Added digital mixer goroutine

cmd/client/main.go

@@ -16,7 +16,8 @@ var decoders = map[pnyx.PeerID]chan[]byte{}
 var encoder *opus.Encoder
 var sample_rate int = 0
 var mic = make(chan []byte, 0)
-var speaker = make(chan []byte, 0)
+var speaker = make(chan []int16, 0)
+var audio_data = make(chan []int16, 0)
 
 func set_sample_rate(new_sample_rate int) error {
   sample_rate = new_sample_rate
@@ -47,22 +48,26 @@ func handle_peer_decode(peer_id pnyx.PeerID, decode_chan chan[]byte, sample_rate
   }
 
   running := true
+  missed := 0
   for running {
     select {
     case <-time.After(20*time.Millisecond):
+      missed += 1
+
+      if missed > 100 {
+        fmt.Printf("Missed 100 packets from %x, stopping stream until data received\n", peer_id)
+        decode_chan <- <- decode_chan
+      }
+
       pcm := make([]int16, sample_rate/50)
       err := decoder.DecodePLC(pcm)
       if err != nil {
         panic(err)
       }
-
-      pcm_bytes := make([]byte, sample_rate/50*2)
-      for i := 0; i < sample_rate/50; i++ {
-        binary.LittleEndian.PutUint16(pcm_bytes[i*2:], uint16(pcm[i]))
-      }
-      speaker <- pcm_bytes
+      audio_data <- pcm
 
     case data := <-decode_chan:
+      missed = 0
       if data == nil {
         running = false
       } else {
@@ -71,18 +76,31 @@ func handle_peer_decode(peer_id pnyx.PeerID, decode_chan chan[]byte, sample_rate
         if err != nil {
           panic(err)
         }
-
-        pcm_bytes := make([]byte, written*2)
-        for i := 0; i < written; i++ {
-          binary.LittleEndian.PutUint16(pcm_bytes[i*2:], uint16(pcm[i]))
+        audio_data <- pcm[:written]
+      }
+    }
+  }
+  fmt.Printf("Stopping decoder routine for %x with sample_rate %d\n", peer_id, sample_rate)
 }
 
-        speaker <- pcm_bytes
+func mixer(data_chan chan []int16, speaker_chan chan []int16) {
+  var samples []int16 = nil
+  for true {
+    if samples == nil {
+      samples = <- data_chan
+    } else {
+      select {
+      case new_samples := <- data_chan:
+        for i, sample := range(new_samples) {
+          samples[i] += sample
         }
+      case speaker_chan <- samples:
+        samples = nil
       }
     }
-  fmt.Printf("Stopping decoder routine for %x with sample_rate %d\n", peer_id, sample_rate)
   }
+}
+
 
 func main() {
   ctx, err := malgo.InitContext(nil, malgo.ContextConfig{}, nil)
@@ -90,6 +108,8 @@ func main() {
     panic(err)
   }
 
+  go mixer(audio_data, speaker)
+
   defer ctx.Free()
   defer ctx.Uninit()
 
@@ -153,8 +173,10 @@ func main() {
 
   onSendFrames := func(output_samples []byte, input_samples []byte, framecount uint32) {
     select {
-    case data := <- speaker:
-      copy(output_samples, data)
+    case pcm := <- speaker:
+      for i := 0; i < sample_rate/50; i++ {
+        binary.LittleEndian.PutUint16(output_samples[i*2:], uint16(pcm[i]))
+      }
     default:
     }
   }