Android: Audio

Overview

On an established CXRLink session, start the glasses-side audio stream. The SDK delivers PCM chunks via IAudioStreamCbk.onAudioReceived. Typical format: 16 kHz, mono, 16 bit.

Prerequisites

• Global CXRLink created and connect completed.
• Scene building completed:
  • CustomView: customViewOpen succeeded and onCustomViewOpened received
  • CustomApp: target app started via appStart
• GlassPermission.MICROPHONE recommended.

Do not call startAudioStream with link-only connectivity before scene building.

Core APIs

Method	Description
setCXRAudioCbk(IAudioStreamCbk)	Register audio callbacks
startAudioStream(codecType: Int)	Start capture; use codecType = 1
stopAudioStream()	Stop capture

IAudioStreamCbk callbacks

Callback	Description
onAudioReceived(data, offset, length)	PCM chunk; guard offset/length bounds
onAudioStreamStateChanged(started: Boolean)	Stream state
onAudioError(code, info?)	Error; stop stream and notify user

PCM parameters

Parameter	Value
Sample rate	16000 Hz
Channels	1 (mono)
Bit depth	16 bit

Duration estimate: pcmBytes / (16000 * 2) seconds.

Lifecycle

• Call stopAudioStream() in sub-page onDestroy; do not disconnect().
• Stop capture before page destruction.
• Optional: use onGlassAiInterrupt to auto-start recording on AI interrupt.

Constraints

• Do not stream when link is down.
• Flush writes periodically for file persistence.
• Both CustomView and CustomApp support audio after scene building.

Appendix: reference sample

RenewCXRLSample AudioUsageViewModel — PCM capture, WAV packaging, playback.