Better isons placement

ABStemPlayer/ViewModels/WaveformBandViewModel.cs

@@ -47,7 +47,7 @@ public partial class WaveformBandViewModel : ObservableObject
             return;
         }
 
-        double ratio = current.TotalSeconds / total.TotalSeconds;
+        double ratio = current.TotalMicroseconds / total.TotalMicroseconds;
         PlaybackX = ratio * CanvasWidth;
     }
 

ABStemPlayer/Views/PlaybackControls.axaml

@@ -37,8 +37,8 @@
 
                     <!-- File Open -->
                     <Button Command="{Binding OpenFileCommand}"
-                            Width="32"
+                            Width="43"
-                            Height="32"
+                            Height="43"
                             Background="Black"
                             Grid.Column="0"
                             Margin="0,0,6,0"
@@ -46,6 +46,9 @@
                         <Path Fill="#e0e0e0"
                               Stretch="None"
                               RenderTransformOrigin="0,0">
+                            <Path.RenderTransform>
+                                <TranslateTransform X="0" Y="3"/>
+                            </Path.RenderTransform>
                             <Path.Data>
                                 M1 4C1 2.34315 2.34315 1 4 1H7.76393C8.90025 1 9.93904 1.64201 10.4472 2.65836L11.3416 4.44721C11.511 4.786 11.8573 5 12.2361 5H20C21.6569 5 23 6.34315 23 8V20C23 21.6569 21.6569 23 20 23H4C2.34315 23 1 21.6569 1 20V4ZM4 3C3.44772 3 3 3.44772 3 4V20C3 20.5523 3.44772 21 4 21H20C20.5523 21 21 20.5523 21 20V8C21 7.44772 20.5523 7 20 7H12.2361C11.0998 7 10.061 6.35799 9.55279 5.34164L8.65836 3.55279C8.48897 3.214 8.1427 3 7.76393 3H4Z
                             </Path.Data>
@@ -54,8 +57,8 @@
 
                     <!-- Rewind -->
                     <Button Command="{Binding RewindCommand}"
-                            Width="32"
+                            Width="43"
-                            Height="32"
+                            Height="43"
                             Background="Black"
                             Grid.Column="1"
                             Margin="0,0,6,0"
@@ -63,6 +66,9 @@
                         <Path Fill="#e0e0e0"
                               Stretch="None"
                               RenderTransformOrigin="0,0">
+                            <Path.RenderTransform>
+                                <TranslateTransform X="0" Y="3"/>
+                            </Path.RenderTransform>
                             <Path.Data>
                                 M18.3956 19.7691C19.0541 20.2687 20 19.799 20 18.9724L20 5.02764C20 4.20106 19.0541 3.73137 18.3956 4.23095L9.20476 11.2033C8.67727 11.6035 8.67727 12.3965 9.20476 12.7967L18.3956 19.7691ZM22 18.9724C22 21.4521 19.1624 22.8612 17.1868 21.3625L7.99598 14.3901C6.41353 13.1896 6.41353 10.8104 7.99599 9.60994L17.1868 2.63757C19.1624 1.13885 22 2.5479 22 5.02764L22 18.9724Z
                                 M2 3C2 2.44772 2.44772 2 3 2C3.55228 2 4 2.44772 4 3V21C4 21.5523 3.55228 22 3 22C2.44772 22 2 21.5523 2 21V3Z
@@ -71,9 +77,9 @@
                     </Button>
 
                     <!-- Play -->
-                    <Button Width="32"
+                    <Button Background="Black"
-                            Height="32"
+                            Width="43"
-                            Background="Black"
+                            Height="43"
                             Grid.Column="2"
                             Margin="0,0,6,0"
                             ToolTip.Tip="Play/Pause"
@@ -83,13 +89,16 @@
                               Stretch="None"
                               RenderTransformOrigin="0,0"
                               Data="{Binding IsPlaying, Converter={StaticResource PlayPauseGeometry}}">
+                            <Path.RenderTransform>
+                                <TranslateTransform X="0" Y="3"/>
+                            </Path.RenderTransform>
                         </Path>
                     </Button>
 
