Hi techq,
We suggest that you enable the EMS event notification system and subscribe to the processStarted event. You can then check for the stream name once you received this event (the stream name is part of the arguments included in this event).
If at this point, the stream name is still not found, then that means there were other issues such as source is not available, avconv transcode problem, etc.
Let us know if you have concerns setting up and/or using this feature.
Cheers,
IC