Merge pull request #170 from alnitak/newLimiter

Limiter filter outputCeiling + attackTime

.vscode/launch.json

@@ -8,7 +8,7 @@
             "name": "Flutter debug",
             "type": "dart",
             "request": "launch",
-            "program": "lib/main.dart",
+            "program": "lib/filters/limiter.dart",
             "flutterMode": "debug",
             "cwd": "${workspaceFolder}/example"
         },

example/lib/filters/limiter.dart

@@ -18,8 +18,8 @@ import 'package:logging/logging.dart';
 /// - `wet`: Wet/dry mix ratio, 1.0 means fully wet, 0.0 means fully dry
 /// - `threshold`: The threshold in dB. Signals above this level are reduced
 /// in gain. A lower value means more aggressive limiting.
-/// - `makeupGain`: The make-up gain in dB applied after limiting to bring up
-/// the output level.
+/// - `outputCeiling`: The maximum output level in dB (should be < 0dB to
+/// prevent clipping)
 /// - `kneeWidth`: The width of the knee in dB. A larger value results in a
 /// softer transition into limiting.
 /// - `releaseTime`: The release time in milliseconds. Determines how quickly
@@ -72,9 +72,10 @@ class _LimiterExampleState extends State<LimiterExample> {
   AudioSource? sound;
   late double wet;
   late double threshold;
-  late double makeupGain;
+  late double outputCeiling;
   late double kneeWidth;
   late double releaseTime;
+  late double attackTime;
   bool isFilterActive = false;
 
   @override
@@ -83,9 +84,10 @@ class _LimiterExampleState extends State<LimiterExample> {
 
     wet = limiter.queryWet.def;
     threshold = limiter.queryThreshold.def;
-    makeupGain = limiter.queryMakeupGain.def;
+    outputCeiling = limiter.queryOutputCeiling.def;
     kneeWidth = limiter.queryKneeWidth.def;
     releaseTime = limiter.queryReleaseTime.def;
+    attackTime = limiter.queryAttackTime.def;
   }
 
   @override
@@ -105,7 +107,11 @@ class _LimiterExampleState extends State<LimiterExample> {
           children: [
             const Text(
               'WARNING: lower the volume down!',
-              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
+              style: TextStyle(
+                fontSize: 18,
+                fontWeight: FontWeight.bold,
+                color: Colors.red,
+              ),
             ),
             Row(
               mainAxisSize: MainAxisSize.min,
@@ -118,9 +124,10 @@ class _LimiterExampleState extends State<LimiterExample> {
                       limiter.activate();
                       limiter.wet.value = wet;
                       limiter.threshold.value = threshold;
-                      limiter.makeupGain.value = makeupGain;
+                      limiter.outputCeiling.value = outputCeiling;
                       limiter.kneeWidth.value = kneeWidth;
                       limiter.releaseTime.value = releaseTime;
+                      limiter.attackTime.value = attackTime;
                     } else {
                       limiter.deactivate();
                     }
@@ -143,11 +150,16 @@ class _LimiterExampleState extends State<LimiterExample> {
             ///
             ElevatedButton(
               onPressed: () {
-                SoLoud.instance.play(sound!, looping: true);
-                SoLoud.instance.play(sound!, looping: true);
-                SoLoud.instance.play(sound!, looping: true);
-                SoLoud.instance.play(sound!, looping: true);
-                SoLoud.instance.play(sound!, looping: true);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
+                SoLoud.instance.play(sound!, looping: true, volume: 2);
               },
               child: const Text('play sound'),
             ),
@@ -199,16 +211,16 @@ class _LimiterExampleState extends State<LimiterExample> {
             ),
             Row(
               children: [
-                Text('Makeup gain ${makeupGain.toStringAsFixed(2)}'),
+                Text('Outpout ceiling ${outputCeiling.toStringAsFixed(2)}'),
                 Expanded(
                   child: Slider(
-                    value: makeupGain,
-                    min: limiter.queryMakeupGain.min,
-                    max: limiter.queryMakeupGain.max,
+                    value: outputCeiling,
+                    min: limiter.queryOutputCeiling.min,
+                    max: limiter.queryOutputCeiling.max,
                     onChanged: (value) {
                       setState(() {
-                        makeupGain = value;
-                        limiter.makeupGain.value = value;
+                        outputCeiling = value;
+                        limiter.outputCeiling.value = value;
                       });
                     },
                   ),
@@ -251,6 +263,24 @@ class _LimiterExampleState extends State<LimiterExample> {
                 ),
               ],
             ),
+            Row(
+              children: [
+                Text('Attack time ${attackTime.toStringAsFixed(2)}'),
+                Expanded(
+                  child: Slider(
+                    value: attackTime,
+                    min: limiter.queryAttackTime.min,
+                    max: limiter.queryAttackTime.max,
+                    onChanged: (value) {
+                      setState(() {
+                        attackTime = value;
+                        limiter.attackTime.value = value;
+                      });
+                    },
+                  ),
+                ),
+              ],
+            ),
           ],
         ),
       ),

example/lib/main.dart

@@ -1,4 +1,3 @@
-import 'dart:async';
 import 'dart:developer' as dev;
 
 import 'package:flutter/foundation.dart';

lib/src/filter_params.dart

@@ -137,13 +137,14 @@ const FxParams fxLimiter = (
   names: [
     'Wet',
     'Threshold',
-    'Makeup Gain',
+    'Output Ceiling',
     'Knee Width',
     'Release Time',
+    'Attack Time',
   ],
-  mins: [0, -60, -60, 0, 1],
-  maxs: [1, 0, 30, 30, 1000],
-  defs: [1, -6, 0, 2, 100],
+  mins: [0, -60, -60, 0, 1, 0.1],
+  maxs: [1, 0, 30, 0, 1000, 200],
+  defs: [1, -6, 0, -1, 100, 1],
 );
 
