Protocol improvements

channel.go

@@ -5,16 +5,20 @@ import (
   "fmt"
 )
 
-type ChannelID uint32
+type ChannelID byte
 
 const (
   MODE_CHANNEL ModeID = iota
   MODE_RAW
+  MODE_AUDIO
 
   CHANNEL_JOIN byte = iota
   CHANNEL_LEAVE
   CHANNEL_MEMBERS
 
+  AUDIO_SET_SAMPLE_RATE = iota
+  AUDIO_GET_SAMPLE_RATE
+
   RAW_DATA = iota
 )
 
@@ -38,9 +42,9 @@ func(channel *Channel) Data(session *Session, mode ModeID, data []byte) []SendPa
   }
 }
 
-func(channel *Channel) Command(session *Session, mode ModeID, command byte, data []byte) ([]SendPacket, error) {
-  if mode == MODE_CHANNEL {
-    switch command {
+func(channel *Channel) Command(session *Session, packet ChannelCommandPacket) ([]SendPacket, error) {
+  if packet.Mode == MODE_CHANNEL {
+    switch packet.Command {
     case CHANNEL_JOIN:
       if slices.Contains(channel.sessions, session.ID) {
         return nil, fmt.Errorf("Session %s already in channel %d, can't join", session.ID, channel.id)
@@ -57,14 +61,14 @@ func(channel *Channel) Command(session *Session, mode ModeID, command byte, data
         return nil, nil
       }
     default:
-      return nil, fmt.Errorf("Unknown MODE_CHANNEL command: 0x%02x", command)
+      return nil, fmt.Errorf("Unknown MODE_CHANNEL command: 0x%02x", packet.Command)
     }
   } else {
-    mode, has_mode := channel.modes[mode]
+    mode, has_mode := channel.modes[packet.Mode]
     if has_mode == false {
       return nil, fmt.Errorf("Channel has no mode 0x%02x", mode)
     } else {
-      return mode.Command(session, channel, command, data)
+      return mode.Command(session, channel, packet)
     }
   }
 }
@@ -76,14 +80,15 @@ type SendPacket struct {
 
 type Mode interface {
   // Process takes incoming packets from a session and returns a list of packets to send
-  Command(session *Session, channel *Channel, command byte, data []byte) ([]SendPacket, error)
+  Command(session *Session, channel *Channel, packet ChannelCommandPacket) ([]SendPacket, error)
   Data(session *Session, channel *Channel, data []byte) []SendPacket
 }
 
-func multiplex(session *Session, packet *Packet, sessions []SessionID) []SendPacket {
-  send_packets := make([]SendPacket, len(sessions))
-  for i, session_id := range(sessions) {
-    if session_id == session.ID {
+func multiplex_without_sender(origin SessionID, packet *Packet, sessions []SessionID) []SendPacket {
+  send_packets := make([]SendPacket, len(sessions) - 1)
+  i := 0
+  for _, session_id := range(sessions) {
+    if session_id == origin {
       continue
     }
 
@@ -91,6 +96,19 @@ func multiplex(session *Session, packet *Packet, sessions []SessionID) []SendPac
       Packet: packet,
       Session: session_id,
     }
+    i += 1
+  }
+
+  return send_packets
+}
+
+func multiplex(packet *Packet, sessions []SessionID) []SendPacket {
+  send_packets := make([]SendPacket, len(sessions))
+  for i, session_id := range(sessions) {
+    send_packets[i] = SendPacket{
+      Packet: packet,
+      Session: session_id,
+    }
   }
 
   return send_packets
@@ -99,14 +117,60 @@ func multiplex(session *Session, packet *Packet, sessions []SessionID) []SendPac
 type RawMode struct {
 }
 
-func(mode *RawMode) Command(session *Session, channel *Channel, command byte, data []byte) ([]SendPacket, error) {
-  return nil, fmt.Errorf("unknown raw mode command 0x%02x", command)
+func(mode *RawMode) Command(session *Session, channel *Channel, packet ChannelCommandPacket) ([]SendPacket, error) {
+  return nil, fmt.Errorf("unknown raw mode command 0x%02x", packet.Command)
 }
 
