feat: add a real WMAv2 encoder

CLAUDE.md

@@ -33,7 +33,7 @@ dotnet test src/EggEncoder.UnitTests/EggEncoder.UnitTests.csproj --configuration
 | `Flac/` | `FlacDecoder`/`FlacEncoder` — thin wrappers over native `libFLAC` P/Invoke bindings |
 | `Mp3/` | `Mp3Decoder` (via the `NLayer` managed decoder), `Mp3Encoder` (native `libmp3lame` P/Invoke), `Mp3Probe` (manual frame-header parsing, no native call) |
 | `Wav/` | `WavReader`/`WavWriter` — RIFF/WAVE PCM I/O, the common source/sink format all codecs read from or write to |
-| `Wma/` | `WmaDecoder` + `AsfContainerReader` (ASF/WMA container parsing) + `WmaTables` |
+| `Wma/` | Pure managed WMAv2 decoder/encoder (`WmaDecoder`, `WmaEncoder`, `WmaEncoderSession`, `WmaFrameEncoder`) + `AsfContainerReader`/`AsfContainerWriter` (ASF/WMA container I/O) + `WmaTables` |
 | `Mov/` | `MovProbe` — MOV/MP4 atom-tree walker for metadata-only probing (no audio decode) |
 | `AudioCutter.cs` | Format-dispatching `Convert`/`Cut` used by `NativeEncoder`; defines the internal `IAudioSink` interface implemented by each codec's writer/session type |
 

README.md

@@ -1,6 +1,6 @@
 # 🥚 EggEncoder
 
-> **Audio encoding/decoding toolkit for .NET** — native MP3/FLAC codec bindings, managed AAC/WMA decode, and built-in waveform generation, all behind one `IMediaEncoder` interface.
+> **Audio encoding/decoding toolkit for .NET** — native MP3/FLAC codec bindings, managed AAC/WMA encode/decode, and built-in waveform generation, all behind one `IMediaEncoder` interface.
 
 Sponsored by [eggspot.app](https://eggspot.app)
 
@@ -72,7 +72,7 @@ var probeResult = await encoder.Probe("track.flac");
 | FLAC   | ✅ | ✅ | ✅ |
 | MP3    | ✅ | ✅ | ✅ |
 | AAC    | ✅ | ✅ | ✅ |
-| WMA    | ✅ | ✅ | ❌ |
+| WMA    | ✅ | ✅ | ✅ |
 | MOV/MP4 (metadata only) | ✅ | ❌ | ❌ |
 
 `IMediaEncoder.CutFile` decodes any supported source (WAV, FLAC, MP3, AAC, WMA) and can cut into any supported destination format, including converting as it trims — sample-accurate, no re-encode of the untouched region.

docs/API-Reference.html

@@ -175,8 +175,13 @@ <h3>WMA — <code>EggEncoder.Codecs.Wma</code></h3>
       <pre><code class="language-csharp">public static class WmaDecoder
 {
     public static WmaStreamInfo Decode(string wmaFilePath, AudioBlockDecodedCallback onBlockDecoded);
+}
+
+public static class WmaEncoder
+{
+    public static void Encode(string destFilePath, IReadOnlyList&lt;short&gt; interleavedSamples, int channels, int sampleRate);
 }</code></pre>
-      <p>Decode-only — mono only (mid/side stereo coding, used by real-world WMAv2 encoders including ffmpeg's, is not supported and throws <code>NotSupportedException</code>).</p>
+      <p>Mono or independently-coded stereo only. Mid/side stereo coding (used by most real-world WMAv2 encoders, including ffmpeg's) is not supported for decode and throws <code>NotSupportedException</code>; <code>WmaEncoder</code> never produces mid/side output, so this library's own encoder/decoder round-trip always works.</p>
 
       <h3>MOV/MP4 — <code>EggEncoder.Codecs.Mov</code></h3>
       <pre><code class="language-csharp">public static class MovProbe

docs/Advanced-Features.html

@@ -58,7 +58,7 @@ <h2>Waveform Generation</h2>
       <p><code>WaveformCalculator</code> streams — call <code>AddBlock</code> as many times as you like across however many decode callbacks the codec produces; it does not need the full signal in memory at once.</p>
 
