Function newUpdateCallTraffic

Control/L3StateMachine.cpp:703–749

Update vocoder data transfers in both directions. @param transaction The transaction object for this call. @param TCH The traffic channel for this call. @return bytes transferred. */

	@return bytes transferred.
*/
static unsigned newUpdateCallTraffic(TranEntry *transaction, GSM::TCHFACCHLogicalChannel *TCH)
{
	// We dont set the state Active until both SIP dialog and MS side have acked.
	LOG(DEBUG);
	if (transaction->getGSMState() != CCState::Active) { return false; }
	unsigned activity = 0;

	// Both the rx and tx directions block if rtp_session_set_blocking_mode() is true.

	// Transfer in the uplink direction (GSM->RTP).
	// Flush FIFO to limit latency.
	unsigned numFlushed = 0;
	{
		unsigned maxQ = gConfig.getNum("GSM.MaxSpeechLatency");
		static Timeval testTimeStart;
		while (TCH->queueSize()>maxQ) {
			if (numFlushed == 0) testTimeStart.now();
			numFlushed++;
			// (pat) LOG is too slow to call in here.  With 1000 backed up the delay is 1/2 sec.
			//LOG(DEBUG) <<TCH <<" ulFrame flushed"<<LOGVAR(TCH->queueSize());
			delete TCH->recvTCH();
		}
		if (numFlushed) { LOG(DEBUG) <<TCH <<" ulFrame flushed "<<numFlushed <<" in "<<testTimeStart.elapsed() << " msecs"; }
	}
	if (GSM::AudioFrame *ulFrame = TCH->recvTCH()) {
		activity += ulFrame->sizeBytes();
		// Send on RTP.
		LOG(DEBUG) <<TCH <<LOGVAR(*ulFrame);
		transaction->txFrame(ulFrame,numFlushed);
		delete ulFrame;
	}

	// Transfer in the downlink direction (RTP->GSM).
	// Blocking call.  On average returns 1 time per 20 ms.
	// Returns non-zero if anything really happened.
	// Make the rxFrame buffer big enough for G.711.
	if (GSM::AudioFrame *dlFrame = transaction->rxFrame()) {
		activity += dlFrame->sizeBytes();
		if (activity == 0) { activity++; }	// Make sure we signal activity.
		LOG(DEBUG) <<TCH <<LOGVAR(*dlFrame);
		TCH->sendTCH(dlFrame);
	}

	// Return a flag so the caller will know if anything transferred.
	LOG(DEBUG) <<LOGVAR(activity);
	return activity;
}

// Check for any message or timer activity on this channel.  Return true if something happened.
// The delay is how often we poll, used on SDCCH.