UCMA 3.0 - Recording an incoming call - ucma

Question

I am new to UCMA and I am learning as I go through examples. I am trying to build 2 Lync clients A and B with the scenario as follows,
A calls B
B answers
A plays audio
B records it using Recorder.
I am stuck at trying to record the call at B. For B its an incoming call. I need to attach the audiovideoflow to the recorder, but I am not sure on how to do it. I will appreciate any help.
Apologies on the unformatted code, I am not sure how to format it properly, I tried.
Thanks.
Kris
Client B Code:
Accepts an incoming call
Records the media received in the incoming call. ***This is the part I have trouble
using System;
using System.Threading;
using Microsoft.Rtc.Collaboration;
using Microsoft.Rtc.Collaboration.AudioVideo;
using Microsoft.Rtc.Signaling;
using Microsoft.Rtc.Collaboration.Lync;
namespace Microsoft.Rtc.Collaboration.LyncUAS
{
public class LyncUAS
{
#region Locals
private LyncUASConfigurationHelper _helper;
private UserEndpoint _userEndpoint;
private AudioVideoCall _audioVideoCall;
private AudioVideoFlow _audioVideoFlow;
private Conversation _incomingConversation;
//Wait handles are only present to keep things synchronous and easy to read.
private AutoResetEvent _autoResetEvent = new AutoResetEvent(false);
private EventHandler<AudioVideoFlowConfigurationRequestedEventArgs> _audioVideoFlowConfigurationRequestedEventHandler;
private EventHandler<MediaFlowStateChangedEventArgs> _audioVideoFlowStateChangedEventHandler;
private AutoResetEvent _waitForAudioVideoCallEstablishCompleted = new AutoResetEvent(false);
private AutoResetEvent _waitForAudioVideoFlowStateChangedToActiveCompleted = new AutoResetEvent(false);
private AutoResetEvent _waitForPrepareSourceCompleted = new AutoResetEvent(false);
#endregion
#region Methods
/// <summary>
/// Instantiate and run the DeclineIncomingCall quickstart.
/// </summary>
/// <param name="args">unused</param>
public static void Main(string[] args)
{
LyncUAS lyncUAS = new LyncUAS();
lyncUAS.Run();
}
private void Run()
{
string filename = "received.wma";
_helper = new LyncUASConfigurationHelper();
// Create a user endpoint, using the network credential object
// defined above.
_userEndpoint = _helper.CreateEstablishedUserEndpoint("Lync UAS" /*endpointFriendlyName*/);
_userEndpoint.RegisterForIncomingCall<AudioVideoCall>(On_AudioVideoCall_Received);
Console.WriteLine("Waiting for incoming call...");
_autoResetEvent.WaitOne();
Console.WriteLine("came after call is connected");
//start recording for audio.
Recorder recorder = new Recorder();
recorder.StateChanged += new EventHandler<RecorderStateChangedEventArgs>(recorder_StateChanged);
recorder.VoiceActivityChanged += new EventHandler<VoiceActivityChangedEventArgs>(recorder_VoiceActivityChanged);
//**********This is the issue, currently _audioVideoFlow is null, it is not attached to the flow
//So this will fail, how to attach _audioVideoFlow to an incoming call ?? HELP !!!
// recorder.AttachFlow(_audioVideoFlow); ------------> HELP!
WmaFileSink sink = new WmaFileSink(filename);
recorder.SetSink(sink);
recorder.Start();
Console.WriteLine("Started Recording ...");
_autoResetEvent.WaitOne();
recorder.Stop();
Console.WriteLine("Stopped Recording ...");
recorder.DetachFlow();
Console.WriteLine("Exiting");
Thread.Sleep(2000);
}
private void audioVideoFlow_StateChanged(object sender, MediaFlowStateChangedEventArgs e)
{
Console.WriteLine("Flow state changed from " + e.PreviousState + " to " + e.State);
//When flow is active, media operations can begin
if (e.State == MediaFlowState.Active)
{
// Flow-related media operations normally begin here.
_waitForAudioVideoFlowStateChangedToActiveCompleted.Set();
}
// call sample event handler
if (_audioVideoFlowStateChangedEventHandler != null)
{
_audioVideoFlowStateChangedEventHandler(sender, e);
}
}
void recorder_VoiceActivityChanged(object sender, VoiceActivityChangedEventArgs e)
{
Console.WriteLine("Recorder detected " + (e.IsVoice ? "voice" : "silence") + " at " + e.TimeStamp);
}
void recorder_StateChanged(object sender, RecorderStateChangedEventArgs e)
{
Console.WriteLine("Recorder state changed from " + e.PreviousState + " to " + e.State);
}
void On_AudioVideoCall_Received(object sender, CallReceivedEventArgs<AudioVideoCall> e)
{
//Type checking was done by the platform; no risk of this being any
// type other than the type expected.
_audioVideoCall = e.Call;
// Call: StateChanged: Only hooked up for logging, to show the call
// state transitions.
_audioVideoCall.StateChanged += new
EventHandler<CallStateChangedEventArgs>(_audioVideoCall_StateChanged);
_incomingConversation = new Conversation(_userEndpoint);
Console.WriteLine("Call Received! From: " + e.RemoteParticipant.Uri + " Toast is: " +e.ToastMessage.Message);
_audioVideoCall.BeginAccept(
ar =>
{
try {
_audioVideoCall.EndAccept(ar);
Console.WriteLine("Call must be connected at this point. "+_audioVideoCall.State);
_autoResetEvent.Set();
} catch (RealTimeException ex) { Console.WriteLine(ex); }
}, null);
}
//Just to record the state transitions in the console.
void _audioVideoCall_StateChanged(object sender, CallStateChangedEventArgs e)
{
Console.WriteLine("Call has changed state. The previous call state was: " + e.PreviousState +
" and the current state is: " + e.State);
if (e.State == CallState.Terminated)
{
Console.WriteLine("Shutting down");
_autoResetEvent.Set();
_helper.ShutdownPlatform();
}
}
#endregion
}
}

