/// <summary>
/// Parses 1 RTCP packet from the specified buffer.
/// </summary>
/// <param name="buffer">Buffer which contains RTCP packet.</param>
/// <param name="offset">Offset in buffer.</param>
/// <param name="noException">If true and parsing failed, no exception is raised.</param>
/// <returns>Returns parsed RTCP packet or null if parsing is failed and <b>noException=true</b>.</returns>
/// <exception cref="ArgumentNullException">Is raised when <b>buffer</b> is null.</exception>
/// <exception cref="ArgumentException">Is raised when any of the arguments has invalid value.</exception>
public static RTCP_Packet Parse(byte[] buffer, ref int offset, bool noException)
{
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
if (offset < 0)
{
throw new ArgumentException("Argument 'offset' value must be >= 0.");
}
/* RFC 3550 RTCP header.
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* header |V=2|P| XX | type | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
int type = buffer[offset + 1];
// SR
if (type == RTCP_PacketType.SR)
{
RTCP_Packet_SR packet = new RTCP_Packet_SR();
packet.ParseInternal(buffer, ref offset);
return(packet);
}
// RR
else if (type == RTCP_PacketType.RR)
{
RTCP_Packet_RR packet = new RTCP_Packet_RR();
packet.ParseInternal(buffer, ref offset);
return(packet);
}
// SDES
else if (type == RTCP_PacketType.SDES)
{
RTCP_Packet_SDES packet = new RTCP_Packet_SDES();
packet.ParseInternal(buffer, ref offset);
return(packet);
}
// BYE
else if (type == RTCP_PacketType.BYE)
{
RTCP_Packet_BYE packet = new RTCP_Packet_BYE();
packet.ParseInternal(buffer, ref offset);
return(packet);
}
// APP
else if (type == RTCP_PacketType.APP)
{
RTCP_Packet_APP packet = new RTCP_Packet_APP();
packet.ParseInternal(buffer, ref offset);
return(packet);
}
else
{
// We need to move offset.
offset += 2;
int length = buffer[offset++] << 8 | buffer[offset++];
offset += length;
if (noException)
{
return(null);
}
else
{
throw new ArgumentException("Unknown RTCP packet type '" + type + "'.");
}
}
}