Changes for making playback working (still doesn't).

AudioCore/Impl/BlockingRingBuffer.cs

@@ -22,7 +22,11 @@ public class BlockingRingBuffer
 
         while (written < srcLen)
         {
-            ct.ThrowIfCancellationRequested();
+            if ( ct.IsCancellationRequested )
+            {
+                Debug.WriteLine("BlockingRingBuffer: No room in the buffer to write. Timeout.");
+                return;
+            }
 
             int remaining = srcLen - written;
 
@@ -33,12 +37,11 @@ public class BlockingRingBuffer
                 ? _ringWrite - _ringRead
                 : _ring.Length - _ringRead + _ringWrite;
 
-                free = _ring.Length - used - 1; // leave 1 byte to distinguish full/empty
+                free = _ring.Length - used - 1;
             }
 
             if (free <= 0)
             {
-                // No room → block until space becomes available
                 Thread.Sleep(1);
                 continue;
             }
@@ -49,7 +52,6 @@ public class BlockingRingBuffer
             {
                 int first = Math.Min(toWrite, _ring.Length - _ringWrite);
 
-                // Write first segment
                 src.Slice(written, first)
                    .CopyTo(new Span<byte>(_ring, _ringWrite, first));
 
@@ -58,7 +60,6 @@ public class BlockingRingBuffer
                 int leftover = toWrite - first;
                 if (leftover > 0)
                 {
-                    // Wrap-around segment
                     src.Slice(written + first, leftover)
                        .CopyTo(new Span<byte>(_ring, _ringWrite, leftover));
 
@@ -72,8 +73,14 @@ public class BlockingRingBuffer
 
     public int WaitForOutput(CancellationToken token)
     {
-        while (!token.IsCancellationRequested)
+        while (true)
         {
+            if (token.IsCancellationRequested)
+            {
+                Debug.WriteLine("BlockingRingBuffer: No data in the buffer to read. Timeout.");
+                return 0;
+            }
+
             lock (_ringLock)
             {
                 var available = (_ringWrite >= _ringRead)
@@ -86,9 +93,6 @@ public class BlockingRingBuffer
 
             Thread.Sleep(2);
         }
-
-        Debug.WriteLine("BlockingRingBuffer: Timeout waiting for output");
-        return 0;
     }
 
     public int DrainRing(Span<byte> dest, int maxBytes)

AudioCore/Impl/RubberBandTimeStretchEngine.cs

@@ -27,7 +27,7 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IDisposabl
         _channels          = channels;
 
         var bytesPerSecond = sampleRate * channels * sizeof(float);
-        _ring              = new BlockingRingBuffer(1 * bytesPerSecond);
+        _ring              = new BlockingRingBuffer(10 * bytesPerSecond);
     }
 
     public void Configure(PlaybackSpeedSettings settings)
@@ -37,25 +37,17 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IDisposabl
 
         _speed = settings.Speed;
 
-        if (Math.Abs(_speed - 1.0f) < 0.01f)
-        {
         DisposeProcess();
         _ring.ResetRing();
     }
-        else
-        {
-            RestartProcess();
-        }
-    }
 
-    public Task Submit(MixedAudioBlock input)
+    public Task Submit(MixedAudioBlock input, CancellationToken token)
     {
         // No-stretch path: enqueue block and signal semaphore
         if (Math.Abs(_speed - 1.0f) < 0.01f)
         {
-            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
             var b = MemoryMarshal.AsBytes(input.Buffer.Span);
-            _ring.WriteToOutput(b, b.Length, cts.Token);
+            _ring.WriteToOutput(b, b.Length, token);
 
             return Task.CompletedTask;
         }
@@ -72,21 +64,19 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IDisposabl
         return Task.CompletedTask;
     }
 
-    public async Task<TimeStretchedAudioBlock> Receive()
+    public async Task<TimeStretchedAudioBlock> Receive(CancellationToken token)
     {
-        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
-
         int available = 0;
-        while (!cts.IsCancellationRequested)
+        while (!token.IsCancellationRequested)
         {
-            available = _ring.WaitForOutput(cts.Token);
+            available = _ring.WaitForOutput(token);
             if (available > 0)
                 break;
 
             await Task.Delay(2).ConfigureAwait(false);
         }
 
-        if (cts.IsCancellationRequested)
+        if (token.IsCancellationRequested)
             return default;
 
         var maxFloats = available / sizeof(float);
@@ -132,13 +122,6 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IDisposabl
         _readerThread.Start();
     }
 
-    private void RestartProcess()
-    {
-        DisposeProcess();
-        _ring.ResetRing();
-        StartProcess();
-    }
-
     private void ReaderLoop()
     {
         var buf = new byte[4096];

