feat: Add audio jitter/RTT metrics and toggle audio output API

CHANGELOG.md

@@ -1,3 +1,9 @@
+## [Unreleased]
+
+### Added
+* Added `audioSendJitterMs`, `audioReceiveJitterMs`, and `audioRttMs` to `ObservableMetric` for audio quality monitoring
+* Added `realtimePlaybackMute()` and `realtimePlaybackUnmute()` to `RealtimeControllerFacade` for muting/unmuting audio output
+
 ## [0.25.3] - 2026-02-06
 
 ### Fixed

README.md

@@ -384,14 +384,24 @@ meetingSession.audioVideo.start(audioVideoConfiguration) // starts the audio vid
 
 > Note: So far, you've added observers to receive device and session lifecycle events. In the following use cases, you'll use the real-time API methods to send and receive volume indicators and control mute state.
 
-#### Use case 9. Mute and unmute an audio input.
+#### Use case 9. Mute and unmute audio input and output.
+
+To mute and unmute audio input:
 
 ```kotlin
 val muted = meetingSession.audioVideo.realtimeLocalMute() // returns true if muted, false if failed
 
 val unmuted = meetingSession.audioVideo.realtimeLocalUnmute() // returns true if unmuted, false if failed
 ```
 
+To mute and unmute audio playback (output):
+
+```kotlin
+val muted = meetingSession.audioVideo.realtimePlaybackMute() // returns true if muted, false if failed
+
+val unmuted = meetingSession.audioVideo.realtimePlaybackUnmute() // returns true if unmuted, false if failed
+```
+
 #### Use case 10. Add an observer to receive realtime events such as volume changes/signal change/muted status attendees.
 
 You can use this to build real-time indicators UI and get them updated for changes delivered by the array.

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/audiovideo/DefaultAudioVideoFacade.kt

@@ -140,6 +140,14 @@ class DefaultAudioVideoFacade(
         return realtimeController.realtimeLocalUnmute()
     }
 
+    override fun realtimePlaybackMute(): Boolean {
+        return realtimeController.realtimePlaybackMute()
+    }
+
+    override fun realtimePlaybackUnmute(): Boolean {
+        return realtimeController.realtimePlaybackUnmute()
+    }
+
     override fun addRealtimeObserver(observer: RealtimeObserver) {
         realtimeController.addRealtimeObserver(observer)
     }

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/audiovideo/metric/ObservableMetric.kt

@@ -20,6 +20,21 @@ enum class ObservableMetric {
      */
     audioSendPacketLossPercent,
 
+    /**
+     * Upstream audio jitter (ms)
+     */
+    audioSendJitterMs,
+
+    /**
+     * Downstream audio jitter (ms)
+     */
+    audioReceiveJitterMs,
+
+    /**
+     * Audio round-trip time (ms) between client and server
+     */
+    audioRttMs,
+
     /**
      * Estimated uplink bandwidth from perspective of video client
      */

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/internal/audio/AudioClientController.kt

@@ -38,6 +38,7 @@ interface AudioClientController {
 
     fun stop()
     fun setMute(isMuted: Boolean): Boolean
+    fun setPlaybackMute(isMuted: Boolean): Boolean
     fun setVoiceFocusEnabled(enabled: Boolean): Boolean
     fun isVoiceFocusEnabled(): Boolean
     fun promoteToPrimaryMeeting(credentials: MeetingSessionCredentials, observer: PrimaryMeetingPromotionObserver)

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/internal/audio/DefaultAudioClientController.kt

@@ -325,6 +325,12 @@ class DefaultAudioClientController(
         )
     }
 
+    override fun setPlaybackMute(isMuted: Boolean): Boolean {
+        return audioClientState == AudioClientState.STARTED && AudioClient.AUDIO_CLIENT_OK == audioClient.setSpkMute(
+            isMuted
+        )
+    }
+
     override fun setVoiceFocusEnabled(enabled: Boolean): Boolean {
         if (audioClientState == AudioClientState.STARTED) {
             val result = audioClient.setVoiceFocusNoiseSuppression(enabled)

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/internal/metric/DefaultClientMetricsCollector.kt

@@ -29,6 +29,12 @@ class DefaultClientMetricsCollector :
             metrics[AudioClient.AUDIO_CLIENT_METRIC_POST_JB_SPK_1S_PACKETS_LOST_PERCENT]
         cachedObservableMetrics[ObservableMetric.audioSendPacketLossPercent] =
             metrics[AudioClient.AUDIO_SERVER_METRIC_POST_JB_MIC_1S_PACKETS_LOST_PERCENT]
+        cachedObservableMetrics[ObservableMetric.audioSendJitterMs] =
+            metrics[AudioClient.AUDIO_SERVER_METRIC_MIC_JITTER_MS]
+        cachedObservableMetrics[ObservableMetric.audioReceiveJitterMs] =
+            metrics[AudioClient.AUDIO_CLIENT_METRIC_SPK_JITTER_MS]
+        cachedObservableMetrics[ObservableMetric.audioRttMs] =
+            metrics[AudioClient.AUDIO_CLIENT_METRIC_RTT_MS]
         maybeEmitMetrics()
     }
 

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/realtime/DefaultRealtimeController.kt

@@ -27,6 +27,14 @@ class DefaultRealtimeController(
         return audioClientController.setMute(false)
     }
 
