From 97f6b060f8dce5c0b25a45cfe21faac5e523ab95 Mon Sep 17 00:00:00 2001
From: Max Heimbrock <43608204+MaxHeimbrock@users.noreply.github.com>
Date: Mon, 10 Aug 2026 11:34:33 +0200
Subject: [PATCH] Audio boost script

---
 .../Meet/Assets/Runtime/AudioBoostFilter.cs   | 54 +++++++++++++++++++
 .../Assets/Runtime/AudioBoostFilter.cs.meta   | 11 ++++
 Samples~/Meet/Assets/Runtime/MeetManager.cs   | 12 +++++
 3 files changed, 77 insertions(+)
 create mode 100644 Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs
 create mode 100644 Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs.meta

diff --git a/Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs b/Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs
new file mode 100644
index 00000000..18b07046
--- /dev/null
+++ b/Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs
@@ -0,0 +1,54 @@
+using UnityEngine;
+
+/// <summary>
+/// Boosts the audio of the <see cref="AudioSource"/> on this GameObject by a linear
+/// gain multiplier, e.g. for devices that play WebRTC audio at very low volume.
+/// Values above 1 are hard-clipped at full scale, so expect distortion on loud
+/// passages at higher settings.
+///
+/// Must be added AFTER the <see cref="LiveKit.AudioStream"/> for this source has been
+/// created: Unity runs audio filters in component order and the SDK's probe overwrites
+/// the buffer, so this filter only has an effect while it sits below the probe.
+/// </summary>
+public class AudioBoostFilter : MonoBehaviour
+{
+    [Tooltip("Linear gain applied to the audio. 1 = unchanged.")]
+    [Range(1f, 10f)]
+    public float multiplier = 1f;
+
+    private void OnEnable()
+    {
+        AudioSettings.OnAudioConfigurationChanged += OnAudioConfigurationChanged;
+    }
+
+    private void OnDisable()
+    {
+        AudioSettings.OnAudioConfigurationChanged -= OnAudioConfigurationChanged;
+    }
+
+    // AudioStream reacts to this same event by destroying and re-adding its probe,
+    // which appends the new probe below this filter — the probe would then overwrite
+    // the boosted output. Re-adding this component moves the gain back to the end of
+    // the filter chain. AudioStream subscribed to the event before this component
+    // existed, so the new probe is already in place when this handler runs.
+    private void OnAudioConfigurationChanged(bool deviceWasChanged)
+    {
+        var replacement = gameObject.AddComponent<AudioBoostFilter>();
+        replacement.multiplier = multiplier;
+        Destroy(this);
+    }
+
+    // Called by Unity on the audio thread.
+    private void OnAudioFilterRead(float[] data, int channels)
+    {
+        var gain = multiplier;
+        if (gain == 1f)
+            return;
+
+        for (int i = 0; i < data.Length; i++)
+        {
+            var boosted = data[i] * gain;
+            data[i] = boosted > 1f ? 1f : (boosted < -1f ? -1f : boosted);
+        }
+    }
+}
diff --git a/Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs.meta b/Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs.meta
new file mode 100644
index 00000000..f08ce2ac
--- /dev/null
+++ b/Samples~/Meet/Assets/Runtime/AudioBoostFilter.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: ceba6fcb200fd43deb998fefd5af0d60
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Samples~/Meet/Assets/Runtime/MeetManager.cs b/Samples~/Meet/Assets/Runtime/MeetManager.cs
index 1dc27c71..f5f801f4 100644
--- a/Samples~/Meet/Assets/Runtime/MeetManager.cs
+++ b/Samples~/Meet/Assets/Runtime/MeetManager.cs
@@ -44,6 +44,13 @@ public class MeetManager : MonoBehaviour
     [Tooltip("Prefer hardware audio processing (e.g., iOS VPIO). Lower latency but may have different quality characteristics.")]
     [SerializeField] private bool preferHardwareProcessing = true;
 
+    [Header("Audio Playback (Unity Audio mode only)")]
+    [Tooltip("Linear gain applied to remote audio played through Unity AudioSources, " +
+             "for devices with very low playout volume. 1 = unchanged. " +
+             "Can also be tweaked per track at runtime on the AudioTrack GameObjects.")]
+    [Range(1f, 10f)]
+    [SerializeField] private float remoteAudioBoost = 1f;
+
     private const string PlaceholderTextureResourceName = "PlaceholderTileSquare";
     private Texture _placeholderTexture;
 
@@ -375,6 +382,11 @@ private void AddRemoteAudioTrack(RemoteAudioTrack audioTrack)
         var audiostream = new AudioStream(audioTrack, source);
         _audioStreams.Add(sid, audiostream);
 
+        // Must be added after the AudioStream so the boost filter runs after the
+        // SDK's probe in Unity's filter chain.
+        var boost = audioObject.AddComponent<AudioBoostFilter>();
+        boost.multiplier = remoteAudioBoost;
+
         _audioObjects[sid] = audioObject;
     }