Forwarding RTMP Icecast metadata through Live Transcoder

RTMP protocol has the ability to carry Icecast metadata. Nimble Streamer can forward that metadata into output stream when transmuxing from RTMP to Icecast. However some scenarios may require Live Transcoder to be involved in order to transform audio. In this case the metadata from RTMP stream need to be carried through the transcoder pipeline by setting parameters in a transcoding scenario. Let's see how this can be done.

Notice that Nimble Live Transcoder is able to passthrough the Icecast metadata. Please make appropriate setup for respective protocol use case. 

If you have incoming Icecast with Icecast metadata, please follow this instruction and skip this article.

If you have incoming RTMP with Icecast metadata, you need to follow the instruction below.

Enable RTMP Icecast metadata

First, the incoming stream must have the RTMP Icecast metadata delivered. So you need to enable RTMP Icecast metadata processing as described in this article. If you don't set up the designated application or entire server processing the RTMP Icecast metadata, it will not be available for transcoder scenarios.

Set up Transcoder

In this sample scenario we use transcoder for re-sampling audio from the existing RTMP stream. You may see a decoder, then a filter to perform sampling and then an encoder.

The forwarding needs to be specified on both decoder and encoder sides. In the audio decoder element you need to check the Forward RTMP metadata checkbox to set the transcoder to take metadata into the pipeline.

Now go to video encoder element and click on Expert setup.

Here you need to check the Forward RTMP metadata checkbox to make the transcoder grab the metadata from the pipeline and make it part of output stream.

Once you save the scenario and re-start the input stream, the output stream will have the metadata which then can be used for transmuxing into Icecast or re-publishing.

Contact us if you have any questions regarding any of our features.

Related documentation

Live Transcoder for Nimble Streamer, Audio streaming feature set, RTMP support