September 19, 2022

Play audio-only SLDP with Opus on iPhone

When using WebRTC as a source of your content, you need to consider that the audio codec for that protocol is Opus. So in order to play sound on a user device side, the streaming provider has two options.

The first option is to transcode it into commonly used AAC codec. It's a default option for many customers and we describe the transcoding in our WebRTC setup video and WebRTC to MPEGTS UDP video.

The second option is to pass Opus content through into the player without transcoding. In this case the protocol must be able to contain this codec. SLDP - low latency playback protocol from Softvelum - is able to carry Opus.

The playback though will depend on the platform your consumer uses.

Video+audio SLDP with Opus can be played in Windows, Linux and Android browsers via HTML5 SLDP Player, and also using native Larix Player for Android and Larix Player for iOS.

Opus on iPhone

Apple's platforms have limitations on Opus playback using system components. So out-of-box, it's impossible to play any video with Opus audio there.

This is why we made a step forward and created our own playback implementation there.

Opus audio can be played in iPhone browser in audio-only mode using SLDP HTML5 Player. You can embed the web player and play audio streams.

So when you're receiving audio via your WebRTC input you can avoid additional transcoding and play it directly with the lowest possible latency.

Premium feature from SDK

Notice that Opus audio-only playback in iPhone is a premium feature available only as part of SLDP HTML5 Player SDK. Feel free to subscribe in order to get access to this and other capabilities of SLDP web player.

Related documentation

WebRTC publish setup in Nimble StreamerSLDP low latency playback protocol, Audio streaming in Nimble Streamer, WebRTC processing in Nimble Streamer, Softvelum players,