Feat/wsola tests

.claude/skills/utilities/SKILL.md

@@ -231,6 +231,22 @@ Higher-level DSP blocks. Read each header before use.
 
 ---
 
+### `WsolaTimeStretcher.h` — pitch-preserving time stretch
+
+Needs ~`getRequiredInputFrames()` of PCM in its internal queue before the first OLA
+iteration.
+
+- **File / AudioTag:** early `SeekDecoderDaemon` fills the SPSC; construction
+  `primeWsolaInputFromDecoder()` waits until the analysis queue is full (no wall-clock
+  deadline). No first-quantum warmup — process only feeds the current quantum.
+- **Buffer sources:** `AudioBufferSourceNode::start` calls `primeWsolaInput()` after
+  setting `vReadIndex_` (advances cursor by frames fed). Prefill happens only there;
+  `processWithPitchCorrection` feeds one quantum's input. Compare cold-start with DC
+  ones sample + abs/relative first-sound logs in `WsolaTimeStretcher`. Scratch sized
+  with `scratchBufferFrames(sampleRate)`.
+
+---
+
 ### `SpectrumAnalyser.h` — shared windowed-FFT magnitude spectrum
 
 Owns FFT scratch state (Blackman window, temp array, complex scratch, magnitude

apps/common-app/src/examples/AudioTag/AudioTag.tsx

@@ -1,11 +1,10 @@
 import React, {
   useCallback,
   useEffect,
-  useMemo,
   useRef,
   useState,
 } from 'react';
-import { Text, useWindowDimensions, View } from 'react-native';
+import { useWindowDimensions, View } from 'react-native';
 import {
   Audio,
   AudioTagHandle,
@@ -97,41 +96,25 @@ const AudioTag: React.FC = () => {
     // console.log('onVolumeChange', volume);
   }, []);
 
-  const audioTagElement = useMemo(
-    () => (
-      <Audio
-        source={DEMO_AUDIO_URL}
-        ref={audioRef}
-        context={audioContextRef.current}
-        loop
-        controls
-        onLoadStart={handleLoadStart}
-        onLoad={handleLoad}
-        onError={handleError}
-        onPositionChange={handlePositionChange}
-        onEnded={handleEnded}
-        onPlay={handlePlay}
-        onPause={handlePause}
-        onVolumeChange={handleVolumeEvent}
-      />
-    ),
-    [
-      handleEnded,
-      handleError,
-      handleLoad,
-      handleLoadStart,
-      handlePause,
-      handlePlay,
-      handlePositionChange,
-      handleVolumeEvent,
-    ]
-  );
-
   return (
     <Container disablePadding>
       <View style={{ flex: 1, justifyContent: 'center', alignItems: 'center' }}>
         <View style={{ width: '90%' }}>
-          {audioTagElement}
+          <Audio
+            source={DEMO_AUDIO_URL}
+            ref={audioRef}
+            context={audioContextRef.current}
+            loop
+            controls
+            onLoadStart={handleLoadStart}
+            onLoad={handleLoad}
+            onError={handleError}
+            onPositionChange={handlePositionChange}
+            onEnded={handleEnded}
+            onPlay={handlePlay}
+            onPause={handlePause}
+            onVolumeChange={handleVolumeEvent}
+          />
           <Spacer.Vertical size={20} />
           <Slider
             label="Volume"