                     <!-- Stop -->
                     <Button Command="{Binding StopCommand}"
-                            Width="32"
+                            Width="43"
-                            Height="32"
+                            Height="43"
                             Background="Black"
                             Grid.Column="4"
                             Margin="0,0,6,0"
@@ -97,6 +106,9 @@
                         <Path Fill="#e0e0e0"
                               Stretch="None"
                               RenderTransformOrigin="0,0">
+                            <Path.RenderTransform>
+                                <TranslateTransform X="0" Y="3"/>
+                            </Path.RenderTransform>
                             <Path.Data>
                                 M22 5C22 3.34315 20.6569 2 19 2H5C3.34315 2 2 3.34315 2 5V19C2 20.6569 3.34315 22 5 22H19C20.6569 22 22 20.6569 22 19V5ZM20 5C20 4.44772 19.5523 4 19 4H5C4.44772 4 4 4.44772 4 5V19C4 19.5523 4.44772 20 5 20H19C19.5523 20 20 19.5523 20 19V5Z
                             </Path.Data>
@@ -105,14 +117,17 @@
 
                     <!-- Fast Forward -->
                     <Button Command="{Binding FastForwardCommand}"
-                            Width="32"
+                            Width="43"
-                            Height="32"
+                            Height="43"
                             Background="Black"
                             Grid.Column="5"
                             ToolTip.Tip="Fast Forward">
                         <Path Fill="#e0e0e0"
                               Stretch="None"
                               RenderTransformOrigin="0,0">
+                            <Path.RenderTransform>
+                                <TranslateTransform X="0" Y="3"/>
+                            </Path.RenderTransform>
                             <Path.Data>
                                 M5.60439 4.23093C4.94586 3.73136 4 4.20105 4 5.02762V18.9724C4 19.799 4.94586 20.2686 5.60439 19.7691L14.7952 12.7967C15.3227 12.3965 15.3227 11.6035 14.7952 11.2033L5.60439 4.23093ZM2 5.02762C2 2.54789 4.83758 1.13883 6.81316 2.63755L16.004 9.60993C17.5865 10.8104 17.5865 13.1896 16.004 14.3901L6.81316 21.3625C4.83758 22.8612 2 21.4521 2 18.9724V5.02762Z
                                 M20 3C20 2.44772 20.4477 2 21 2C21.5523 2 22 2.44772 22 3V21C22 21.5523 21.5523 22 21 22C20.4477 22 20 21.5523 20 21V3Z
@@ -169,8 +184,8 @@
                                   Margin="0,0,6,0"/>
 
                     <Button Command="{Binding SetPointACommand}"
-                            Width="32"
+                            Width="43"
-                            Height="32"
+                            Height="43"
                             Grid.Column="1"
                             Background="Black"
                             Margin="0,0,6,0"
@@ -179,6 +194,9 @@
                             <Path Fill="#e0e0e0"
                                   Stretch="None"
                                   RenderTransformOrigin="0,0">
+                                <Path.RenderTransform>
+                                    <TranslateTransform X="0" Y="3"/>
+                                </Path.RenderTransform>
                                 <Path.Data>
                                     M18.3956 19.7691C19.0541 20.2687 20 19.799 20 18.9724L20 5.02764C20 4.20106 19.0541 3.73137 18.3956 4.23095L9.20476 11.2033C8.67727 11.6035 8.67727 12.3965 9.20476 12.7967L18.3956 19.7691ZM22 18.9724C22 21.4521 19.1624 22.8612 17.1868 21.3625L7.99598 14.3901C6.41353 13.1896 6.41353 10.8104 7.99599 9.60994L17.1868 2.63757C19.1624 1.13885 22 2.5479 22 5.02764L22 18.9724Z
                                     M2 3C2 2.44772 2.44772 2 3 2C3.55228 2 4 2.44772 4 3V21C4 21.5523 3.55228 22 3 22C2.44772 22 2 21.5523 2 21V3Z
@@ -188,8 +206,8 @@
                     </Button>
 
                     <Button Command="{Binding SetPointBCommand}"
-                            Width="32"
+                            Width="43"
-                            Height="32"
+                            Height="43"
                             Background="Black"
                             Grid.Column="2"
                             ToolTip.Tip="Set Loop Point B">
@@ -197,6 +215,9 @@
                             <Path Fill="#e0e0e0"
                                   Stretch="None"
                                   RenderTransformOrigin="0,0">
+                                <Path.RenderTransform>
+                                    <TranslateTransform X="0" Y="3"/>
+                                </Path.RenderTransform>
                                 <Path.Data>
                                     M5.60439 4.23093C4.94586 3.73136 4 4.20105 4 5.02762V18.9724C4 19.799 4.94586 20.2686 5.60439 19.7691L14.7952 12.7967C15.3227 12.3965 15.3227 11.6035 14.7952 11.2033L5.60439 4.23093ZM2 5.02762C2 2.54789 4.83758 1.13883 6.81316 2.63755L16.004 9.60993C17.5865 10.8104 17.5865 13.1896 16.004 14.3901L6.81316 21.3625C4.83758 22.8612 2 21.4521 2 18.9724V5.02762Z
                                     M20 3C20 2.44772 20.4477 2 21 2C21.5523 2 22 2.44772 22 3V21C22 21.5523 21.5523 22 21 22C20.4477 22 20 21.5523 20 21V3Z

