Simple Multiparty

Kotlin

Each remote client appears as a Stream. Implement onStreamReceived / onStreamDropped:

For each new stream, build a Subscriber, call session.subscribe(subscriber), then attach subscriber.view to a dedicated cell in your layout.

This sample uses a fixed number of slots (maxSubscribers): parallel arrays for Subscriber?, optional stream IDs, and FrameLayout? cells. The next free index gets the new participant; if all slots are full, ignore or replace according to your product rules.

private val maxSubscribers = 4
private val subscribers = arrayOfNulls<Subscriber>(maxSubscribers)
private val subscriberContainers = arrayOfNulls<FrameLayout>(maxSubscribers)
private val subscriberStreamIds = arrayOfNulls<String>(maxSubscribers)

override fun onStreamReceived(session: Session, stream: Stream) {
    val subscriber = Subscriber.Builder(this@MainActivity, stream).build()
    session.subscribe(subscriber)
    addSubscriber(subscriber) 
}

private fun addSubscriber(subscriber: Subscriber) {
    val index = subscribers.indexOfFirst { it == null }
    if (index == -1) {
        Toast.makeText(
            this,
            "New subscriber ignored, maxSubscribers limit reached",
            Toast.LENGTH_LONG
        ).show()
        return
    }

    subscribers[index] = subscriber
    subscriberStreamIds[index] = subscriber.stream.streamId

    subscriber.setStyle(BaseVideoRenderer.STYLE_VIDEO_SCALE, BaseVideoRenderer.STYLE_VIDEO_FILL)
    subscriber.subscribeToAudio = true

    runOnUiThread {
        subscriberContainers[index]?.removeAllViews()
        subscriberContainers[index]?.addView(subscriber.view)
    }

    subscriberAudioEnabled[index] = true
    subscriberVisible[index] = true
}

When a stream ends, remove that subscriber’s view and free the slot.

override fun onStreamDropped(session: Session, stream: Stream) {
    val index = subscriberStreamIds.indexOfFirst { it == stream.streamId }
    if (index == -1) return

    val subscriber = subscribers[index] ?: return

    runOnUiThread {
        subscriberContainers[index]?.removeView(subscriber.view)
    }
    subscribers[index] = null
    subscriberStreamIds[index] = null
    subscriberVisible[index] = false
    subscriberAudioEnabled[index] = true
}

Toggle remote audio with subscriber.subscribeToAudio = enabled. Toggle your outgoing A/V with publisher.publishAudio / publisher.publishVideo.

Tear Down Cleanly

On exit, unsubscribe each subscriber, unpublish the publisher, then session.disconnect(). Doing this avoids leaked sessions and blocked cameras/mics on some devices.

Simple Multiparty

Learn how to use the Vonage Android SDK for a multi-party call. The application publishes audio/video from a device and can connect to multiple subscribers.

Available on:

Kotlin

Steps

Introduction

Getting Started

Creating a new project

Adding the Android SDK

Setting up authentication

Requesting permissions

Connect publish and show yourself

Multiparty subscribe to every remote stream

Host SDK views in AndroidView