private void TryWriteSource(Span <byte> bytes, int?sourceIdentifier, int index)
{
if (sourceIdentifier.HasValue)
{
NetworkBitConverter.WriteBytes(bytes.Slice(index * IdentifierLength, IdentifierLength), sourceIdentifier.Value);
}
}
public bool MoveNext()
{
currentSourceIdentifier = null;
if (remainsOfBytes.IsEmpty)
{
return(false);
}
var identifierBytes = remainsOfBytes.Span.Slice(0, IdentifierLength);
currentSourceIdentifier = NetworkBitConverter.ToInt32(identifierBytes);
remainsOfBytes = remainsOfBytes.Slice(IdentifierLength);
return(true);
}
public static bool TryParse(ReadOnlyMemory <byte> bytes, out RtpMessage message)
{
message = new RtpMessage();
if (bytes.Length < MinLength)
{
return(false);
}
var first2Bytes = bytes.Span.Slice(0, 2);
var version = first2Bytes[0] >> 6;
if (version != CurrentVersion)
{
return(false);
}
var isPadded = Convert.ToBoolean((first2Bytes[0] >> 5) & 1);
var paddedByteCount = 0;
if (isPadded)
{
paddedByteCount = bytes.Span[bytes.Length - 1];
}
if (paddedByteCount > bytes.Length - MinLength)
{
return(false);
}
var notPaddedBytes = bytes.Slice(0, bytes.Length - paddedByteCount);
var remainsOfBytes = notPaddedBytes.Slice(MinLength);
var hasHeaderExtension = Convert.ToBoolean((first2Bytes[0] >> 4) & 1);
var CSRCCount = first2Bytes[0] & 15;
var CSRCLength = CSRCCount * IdentifierLength;
if (remainsOfBytes.Length < CSRCLength)
{
return(false);
}
var CSRCBytes = remainsOfBytes.Slice(0, CSRCLength);
var payload = remainsOfBytes.Slice(CSRCLength);
var sources = new SourceIdentifiers(CSRCBytes, CSRCCount);
var isMarker = Convert.ToBoolean(first2Bytes[1] >> 7);
var payloadType = first2Bytes[1] & 127;
var sequenceNumber = NetworkBitConverter.ToUInt16(bytes.Span.Slice(2, 2));
var timestamp = NetworkBitConverter.ToInt32(bytes.Span.Slice(4, 4));
var sourceIdentifier = NetworkBitConverter.ToInt32(bytes.Span.Slice(8, 4));
message = new RtpMessage(version,
hasHeaderExtension,
isMarker,
payloadType,
sequenceNumber,
timestamp,
sourceIdentifier,
sources,
payload);
return(true);
}
private Span <byte> WriteSourceIdentifier(Span <byte> bytes)
{
NetworkBitConverter.WriteBytes(bytes.Slice(0, 4), state.sourceIdentifier);
return(bytes.Slice(4));
}
private Span <byte> WriteTimestamp(Span <byte> bytes)
{
NetworkBitConverter.WriteBytes(bytes.Slice(0, 4), state.timestamp);
return(bytes.Slice(4));
}
private Span <byte> WriteSequenceNumber(Span <byte> bytes)
{
NetworkBitConverter.WriteBytes(bytes.Slice(0, 2), state.sequenceNumber);
return(bytes.Slice(2));
}