       <h2>Sample-Accurate Cutting</h2>
-      <p><code>NativeEncoder.CutFile</code> (backed by <code>AudioCutter.Cut</code>) decodes any supported source (WAV, FLAC, MP3, AAC, WMA) and writes any supported destination format (WAV, FLAC, MP3, AAC) without re-encoding the untouched region where the format allows frame-boundary slicing:</p>
+      <p><code>NativeEncoder.CutFile</code> (backed by <code>AudioCutter.Cut</code>) decodes any supported source (WAV, FLAC, MP3, AAC, WMA) and writes any supported destination format (WAV, FLAC, MP3, AAC, WMA) without re-encoding the untouched region where the format allows frame-boundary slicing:</p>
       <pre><code class="language-csharp">using EggEncoder.Codecs;
 
 bool produced = AudioCutter.Cut(sourcePath, destPath, startInSeconds: 30, endInSeconds: 90);

docs/index.html

@@ -4,7 +4,7 @@
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>Home — EggEncoder</title>
-  <meta name="description" content="EggEncoder — audio encoding/decoding toolkit for .NET. Native MP3/FLAC codec bindings, managed AAC/WMA decode, and built-in waveform generation, behind one IMediaEncoder interface.">
+  <meta name="description" content="EggEncoder — audio encoding/decoding toolkit for .NET. Native MP3/FLAC codec bindings, managed AAC/WMA encode/decode, and built-in waveform generation, behind one IMediaEncoder interface.">
   <link rel="icon" href="favicon.ico">
   <link rel="stylesheet" href="assets/css/eggspot.css">
   <link rel="stylesheet" href="assets/css/prism-eggspot.css">
@@ -45,7 +45,7 @@
     <section class="hero">
       <div class="hero-badge">Free &amp; MIT Licensed</div>
       <h1>Audio encode/decode <span class="accent">without the ceremony</span></h1>
-      <p class="hero-sub">One <code>IMediaEncoder</code> interface, fully native and in-process. Direct P/Invoke bindings to LAME and libFLAC, managed AAC/WMA decode, and built-in waveform generation — no ffmpeg, no subprocess.</p>
+      <p class="hero-sub">One <code>IMediaEncoder</code> interface, fully native and in-process. Direct P/Invoke bindings to LAME and libFLAC, managed AAC/WMA encode/decode, and built-in waveform generation — no ffmpeg, no subprocess.</p>
       <div class="btn-group">
         <a class="btn btn-primary" href="Getting-Started.html">Get Started</a>
         <a class="btn btn-outline" href="https://github.com/eggspot/EggEncoder" target="_blank" rel="noopener">View on GitHub</a>

llms-full.txt

@@ -1,6 +1,6 @@
 # EggEncoder — Full Reference
 
-> Audio encoding/decoding toolkit for .NET — native MP3/FLAC codec bindings, managed AAC/WMA decode, and built-in waveform generation, behind one IMediaEncoder interface.
+> Audio encoding/decoding toolkit for .NET — native MP3/FLAC codec bindings, managed AAC/WMA encode/decode, and built-in waveform generation, behind one IMediaEncoder interface.
 
 ## Overview
 
@@ -105,10 +105,10 @@ public class TranscodeWorker(IServiceProvider serviceProvider)
 | FLAC   | yes | yes | yes |
 | MP3    | yes | yes | yes |
 | AAC    | yes | yes | yes |
-| WMA    | yes | yes | no  |
+| WMA    | yes | yes | yes |
 | MOV/MP4 (metadata only) | yes | no | no |
 
