Wowza Community

G711 audio works on flash (rtmp) but does not work with rtsp

Hello,

Our IP cameras have H.264 video + G.711 audio.

We re-stream the video from wowza to clients. We use flash for web clients and rtsp for android clients.

We have no problems listening to g.711 audio with the web clients using strobe flash player.

However there is no audio in the rtsp stream.

It looks like wowza strips audio stream from the rtsp streams while restreaming but does not do that for rtmp streams, is this correct?

If yes is it possible to tell wowza not to do this? We want it to keep the audio track inside the rtsp stream while restreaming.

Since it keeps the audio for the rtmp streams I hope that this might be possible.

Note: we dont want to use wowza transcoder to convert audio to aac.

Best Regards,

Özgür

G711 works in Flash 11+ without transcoder.

Android devices do not support G711:

Android Developers Website

If your camera does not have support for another audio format you will need to use Wowza’s Transcoder Addon.

Salvadore

You should be able to playback a stream with g.711 audio in Flash RTMP and Flash HTTP players. At present, g.711 is not packetized for RTSP clients and it doesn’t work on HLS or HDS clients

Richard

Özgür,

Yes, the Wowza Transcoder supports g.711 for decode. It will transcode the audio to AAC which will play in all supported clients.

Richard

Ozgur,

Without the Transcoder, Wowza just reflects streams. So this is a codec/player issue really, Wowza is just in between. You can try to do what you describe, but I don’t have any example and would probably not be able to support that effort through Wowza free Support.

Richard

Özgür,

Right, Wowza only really reflects g.711 audio to Flash RTMP clients.

Wowza does not provide professional service directly, but I will submit this as a request to backlog, which would be the best thing to do.

Richard

Özgür,

Not as far as I know. It is a backlog item. I will ask for info on Tuesday.

Richard

Janet,

Not that I see in release notes, or recall otherwise but I will try, I have a camera with g.711 audio.

Richard

I tested in case I missed anything, but it is same. It is in the backlog, but there has been a focus on the Wowza 4 release. I don’t have a time frame for this.

Richard

Dear Salvadore,

Thank you for your reply.

We have imported the FFMPEG library to the Android platform.

So our android application does supoort G.711 streams.

We can get g.711 audio from our camera if we use the camera rtsp steram directly i.e. if we dont restream from wowza.

But wowza just strips the g.711 track from the stream while restreaming. We have verified this using vlc as well.

So is it possible to tell wowza not to discard the audio track from the rtsp stream?

Özgür

Dear Richard,

Thank you for your reply.

Is there any workaround for this?

Can we tell wowza to just pass the stream as is without any processing?

Or maybe can we write our own module module to packetize g.711? I assume this must be quite difficult.

Can you give us advice on how to solve this problem without using wowza transcoder and without changing the camera?

Best Regards,

Özgür

Dear Richard,

I think I did not make myself clear.

We dont want to use Wowza Transcoder because it is too expensive since it is billed per stream.

Is there any workaround for this?

Do you think it is possible for us to write our own packetizer module that packetizes G.711 audio for RTSP streams.

We have a strong development team, I think we can do it if there is any documentation or samples etc.

Or maybe we can hire professional services from wowza to do it for us?

Can you please suggest how we should proceed.

Best Regards,

Ozgur

Dear Richard,

Thank you for your answer. I will just ask my last set of questions about this issue.

Since you said wowza only reflects these streams, I wonder If misunderstood your last post.

All I need is wowza to reflect the stream as is, without changing it.

However it does not do this, it strips the g.711 audio from the stream.

And the reason is that a g.711 packetizer for rtsp streams is not implemented. Is this correct?

And there is no way to make wowza just reflect the stream without using its own packetizers. Is this also correct?

And finally can we get any professional services from wowza to implement a g.711 paketizer fo this for us?

Best Regards,

Özgür Deniz Önür

Dear Richard,

Do you know if there is any progress about G.711 packetizer for RTSP or HLS?

Latest wowza release notes contain some info about G.711 depacketizer but I doubt that they are related to rtsp packetizer for G.711.

Özgür

Hi,

Has there been any movement on re-streaming G711 ulaw to an RTSP client? My Wowza customer would like to do this as well.

Thanks,

Janet

Thank you for taking the time to test it, Richard. It’s very appreciated… I wish the result had been different, but it is what it is.

Janet

Hi, rrlanham

Thanks for supporting.