Merge pull request #190 from alnitak/newAudioData

added `alwaysReturnData` to `AudioData.getAudioData`

Author: alnitak

.vscode/launch.json

@@ -89,7 +89,7 @@
             "cwd": "${workspaceFolder}"
         },
         {
-            "name": "Chrome",
+            "name": "Chrome release",
             "type": "chrome",
             "preLaunchTask": "compile web wasm release",
             "request": "launch"

.vscode/tasks.json

@@ -9,7 +9,7 @@
         },
         {
             "label": "compile linux debug",
-            "command": "cd ${workspaceFolder}/example; flutter build linux -t lib/main.dart --debug",
+            "command": "cd ${workspaceFolder}/example; flutter build linux -t lib/audio_data/audio_data.dart --debug",
             "type": "shell"
         },
         {

CHANGELOG.md

@@ -1,3 +1,7 @@
+### 3.1.0 (18 Mar 2025)
+- wWhen calling `AudioData.getAudioData` is now possible to check if the audio data is the same as before. Useful to visualize waveforms. This is because `AudioData.getAudioData` returns the current data in the buffer and if it is called before the buffer has been updated, it will return the previous data.
+- added `resetBufferStream` method to `SoLoud`. It happens that when playing a stream, maybe from the web, it is needed to change it to another source. The player continues to play the already added audio data to the buffer. This method can be used to reset the buffer and start with the new audio data.
+
 ### 3.0.3 (7 Mar 2025)
 - it's now possible to choose to not link opus and ogg libraries (see `NO_OPUS_OGG_LIBS.md`). Fix for #191 and #192.
 

example/lib/audio_data/audio_data.dart

@@ -39,7 +39,7 @@ void main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
   /// Initialize the player.
-  await SoLoud.instance.init();
+  await SoLoud.instance.init(bufferSize: 1024, channels: Channels.mono);
 
   /// Activate the visualization. Mandatory to acquire audio data.
   SoLoud.instance.setVisualizationEnabled(true);

example/lib/audio_data/data_widget.dart

@@ -14,8 +14,8 @@ class AudioDataWidgetState extends State<AudioDataWidget>
     with SingleTickerProviderStateMixin {
   Ticker? ticker;
 
-  /// Set [AudioData] to use a `linear` data kind. This is the way to get both
-  /// wave and FFT data.
+  /// Set [AudioData] to use a [GetSamplesKind.linear] data kind.
+  /// This is the way to get both wave and FFT data in a single list.
   final AudioData audioData = AudioData(GetSamplesKind.linear);
 
   @override
@@ -35,7 +35,7 @@ class AudioDataWidgetState extends State<AudioDataWidget>
   void _tick(Duration elapsed) {
     if (context.mounted) {
       try {
-        /// Internally update the audio data to be used later
+        /// Internally update the audio data to be get later
         /// with `audioData.getLinear*()` in [WavePainter]
         audioData.updateSamples();
         setState(() {});
@@ -71,8 +71,7 @@ class AudioDataWidgetState extends State<AudioDataWidget>
   }
 }
 
-/// Custom painter to draw the wave in a circle
-///
+/// Custom painter to draw the wave and the FFT
 class WavePainter extends CustomPainter {
   const WavePainter({
     required this.audioData,
@@ -81,13 +80,18 @@ class WavePainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
+    // ignore: avoid_redundant_argument_values
+    final samples = audioData.getAudioData(alwaysReturnData: true);
+    // Using `alwaysReturnData: true` this will always return a non-empty list
+    // even if the audio data is the same as the previous one.
+    if (samples.isEmpty) {
+      return;
+    }
     final barWidth = size.width / 256;
     final paint = Paint()
       ..strokeWidth = barWidth * 0.8
       ..color = Colors.yellowAccent;
 
-    final samples = audioData.getAudioData();
-
     double waveHeight;
     double fftHeight;
 