-`AudioCutter.Cut` (used by `NativeEncoder.CutFile`) decodes any supported source format (WAV, FLAC, MP3, AAC, WMA) and writes to any supported destination format, including WAV, FLAC, MP3, or AAC — it can transcode while trimming; source and destination extensions no longer need to match. Sample-accurate, no re-encode of the untouched region. `WmaDecoder` is decode-only and mono-only: real-world WMAv2 stereo encoders (including ffmpeg's) default to mid/side stereo coding, which is unsupported and throws `NotSupportedException`.
+`AudioCutter.Cut` (used by `NativeEncoder.CutFile`) decodes any supported source format (WAV, FLAC, MP3, AAC, WMA) and writes to any supported destination format, including WAV, FLAC, MP3, AAC, or WMA — it can transcode while trimming; source and destination extensions no longer need to match. Sample-accurate, no re-encode of the untouched region. `WmaDecoder` supports mono and independently-coded stereo; real-world WMAv2 stereo encoders (including ffmpeg's) default to mid/side stereo coding, which is unsupported and throws `NotSupportedException`. `WmaEncoder` always writes independently-coded channels, so its own output is always decodable by `WmaDecoder`.
 
 ## Codec Reference
 
@@ -203,11 +203,17 @@ Every other codec's `Convert`/`Cut` path reads from or writes to WAV as the comm
 public static class WmaDecoder
 {
     public static WmaStreamInfo Decode(string wmaFilePath, AudioBlockDecodedCallback onBlockDecoded);
-    // throws NotSupportedException for stereo (mid/side coding unsupported) or channel counts other than 1/2
+    // throws NotSupportedException for mid/side-coded stereo or channel counts other than 1/2
+}
+
+public static class WmaEncoder
+{
+    public static void Encode(string destFilePath, IReadOnlyList<short> interleavedSamples, int channels, int sampleRate);
+    // mono or stereo only; always writes independently-coded channels (no mid/side stereo)
 }
 ```
 
-Container parsing via the internal `AsfContainerReader`. Decode-only — there is no `WmaEncoder`.
+Container parsing/writing via the internal `AsfContainerReader`/`AsfContainerWriter`. `WmaEncoderSession` implements the same streaming `IAudioSink` used by the other codecs' `AudioCutter` integration.
 
 ### MOV/MP4 — `EggEncoder.Codecs.Mov`
 
@@ -240,7 +246,7 @@ public static class AudioCutter
 
     public static bool Cut(string sourceFilePath, string destFilePath, int startInSeconds, int endInSeconds);
     // decodes any supported source (.wav/.flac/.mp3/.aac/.wma) and writes any supported dest
-    // extension (.wav/.flac/.mp3/.aac) -- source and dest extensions no longer need to match,
+    // extension (.wav/.flac/.mp3/.aac/.wma) -- source and dest extensions no longer need to match,
     // so Cut can transcode while it trims
     // returns false (and writes no file) if the requested range is entirely outside the source duration
 }
@@ -282,7 +288,7 @@ Every codec's `Decode` method streams blocks through the same `AudioBlockDecoded
 ## Constraints and Gotchas
 
 - **Windows x64 only.** `NativeEncoder` and its codec bindings P/Invoke into bundled `win-x64` binaries. There is no cross-platform build or fallback engine — this library does not run on Linux/macOS/ARM.
-- **WMA is decode-only and mono-only.** Genuine stereo WMA files (mid/side coded, the real-world default) throw `NotSupportedException` by design rather than decoding incorrectly.
+- **WMA supports mono and independently-coded stereo only.** Genuine mid/side-coded stereo WMA files (the real-world default for most third-party encoders) throw `NotSupportedException` on decode rather than decoding incorrectly; `WmaEncoder` never produces mid/side output, so round-tripping through this library's own encoder/decoder always works.
 - **`AudioCutter.Cut` can transcode while it trims.** Source and destination extensions no longer need to match -- it decodes any supported source and writes any supported destination format.
 - **AAC encoding is mono-only** and restricted to a fixed set of MPEG-4 sample rates (see `AacTables.SampleRates`); other combinations throw `NotSupportedException`.
 

llms.txt

@@ -1,6 +1,6 @@