 /// Compressor filter

lib/src/filters/filters.dart

@@ -107,12 +107,15 @@ final class FiltersSingle {
   /// - `threshold`: The threshold in dB. Signals above this level are reduced
   /// in gain. A lower value means more aggressive limiting.
   ///
-  /// - `makeupGain`: The make-up gain in dB applied after limiting to bring up
-  /// the output level.
+  /// - `outputCeiling`: The maximum output level in dB (should be < 0dB to
+  /// prevent clipping)
   ///
   /// - `kneeWidth`: The width of the knee in dB. A larger value results in a
   /// softer transition into limiting.
   ///
+  /// - `attackTime`: The attack time in milliseconds. Determines how quickly
+  /// the gain reduction recovers after a signal peaks above the threshold.
+  ///
   /// - `releaseTime`: The release time in milliseconds. Determines how quickly
   /// the gain reduction recovers after a signal drops below the threshold.
   LimiterSingle get limiterFilter => LimiterSingle(soundHash);
@@ -188,8 +191,8 @@ final class FiltersGlobal {
   /// - `threshold`: The threshold in dB. Signals above this level are reduced
   /// in gain. A lower value means more aggressive limiting.
   ///
-  /// - `makeupGain`: The make-up gain in dB applied after limiting to bring up
-  /// the output level.
+  /// - `outputCeiling`: The maximum output level in dB (should be < 0dB to
+  /// prevent clipping)
   ///
   /// - `kneeWidth`: The width of the knee in dB. A larger value results in a
   /// softer transition into limiting.

lib/src/filters/limiter.dart

@@ -7,13 +7,14 @@ import 'package:flutter_soloud/src/sound_hash.dart';
 enum Limiter {
   wet,
   threshold,
-  makeupGain,
+  outputCeiling,
   kneeWidth,
-  releaseTime;
+  releaseTime,
+  attackTime;
 
-  final List<double> _mins = const [0, -60, -60, 0, 1];
-  final List<double> _maxs = const [1, 0, 30, 30, 1000];
-  final List<double> _defs = const [1, -6, 0, 2, 100];
+  final List<double> _mins = const [0, -60, -60, 0, 1, 0.1];
+  final List<double> _maxs = const [1, 0, 0, 30, 1000, 200];
+  final List<double> _defs = const [1, -6, -1, 2, 100, 1];
 
   double get min => _mins[index];
   double get max => _maxs[index];
@@ -23,9 +24,10 @@ enum Limiter {
   String toString() => switch (this) {
         Limiter.wet => 'Wet',
         Limiter.threshold => 'Threshold',
-        Limiter.makeupGain => 'Makeup Gain',
+        Limiter.outputCeiling => 'Output Ceiling',
         Limiter.kneeWidth => 'Knee Width',
         Limiter.releaseTime => 'Release Time',
+        Limiter.attackTime => 'Attack Time',
       };
 }
 
@@ -35,9 +37,10 @@ abstract class _LimiterInternal extends FilterBase {
 
   Limiter get queryWet => Limiter.wet;
   Limiter get queryThreshold => Limiter.threshold;
-  Limiter get queryMakeupGain => Limiter.makeupGain;
+  Limiter get queryOutputCeiling => Limiter.outputCeiling;
   Limiter get queryKneeWidth => Limiter.kneeWidth;
   Limiter get queryReleaseTime => Limiter.releaseTime;
+  Limiter get queryAttackTime => Limiter.attackTime;
 }
 
 class LimiterSingle extends _LimiterInternal {
@@ -59,12 +62,12 @@ class LimiterSingle extends _LimiterInternal {
         Limiter.threshold.max,
       );
 
-  FilterParam makeupGain({SoundHandle? soundHandle}) => FilterParam(
+  FilterParam outputCeiling({SoundHandle? soundHandle}) => FilterParam(
         soundHandle,
         filterType,
-        Limiter.makeupGain.index,
-        Limiter.makeupGain.min,
-        Limiter.makeupGain.max,
+        Limiter.outputCeiling.index,
+        Limiter.outputCeiling.min,
+        Limiter.outputCeiling.max,
       );
 
   FilterParam kneeWidth({SoundHandle? soundHandle}) => FilterParam(
@@ -82,6 +85,14 @@ class LimiterSingle extends _LimiterInternal {
         Limiter.releaseTime.min,
         Limiter.releaseTime.max,
       );
+
+  FilterParam attackTime({SoundHandle? soundHandle}) => FilterParam(
+        soundHandle,
+        filterType,
+        Limiter.attackTime.index,
+        Limiter.attackTime.min,
+        Limiter.attackTime.max,
+      );
 }
 
 class LimiterGlobal extends _LimiterInternal {
@@ -103,12 +114,12 @@ class LimiterGlobal extends _LimiterInternal {
         Limiter.threshold.max,
       );
 
-  FilterParam get makeupGain => FilterParam(
+  FilterParam get outputCeiling => FilterParam(
         null,
         filterType,
-        Limiter.makeupGain.index,
-        Limiter.makeupGain.min,
-        Limiter.makeupGain.max,
+        Limiter.outputCeiling.index,
+        Limiter.outputCeiling.min,
+        Limiter.outputCeiling.max,
       );
 
   FilterParam get kneeWidth => FilterParam(
@@ -126,4 +137,12 @@ class LimiterGlobal extends _LimiterInternal {
         Limiter.releaseTime.min,
         Limiter.releaseTime.max,
       );
+
+  FilterParam get attackTime => FilterParam(
+        null,
+        filterType,
+        Limiter.attackTime.index,
+        Limiter.attackTime.min,
+        Limiter.attackTime.max,
+      );
 }