func (c *Client) handleUdpTunnel(buffer []byte) error {
reader := bytes.NewReader(buffer)
var bytesRead int64
var audioType byte
var audioTarget byte
var user *User
var audioLength int
// Header byte
typeTarget, err := varint.ReadByte(reader)
if err != nil {
return err
}
audioType = (typeTarget >> 5) & 0x7
audioTarget = typeTarget & 0x1F
// Opus only
// TODO: add handling for other packet types
if audioType != audioCodecIDOpus {
return errUnsupportedAudio
}
bytesRead++
// Session
session, n, err := varint.ReadFrom(reader)
if err != nil {
return err
}
user = c.Users[uint32(session)]
if user == nil {
return errInvalidProtobuf
}
bytesRead += n
decoder := user.decoder
if decoder == nil {
return nil
}
// Sequence
sequence, n, err := varint.ReadFrom(reader)
if err != nil {
return err
}
bytesRead += n
// Length
length, n, err := varint.ReadFrom(reader)
if err != nil {
return err
}
// Opus audio packets set the 13th bit in the size field as the terminator.
audioLength = int(length) &^ 0x2000
if audioLength > reader.Len() {
return errInvalidProtobuf
}
audioLength64 := int64(audioLength)
bytesRead += n
raw := buffer[bytesRead : bytesRead+audioLength64]
pcm, err := decoder.Decode(raw, AudioMaximumFrameSize)
if err != nil {
return err
}
event := AudioPacketEvent{
Client: c,
}
event.AudioPacket.Sender = user
event.AudioPacket.Target = int(audioTarget)
event.AudioPacket.Sequence = int(sequence)
event.AudioPacket.PositionalAudioBuffer.AudioBuffer = pcm
reader.Seek(audioLength64, 1)
binary.Read(reader, binary.LittleEndian, &event.AudioPacket.PositionalAudioBuffer.X)
binary.Read(reader, binary.LittleEndian, &event.AudioPacket.PositionalAudioBuffer.Y)
binary.Read(reader, binary.LittleEndian, &event.AudioPacket.PositionalAudioBuffer.Z)
c.audioListeners.OnAudioPacket(&event)
return nil
}
func handleUdpTunnel(c *Client, buffer []byte) error {
reader := bytes.NewReader(buffer)
var bytesRead int64
var audioType byte
var audioTarget byte
var user *User
var audioLength int
// Header byte
typeTarget, err := varint.ReadByte(reader)
if err != nil {
return err
}
audioType = (typeTarget >> 5) & 0x7
audioTarget = typeTarget & 0x1F
// Opus only
if audioType != 4 {
return errInvalidProtobuf
}
bytesRead++
// Session
session, n, err := varint.ReadFrom(reader)
if err != nil {
return err
}
user = c.users[uint(session)]
if user == nil {
return errInvalidProtobuf
}
bytesRead += n
// Sequence
sequence, n, err := varint.ReadFrom(reader)
if err != nil {
return err
}
bytesRead += n
// Length
length, n, err := varint.ReadFrom(reader)
if err != nil {
return err
}
// Opus audio packets set the 13th bit in the size field as the terminator.
audioLength = int(length) &^ 0x2000
if audioLength > reader.Len() {
return errInvalidProtobuf
}
bytesRead += n
opus := buffer[bytesRead : bytesRead+int64(audioLength)]
pcm, err := user.decoder.Decode(opus, AudioMaximumFrameSize, false)
if err != nil {
return err
}
event := AudioPacketEvent{
Client: c,
AudioPacket: AudioPacket{
Sender: user,
Target: int(audioTarget),
Sequence: int(sequence),
Pcm: pcm,
},
}
c.audioListeners.OnAudioPacket(&event)
return nil
}