 # EggEncoder
 
-> Audio encoding/decoding toolkit for .NET — native MP3/FLAC codec bindings, managed AAC/WMA decode, and built-in waveform generation, behind one IMediaEncoder interface.
+> Audio encoding/decoding toolkit for .NET — native MP3/FLAC codec bindings, managed AAC/WMA encode/decode, and built-in waveform generation, behind one IMediaEncoder interface.
 
 ## What is EggEncoder?
 
@@ -61,12 +61,12 @@ var probeResult = await encoder.Probe("track.flac");
 
 ## Supported Formats
 
-WAV, FLAC, MP3, AAC, WMA (decode-only, mono-only); MOV/MP4 metadata probing via `MovProbe` (no audio decode).
+WAV, FLAC, MP3, AAC, WMA (encode + decode); MOV/MP4 metadata probing via `MovProbe` (no audio decode).
 
 ## Constraints
 
 - Native codec binaries are Windows x64 only — there is no cross-platform fallback
-- `WmaDecoder` does not support mid/side stereo coding (the default for most real-world WMAv2 encoders) — throws `NotSupportedException` for genuine stereo files
+- `WmaDecoder` does not support mid/side stereo coding (the default for most real-world WMAv2 encoders) — throws `NotSupportedException` for genuine stereo files. `WmaEncoder` always writes independently-coded channels, so its own output is always decodable.
 - `AudioCutter.Cut` decodes any supported source and can write any supported destination format — it can transcode while trimming, source and destination extensions no longer need to match
 
 ## Links

src/EggEncoder.UnitTests/Codecs/AudioCutterTest.cs

@@ -2,6 +2,7 @@
 using EggEncoder.Codecs.Flac;
 using EggEncoder.Codecs.Mp3;
 using EggEncoder.Codecs.Wav;
+using EggEncoder.Codecs.Wma;
 using EggEncoder.UnitTests.TestUtilities;
 using FluentAssertions;
 
@@ -323,6 +324,62 @@ public void Convert_Mp3ToFlac_Should_Produce_Correct_Duration_And_NonSilent_Outp
             }
         }
 
+        [Fact]
+        public void Convert_WavToWma_Should_Produce_Correct_Duration_And_NonSilent_Output()
+        {
+            var tempDirectory = CreateTempDirectory();
+
+            try
+            {
+                var destWmaPath = Path.Combine(tempDirectory, "dest.wma");
+
+                AudioCutter.Convert(_wavFixturePath, destWmaPath);
+
+                var decodedSamples = new List<int>();
+                var streamInfo = WmaDecoder.Decode(destWmaPath, (block, _, _, _, _) => decodedSamples.AddRange(block.ToArray()));
+
+                streamInfo.Channels.Should().Be(2);
+                streamInfo.SampleRate.Should().Be(44100);
+                decodedSamples.Should().NotBeEmpty();
+
+                var rootMeanSquare = Math.Sqrt(decodedSamples.Average(sample => (double)sample * sample));
+                rootMeanSquare.Should().BeGreaterThan(1000, $"expected a real, non-silent decoded signal, got RMS={rootMeanSquare}");
+            }
+            finally
+            {
+                Directory.Delete(tempDirectory, recursive: true);
+            }
+        }
+
+        [Fact]
+        public void Cut_WavToWma_Should_Produce_Trimmed_NonSilent_Output()
+        {
+            var tempDirectory = CreateTempDirectory();
+
+            try
+            {
+                var destWmaPath = Path.Combine(tempDirectory, "cut.wma");
+
+                var wasCut = AudioCutter.Cut(_wavFixturePath, destWmaPath, startInSeconds: 0, endInSeconds: 1);
+
+                wasCut.Should().BeTrue();
+
+                var decodedSamples = new List<int>();
+                var streamInfo = WmaDecoder.Decode(destWmaPath, (block, _, _, _, _) => decodedSamples.AddRange(block.ToArray()));
+
+                streamInfo.Channels.Should().Be(2);
+                streamInfo.SampleRate.Should().Be(44100);
+                decodedSamples.Should().NotBeEmpty();
+
+                var rootMeanSquare = Math.Sqrt(decodedSamples.Average(sample => (double)sample * sample));
+                rootMeanSquare.Should().BeGreaterThan(1000, $"expected a real, non-silent decoded signal, got RMS={rootMeanSquare}");
+            }
+            finally
+            {
+                Directory.Delete(tempDirectory, recursive: true);
+            }
+        }
+
         [Fact]
         public void Convert_UnsupportedExtension_Should_Throw()
         {