 func(mode *RawMode) Data(session *Session, channel *Channel, data []byte) []SendPacket {
   if slices.Contains(channel.sessions, session.ID) {
     new_packet := NewChannelPeerPacket(session.Peer, channel.id, MODE_RAW, data)
-    return multiplex(session, new_packet, channel.sessions)
+    return multiplex_without_sender(session.ID, new_packet, channel.sessions)
+  }
+  return nil
+}
+
+type SampleRate byte
+const (
+  SAMPLE_RATE_UNSET SampleRate = 0xFF
+  SAMPLE_RATE_24KHZ = 0x01
+  SAMPLE_RATE_48KHZ = 0x02
+)
+
+type AudioMode struct {
+  SampleRate SampleRate
+}
+
+func(mode *AudioMode) Command(session *Session, channel *Channel, packet ChannelCommandPacket) ([]SendPacket, error) {
+  switch packet.Command {
+  case AUDIO_SET_SAMPLE_RATE:
+    if len(packet.Data) == 1 {
+      switch SampleRate(packet.Data[0]) {
+      case SAMPLE_RATE_24KHZ:
+        fallthrough
+      case SAMPLE_RATE_48KHZ:
+        mode.SampleRate = SampleRate(packet.Data[0])
+        update_packet := NewChannelCommandPacket(packet.ReqID, channel.id, MODE_AUDIO, AUDIO_SET_SAMPLE_RATE, packet.Data)
+        return multiplex(update_packet, channel.sessions), nil
+      default:
+        return nil, fmt.Errorf("Invalid sample rate: %x", packet.Data[0])
+      }
+    } else {
+      return nil, fmt.Errorf("Invalid AUDIO_SET_SAMPLE_RATE payload: %x", packet.Data)
+    }
+  case AUDIO_GET_SAMPLE_RATE:
+    return []SendPacket{{
+      Packet: NewChannelCommandPacket(packet.ReqID, channel.id, MODE_AUDIO, AUDIO_SET_SAMPLE_RATE, []byte{byte(mode.SampleRate)}),
+      Session: session.ID,
+    }}, nil
+  default:
+    return nil, fmt.Errorf("unknown audio mode command 0x%02x", packet.Command)
+  }
+}
+
+func(mode *AudioMode) Data(session *Session, channel *Channel, data []byte) []SendPacket {
+  if slices.Contains(channel.sessions, session.ID) {
+    new_packet := NewChannelPeerPacket(session.Peer, channel.id, MODE_AUDIO, data)
+    return multiplex_without_sender(session.ID, new_packet, channel.sessions)
   }
   return nil
 }

cmd/client/main.go

@@ -8,16 +8,83 @@ import (
 
 	"git.metznet.ca/MetzNet/pnyx"
 	"github.com/gen2brain/malgo"
+	"github.com/google/uuid"
 	"github.com/hraban/opus"
 )
 
-func main() {
-  decoders := map[pnyx.PeerID]chan[]byte{}
-  encoder, err := opus.NewEncoder(48000, 1, opus.AppVoIP)
+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)
+
+func set_sample_rate(new_sample_rate int) error {
+  sample_rate = new_sample_rate
+
+  var err error
+  fmt.Printf("Creating encoder with sample_rate %d\n", new_sample_rate)
+  encoder, err = opus.NewEncoder(new_sample_rate, 1, opus.AppVoIP)
+  if err != nil {
+    return err
+  }
+
+  for peer_id, decoder_chan := range(decoders) {
+    if decoder_chan != nil {
+      decoder_chan <- nil
+    }
+    new_chan := make(chan[]byte, 1000)
+    decoders[peer_id] = new_chan
+    go handle_peer_decode(peer_id, decoders[peer_id], sample_rate)
+  }
+  return nil
+}
+
+func handle_peer_decode(peer_id pnyx.PeerID, decode_chan chan[]byte, sample_rate int){
+  fmt.Printf("Starting decoder routine for %x with sample_rate %d\n", peer_id, sample_rate)
+  decoder, err := opus.NewDecoder(sample_rate, 1)
+  if err != nil {
+    panic(err)
+  }
+
+  running := true
+  for running {
+    select {
+    case <-time.After(20*time.Millisecond):
+      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
+
+    case data := <-decode_chan:
+      if data == nil {
+        running = false
+      } else {
+        pcm := make([]int16, sample_rate/50*2)
+        written, err := decoder.Decode(data, pcm)
         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]))
+        }
+
+        speaker <- pcm_bytes
+      }
+    }
+  }
+  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)
   if err != nil {
     panic(err)
@@ -84,9 +151,6 @@ func main() {
 	outDeviceConfig.Alsa.NoMMap = 1
   outDeviceConfig.Playback.ShareMode = malgo.Shared
 