example/pubspec.lock

@@ -77,18 +77,18 @@ packages:
     dependency: transitive
     description:
       name: ffi
-      sha256: "16ed7b077ef01ad6170a3d0c57caa4a112a38d7a2ed5602e0aca9ca6f3d98da6"
+      sha256: "289279317b4b16eb2bb7e271abccd4bf84ec9bdcbe999e278a94b804f5630418"
       url: "https://pub.dev"
     source: hosted
-    version: "2.1.3"
+    version: "2.1.4"
   file_picker:
     dependency: "direct main"
     description:
       name: file_picker
-      sha256: "3d57312a53746ed4eb8c843dc50372454bbda37dd0c01a4d40fedc83e2ce4921"
+      sha256: ab13ae8ef5580a411c458d6207b6774a6c237d77ac37011b13994879f68a8810
       url: "https://pub.dev"
     source: hosted
-    version: "8.3.5"
+    version: "8.3.7"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -98,17 +98,17 @@ packages:
     dependency: transitive
     description:
       name: flutter_plugin_android_lifecycle
-      sha256: "615a505aef59b151b46bbeef55b36ce2b6ed299d160c51d84281946f0aa0ce0e"
+      sha256: "5a1e6fb2c0561958d7e4c33574674bda7b77caaca7a33b758876956f2902eea3"
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.24"
+    version: "2.0.27"
   flutter_soloud:
     dependency: "direct main"
     description:
       path: ".."
       relative: true
     source: path
-    version: "3.0.3"
+    version: "3.1.0"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -211,10 +211,10 @@ packages:
     dependency: transitive
     description:
       name: path_provider_android
-      sha256: "4adf4fd5423ec60a29506c76581bc05854c55e3a0b72d35bb28d661c9686edf2"
+      sha256: "0ca7359dad67fd7063cb2892ab0c0737b2daafd807cf1acecd62374c8fae6c12"
       url: "https://pub.dev"
     source: hosted
-    version: "2.2.15"
+    version: "2.2.16"
   path_provider_foundation:
     dependency: transitive
     description:
@@ -352,10 +352,10 @@ packages:
     dependency: transitive
     description:
       name: web
-      sha256: cd3543bd5798f6ad290ea73d210f423502e71900302dde696f8bff84bf89a1cb
+      sha256: "868d88a33d8a87b18ffc05f9f030ba328ffefba92d6c127917a2ba740f9cfe4a"
       url: "https://pub.dev"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   web_socket:
     dependency: transitive
     description:
@@ -376,10 +376,10 @@ packages:
     dependency: transitive
     description:
       name: win32
-      sha256: daf97c9d80197ed7b619040e86c8ab9a9dad285e7671ee7390f9180cc828a51e
+      sha256: dc6ecaa00a7c708e5b4d10ee7bec8c270e9276dfcab1783f57e9962d7884305f
       url: "https://pub.dev"
     source: hosted
-    version: "5.10.1"
+    version: "5.12.0"
   xdg_directories:
     dependency: transitive
     description:
@@ -389,5 +389,5 @@ packages:
     source: hosted
     version: "1.1.0"
 sdks:
-  dart: ">=3.7.0-0 <4.0.0"
-  flutter: ">=3.24.0"
+  dart: ">=3.7.0 <4.0.0"
+  flutter: ">=3.27.0"

lib/src/bindings/audio_data.dart

@@ -122,7 +122,7 @@ class AudioData {
   /// The callback used to get new audio samples.
   /// This callback is used in [updateSamples] to avoid to
   /// do [GetSamplesKind] checks on every calls.
-  late void Function(AudioData) _updateCallback;
+  late bool Function(AudioData) _updateCallback;
 
   /// Update the content of samples memory to be read later
   /// using [getAudioData].
@@ -136,7 +136,7 @@ class AudioData {
   /// [GitHub](https://github.com/alnitak/flutter_soloud/issues) providing
   /// a simple working example.
   void updateSamples() {
-    _updateCallback(this);
+    ctrl.dataIsTheSameAsBefore = _updateCallback(this);
   }
 
   /// Changes the input device from which to retrieve audio data and its kind.
@@ -152,23 +152,39 @@ class AudioData {
     ctrl.dispose(_getSamplesKind);
   }
 
-  /// Get audio data data.
+  /// Get audio data only for visualization purposes. Don't use this method
+  /// for audio processing or for saving audio data.
   ///
   /// Depending on the [GetSamplesKind] used to initialize [AudioData],
   /// the returned data will be a [Float32List]. See [GetSamplesKind] for
   /// more information.
-  Float32List getAudioData() {
+  ///
+  /// [alwaysReturnData] if true, the audio data list will be returned even if
+  /// it is the same as the previous one.
+  /// When this method is callled, the returned audio data is the current
+  /// audio buffer shrinked to 256 samples currently playing. For example,
+  /// when initializing the engine with a buffer of 2048, this will return
+  /// the average of that data grouped by 8 samples. For a good visualization
+  /// should be better to use a buffer size of 1024 or maybe 512.
+  /// When calling this method 2 times and before all the buffer is played,
+  /// the returned data will be the same. The purpose of [alwaysReturnData] is
+  /// to avoid this and when this happens, the returned data will be an
+  /// empty list when [alwaysReturnData] is false.
+  Float32List getAudioData({bool alwaysReturnData = true}) {
+    /// Non blocking condition.
+    if (!SoLoudController().soLoudFFI.isInited()) {
+      return Float32List(0);
+    }
     if (!SoLoudController().soLoudFFI.getVisualizationEnabled()) {
       throw const SoLoudVisualizationNotEnabledException();
     }
-
     switch (_getSamplesKind) {
       case GetSamplesKind.wave:
-        return ctrl.getWave();
+        return ctrl.getWave(alwaysReturnData: alwaysReturnData);
       case GetSamplesKind.linear:
-        return ctrl.getFftAndWave();
+        return ctrl.getFftAndWave(alwaysReturnData: alwaysReturnData);
       case GetSamplesKind.texture:
-        return ctrl.get2DTexture();
+        return ctrl.get2DTexture(alwaysReturnData: alwaysReturnData);
     }
   }
 }