AudioCore/AudioCore.csproj

@@ -3,9 +3,7 @@
   <PropertyGroup>
     <IsPackable>true</IsPackable>
     <Authors>Alexander Shabarshov</Authors>
-    <Description>
+    <Description>Audio engine core for ABStemPlayer. Audio pipeline. </Description>
-        Audio engine core for ABStemPlayer. Audio pipeline.
-    </Description>
     <PackageProjectUrl>https://github.com/unclshura/ABStemPlayer</PackageProjectUrl>
     <PackageTags>audio, player, ab, guitar, drums, piano, stem, mixer, c#</PackageTags>
     <PackageReadmeFile>README.md</PackageReadmeFile>
@@ -33,7 +31,9 @@
 
   <PropertyGroup>
     <Version>1.0.0</Version>
-    <InformationalVersion>$(Version).$(BuildNumber)+$(SourceRevisionId)</InformationalVersion>
+    <BuildNumber>0</BuildNumber>
+    <SourceRevisionId></SourceRevisionId>
+    <InformationalVersion>$(Version).$(BuildNumber)$(SourceRevisionId)</InformationalVersion>
     <AssemblyVersion>$(Version)</AssemblyVersion>
     <FileVersion>$(Version).$(BuildNumber)</FileVersion>
   </PropertyGroup>

AudioCore/Impl/RubberBandTimeStretchEngine.cs

@@ -10,6 +10,15 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IAsyncDisp
     private readonly int             _sampleRate;
     private long[] _sourcePositions;
 
+    private sealed class SourceChunkInfo
+    {
+        public long SourcePosition;   // starting frame index in source stream
+        public int  SourceFrames;     // number of frames in this chunk
+    }
+
+    private readonly Queue<SourceChunkInfo>[] _pendingInput;
+    private double[] _fractionalInput;
+
     // One RubberBand/ffmpeg process per stem (each is stereo: 2 channels)
     private sealed class StemProcess : IDisposable
     {
@@ -51,6 +60,12 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IAsyncDisp
         _stemProcesses.Capacity = stemCount;
         _stemCount              = stemCount;
         _sourcePositions = new long[_stemCount];
+        _fractionalInput = new double[_stemCount];
+
+        _pendingInput = Enumerable.Range(0, _stemCount)
+            .Select(_ => new Queue<SourceChunkInfo>())
+            .ToArray();
+
     }
 
     public async Task Configure(PlaybackSpeedSettings settings, CancellationToken token)
@@ -75,32 +90,48 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IAsyncDisp
 
     public Task SubmitStems(IReadOnlyList<AudioBlock> stemBlocks, CancellationToken token)
     {
-        if ( stemBlocks.Count != _stemCount)
+        if (stemBlocks.Count != _stemCount)
             throw new ArgumentException($"Expected {_stemCount} stems, but got {stemBlocks.Count}.");
 
+        EnsureStemProcesses(stemBlocks.Count);
+
         // No-stretch path: just enqueue into per-stem rings
         if (Math.Abs(_speed - 1.0f) < 0.01f)
         {
-            EnsureStemProcesses(stemBlocks.Count);
-
             for (int i = 0; i < stemBlocks.Count; i++)
             {
-                var proc = _stemProcesses[i];
+                var block = stemBlocks[i];
-                var bytes = MemoryMarshal.AsBytes(stemBlocks[i].Buffer.Span);
+
-                proc.Ring.Write(bytes, bytes.Length, token);
+                // Track source position for passthrough mode
+                _pendingInput[i].Enqueue(new SourceChunkInfo
+                {
+                    SourcePosition = block.Position,
+                    SourceFrames = block.Frames
+                });
+
+                var bytes = MemoryMarshal.AsBytes(block.Buffer.Span);
+                _stemProcesses[i].Ring.Write(bytes, bytes.Length, token);
             }
 
             return Task.CompletedTask;
         }
 
         // Stretch path: one ffmpeg+rubberband per stem
-        EnsureStemProcesses(stemBlocks.Count);
         StartProcessesIfNeeded(stemBlocks.Count);
 
         for (int i = 0; i < stemBlocks.Count; i++)
         {
+            var block = stemBlocks[i];
+
+            // Track source position for stretched mode
+            _pendingInput[i].Enqueue(new SourceChunkInfo
+            {
+                SourcePosition = block.Position,
+                SourceFrames = block.Frames
+            });
+
             var proc  = _stemProcesses[i];
-            var span  = stemBlocks[i].Buffer.Span;
+            var span  = block.Buffer.Span;
             var bytes = MemoryMarshal.AsBytes(span);
 
             try
@@ -108,29 +139,31 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IAsyncDisp
                 if (token.IsCancellationRequested)
                     return Task.CompletedTask;
 
