Tai Phan Mem Pitch Shifter - Html5 Apr 2026

// Replace function globally createAndStartSource = patchedCreateAndStartSource.bind(this);

footer font-size: 0.7rem; text-align: center; margin-top: 2rem; color: #4b556b;

.btn background: #1e2a3e; border: none; padding: 10px 20px; border-radius: 60px; font-weight: 600; color: white; display: inline-flex; align-items: center; gap: 8px; cursor: pointer; transition: 0.1s; flex: 1; justify-content: center; font-size: 0.9rem; box-shadow: 0 3px 6px rgba(0,0,0,0.3); border-bottom: 1px solid #3b82f640;

// Update UI from current semitone value function updatePitchUI(semitones) currentPitchSemitones = semitones; pitchSlider.value = semitones; const sign = semitones >= 0 ? '+' : ''; pitchDisplay.innerText = `$sign$semitones.toFixed(1) semitones`; const rate = semitonesToRate(semitones); pitchFactorSpan.innerText = rate.toFixed(4); // If a source is active and playing, we need to update playbackRate dynamically if (sourceNode && isPlaying && audioContext && audioContext.state === 'running') try sourceNode.playbackRate.value = rate; catch(e) /* ignore if source disconnected */ tai phan mem pitch shifter - html5

input[type="file"] display: none;

input[type="range"]:focus outline: none;

// update pause logic using new tracking function patchedPauseAudio() { if (!isPlaying || !sourceNode || !audioContext) return; if (sourceNode && audioContext && window._sourceStartTime !== null) 0) + effectiveElapsed; if (newOffset >= audioBuffer.duration) newOffset = audioBuffer.duration; pauseOffset = newOffset; if (sourceNode) { try sourceNode.stop(); catch(e) {} sourceNode.disconnect(); sourceNode = null; } isPlaying = false; window._sourceStartTime = null; updatePlayButtonsState(); statusTextSpan.innerText = "Paused"; } footer font-size: 0.7rem

// initial setup updatePitchUI(0); updatePlayButtonsState(); // pre-initialize context but suspended (chrome policy) initAudioContext(); if (audioContext) audioContext.suspend(); // initially suspended, will resume on play statusTextSpan.innerText = "Ready — load audio"; })(); </script> </body> </html>

// --- Audio context & nodes --- let audioContext = null; let sourceNode = null; // current active buffer source let audioBuffer = null; // decoded audio data let isPlaying = false; let currentPitchSemitones = 0; // value in semitones (-12..12) let startTime = 0; let pauseOffset = 0; // seconds where playback paused let isContextSuspended = false;

function patchedCreateAndStartSource(offsetSec) { if (!audioContext || !audioBuffer) return null; if (audioContext.state === 'suspended') audioContext.resume().then(() => patchedCreateAndStartSource(offsetSec)); return null; if (sourceNode) { try sourceNode.stop(); catch(e) {} sourceNode.disconnect(); } const newSource = audioContext.createBufferSource(); newSource.buffer = audioBuffer; const rate = semitonesToRate(currentPitchSemitones); newSource.playbackRate.value = rate; newSource.connect(audioContext.destination); const startTime = audioContext.currentTime; newSource.start(startTime, offsetSec); sourceNode = newSource; window._sourceStartTime = startTime; isPlaying = true; newSource.onended = () => if (sourceNode === newSource) isPlaying = false; // if ended naturally, reset pauseOffset pauseOffset = 0; sourceNode = null; window._sourceStartTime = null; updatePlayButtonsState(); statusTextSpan.innerText = "Stopped"; ; updatePlayButtonsState(); return newSource; } .btn background: #1e2a3e

// Event binding pitchSlider.addEventListener('input', (e) => { const val = parseFloat(e.target.value); updatePitchUI(val); // If currently playing, dynamically update the playback rate on the fly if (sourceNode && isPlaying && audioContext && audioContext.state === 'running') { try sourceNode.playbackRate.value = semitonesToRate(currentPitchSemitones); catch(err) {} } });

input[type="range"]::-webkit-slider-thumb -webkit-appearance: none; width: 20px; height: 20px; background: #3b82f6; border-radius: 50%; cursor: pointer; box-shadow: 0 0 8px #3b82f6; border: 2px solid white;