-  mic := make(chan []byte, 0)
-  speaker := make(chan []byte, 0)
-
   onSendFrames := func(output_samples []byte, input_samples []byte, framecount uint32) {
     select {
     case data := <- speaker:
@@ -115,6 +179,7 @@ func main() {
   defer outDevice.Stop()
 
 	onRecvFrames := func(output_samples []byte, input_samples []byte, framecount uint32) {
+    if encoder != nil {
       pcm := make([]int16, len(input_samples)/2)
       for i := 0; i < len(input_samples)/2; i++ {
         pcm[i] = int16(binary.LittleEndian.Uint16(input_samples[2*i:]))
@@ -125,10 +190,10 @@ func main() {
       if err != nil {
         panic(err)
       }
-
       select {
       case mic <- data[:written]:
       default:
+      }
     }
 	}
 
@@ -182,67 +247,70 @@ func main() {
       }
 
       switch packet := packet.(type) {
-      case pnyx.ChannelPeerPacket:
+      case pnyx.ChannelCommandPacket:
         if packet.Channel == pnyx.ChannelID(0) {
-          decode_chan, exists := decoders[packet.Peer]
-          if exists == false {
-            decode_chan = make(chan[]byte, 1000)
-            decoders[packet.Peer] = decode_chan
-
-            go func(decode_chan chan[]byte){
-              decoder, err := opus.NewDecoder(48000, 1)
-              if err != nil {
-                panic(err)
-              }
-
-              for true {
-                select {
-                case <-time.After(20*time.Millisecond):
-                  pcm := make([]int16, 960)
-                  err := decoder.DecodePLC(pcm)
-                  if err != nil {
-                    panic(err)
-                  }
-
-                  pcm_bytes := make([]byte, 960*2)
-                  for i := 0; i < 960; i++ {
-                    binary.LittleEndian.PutUint16(pcm_bytes[i*2:], uint16(pcm[i]))
+          if packet.Mode == pnyx.MODE_AUDIO {
+            if packet.Command == pnyx.AUDIO_SET_SAMPLE_RATE {
+              fmt.Printf("GOT NEW SAMPLE RATE 0x%02x\n", packet.Data)
+              var new_sample_rate int
+              switch packet.Data[0] {
+              case byte(pnyx.SAMPLE_RATE_24KHZ):
+                new_sample_rate = 24000
+              case byte(pnyx.SAMPLE_RATE_48KHZ):
+                new_sample_rate = 48000
+              default:
+                continue
               }
-                  speaker <- pcm_bytes
-                case data := <-decode_chan:
-                  pcm := make([]int16, 960)
-                  written, err := decoder.Decode(data, pcm)
+              err := set_sample_rate(new_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]))
             }
-                  speaker <- pcm_bytes
           }
         }
-
-            }(decoders[packet.Peer])
+      case pnyx.ChannelPeerPacket:
+        if packet.Channel == pnyx.ChannelID(0) {
+          decode_chan, exists := decoders[packet.Peer]
+          if exists == false {
+            if sample_rate != 0 {
+              decode_chan = make(chan[]byte, 1000)
+              decoders[packet.Peer] = decode_chan
+              go handle_peer_decode(packet.Peer, decoders[packet.Peer], sample_rate)
+              decode_chan <- packet.Data
+            } else {
+              decoders[packet.Peer] = nil
             }
+          } else if decode_chan != nil {
             decode_chan <- packet.Data
           }
+        }
       default:
         fmt.Printf("Unhandled packet type: %s\n", packet)
       }
     }
   }()
 
-  join_packet, _ := pnyx.NewChannelCommandPacket(pnyx.ChannelID(0), pnyx.MODE_CHANNEL, pnyx.CHANNEL_JOIN, nil)
+  add_packet, _ := pnyx.NewServerCommandPacket(pnyx.SERVER_COMMAND_ADD_CHANNEL, []byte{0xFF})
+  err = client.Send(add_packet)
+  if err != nil {
+    panic(err)
+  }
+
+  join_packet := pnyx.NewChannelCommandPacket(uuid.New(), pnyx.ChannelID(0), pnyx.MODE_CHANNEL, pnyx.CHANNEL_JOIN, nil)
   err = client.Send(join_packet)
   if err != nil {
     panic(err)
   }
 