+                // Only write if ffmpeg is alive
                 if (proc.Stdin != null && !(proc.Ff?.Proc?.HasExited ?? true))
+                {
                     proc.Stdin.Write(bytes);
 
-                if (token.IsCancellationRequested)
-                    return Task.CompletedTask;
                     try
                     {
                         proc.Stdin.Flush();
                     }
-                catch (System.ObjectDisposedException)
+                    catch (ObjectDisposedException)
                     {
-                    // process has exited
+                        // ffmpeg exited early
+                    }
                 }
             }
             catch
             {
-                // ignore
+                // Ignore write errors (ffmpeg may exit early)
             }
         }
 
         return Task.CompletedTask;
     }
 
+
     public async Task<TimeStretchedAudioBlock[]> ReceiveStems(CancellationToken token)
     {
         EnsureStemProcesses(_stemCount);
@@ -195,10 +228,10 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IAsyncDisp
             var outBytes = MemoryMarshal.AsBytes(outBuf.Span);
             temp.AsSpan().CopyTo(outBytes);
 
-            // Compute source position
+            //
-            long sourceFrames = (long)(framesToRead * _speed);
+            // *** Correct source-position mapping ***
-            long sourcePos    = _sourcePositions[i];
+            //
-            _sourcePositions[i] += sourceFrames;
+            long sourcePos = ComputeSourcePosition(i, framesToRead);
 
             result[i] = new TimeStretchedAudioBlock(
                 outBuf,
@@ -211,6 +244,54 @@ public sealed class RubberBandTimeStretchEngine : ITimeStretchEngine, IAsyncDisp
         return result;
     }
 
+private long ComputeSourcePosition(int stemIndex, int outputFrames)
+    {
+        // inputFrames = outputFrames / speed
+        double neededInputFrames = outputFrames / _speed;
+
+        // Add fractional requirement
+        _fractionalInput[stemIndex] += neededInputFrames;
+
+        long sourcePos = 0;
+        bool first = true;
+
+        var queue = _pendingInput[stemIndex];
+
+        // If no input chunks exist (warm-up), return last known position
+        if (queue.Count == 0)
+            return _sourcePositions[stemIndex];
+
+        while (_fractionalInput[stemIndex] >= 1 && queue.Count > 0)
+        {
+            var chunk = queue.Peek();
+
+            int take = (int)Math.Min(chunk.SourceFrames, Math.Floor(_fractionalInput[stemIndex]));
+
+            if (take <= 0)
+                break;
+
+            if (first)
+            {
+                sourcePos = chunk.SourcePosition;
+                first = false;
+            }
+
+            chunk.SourceFrames -= take;
+            _fractionalInput[stemIndex] -= take;
+
+            if (chunk.SourceFrames == 0)
+                queue.Dequeue();
+        }
+
+        // If we consumed nothing (fraction < 1), use last known position
+        if (first)
+            sourcePos = _sourcePositions[stemIndex];
+
+        _sourcePositions[stemIndex] = sourcePos;
+        return sourcePos;
+    }
+
+
 
     private void EnsureStemProcesses(int stemCount)
     {

AudioCore/Impl/StemPlaybackEngine.cs

@@ -39,7 +39,6 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
 
     private LoopRegion                   _loopRegion = new();
 
-    private long                         _decodedFramePosition;
     private long                         _loopStartFrames;
     private long                         _loopEndFrames;
 
@@ -96,7 +95,6 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
             }
 
             _pendingSeekFrames = 0;
-            _decodedFramePosition = 0;
         }
     }
 
@@ -126,7 +124,6 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
                 d.Seek(_pendingSeekFrames);
             }
 
-            _decodedFramePosition = _pendingSeekFrames;
         }
 
         _pipeline.RenderTask = Task.Run(() => RenderLoopAsync(_pipeline, _pipeline.Cts.Token));
@@ -163,7 +160,6 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
             if (!IsPlaying && _pipeline is null)
                 return;
 
