public PesPacket(byte[] buffer, int offset = 0)
{
int position = offset;
if (buffer[position++] != 0 || buffer[position++] != 0 || buffer[position++] != 1)
throw new ArgumentException("PES Packet does not start with 0x000001 Start Code Prefix.");
StreamIdentifier = (StreamIdentifier) buffer[position++];
PacketLength = (buffer[position++] << 8) | buffer[position++];
if (PacketLength == 0) PacketLength = buffer.Length - offset - 6;
if (StreamIdentifier != StreamIdentifier.ProgramStreamMap
&& StreamIdentifier != StreamIdentifier.PaddingStream
&& StreamIdentifier != StreamIdentifier.PrivateStream2
&& StreamIdentifier != StreamIdentifier.EcmStream
&& StreamIdentifier != StreamIdentifier.EmmStream
&& StreamIdentifier != StreamIdentifier.ProgramStreamDirectory
&& StreamIdentifier != StreamIdentifier.DsmCcStream
&& StreamIdentifier != StreamIdentifier.TypeEStream)
{
Header = new PESHeader(buffer, position);
position += Header.Length;
Data = new byte[PacketLength - Header.Length];
// TODO: Something may be squirrely here. position+PacketLength should never be > buffer.Length
// Either ffmpeg is producing bad PES packets or we are reassembling units incorrectly.
// Math.Min() here prevents the exception but doesn't fix the underlying problem.
if (PacketLength > 0) Buffer.BlockCopy(buffer, position, Data, 0, Math.Min(Data.Length, buffer.Length - position));
}
else if (StreamIdentifier == StreamIdentifier.ProgramStreamMap
|| StreamIdentifier == StreamIdentifier.PrivateStream2
|| StreamIdentifier == StreamIdentifier.EcmStream
|| StreamIdentifier == StreamIdentifier.EmmStream
|| StreamIdentifier == StreamIdentifier.ProgramStreamDirectory
|| StreamIdentifier == StreamIdentifier.DsmCcStream
|| StreamIdentifier == StreamIdentifier.TypeEStream)
{
Data = new byte[PacketLength];
if (PacketLength > 0) Buffer.BlockCopy(buffer, position, Data, 0, Math.Min(Data.Length, buffer.Length - position));
}
else if (StreamIdentifier == StreamIdentifier.PaddingStream)
{
Stuffing = new byte[PacketLength];
if (PacketLength > 0) Buffer.BlockCopy(buffer, position, Data, 0, Math.Min(Data.Length, buffer.Length - position));
}
#if DEBUG
if(Data!=null && Data.Length > 0)
{
Debug.WriteLine("First 40 bytes of PES Data: " + String.Concat(Data.Take(40).Select((b) => b.ToString("X2")).ToArray()));
}
#endif
}
public PesPacket(byte[] buffer, int offset = 0)
{
int position = offset;
if (buffer[position++] != 0 || buffer[position++] != 0 || buffer[position++] != 1)
{
throw new ArgumentException("PES Packet does not start with 0x000001 Start Code Prefix.");
}
StreamIdentifier = (StreamIdentifier)buffer[position++];
PacketLength = (buffer[position++] << 8) | buffer[position++];
if (PacketLength == 0)
{
PacketLength = buffer.Length - offset - 6;
}
if (StreamIdentifier != StreamIdentifier.ProgramStreamMap &&
StreamIdentifier != StreamIdentifier.PaddingStream &&
StreamIdentifier != StreamIdentifier.PrivateStream2 &&
StreamIdentifier != StreamIdentifier.EcmStream &&
StreamIdentifier != StreamIdentifier.EmmStream &&
StreamIdentifier != StreamIdentifier.ProgramStreamDirectory &&
StreamIdentifier != StreamIdentifier.DsmCcStream &&
StreamIdentifier != StreamIdentifier.TypeEStream)
{
Header = new PESHeader(buffer, position);
position += Header.Length;
Data = new byte[PacketLength - Header.Length];
// TODO: Something may be squirrely here. position+PacketLength should never be > buffer.Length
// Either ffmpeg is producing bad PES packets or we are reassembling units incorrectly.
// Math.Min() here prevents the exception but doesn't fix the underlying problem.
if (PacketLength > 0)
{
Buffer.BlockCopy(buffer, position, Data, 0, Math.Min(Data.Length, buffer.Length - position));
}
}
else if (StreamIdentifier == StreamIdentifier.ProgramStreamMap ||
StreamIdentifier == StreamIdentifier.PrivateStream2 ||
StreamIdentifier == StreamIdentifier.EcmStream ||
StreamIdentifier == StreamIdentifier.EmmStream ||
StreamIdentifier == StreamIdentifier.ProgramStreamDirectory ||
StreamIdentifier == StreamIdentifier.DsmCcStream ||
StreamIdentifier == StreamIdentifier.TypeEStream)
{
Data = new byte[PacketLength];
if (PacketLength > 0)
{
Buffer.BlockCopy(buffer, position, Data, 0, Math.Min(Data.Length, buffer.Length - position));
}
}
else if (StreamIdentifier == StreamIdentifier.PaddingStream)
{
Stuffing = new byte[PacketLength];
if (PacketLength > 0)
{
Buffer.BlockCopy(buffer, position, Data, 0, Math.Min(Data.Length, buffer.Length - position));
}
}
#if DEBUG
if (Data != null && Data.Length > 0)
{
Debug.WriteLine("First 40 bytes of PES Data: " + string.Concat(Data.Take(40).Select((b) => b.ToString("X2")).ToArray()));
}
#endif
}