nil, err
-	}
-
 	w := &ScWriter{
 		options: Options{
 			DeviceName:      "default",

audio/sources/scReader/scReader.go

@@ -26,10 +26,6 @@ type ScReader struct {
 // asynchronously from an a local audio device (e.g. a microphone).
 func NewScReader(opts ...Option) (*ScReader, error) {
 
-	if err := pa.Initialize(); err != nil {
-		return nil, err
-	}
-
 	r := &ScReader{
 		options: Options{
 			HostAPI:         "default",

cmd/client_nats.go

@@ -158,7 +158,9 @@ func natsAudioClient(cmd *cobra.Command, args []string) {
 	natsBrokerPort := viper.GetInt("nats.broker-port")
 	serverName := viper.GetString("server.name")
 
-	portaudio.Initialize()
+	if err := portaudio.Initialize(); err != nil {
+		exit(err)
+	}
 	defer portaudio.Terminate()
 
 	if len(serverName) > 0 && strings.ContainsAny(serverName, " _\n\r") {
@@ -323,7 +325,7 @@ func natsAudioClient(cmd *cobra.Command, args []string) {
 	rx.Sources.AddSource("fromNetwork", fromNetwork)
 	// set and enable speaker as default sink
 	rx.Sinks.AddSink("speaker", speaker, true)
-	// start streaming to the network immediately
+	// start streaming from the network immediately
 	rx.Sources.SetSource("fromNetwork")
 
 	tx.Sources.AddSource("mic", mic)

cmd/enumerate.go

@@ -47,7 +47,10 @@ Available audio devices and supported Host APIs:
 
 // enumerate lists all available Audio devices on the system
 func enumerate() {
-	portaudio.Initialize()
+	if err := portaudio.Initialize(); err != nil {
+		exit(err)
+	}
+
 	defer portaudio.Terminate()
 
 	hs, err := portaudio.HostApis()

cmd/server_nats.go

@@ -130,7 +130,10 @@ func natsAudioServer(cmd *cobra.Command, args []string) {
 	natsBrokerPort := viper.GetInt("nats.broker-port")
 	natsAddr := fmt.Sprintf("nats://%s:%v", natsBrokerURL, natsBrokerPort)
 
-	portaudio.Initialize()
+	if err := portaudio.Initialize(); err != nil {
+		exit(err)
+	}
+
 	defer portaudio.Terminate()
 
 	// start from default nats config and add the common options
@@ -301,10 +304,17 @@ func natsAudioServer(cmd *cobra.Command, args []string) {
 
 	// add audio sinks & sources to the tx audio chain
 	tx.Sources.AddSource("fromNetwork", fromNetwork)
-	tx.Sinks.AddSink("mic", mic, false)
+	// stream immediately audio from the network to the radio
+	if err := tx.Sources.SetSource("fromNetwork"); err != nil {
+		exit(err)
+	}
+	tx.Sinks.AddSink("mic", mic, true)
 
 	// add audio sinks & sources to the rx audio chain
 	rx.Sources.AddSource("radioAudio", radioAudio)
+	if err := rx.Sources.SetSource("radioAudio"); err != nil {
+		exit(err)
+	}
 	rx.Sinks.AddSink("toNetwork", toNetwork, false)
 
 	// assign the rx and tx audio chain to our natsServer
@@ -342,17 +352,9 @@ func natsAudioServer(cmd *cobra.Command, args []string) {
 	}
 	ns.txAudioSub = sub
 
-	// register our Rotator RPC handler
+	// register our RPC handler
 	sbAudio.RegisterServerHandler(rs.Server(), ns)
 
-	rx.Sources.SetSource("radioAudio")
-
-	// stream immediately audio from the network to the radio
-	tx.Sources.SetSource("fromNetwork")
-	if err := tx.Enable(true); err != nil {
-		exit(err)
-	}
-
 	// when no ping is received, turn of the audio stream
 	go ns.checkTimeout()