-            _decodedFramePosition = 0;
             _pendingSeekFrames = 0;
 
             pipelineToDispose = _pipeline;
@@ -201,12 +197,6 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
             {
                 foreach (var d in _pipeline.Decoders)
                     d.Seek(frameIndex);
-
-                _decodedFramePosition = frameIndex;
-            }
-            else
-            {
-                _decodedFramePosition = frameIndex;
             }
         }
 
@@ -349,15 +339,9 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
                         try { d.Seek(loopStart); } catch { }
                     }
 
-                    lock (_stateLock)
-                        _decodedFramePosition = loopStart;
-
                     // continue decoding from the loop start
                     continue;
                 }
-
-                lock (_stateLock)
-                    _decodedFramePosition = nextPosition;
             }
         }
         catch { }
@@ -430,19 +414,7 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
                 _outputDevice.Write(mixed.Buffer.Span);
                 gotFirstBlock = true;
 
-                try
+                await ReportProgress(mixed).ConfigureAwait(false);
-                {
-                    double progress;
-                    lock (_stateLock)
-                    {
-                        var total = _session?.StemSet.TotalFrames ?? 1L;
-                        progress = (double)mixed.Position / Math.Max(total, 1L);
-                    }
-
-                    if (_progressReporter != null)
-                        await _progressReporter.ReportProgress(progress).ConfigureAwait(false);
-                }
-                catch { }
 
                 try { mixed.Dispose(); } catch { }
                 foreach (var b in stretchedBlocks)
@@ -459,6 +431,25 @@ public sealed class StemPlaybackEngine : IStemPlaybackEngine, IDisposable
         }
     }
 
+    private async Task ReportProgress(MixedAudioBlock mixed)
+    {
+        if (_progressReporter == null)
+            return;
+
+        try
+        {
+            double progress;
+            lock (_stateLock)
+            {
+                var total = _session?.StemSet.TotalFrames ?? 1L;
+                progress = (double)mixed.Position / Math.Max(total, 1L);
+            }
+
+            await _progressReporter.ReportProgress(progress).ConfigureAwait(false);
+        }
+        catch { }
+    }
+
     private long TimeToFrames(TimeSpan time)
     {
         return (long)(time.TotalSeconds * _outputDevice.SampleRate);

AudioCore/Models/AudioBlock.cs

@@ -2,7 +2,7 @@ using AudioCore.Impl;
 
 namespace AudioCore.Models;
 
-public readonly struct AudioBlock : IDisposable
+public readonly struct AudioBlock : IAudioBlock, IDisposable
 {
     public AudioBuffer<float> Buffer { get; }
     public int SampleRate { get; }

AudioCore/Models/IAudioBlock.cs

@@ -0,0 +1,14 @@
+using AudioCore.Impl;
+
+namespace AudioCore.Models;
+
+public interface IAudioBlock : IDisposable
+{
+    AudioBuffer<float> Buffer { get; }
+    int SampleRate { get; }
+    int Channels { get; }
+    long Position { get; }
+    int Frames { get; }
+    int Length { get; }
+    Span<float> Span { get; }
+}

AudioCore/Models/MixedAudioBlock.cs

@@ -2,7 +2,7 @@ using AudioCore.Impl;
 
 namespace AudioCore.Models;
 
-public readonly struct MixedAudioBlock : IDisposable
+public readonly struct MixedAudioBlock : IAudioBlock, IDisposable
 {
     public AudioBuffer<float> Buffer         { get; }
     public int         Frames         { get; }
@@ -10,6 +10,8 @@ public readonly struct MixedAudioBlock : IDisposable
     public int         SampleRate     { get; }
     public long        Position       { get; }
 
+    public Span<float> Span => Buffer.Span;
+    public int Length => Buffer.Length;
     public MixedAudioBlock(AudioBuffer<float> buffer, int frames, int channels, int sampleRate, long samplePosition)
     {
         Buffer     = buffer;

AudioCore/Models/TimeStretchedAudioBlock.cs

@@ -2,7 +2,7 @@ using AudioCore.Impl;
 
 namespace AudioCore.Models;
 
-public readonly struct TimeStretchedAudioBlock : IDisposable
+public readonly struct TimeStretchedAudioBlock : IAudioBlock, IDisposable
 {
     public AudioBuffer<float> Buffer { get; }
     public int Frames     { get; }
@@ -10,6 +10,8 @@ public readonly struct TimeStretchedAudioBlock : IDisposable
     public int SampleRate { get; }
     public long Position  { get; }
 
+    public Span<float> Span => Buffer.Span;
+    public int Length => Buffer.Length;
     public TimeStretchedAudioBlock(AudioBuffer<float> buffer, int frames, int channels, int sampleRate, long position)
     {
         Buffer     = buffer;