Answer 1

I think I have figured out what's not quite right here.
Your Code
// Create a user endpoint, using the network credential object
// defined above.
_userEndpoint = _helper.CreateEstablishedUserEndpoint("Lync UAS" /*endpointFriendlyName*/);
_userEndpoint.RegisterForIncomingCall<AudioVideoCall>(On_AudioVideoCall_Received);
Console.WriteLine("Waiting for incoming call...");
_autoResetEvent.WaitOne();
Console.WriteLine("came after call is connected");
//start recording for audio.
Recorder recorder = new Recorder();
recorder.StateChanged += new EventHandler<RecorderStateChangedEventArgs>(recorder_StateChanged);
recorder.VoiceActivityChanged += new EventHandler<VoiceActivityChangedEventArgs>(recorder_VoiceActivityChanged);
//**********This is the issue, currently _audioVideoFlow is null, it is not attached to the flow //So this will fail, how to attach _audioVideoFlow to an incoming call ?? HELP !!!
// recorder.AttachFlow(_audioVideoFlow); ------------> HELP!
Looking good so far. I'm assuming you're establishing and such in your CreateEstablishedUserEndpoint method, but I'm not seeing where you're getting the value for _audioVideoFlow.
I'm guessing you might be doing it elsewhere, but on the off chance that's actually where you're running into problems, here's that bit:
Simplest pattern to get AVFlow
public static void RegisterForIncomingCall(LocalEndpoint localEndpoint)
{
localEndpoint.RegisterForIncomingCall
<AudioVideoCall>(IncomingCallDelegate);
}
private static void IncomingCallDelegate(object sender, CallReceivedEventArgs<AudioVideoCall> e)
{
e.Call.AudioVideoFlowConfigurationRequested += IncomingCallOnAudioVideoFlowConfigurationRequested;
}
private static void IncomingCallOnAudioVideoFlowConfigurationRequested(object sender, AudioVideoFlowConfigurationRequestedEventArgs e)
{
AudioVideoFlow audioVideoFlow = e.Flow; // <--- There's your flow, gentleman.
}
Now, instead of registering for your incoming call, just call RegisterForIncomingCall(_userEndpoint);.
Your AVFlow will be hanging off e.Flow above, you could then pass that into your recorder: recorder.AttachFlow(e.Flow) or simply assign the flow to a field in your class and autoResetEvent.WaitOne(); and set that up where you're setting that up now.
Obviously this is a pretty naive implementation. A lot can go wrong in those few lines of code (exception handling/static event handler memory leak comes immediately to mind); don't forget to wire up events related to status changes on the conversation/call and endpoints, as well as any of the recovery related items.