Michael Manousos [EMAIL PROTECTED] wrote: > Kevin Walsh wrote: > > Michael Manousos [EMAIL PROTECTED] wrote: > > > a) The transmitter detected silence and sent nothing but the last CN > > > packet was lost. According to the above interpretations, the receiver > > > will try to conseal a packet loss, which is wrong. > > > > > > > I would propose that after x lost packets, Asterisk should treat > > all further lost packets as CN. The proceeding x packets should be > > interpreted as RTP packet loss and run through the concealment routine. > > > Well, no matter what kind of concealment algorithm is used, just the > first one or two packets will be concealed. The rest losses will result > in no-playback. No CN interpretation, just absolute silence. > That's true - unless there's some logic to say that after x lost packets, the line state should switch to CN generation instead of silence.
The line state would switch back once a fresh RTP packet is received. > > > > > > b) The transmitter sent an RTP packet, that packet was lost and the > > > last packet correctly received at the receiver was a CN packet. Again, > > > following the above interpretation, the receiver will do nothing (or > > > more accurate, will play some background noise), while it should > > > conseal the packet loss. > > > > > In this case, there is nothing to conceal anyway, as the last received > > data was a CN packet. In this case, the CN state should be continued > > until an RTP packet is received and the line state can be changed. > > > Exactly. So the receiver, in case of no-receiption, should go back and > see what was the last packet correctly received and act as I described > above. > Maintaining an audio state flag (CN/RTP) would be the key here. > > > > The difficult part to handle would be late or out-of-sequence RTP > > packets. These should be ironed out by the jitter buffer. Late, > > lost and juggled packets are to be expected when dealing with UDP. > > > Actually this is not so difficult, if there is a jitter buffer. > Right. -- _/ _/ _/_/_/_/ _/ _/ _/_/_/ _/ _/ _/_/_/ _/_/ _/ _/ _/ _/_/ _/ K e v i n W a l s h _/ _/ _/ _/ _/ _/ _/ _/_/ [EMAIL PROTECTED] _/ _/ _/_/_/_/ _/ _/_/_/ _/ _/ _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users