Publish externel live source with multicast

Question

hello
first i can not use fmle to broadcast the stream i need to publish from an externel source (like on an linux server)
first i have an working app with attachAudio and attachCamara this works greate BUT
i need other sources (Video file with h264 codes in flv container like fmle do it)
so i make some tests first i load a flv file with URLStream from an http push server like vlc do it
in the PROGRESS event
i do
private function urlStreamProgress(event:ProgressEvent):void
if (event.target.bytesAvailable >= 60000) {
    var encr:ByteArray = new ByteArray();
        event.target.readBytes(encr);
        netStream.send("onStreamData", encr,i);
        ns.appendBytes(encr);
        i++;
the netStream is the outgoing stream an will published with
netStream.publish("stream");
the ns stream is the video player netstream in play(null) status and attached the video
the video plays fine on the broadcaster
so on clients
i have an netstream with netstream.play("stream");
and a second ns for the video play (ns.play(null) mode)
on the send onStreamData event i do
var clientObj:Object = new Object();
clientObj.onStreamData = function(file:ByteArray,i:int):void{
                                                StatusMessage("Received "+file.bytesAvailable+ " " + i + "\n");
                                                StatusMessage("ns bytesTotal "+ns.bytesTotal+  "\n");
                                                StatusMessage("ns bytesLoaded "+ns.bytesLoaded+ "\n");
                                                ns.appendBytes(file);
on the client i see i get lot of packages in NetStream all works fine
Download speed: 1.17 Mbit/s ( 142.67 KB/s )
Upload speed: 0 ( 0 )
Total Bytes Pushed From/To Peers: 436.89 KB / 0
Total Bytes Requested From Peers: 1.03 MB
but my ns netStream i empty and no video is shown :-/
ns bytesTotal 0
ns bytesLoaded 0
Received 62264 4872
ns bytesTotal 0
ns bytesLoaded 0
any idea whats wrong ?
the other question is  when i use send is the network multicast send send to all clients i think?
what is the best practice to broadcast an live stream from an external source?
best regards
whwi

Answer 1

the problem is a P2P multicast isn't 100% reliable (you can occasionally miss pieces), and late joiners won't necessarily get the beginning of a stream.  this is a problem because NetStream.appendBytes() requires a *perfect* FLV to be input.
if you miss the very first message of the multicast, you'll miss (among other things) the FLV header.  if you miss *any* message of the multicast, you'll at least be out-of-sync.
also, in an FLV with H.264 video and AAC audio, you'll only have the H.264 AVCC and AAC AudioSpecificConfig messages once at the very beginning of the FLV.  so if you miss those messages, the H.264 and AAC won't be decodable even if you somehow otherwise stayed in sync adding FLV tags into appendBytes.
this means you can't simply get data directly out of a multicast and send it into appendBytes.  you're guaranteed to go out-of-sync, and the appendBytes FLV parser won't be able to work anymore.
you'll need to do more work if you want to use appendBytes like this, in particular by being able to recover whole FLV tags, and by resending AVCC and AudioSpecificConfig messages from time to time for the late joiners.  and you'll need to make sure that when you're putting bytes into appendBytes that you don't get out of FLV tag sync.