Audio Output Issue in OpenTok (WebRTC) with Non-Original Headsets on iOS

[DimaIgorevich]

Describe the bug
I am using the OpenTok SDK for iOS in my application and have encountered an issue with audio playback when connecting a non-original wired headset with a 3.5mm jack through a Lightning → 3.5mm adapter.

When using the non-original adapter, OpenTok SDK fails to output audio through the headset. In some cases, if the output source is switched to speaker mode and then back to the headset (if the app supports this feature), the sound may return.

Questions:
Are there any known issues with OpenTok SDK handling non-original audio devices on iOS?
Is there a way to manually set the audio output in WebRTC/OpenTok to ensure proper functionality with adapters?
How can I verify if OpenTok correctly initializes the audio device at session startup?
What tools or logs can be used to debug audio routing issues in OpenTok WebRTC?
I would appreciate any recommendations or insights on how to resolve this issue.

Environment & Setup:
Device: iPhone 12 Pro Max
iOS Version: 17.6.1
SDK: OpenTok WebRTC
Audio Devices Used:
Original Apple wired headphones (Lightning)
Non-original wired headphones (Lightning)
Wired headphones with a 3.5mm jack through a non-original Lightning → 3.5mm adapter

Additional context

1. WebRTC may not recognize the adapter as a valid audio device. OpenTok SDK could be using system APIs for selecting the audio output, and the adapter might not provide the necessary metadata.
2. The issue could be related to AVAudioSession behavior. Some non-original adapters might not fully support iOS audio streams, leading to WebRTC misconfiguration.
3. There might be a bug in WebRTC or OpenTok SDK. Explicitly setting AVAudioSessionCategory before connecting to WebRTC might help.