Wowza Community

Audio delayed to start playing on live streaming

After I updated to Wowza 3.6.2 the player on mobile devices (Android/iPhone) is taking too long to start playing live audio streams. It takes 8sec to start playing, but the latency is less than 2sec after starts. It only affects mobile devices. It seems that a stream is created and start to play (no audio yet), then pauses, then starts it the audio.

(play is pushed down on player)

INFO rtsp connect 1335425495 -

INFO stream create - -

INFO rtsp describe 1335425495 -

INFO server comment - RTPUDPTransport.bind[live/definst]: in:/10.151.10.146:6980 out:/68.174.94.220:11806

INFO server comment - RTPUDPTransport.bind[live/definst]: in:/10.151.10.146:6981 out:/68.174.94.220:11807

INFO stream play channel_1.stream -

INFO rtsp play 1335425495 -

(8 sec later- audio starts playing on device)

INFO stream pause channel_1.stream -

INFO rtsp pause 1335425495 -

INFO stream play channel_1.stream -

INFO rtsp play 1335425495 -

(stop is pushed down on player)

INFO stream stop channel_1.stream -

INFO stream destroy channel_1.stream -

INFO server comment - RTPUDPTransport.unbindAll[live/definst]: /10.151.10.146:6981

INFO server comment - RTPUDPTransport.unbindAll[live/definst]: /10.151.10.146:6980

INFO rtsp disconnect 1335425495 -

Thanks in advance for any help.

It is possible that the device is failing-over from UDP to TCP. I know many Android devices will not fail-over, will just fail in that case, but some may. VLC does that. Do you see a delay when you playback in VLC? If so, check Tools > Codec info to see if there are two audio info blocks, that would indicate UDP ports are blocked

Or a network issue, something occurring at that time. I don’t think it has anything to do with the version of Wowza or the upgrade.

Richard

Did you do the test I suggested in VLC?

Are you doing RTSP playback? Or something else?

Richard

It is possible that the device is failing-over from UDP to TCP. I know many Android devices will not fail-over, will just fail in that case, but some may. VLC does that. Do you see a delay when you playback in VLC? If so, check Tools > Codec info to see if there are two audio info blocks, that would indicate UDP ports are blocked

Or a network issue, something occurring at that time. I don’t think it has anything to do with the version of Wowza or the upgrade.

Richard

Thanks for the reply, Richard.

The problem is not the delay due to latency itself, it is the time the player is taking to start to play. Let’s say: if the player takes 8 seconds to start playing then it should play 8 seconds behind the original stream, that’s the time it takes to fill up the buffers. Instead, it is taking 8 seconds to start playing and plays only 2 seconds behind the original stream. Why is taking those extra 6 seconds to establish the connection? Any help is appreciated, thanks.

The VLC works fine, I can see on VLC the buffer being filled up and starts to play right away. From the moment I press down the play button it takes about 2 seconds to start the audio, which it is what I expect.

I am doing a live event audio streaming only. I use an audio encoder hardware to stream to Wowza over http.Till last couple of weeks, I could switch from one channel to another in 1-2 seconds, now it takes 8+ seconds to do the same on our app. We use an app on iPhone/Android where we broadcast the live audio to the audience. The app has 4-8 channels that plays one channel at once.(all live)

This is a wowza install on amazon-ec2

This is what happen when I use iPod/android:

INFO rtsp connect 1700760751 -

INFO stream create - -

INFO rtsp describe 1700760751 -

INFO server comment - RTPUDPTransport.bind[live/definst]: in:/10.28.203.156:6978 out:/68.174.94.220:11070

INFO server comment - RTPUDPTransport.bind[live/definst]: in:/10.28.203.156:6979 out:/68.174.94.220:11071

INFO stream play channel_1.stream -

INFO rtsp play 1700760751 -

(8 sec gap)

INFO stream pause channel_1.stream -

INFO rtsp pause 1700760751 -

INFO stream play channel_1.stream -

INFO rtsp play 1700760751 -

(VLC)

INFO rtsp connect 469006943 -

INFO stream create - -

INFO rtsp describe 469006943 -

INFO stream play channel_1.stream -

INFO rtsp play 469006943 -

I think it proves what you says, but what can I do to work around this?

Thanks again,