lib/src/bindings/audio_data_ffi.dart

@@ -6,7 +6,6 @@ import 'package:ffi/ffi.dart' show calloc;
 import 'package:flutter/foundation.dart';
 import 'package:flutter_soloud/src/bindings/audio_data.dart';
 import 'package:flutter_soloud/src/bindings/soloud_controller.dart';
-import 'package:flutter_soloud/src/enums.dart';
 
 class AudioDataCtrl {
   /// To reflect [AudioDataCtrl] for web. Not used with `dart:ffi`
@@ -20,20 +19,23 @@ class AudioDataCtrl {
   late Pointer<Pointer<Float>> samples2D;
 
   /// Where the audio 1D data is stored.
-  late Pointer<Float> samples1D;
+  late Pointer<Pointer<Float>> samples1D;
 
-  final void Function(AudioData) waveCallback =
+  final bool Function(AudioData) waveCallback =
       SoLoudController().soLoudFFI.getWave;
 
-  final void Function(AudioData) textureCallback =
+  final bool Function(AudioData) textureCallback =
       SoLoudController().soLoudFFI.getAudioTexture;
 
-  final PlayerErrors Function(AudioData) texture2DCallback =
+  final bool Function(AudioData) texture2DCallback =
       SoLoudController().soLoudFFI.getAudioTexture2D;
 
+  late bool dataIsTheSameAsBefore;
+
   void allocSamples(AudioData audioData) {
+    dataIsTheSameAsBefore = false;
     samples2D = calloc();
-    samples1D = calloc(512 * 4);
+    samples1D = calloc();
     samplesWave = calloc();
   }
 
@@ -43,35 +45,50 @@ class AudioDataCtrl {
     if (samplesWave != nullptr) calloc.free(samplesWave);
     if (samples1D != nullptr) calloc.free(samples1D);
     if (samples2D != nullptr) calloc.free(samples2D);
+    samplesWave = nullptr;
+    samples1D = nullptr;
+    samples2D = nullptr;
   }
 
-  Float32List getWave() {
-    final val = Pointer<Float>.fromAddress(samplesWave.value.address);
-    if (val == nullptr) return Float32List(0);
+  Float32List getWave({bool alwaysReturnData = true}) {
+    final wavePtr = samplesWave.value;
+    if (!alwaysReturnData && dataIsTheSameAsBefore || wavePtr == nullptr) {
+      return Float32List(0);
+    }
+
     return Float32List.view(
-      val.cast<Uint8>().asTypedList(256 * 4).buffer,
+      wavePtr.cast<Uint8>().asTypedList(256 * 4).buffer,
       0,
       256,
     );
   }
 
-  Float32List getFftAndWave() {
-    final val = Pointer<Float>.fromAddress(samples1D.address);
-    if (val == nullptr) return Float32List(0);
+  Float32List getFftAndWave({bool alwaysReturnData = true}) {
+    final texturePtr = samples1D.value;
+
+    if (!alwaysReturnData && dataIsTheSameAsBefore || texturePtr == nullptr) {
+      return Float32List(0);
+    }
     return Float32List.view(
-      val.cast<Uint8>().asTypedList(512 * 4).buffer,
+      texturePtr.cast<Uint8>().asTypedList(512 * 4).buffer,
       0,
       512,
     );
   }
 
-  Float32List get2DTexture() {
-    final val = Pointer<Float>.fromAddress(samples1D.address);
-    if (val == nullptr) return Float32List(0);
-    return Float32List.view(
-      val.cast<Uint8>().asTypedList(512 * 256 * 4).buffer,
+  Float32List get2DTexture({bool alwaysReturnData = true}) {
+    final texture2DPtr = samples2D.value;
+
+    if (!alwaysReturnData && dataIsTheSameAsBefore || texture2DPtr == nullptr) {
+      return Float32List(0);
+    }
+
+    final ret = Float32List.view(
+      texture2DPtr.cast<Uint8>().asTypedList(512 * 256 * 4).buffer,
       0,
       512 * 256,
     );
+
+    return ret;
   }
 }