Transcoded stream not available after multiple Start <-> Stop loops in mobile Safari [WebRTC]

Wowza Streaming Engine
1

What steps will reproduce the problem?

  1. Start publish video with client without audio. (Press Publish button)
  2. Stop publishing (Press Stop button)
  3. Repeat steps 1 and 2 multiple times

What is the expected result?

Transcoded video becomes available when video is published again almost immediately.

What do you see instead?

Transcoded video becomes available much more then 10 seconds or even won’t available.

Client without audio:

  1. I took original Wowza sample code: https://www.wowza.com/downloads/forums/webrtc/WebRTC.zip (html/publish)

  2. Changed media constraints to: constraints = {video: true, audio: false};

  3. in file webrtc.js (html/publish/webrtc.js) commented line 472 (in other case got error “Can’t set local SDP” )

Original client (with audio) - no problem with transcoded stream

Client without audio - transcoded stream sometimes not available, or delayed for 30

Reproduced on iPhone 6S, Safari

On Android problem can’t be reproduced

I can assume that the problem in bad SDP

Question: How to prepare valid SDP for streaming only video from browser to Wowza through WebRTC?