+  get_sample_rate_packet := pnyx.NewChannelCommandPacket(uuid.New(), pnyx.ChannelID(0), pnyx.MODE_AUDIO, pnyx.AUDIO_SET_SAMPLE_RATE, []byte{byte(pnyx.SAMPLE_RATE_48KHZ)})
+  err = client.Send(get_sample_rate_packet)
+  if err != nil {
+    panic(err)
+  }
+
   for true {
     data := <- mic
-    err = client.Send(pnyx.NewChannelDataPacket(pnyx.ChannelID(0), pnyx.MODE_RAW, data))
+    err = client.Send(pnyx.NewChannelDataPacket(pnyx.ChannelID(0), pnyx.MODE_AUDIO, data))
     if err != nil {
       panic(err)
     }

cmd/server/main.go

@@ -23,7 +23,9 @@ func main() {
     panic(err)
   }
 
-  err = server.AddChannel(pnyx.ChannelID(0), &pnyx.RawMode{})
+  err = server.AddChannel(pnyx.ChannelID(0), &pnyx.RawMode{}, &pnyx.AudioMode{
+    SampleRate: pnyx.SAMPLE_RATE_24KHZ,
+  })
   if err != nil {
     panic(err)
   }

packet.go

@@ -2,7 +2,6 @@ package pnyx
 
 import (
 	"encoding"
-	"encoding/binary"
 	"fmt"
 
 	"github.com/google/uuid"
@@ -10,13 +9,17 @@ import (
 
 type PacketType uint8
 const (
-  PACKET_CHANNEL_COMMAND PacketType = iota
+  PACKET_SERVER_COMMAND PacketType = iota
+  PACKET_CHANNEL_COMMAND 
   PACKET_CHANNEL_DATA
   PACKET_CHANNEL_PEER
 
-  CHANNEL_HEADER_LEN int = 5
+  CHANNEL_HEADER_LEN int = 2
   CHANNEL_COMMAND_LEN = CHANNEL_HEADER_LEN + COMMAND_LENGTH + REQ_ID_LENGTH
   CHANNEL_PEER_LEN = CHANNEL_HEADER_LEN + PEER_ID_LENGTH
+
+  SERVER_COMMAND_ADD_CHANNEL byte = iota
+  SERVER_COMMAND_DEL_CHANNEL
 )
 
 type Payload interface {
@@ -43,6 +46,8 @@ func ParsePacket(data []byte) (Payload, error) {
   }
 
   switch PacketType(data[0]) {
+  case PACKET_SERVER_COMMAND:
+    return ParseServerCommandPacket(data[1:])
   case PACKET_CHANNEL_DATA:
     return ParseChannelDataPacket(data[1:])
   case PACKET_CHANNEL_COMMAND:
@@ -54,24 +59,62 @@ func ParsePacket(data []byte) (Payload, error) {
   }
 }
 
+type ServerCommandPacket struct {
+  ReqID uuid.UUID
+  Command byte
+  Data []byte
+}
+
+func (packet ServerCommandPacket) MarshalBinary() ([]byte, error) {
+  p := make([]byte, 17 + len(packet.Data))
+  copy(p, packet.ReqID[:])
+  p[16] = packet.Command
+  copy(p[17:], packet.Data)
+
+  return p, nil
+}
+
+func NewServerCommandPacket(command byte, data []byte) (*Packet, uuid.UUID) {
+  req_id := uuid.New()
+  return &Packet{
+    Type: PACKET_SERVER_COMMAND,
+    Payload: ServerCommandPacket{
+      ReqID: req_id,
+      Command: command,
+      Data: data,
+    },
+  }, req_id
+}
+
+func ParseServerCommandPacket(data []byte) (ServerCommandPacket, error) {
+  if len(data) < 17 {
+    return ServerCommandPacket{}, fmt.Errorf("Not enough data to decode ServerCommandPacket: %d/%d", len(data), 17)
+  }
+
+  return ServerCommandPacket{
+    ReqID: uuid.UUID(data[0:16]),
+    Command: data[16],
+    Data: data[17:],
+  }, nil
+}
+
 type ChannelHeader struct {
   Channel ChannelID
   Mode ModeID
 }
 