+    override fun realtimePlaybackMute(): Boolean {
+        return audioClientController.setPlaybackMute(true)
+    }
+
+    override fun realtimePlaybackUnmute(): Boolean {
+        return audioClientController.setPlaybackMute(false)
+    }
+
     override fun addRealtimeObserver(observer: RealtimeObserver) {
         audioClientObserver.subscribeToRealTimeEvents(observer)
     }

amazon-chime-sdk/src/main/java/com/amazonaws/services/chime/sdk/meetings/realtime/RealtimeControllerFacade.kt

@@ -35,6 +35,20 @@ interface RealtimeControllerFacade {
      */
     fun realtimeLocalUnmute(): Boolean
 
+    /**
+     * Mutes the audio output (speaker).
+     *
+     * @return Boolean whether the mute action succeeded
+     */
+    fun realtimePlaybackMute(): Boolean
+
+    /**
+     * Unmutes the audio output (speaker).
+     *
+     * @return Boolean whether the unmute action succeeded
+     */
+    fun realtimePlaybackUnmute(): Boolean
+
     /**
      * Subscribes to real time events with an observer
      *

amazon-chime-sdk/src/test/java/com/amazonaws/services/chime/sdk/meetings/realtime/DefaultRealtimeControllerTest.kt

@@ -108,6 +108,20 @@ class DefaultRealtimeControllerTest {
         verify { audioClientObserver.unsubscribeFromTranscriptEvent(mockTranscriptEventObserver) }
     }
 
+    @Test
+    fun `realtimePlaybackMute should call audioClientController setPlaybackMute with true and return the status`() {
+        every { audioClientController.setPlaybackMute(true) } returns true
+        assertTrue(realtimeController.realtimePlaybackMute())
+        verify { audioClientController.setPlaybackMute(true) }
+    }
+
+    @Test
+    fun `realtimePlaybackUnmute should call audioClientController setPlaybackMute with false and return the status`() {
+        every { audioClientController.setPlaybackMute(false) } returns true
+        assertTrue(realtimeController.realtimePlaybackUnmute())
+        verify { audioClientController.setPlaybackMute(false) }
+    }
+
     @Test
     fun `realtimeSetVoiceFocusEnabled(true) should call audioClientController setVoiceFocusEnabled with true and return the status`() {
         every { audioClientController.setVoiceFocusEnabled(true) } returns true

app/src/main/java/com/amazonaws/services/chime/sdkdemo/fragment/MeetingFragment.kt

@@ -645,7 +645,8 @@ class MeetingFragment : Fragment(),
             context?.getString(if (meetingModel.isUsingCpuVideoProcessor) R.string.disable_cpu_filter else R.string.enable_cpu_filter),
             context?.getString(if (meetingModel.isUsingGpuVideoProcessor) R.string.disable_gpu_filter else R.string.enable_gpu_filter),
             context?.getString(if (meetingModel.isUsingCameraCaptureSource) R.string.disable_custom_capture_source else R.string.enable_custom_capture_source),
-            context?.getString(R.string.video_configuration)
+            context?.getString(R.string.video_configuration),
+            context?.getString(if (meetingModel.isPlaybackMuted) R.string.unmute_playback else R.string.mute_playback)
         )
         if (inReplicaMeeting()) {
             additionalToggles.add(context?.getString(R.string.demote_from_primary_meeting))
@@ -662,7 +663,8 @@ class MeetingFragment : Fragment(),
                 4 -> toggleGpuDemoFilter()
                 5 -> toggleCustomCaptureSource()
                 6 -> presentVideoConfigDialog()
-                7 -> { // May not be accessible
+                7 -> togglePlaybackMute()
+                8 -> { // May not be accessible
                     if (inReplicaMeeting()) {
                         demoteFromPrimaryMeeting()
                     } else {
@@ -1003,6 +1005,17 @@ class MeetingFragment : Fragment(),
         }
     }
 
+    private fun togglePlaybackMute() {
+        val mute = !meetingModel.isPlaybackMuted
+        val success = if (mute) audioVideo.realtimePlaybackMute() else audioVideo.realtimePlaybackUnmute()
+        if (success) {
+            meetingModel.isPlaybackMuted = mute
+            notifyHandler("Playback ${if (mute) "muted" else "unmuted"}")
+        } else {
+            notifyHandler("Failed to ${if (mute) "mute" else "unmute"} playback")
+        }
+    }
+
     private fun toggleLiveTranscription(meetingId: String, meetingEndpointUrl: String) {
         if (meetingModel.isLiveTranscriptionEnabled) {
             uiScope.launch {

app/src/main/java/com/amazonaws/services/chime/sdkdemo/model/MeetingModel.kt

@@ -65,6 +65,7 @@ class MeetingModel : ViewModel() {
     val currentCaptionIndices = mutableMapOf<String, Int>()
 
     var isMuted = false
+    var isPlaybackMuted = false
     var isCameraOn = false
     var isDeviceListDialogOn = false
     var isAdditionalOptionsDialogOn = false

app/src/main/res/values/strings.xml

@@ -87,6 +87,8 @@
     <string name="disable_screen_capture_source">Stop sharing screen</string>
     <string name="enable_voice_focus">Turn on Voice Focus (noise suppression)</string>
     <string name="disable_voice_focus">Turn off Voice Focus (noise suppression)</string>
+    <string name="mute_playback">Mute Playback</string>
+    <string name="unmute_playback">Unmute Playback</string>
     <string name="enable_live_transcription">Turn on Live Transcription</string>
     <string name="disable_live_transcription">Turn off Live Transcription</string>
     <string name="enable_flashlight">Turn on flashlight</string>