private async Task VoiceReceiverTask()
{
var token = ReceiverToken;
var client = UdpClient;
while (!token.IsCancellationRequested)
{
if (client.DataAvailable <= 0)
{
continue;
}
byte[] data = null, header = null;
ushort seq = 0;
uint ts = 0, ssrc = 0;
try
{
data = await client.ReceiveAsync().ConfigureAwait(false);
header = new byte[RtpCodec.SIZE_HEADER];
data = Rtp.Decode(data, header);
var nonce = Rtp.MakeNonce(header);
data = Sodium.Decode(data, nonce, Key);
// following is thanks to code from Eris
// https://github.com/abalabahaha/eris/blob/master/lib/voice/VoiceConnection.js#L623
var doff = 0;
Rtp.Decode(header, out seq, out ts, out ssrc, out var has_ext);
if (has_ext)
{
if (data[0] == 0xBE && data[1] == 0xDE)
{
// RFC 5285, 4.2 One-Byte header
// http://www.rfcreader.com/#rfc5285_line186
var hlen = data[2] << 8 | data[3];
var i = 4;
for (; i < hlen + 4; i++)
{
var b = data[i];
// This is unused(?)
//var id = (b >> 4) & 0x0F;
var len = (b & 0x0F) + 1;
i += len;
}
while (data[i] == 0)
{
i++;
}
doff = i;
}
// TODO: consider implementing RFC 5285, 4.3. Two-Byte Header
}
data = Opus.Decode(data, doff, data.Length - doff);
}
catch { continue; }
// TODO: wait for ssrc map?
DiscordUser user = null;
if (SSRCMap.ContainsKey(ssrc))
{
var id = SSRCMap[ssrc];
if (Guild != null)
{
user = Guild._members.FirstOrDefault(xm => xm.Id == id) ?? await Guild.GetMemberAsync(id).ConfigureAwait(false);
}
if (user == null)
{
user = Discord.InternalGetCachedUser(id);
}
if (user == null)
{
user = new DiscordUser {
Discord = Discord, Id = id
}
}
;
}
await _voiceReceived.InvokeAsync(new VoiceReceiveEventArgs(Discord)
{
SSRC = ssrc,
Voice = new ReadOnlyCollection <byte>(data),
VoiceLength = 20,
User = user
}).ConfigureAwait(false);
}
}