 func(packet ChannelHeader) MarshalBinary() ([]byte, error) {
-  p := binary.BigEndian.AppendUint32(nil, uint32(packet.Channel))
-  return append(p, byte(packet.Mode)), nil
+  return []byte{byte(packet.Channel), byte(packet.Mode)}, nil
 }
 
 func ParseChannelHeader(data []byte) (ChannelHeader, error) {
-  if len(data) < 5 {
+  if len(data) < 2 {
     return ChannelHeader{}, fmt.Errorf("Not enough bytes to parse ChannelPacket(%d/%d)", len(data), 6)
   }
 
   return ChannelHeader{
-    Channel: ChannelID(binary.BigEndian.Uint32(data)),
-    Mode: ModeID(data[4]),
+    Channel: ChannelID(data[0]),
+    Mode: ModeID(data[1]),
   }, nil
 }
 
@@ -82,8 +125,7 @@ type ChannelCommandPacket struct {
   Data []byte
 }
 
-func NewChannelCommandPacket(channel ChannelID, mode ModeID, command byte, data []byte) (*Packet, uuid.UUID) {
-  request_id := uuid.New()
+func NewChannelCommandPacket(request_id uuid.UUID, channel ChannelID, mode ModeID, command byte, data []byte) *Packet {
   return &Packet{
     Type: PACKET_CHANNEL_COMMAND,
     Payload: ChannelCommandPacket{
@@ -95,7 +137,7 @@ func NewChannelCommandPacket(channel ChannelID, mode ModeID, command byte, data
       ReqID: request_id,
       Data: data,
     },
-  }, request_id
+  } 
 }
 
 func(packet ChannelCommandPacket) MarshalBinary() ([]byte, error) {
@@ -104,9 +146,12 @@ func(packet ChannelCommandPacket) MarshalBinary() ([]byte, error) {
     return nil, err
   }
 
-  data := append(header, packet.Command)
-  data = append(data, packet.ReqID[:]...)
-  return append(data, packet.Data...), nil
+  data := make([]byte, len(header) + len(packet.Data) + REQ_ID_LENGTH + COMMAND_LENGTH)
+  copy(data, header)
+  data[CHANNEL_HEADER_LEN] = packet.Command
+  copy(data[CHANNEL_HEADER_LEN + COMMAND_LENGTH:], packet.ReqID[:])
+  copy(data[CHANNEL_HEADER_LEN + COMMAND_LENGTH + REQ_ID_LENGTH:], packet.Data)
+  return data, nil
 }
 
 func ParseChannelCommandPacket(data []byte) (ChannelCommandPacket, error) {

server.go

@@ -64,6 +64,7 @@ func NewServer(key ed25519.PrivateKey) (*Server, error) {
 
     modes: map[reflect.Type]ModeID{
       reflect.TypeFor[*RawMode](): MODE_RAW,
+      reflect.TypeFor[*AudioMode](): MODE_AUDIO,
     },
 
     sessions: map[SessionID]*ServerSession{},
@@ -195,6 +196,15 @@ func handle_session_incoming(session *ServerSession, server *Server) {
     }
 
     switch packet := packet.(type) {
+    case ServerCommandPacket:
+      switch packet.Command {
+      case SERVER_COMMAND_ADD_CHANNEL:
+        server.Log("Got add_channel with %x", packet.Data)
+      case SERVER_COMMAND_DEL_CHANNEL:
+        server.Log("Got del_channel with %x", packet.Data)
+      default:
+        server.Log("Unknown server command %x", packet.Command)
+      }
     case ChannelDataPacket:
       var result []SendPacket = nil
 
@@ -218,7 +228,7 @@ func handle_session_incoming(session *ServerSession, server *Server) {
       server.channels_lock.RLock()
       channel, exists := server.channels[packet.Channel]
       if exists == true {
-        result, err = channel.Command(&session.Session, packet.Mode, packet.Command, packet.Data)
+        result, err = channel.Command(&session.Session, packet)
       }
       server.channels_lock.RUnlock()
 
@@ -314,6 +324,7 @@ func(server *Server) handle_session_close(session_close []byte, from *net.UDPAdd
   return nil
 }
 
+// TODO: handle packets without creating so many objects(and preventing an extra copy)
 func(server *Server) handle_session_data(data []byte, from *net.UDPAddr) error {
   session_id := SessionID(data[:SESSION_ID_LENGTH])
   session, exists := server.sessions[session_id]