private void Packetize(IntPtr[] ptrs, int[] lengths, bool prependLengths)
{
// This assumes length member variable has been set already
ApproximatePacketsInFrame();
// Initialize to enter loop
packetsInFrame = 0; // We'll find out real number of packets
RtpPacket packet = null;
int pktAvailable = 0;
int ptrIndex = 0;
int ptrAvailable = 0;
IntPtr ptr = IntPtr.Zero;
bool writePtrLength = false;
int ptrsLength = ptrs.Length;
while (true)
{
// If there is no data left in this ptr, get a new one
if (ptrAvailable == 0)
{
if (ptrIndex + 1 > ptrs.Length)
{
break; // while(true)
}
ptrAvailable = lengths[ptrIndex];
ptr = ptrs[ptrIndex];
ptrIndex++;
// Write the length of the ptr to the packet
if (prependLengths)
{
writePtrLength = true;
if (pktAvailable < 4)
{
pktAvailable = 0; // Get a new packet
}
}
}
// Note:
// pktAvailable == 0 is handled after ptrAvailable == 0 to bypass the case where
// the final ptr fit into the packet perfectly. We want to exit the loop at that
// point before grabbing another packet which won't have anything put in it. The
// case for prepending the length of ptr still works if the previous packet didn't
// have room for the length.
// If there is no room in the current packet, get a new one
if (pktAvailable == 0)
{
packet = GetNextPacket();
// In the event that we re-add support for custom headers, add that data here
// before making the call to packet.MaxPayloadSize - 9/23/2004 JVE
// Find out how much room is left in the packet
packet.Reset(); // Mimic packet.Payload = ...
pktAvailable = packet.MaxPayloadSize - packet.PayloadSize;
}
// Write length of ptr to packet
if (writePtrLength)
{
// Add 4 bytes for length
packet.AppendPayload(ptrAvailable);
pktAvailable -= 4;
writePtrLength = false;
// Place holder ptr
if (ptrAvailable == 0)
{
continue; // Nothing to copy
}
}
// Copy as much as the packet can hold
if (ptrAvailable >= pktAvailable)
{
packet.AppendPayload(ptr, pktAvailable);
// buffer.CopyFrom(ptr, pktAvailable);
ptr = (IntPtr)(ptr.ToInt32() + pktAvailable); // Advance pointer
ptrAvailable -= pktAvailable;
pktAvailable = 0;
}
else // Copy as much as the ptr can provide
{
packet.AppendPayload(ptr, ptrAvailable);
pktAvailable -= ptrAvailable;
ptrAvailable = 0;
}
}
}
