v0.9: VoicePipeline refactor — queue-based pipeline, lock/release model, thread-based TCP

Robovoice.Tts.LibPiper/LibPiperTtsEngine.cs

@@ -120,6 +120,71 @@ public sealed class LibPiperTtsEngine : ITtsEngine
         }
     }
 
+    public IEnumerable<AudioChunk> SynthesizeSync(string text)
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+        if (!_initialized)
+            throw new InvalidOperationException("Engine not initialized.");
+
+        var options = new PiperSynthesizeOptions
+        {
+            SpeakerId = 0,
+            LengthScale = _lengthScale,
+            NoiseScale = _noiseScale,
+            NoiseWScale = _noiseWScale,
+        };
+
+        byte[] textBytes = System.Text.Encoding.UTF8.GetBytes(EnsureTerminator(text) + "\0");
+        GCHandle textPin = GCHandle.Alloc(textBytes, GCHandleType.Pinned);
+        try
+        {
+            int startResult = PiperNative.piper_synthesize_start(
+                _synth, textPin.AddrOfPinnedObject(), in options);
+            if (startResult != PiperNative.PiperOk)
+                throw new InvalidOperationException($"piper_synthesize_start failed: {startResult}");
+
+            while (true)
+            {
+                PiperAudioChunk chunk = default;
+                int result = PiperNative.piper_synthesize_next(_synth, out chunk);
+
+                if (chunk.NumSamples > 0 && chunk.Samples != IntPtr.Zero)
+                {
+                    int numSamples = (int)chunk.NumSamples;
+                    float[] samples = new float[numSamples];
+                    Marshal.Copy(chunk.Samples, samples, 0, numSamples);
+
+                    if (chunk.SampleRate > 0)
+                        _sampleRate = chunk.SampleRate;
+
+                    yield return new AudioChunk(samples, _sampleRate);
+                }
+
+                if (result == PiperNative.PiperDone || chunk.IsLast)
+                    break;
+
+                if (result < 0)
+                    throw new InvalidOperationException($"piper_synthesize_next failed: {result}");
+            }
+        }
+        finally
+        {
+            textPin.Free();
+        }
+    }
+
+    public void SynthesizeDrain()
+    {
+        if (!_initialized || _synth == IntPtr.Zero)
+            return;
+
+        PiperAudioChunk chunk;
+        while (PiperNative.piper_synthesize_next(_synth, out chunk) != PiperNative.PiperDone)
+        {
+            if (chunk.IsLast) break;
+        }
+    }
+
     private static string EnsureTerminator(string text)
     {
         string trimmed = text.TrimEnd();