protected byte[] readSourcePacket() throws IOException {
byte[] packet = new byte[packetSize];
int offset = 0;
while (offset < packetSize) {
int count = is.read(packet, offset, packetSize - offset);
if (count == -1) throw new IOException("end-of-stream");
offset += count;
}
return bp.collapsePacket(packet);
}
protected boolean writeSourcePacket(byte[] packet) throws IOException {
os.write(bp.expandPacket(packet, packetSize));
return true;
}