Use accurate semitone algorithm

YARC-Official · Dec 22, 2023 · 2e96d8c · 2e96d8c
1 parent 7c2219f
commit 2e96d8c
Showing 1 changed file with 4 additions and 11 deletions.
diff --git a/Assets/Script/Audio/Bass/BassStemChannel.cs b/Assets/Script/Audio/Bass/BassStemChannel.cs
@@ -144,17 +144,10 @@ public int Load(float speed)
                 // Have to handle pitch separately for some reason
                 if (_manager.Options.IsChipmunkSpeedup)
                 {
-                    float semitoneShift = speed switch
-                    {
-                        > 1f => speed / 9f - 1f / 9f,
-                        < 1f => speed / 3f - 1f / 3f,
-                        _    => 0f
-                    };
-
-                    semitoneShift = Math.Clamp(semitoneShift, -60f, 60f);
-
-                    if (!Bass.ChannelSetAttribute(StreamHandle, ChannelAttribute.Pitch, semitoneShift) ||
-                        !Bass.ChannelSetAttribute(ReverbStreamHandle, ChannelAttribute.Pitch, semitoneShift))
+                    double accurateSemitoneShift = 12 * Math.Log(speed, 2);
+                    float finalSemitoneShift = (float) Math.Clamp(accurateSemitoneShift, -60, 60);
+                    if (!Bass.ChannelSetAttribute(StreamHandle, ChannelAttribute.Pitch, finalSemitoneShift) ||
+                        !Bass.ChannelSetAttribute(ReverbStreamHandle, ChannelAttribute.Pitch, finalSemitoneShift))
                         Debug.LogError($"Failed to set channel pitch: {Bass.LastError}");
                 }
             }