internal static OpusHeader ParsePacket(byte[] packet, int packetLength)
{
if (packetLength < 19)
{
return(null);
}
if (!"OpusHead".Equals(Encoding.UTF8.GetString(packet, 0, 8)))
{
return(null);
}
OpusHeader header = new OpusHeader();
header.version = packet[8];
header.channel_count = packet[9];
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(packet, 10, 2);
Array.Reverse(packet, 12, 4);
Array.Reverse(packet, 16, 2);
}
header.pre_skip = BitConverter.ToUInt16(packet, 10);
header.input_sample_rate = BitConverter.ToUInt32(packet, 12);
header.output_gain = BitConverter.ToInt16(packet, 16);
header.mapping_family = packet[18];
return(header);
}
/// <summary>
/// Looks for the next opus data packet in the Ogg stream and queues it up.
/// If the end of stream has been reached, this does nothing.
/// </summary>
private void QueueNextPacket()
{
if (_endOfStream)
{
return;
}
DataPacket packet = _packetProvider.GetNextPacket();
if (packet == null || packet.IsEndOfStream)
{
_endOfStream = true;
_nextDataPacket = null;
return;
}
byte[] buf = new byte[packet.Length];
packet.Read(buf, 0, packet.Length);
packet.Done();
if (buf.Length > 8 && "OpusHead".Equals(Encoding.UTF8.GetString(buf, 0, 8)))
{
_header = OpusHeader.ParsePacket(buf, buf.Length);
QueueNextPacket();
}
else if (buf.Length > 8 && "OpusTags".Equals(Encoding.UTF8.GetString(buf, 0, 8)))
{
_tags = OpusTags.ParsePacket(buf, buf.Length);
QueueNextPacket();
}
else
{
_nextDataPacket = buf;
}
}