Increase receive buffer size, how?

Wowza Streaming Engine
1

So I’m testing out the scenario as outlined here: https://www.wowza.com/shoutcast.html

I am noticing that the stream has a very small amount of jitter. How can I increase the receive buffer size of the wowza media server to smooth out the blips?

2

Modify /conf/VHost.xml /HostPort (/Port 1935) /SocketConfiguration /ReceiveBufferSize

Richard

3

What do you mean by jitter. Please explain in more detail the issue.

Charlie

4

Actually, the client side buffer in Flash is more likely the issue. In your player increase the NetStream.setBufferTime(secs). This controls the amount of audio data that is buffered client side.

Charlie

5

JW player has bufferLength Flashvar that you can set.

http://www.longtailvideo.com/support/jw-player/jw-player-for-flash-v5/12536/configuration-options

Richard

6

bufferLength is different than bufferTime. Wowza might fill 30 seconds of bufferLength very quickly, then the player starts playback.

Richard

7

I don’t think there is. To recap, “sometimes the bandwidth on the encoder side is congested for 1 or 2 seconds, so the stream is not so stable from the encoder to the icecast server”. In a Flash publishing scenario, you would increase the NetStream buffer in the encoder app. I don’t think Wowza has any way of fixing this.

Richard

8

Compare different settings, find out if you can get any benefit from changes in these settings, there are inline comments indicating usage, and there is a configuration reference in the documentation folder. If data is just missing as a result of this upstream congestion, as I suspect, they won’t help.

Richard

9

Luca,

Sounds like it is working okay. Wowza does have an 8 second internal buffer for handling live streams, but it is not configurable.

Richard

10

Luca,

I really do not know how Wowza could be ahead of the icecast source that it is re-streaming.

Richard

11

Gaps or silence in the audio.

The source is running a bit low on bandwidth from time to time; to alleviate the problem I’d like to increase the receive buffer size of the Wowza Media server.

12

Oh yes - thanks Richard; I’ll give that a try.

Modify /conf/VHost.xml /HostPort (/Port 1935) /SocketConfiguration /ReceiveBufferSize

Richard

13

Sorry guys,

I’ve a similar problem.

I do an audio aacplus icecast restream but sometimes the bandwidth on the encoder side is congested for 1 or 2 seconds, so the stream is not so stable from the encoder to the icecast server.

We use JWplayer on the client side, so we can’t increase buffer on the client (JWplayer doesn’t support buffer size for rtmp streams).

Is it possible to set wowza to have a good buffer so it can support the stream to the clients even when the encoder is not stable to the icecast server?

For example, is it possible to get a buffer of 10 seconds, so clients will continue listening even if the encoder make a 2 or 3 seconds hole?

Like Richard said, can I modify this parameter:

/conf/VHost.xml /HostPort (/Port 1935) /SocketConfiguration /ReceiveBufferSize ?

If yes, which value do you suggest?

The stream is a 64kbps aacplus stream and I’m using Wowza 3.0.4.

Thanks in advance for your help.

Luca

14

Richard,

I’ve a pro license of JWplayer and I’ve contacted their support team for this problem.

Their first answer was like your, but I’ve said to them to do a test directly from their wizard page:

http://www.longtailvideo.com/support/jw-player-setup-wizard?example=204

You can try to change the bufferlength parameter: set it to 30 seconds, but the video will start always after 1 or 2 seconds.

Their last answer was: “Then rtmp ignores it” :frowning:

So I’ve to find another solution and it would be great if there is something that I can configure on Wowza.

I’ve seen your post about conf/VHost.xml /HostPort (/Port 1935) /SocketConfiguration /ReceiveBufferSize : can you help me?

Can I use it? If yes, could you suggest me a value to set for a 10 seconds buffer?

Luca

15

Ok,

I’ve just done this test: two web pages with JWPlayer to stream the same Wowza stream.

First page no bufferLength parameter set.

Second page with bufferLength parameter set to 30 seconds.

Both players play the same audio at the same timeline (I was expecting that the second player was delayed respect the first one).

Am I doing something wrong or the bufferlength parameter is not working?

Trust me, with rtmp streams bufferlength doesn’t work on JWPlayer.

Take a look at this: http://www.longtailvideo.com/support/forums/jw-player/player-development-and-customization/8877/how-to-change-rtmpmodelas

So, please can I do something on Wowza side to solve my problem?

Luca

16

Hi Richard,

please, could you explain to me the use of ReceiveBufferSize and SendBufferSize parameters on vhost.xml file?

thanks in advance

Luca

17

Richard,

I’ll try to change these parameters, I’ll let you know the result of the test.

During this weekend I’ve done another test to solve my problem and I’d like to know your opinion.

You know, I’m restreaming an icecast stream.

Icecast can do what I need: it is able to buffer on the server side some amount of the stream.

So, I’ve configured 2 streams on icecastcoming from the same encoder.

On one stream I’ve left the default value of the “burst-size” parameter, on the second stream I’ve set a bigger value.

Using JWplayer, without any buffer on the client side, listening both streams I’ve seen that the second stream has got a good delay (about 10 seconds).

Great!

So, I’ve set up Wowza to restream the icecast streams with 2 different streams.

I’ve used again JWPlayer to get the rtmp stream and… they are both at the same timeline (there is no delay).

I’ve checked again and if I listen directly from Icecast the dealy is still present, but wowza seems to get the stream without any delay.

How can it be possible?

I’ve asked to the Icecast developer and he told me that wowza may have some variable prebuffer on relaying which may affect the playback timing.

What do you think? Have you got any idea?

Thanks for your attention

Luca

18

Richard,

I don’t think is working right, I was expecting that Wowza would serve the stream with the same delay served by icecast.

I don’t understand why if I listen the stream from Icecast I get a delay and if I listen the same stream from Wowza I don’t get the delay (using jwplayer for both).

Luca