Audio sampling frequency resample support

Wowza Streaming Engine
1

Hi,

We are using VidiU for live webcast and sometimes also switch to Wowza GoCoder stream from that live stream. Since iOS v10 however this is no longer possible, because VidiU uses 48kHz from the camera and iPhone changed default sampling frequency from 48kHz to 44.1kHz.

Wowza transcoder in such situation will simply change pitch of the audio, when stream source changes.

1.) We contacted support for Wowza GoCoder to add support for 48kHz, but the response was not encouraging. (dismissed as a non-feature).

2.) We contacted Teradek (which have also their own mobile streaming app) and they also are not willing to add 48khz audio option saying it would complicate their user interface too much.

3.) Finally, Teradek wont add ability to change audio sampling frequency on VidiU, because they are selling their 2000 USD devices, which currently support this feature.

4.) There are other streaming sources also, which are mostly pinned to 48kHz, not to mention prerecorded audio files.

5.) So I am asking “again” for the Wowza transcoder team, if they might be willing to consider adding the ability to convert audio sampling frequency on the fly for live streams.

Until that support is somehow provided either by mobile streaming apps or by Wowza Transcoder, the mobile streaming options are bricked for us.

Thanks!

Atmapuri

2

Hello Janez,

We do have this as a feature request, and this is being considered due to the increased need to adjust sample rates for WebRTC delivery.

I have added your post to that feature request.

However, at this time I can’t confirm if the feature will be approved and if so, any time-scales for it’s availability. Please do check back in periodically to our Software Updates page to see if your feature request has been deployed.

WSE
https://www.wowza.com/docs/software-updates

Thank you for the feedback.

Regards,

Jason Hatchett

3

Hello.

+1 for this feature request please.

In our case we utilize the streamPublisher module to create a stream that is a mix of on demand and occasional live sources. This stream is then picked up by the Wowza transcoder.

The transcoder seems to settle on a samplerate when its first initialized, usually from on demand file of 44.1 KHz. When a live source of 44.1 is published, everything is fine. But with a 48 KHz source, the transcoded streams comes out of sync.

Some of our users also use the Teradek VidiU with 48 KHz fixed rate. The ones using Teradek Cube were able to set to 44.1 KHz to match though at least.

Thanks!