Using the Streaming Capability

Phenix provides a streaming capability for both publishing and subscribing. If a user is unable to subscribe using the streaming capability, this may be due to not having streaming set on the published stream.

Publishing

On the publishing side, the streaming capability instructs the Phenix sytem to create a transcoded live stream using adaptive HLS and MPEG-DASH streaming in addition to the typical real-time WebRTC stream. The live stream contains multiple quality options from audio-only to highest video quality unless the streaming-lite capability is also used. When streaming-lite is also present, the system only creates one streaming rendition for the live stream that corresponds to the highest quality level.

Subscribing

On the subscribing side, the streaming capability tells the system that the user wants to subscribe using adaptive live streaming using HLS or MPEG-DASH. This can be used for streaming to clients with network connections with limited bandwidth or highly fluctuating bandwidth, but note that it adds about 8-12 seconds of delivery latency.

Streaming on the subscribing side requires the publisher stream to also have the streaming capability. If the subscriber uses the streaming capability but the published stream does not have the streaming capability, the user will not be able to subscribe to the stream. This interaction is summarized in the figure below.