Kurento RTP and Wowza

[robert.corolea...@gmail.com]

Hello.
I have followed the steps from this post and managed to send an WebRtc stream to a RTP endpoint and then the later to Wowza. Everything work fine, but when I try to test it on IOs devices I get a 25 seconds delay, while the video RTMP video from the Test players has 3 seconds delay.  Am I doing something wrong or is this huge delay a normal thing? I am testing this with the IOs link from the mobile tab of the Test players.

[Ivan Gracia]

Can't tell, we've never streamed to iOS. There is still room for performance improvements in your RTMP config, as we've seen <1s latency using Flowplayer as client. It can very well be that the default configuration of the players in WowzaStreamingEngineManager is not the best one for live apps.

Ivan Gracia

On Fri, Nov 6, 2015 at 12:36 PM, <robert.corolea...@gmail.com> wrote:

Hello.
I have followed the steps from this post and managed to send an WebRtc stream to a RTP endpoint and then the later to Wowza. Everything work fine, but when I try to test it on IOs devices I get a 25 seconds delay, while the video RTMP video from the Test players has 3 seconds delay.  Am I doing something wrong or is this huge delay a normal thing? I am testing this with the IOs link from the mobile tab of the Test players.

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[robert.corolea...@gmail.com]

I see. Can I ask what kind of setup did you use to obtain that low latency? What kind of devices were the clients? Were you using only WebRtc or other endpoint? Did you use Wowza and if not, did you use any other media server/transcoder? I am asking these because I've deployed both Kurento and Wowza on a pretty powerful server and although the delay got smaller it still is pretty big and it gets bigger as the stream goes on. Any detail on the setup would be useful.
Thank you in advance.

[Ivan Gracia]

The setup is quite simple: webrtc emitter -> rtp endpoint -> Wowza.

The client is a Flowplayer client, and the Wowza app is a live streaming app. We had to set the client to not buffer more than 300ms of video, though. I guess that's one important part.

On lun, 23 nov 2015 at 16:43, <robert.corolea...@gmail.com> wrote:

I see. Can I ask what kind of setup did you use to obtain that low latency? What kind of devices were the clients? Were you using only WebRtc or other endpoint? Did you use Wowza and if not, did you use any other media server/transcoder? I am asking these because I've deployed both Kurento and Wowza on a pretty powerful server and although the delay got smaller it still is pretty big and it gets bigger as the stream goes on. Any detail on the setup would be useful.
Thank you in advance.

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[robert.corolea...@gmail.com]

I understand. Were you getting that delay on HLS, and if not on which of the playback types were you getting it? Did you use the Wowza basic settings or have you made some configurations? Can you please show me the sdp format that you use to feed the RtpEndpoint and .sdp file?
Sorry for bombarding you with so many questions but the answers would really help me.
Thank you in advance.

[Ivan Gracia]

Didn't use HLS, so can't help you there mate. We just used Flash, sending media to Wowza through RTP with this SDP. There's a lot of info in the list about how to get this working, but I think you got that covered already, right?

About configurations, we just set the app as live, and set the Flowplayer client to not buffer more than 300ms of video. The configuration will depend on your client. Which client are you using?

​

Ivan Gracia

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[robert.corolea...@gmail.com]

I see. I already made it work. I have a live video chat app project where I use Webrtc for those who support it and Wowza HLS for those who don't(mobile iOS). The only thing I struggle with now is the high delay on HLS and auto-fullscreen on iPhone. I managed to install Flowplayer on the client and made it play HLS and I'm trying to configure it for a lower buffer.
About the client, I am testing this on an iPad(Safari and Chrome).
Thank you for your answers. Since you didn't use HLS (mobile iOS doesn't have Flash) the only thing I can ask is: can you please share the configuration for the flowplayer buffer?

[Ivan Gracia]

We only used the RTMP encoder, yap. Here's the flowplayer configuration

var flowPlayerConfig = {
                clip : {
                    url : <clip-url>,
                    live : true,
                    provider : 'rtmp',
                    autoPlay : true,
                    bufferLength : 0.3,
                },

                plugins : {
                    rtmp : {
                        url : 'flowplayer.rtmp-3.2.13.swf',
                        netConnectionUrl : <net-url>
                    }
                }
        }

​

In any case, have a look at the Flowplayer and Wowza forums, as they'll provide more info. This post is interesting, for instance.

Ivan Gracia

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[Damien Fétis]

Hello robert,
high delay on HLS stream is normal.

Delay on HLS depends on segements size. HLS segements contains few seconds of the video stream (Good description on an other Kurento Group post : https://groups.google.com/forum/#!searchin/kurento/hls|sort:date/kurento/k0Z4ElGklFM/QAFJcDSXBwAJ ).

For exemple Apple recommend 10s of media in a segment => https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/FrequentlyAskedQuestions/FrequentlyAskedQuestions.html

I don't know what is your wooza configuration for HLS segements, but you shoud  try to rediuce it to decrease your delay. (http://www.wowza.com/forums/showthread.php?16196-Reduced-latency-to-iOS-and-cupertinoChunkDurationTarget).

Damien.

[robert.corolea...@gmail.com]

Ivan:
Thank you. It seems the configurations are similar to mine, except I don't use rtmp.
Damien:
The only settings I've modified are the cupertinoChunkDurationTarget, wich I've set to 1s instead of 10 and also the Low latency stream option which I've enabled.
I've also tried to enable the transcoder and set a key frame interval of 1s in the template, but although that decreases the delay to 10 sometimes it also brings some problems(occasional freeze, sometimes video not showing).

Thank you for the answers.