AudioCore/Impl/StemPlaybackEngine.cs

@@ -1,4 +1,6 @@
-namespace AudioCore.Impl;
+using System.Diagnostics;
+
+namespace AudioCore.Impl;
 
 public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
 {
@@ -238,7 +240,7 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
         var decodeTask  = DecodeLoopAsync(pipeline, ct);
         var stretchTask = StretchLoopAsync(pipeline, ct);
 
-        await Task.WhenAny(decodeTask, stretchTask);
+        await Task.WhenAny(decodeTask, stretchTask).ConfigureAwait(false);
 
         // When either loop ends, stop output
         if (pipeline.OutputStarted)
@@ -250,6 +252,8 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
 
     private async Task DecodeLoopAsync(PipelineState pipeline, CancellationToken ct)
     {
+        await Task.Yield();
+
         try
         {
             while (!ct.IsCancellationRequested)
@@ -286,7 +290,8 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
                     if (!decoder.TryDecodeNextBlock(out var block))
                     {
                         eof = true;
-                        foreach (var b in _stemBlocks) b.Dispose();
+                        foreach (var b in _stemBlocks) 
+                            b.Dispose();
                         _stemBlocks.Clear();
                         break;
                     }
@@ -307,7 +312,7 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
                     b.Dispose();
                 _stemBlocks.Clear();
 
-                await _timeStretchEngine.Submit(mixed);
+                await _timeStretchEngine.Submit(mixed, ct).ConfigureAwait(false);
 
                 var progress = TimeSpan.FromSeconds(
                 (double)_currentFramePosition / _outputDevice.SampleRate);
@@ -336,11 +341,12 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
 
     private async Task StretchLoopAsync(PipelineState pipeline, CancellationToken ct)
     {
+        await Task.Yield();
         try
         {
             while (!ct.IsCancellationRequested)
             {
-                var stretched = await _timeStretchEngine.Receive();
+                var stretched = await _timeStretchEngine.Receive(ct).ConfigureAwait(false);
 
                 if (stretched.Buffer == null)
                 {
@@ -357,7 +363,10 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
                 _outputDevice.Write(stretched.Buffer.Span);
             }
         }
-        catch { }
+        catch(Exception ex) 
+        {
+            Debug.WriteLine($"StemPlaybackEngine: Error in StretchLoopAsync: {ex.Message}");
+        }
     }
 
 

AudioCore/Impl/WasapiOutputDevice.cs

@@ -101,17 +101,38 @@ public sealed class WasapiOutputDevice : IAudioOutputDevice, IDisposable
 
     }
 
+    private Lock _lock = new();
+
     private void Send(byte[] bytes)
     {
-        // Wait until buffer has enough free space
+        if (_out.PlaybackState != PlaybackState.Playing)
-        while (_buffer.BufferedBytes + bytes.Length > _buffer.BufferLength)
+            return;
+
+        lock (_lock)
+        {
+
+            int offset = 0;
+
+            while (offset < bytes.Length)
+            {
+                if (_out.PlaybackState != PlaybackState.Playing)
+                    return;
+
+                int free = _buffer.BufferLength - _buffer.BufferedBytes;
+                if (free <= 0)
                 {
-            // Sleep a tiny amount to let WASAPI consume data
                     Thread.Sleep(2);
+                    continue;
                 }
 
-        _buffer.AddSamples(bytes, 0, bytes.Length);
+                int toWrite = Math.Min(free, bytes.Length - offset);
+
+                _buffer.AddSamples(bytes, offset, toWrite);
+                offset += toWrite;
             }
+        }
+    }
+
 
     public void Dispose()
     {

AudioCore/Interfaces/ITimeStretchEngine.cs

@@ -11,6 +11,6 @@ public interface ITimeStretchEngine
     void Configure(PlaybackSpeedSettings settings);
 
     // Streaming block processing
-    Task Submit(MixedAudioBlock input);
+    Task Submit(MixedAudioBlock input, CancellationToken token);
-    Task<TimeStretchedAudioBlock> Receive();
+    Task<TimeStretchedAudioBlock> Receive(CancellationToken token);
 }

AudioCore_Tests/StemPlaybackEngine_Tests.cs

@@ -110,13 +110,13 @@ public sealed class StemPlaybackEngine_Tests
             // no-op for tests
         }
 
-        public Task Submit(MixedAudioBlock input)
+        public Task Submit(MixedAudioBlock input, CancellationToken token)
         {
             _lastInput = input;
             return Task.CompletedTask;
         }
 
-        public Task<TimeStretchedAudioBlock> Receive()
+        public Task<TimeStretchedAudioBlock> Receive(CancellationToken token)
         {
             if (_lastInput.Buffer == null)
                 return Task.FromResult(default(TimeStretchedAudioBlock));

AudioCore_Tests/TimeStretchEngine_Tests.cs

@@ -34,8 +34,8 @@ public sealed class TimeStretchEngine_Tests
 
         var input = MakeBlock(5000);
 
-        await engine.Submit(input);
+        await engine.Submit(input, CancellationToken.None);
-        var output = await engine.Receive();
+        var output = await engine.Receive(CancellationToken.None);
 
         Assert.IsGreaterThan(0, output.Frames);
         Assert.AreEqual(2, output.Channels);
@@ -59,12 +59,12 @@ public sealed class TimeStretchEngine_Tests
         var input = MakeBlock(1000);
 
         for (var i = 0; i < 25; i++)
-            await engine.Submit(input);
+            await engine.Submit(input, CancellationToken.None);
 
         var normalFrames = 0;
         while (true)
         {
-            using var data = await engine.Receive();
+            using var data = await engine.Receive(CancellationToken.None);
             normalFrames += data.Frames;
             if (data.Buffer == null)
                 break;
@@ -75,12 +75,12 @@ public sealed class TimeStretchEngine_Tests
 
 
         for (var i = 0; i < 25; i++)
-            await engine.Submit(input);
+            await engine.Submit(input, CancellationToken.None);
 
         var fasterFrames = 0;
         while (true)
         {
-            using var data = await engine.Receive();
+            using var data = await engine.Receive(CancellationToken.None);
             fasterFrames += data.Frames;
             if (data.Buffer == null)
                 break;
@@ -98,12 +98,12 @@ public sealed class TimeStretchEngine_Tests
         var input = MakeBlock(1000);
 
         for (var i = 0; i < 25; i++)
-            await engine.Submit(input);
+            await engine.Submit(input, CancellationToken.None);
 
         var normalFrames = 0;
         while (true)
         {
-            using var data = await engine.Receive();
+            using var data = await engine.Receive(CancellationToken.None);
             normalFrames += data.Frames;
             if (data.Buffer == null)
                 break;
@@ -112,12 +112,12 @@ public sealed class TimeStretchEngine_Tests
         engine.Configure(new PlaybackSpeedSettings { Speed = 0.5f });
 
         for (var i = 0; i < 25; i++)
-            await engine.Submit(input);
+            await engine.Submit(input, CancellationToken.None);
 
         var slowerFrames = 0;
         while (true)
         {
-            using var data = await engine.Receive();
+            using var data = await engine.Receive(CancellationToken.None);
             slowerFrames += data.Frames;
             if (data.Buffer == null)
                 break;
@@ -135,13 +135,13 @@ public sealed class TimeStretchEngine_Tests
 
         var input = MakeBlock(100);
 
-        await engine.Submit(input);
+        await engine.Submit(input, CancellationToken.None);
-        var before = await engine.Receive();
+        var before = await engine.Receive(CancellationToken.None);
 
         engine.Configure(new PlaybackSpeedSettings { Speed = 0.75f });
 
-        await engine.Submit(input);
+        await engine.Submit(input, CancellationToken.None);
-        var after = await engine.Receive();
+        var after = await engine.Receive(CancellationToken.None);
 
         Assert.AreEqual(0, after.Frames);
     }

Directory.Packages.props

@@ -3,19 +3,19 @@
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="Avalonia" Version="12.0.3" />
+    <PackageVersion Include="Avalonia" Version="12.1.0" />
-    <PackageVersion Include="Avalonia.Desktop" Version="12.0.3" />
+    <PackageVersion Include="Avalonia.Desktop" Version="12.1.0" />
-    <PackageVersion Include="Avalonia.Themes.Fluent" Version="12.0.3" />
+    <PackageVersion Include="Avalonia.Themes.Fluent" Version="12.1.0" />
-    <PackageVersion Include="Avalonia.Fonts.Inter" Version="12.0.3" />
+    <PackageVersion Include="Avalonia.Fonts.Inter" Version="12.1.0" />
-    <PackageVersion Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.1"/>
+    <PackageVersion Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.3" />
     <PackageVersion Include="BunLabs.NAudio.Flac" Version="2.0.1" />
-    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.1" />
+    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.2" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="10.0.9" />
     <PackageVersion Include="Microsoft.ML.OnnxRuntime" Version="1.27.0" />
     <PackageVersion Include="Microsoft.ML.OnnxRuntime.DirectML" Version="1.24.4" />
     <PackageVersion Include="NAudio" Version="2.3.0" />
     <PackageVersion Include="NAudio.Flac" Version="1.0.5702.29018" />
     <PackageVersion Include="System.Text.Json" Version="10.0.5" />
-    <PackageVersion Include="MSTest" Version="4.0.2" />
+    <PackageVersion Include="MSTest" Version="4.3.0" />
   </ItemGroup>
 </Project>