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archived-vdo.ninja/loudness.html
2024-10-17 04:34:18 -04:00

247 lines
10 KiB
HTML

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Adaptive Loudness Transition Analysis</title>
<style>
body {
font-family: Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background-color: #f4f4f4;
}
h1, h2 {
color: #2c3e50;
text-align: center;
}
.input-group {
margin-bottom: 20px;
background-color: #fff;
padding: 20px;
border-radius: 5px;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
label {
display: block;
margin-bottom: 5px;
}
input[type="file"], input[type="number"] {
width: 100%;
padding: 10px;
margin-bottom: 10px;
border: 1px solid #ddd;
border-radius: 4px;
}
#error {
color: #e74c3c;
font-weight: bold;
}
#results, #debug {
background-color: #fff;
padding: 20px;
border-radius: 5px;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
margin-top: 20px;
}
.region {
margin-bottom: 10px;
padding: 10px;
background-color: #ecf0f1;
border-radius: 4px;
}
.region-header {
font-weight: bold;
color: #2980b9;
}
#debug {
font-family: monospace;
white-space: pre-wrap;
background-color: #2c3e50;
color: #ecf0f1;
}
</style>
</head>
<body>
<h1>Adaptive Loudness Transition Analysis</h1>
<div class="input-group">
<label for="audioFile">Select WAV file:</label>
<input type="file" id="audioFile" accept=".wav">
<label for="transitionThreshold">Transition Threshold (dB):</label>
<input type="number" id="transitionThreshold" value="5" min="1" max="20" step="0.5">
<label for="analysisWindowSize">Analysis Window Size (seconds):</label>
<input type="number" id="analysisWindowSize" value="5" min="1" max="30" step="1">
</div>
<div id="error"></div>
<div id="results"></div>
<div id="debug"></div>
<script>
let audioContext;
document.getElementById('audioFile').addEventListener('change', handleFileUpload);
async function handleFileUpload(event) {
const errorDiv = document.getElementById('error');
const resultsDiv = document.getElementById('results');
const debugDiv = document.getElementById('debug');
errorDiv.innerHTML = '';
resultsDiv.innerHTML = '';
debugDiv.innerHTML = '';
try {
audioContext = new (window.AudioContext || window.webkitAudioContext)();
const file = event.target.files[0];
if (!file) {
throw new Error('No file selected');
}
const arrayBuffer = await file.arrayBuffer();
const audioBuffer = await audioContext.decodeAudioData(arrayBuffer);
console.log('Audio duration:', audioBuffer.duration, 'seconds');
debugDiv.innerHTML += `Audio duration: ${audioBuffer.duration.toFixed(2)} seconds\n`;
const loudnessData = analyzeLoudness(audioBuffer);
console.log('Loudness data:', loudnessData);
debugDiv.innerHTML += `Loudness data length: ${loudnessData.length}\n`;
debugDiv.innerHTML += `First 5 loudness data points: ${JSON.stringify(loudnessData.slice(0, 5), null, 2)}\n`;
debugDiv.innerHTML += `Last 5 loudness data points: ${JSON.stringify(loudnessData.slice(-5), null, 2)}\n`;
if (loudnessData.length === 0) {
throw new Error('No loudness data generated. The audio file might be too short.');
}
const silenceThreshold = determineSilenceThreshold(loudnessData);
debugDiv.innerHTML += `Automatically determined silence threshold: ${silenceThreshold.toFixed(2)} dB\n`;
const transitionThreshold = parseFloat(document.getElementById('transitionThreshold').value);
const analysisWindowSize = parseFloat(document.getElementById('analysisWindowSize').value);
const regions = identifyLoudnessTransitions(loudnessData, silenceThreshold, transitionThreshold, analysisWindowSize);
console.log('Regions:', regions);
debugDiv.innerHTML += `Number of regions identified: ${regions.length}\n`;
debugDiv.innerHTML += `Regions: ${JSON.stringify(regions, null, 2)}\n`;
displayResults(regions, audioBuffer.duration, silenceThreshold);
} catch (error) {
console.error('Error:', error);
errorDiv.innerHTML = `Error: ${error.message}`;
debugDiv.innerHTML += `Error stack trace: ${error.stack}\n`;
}
}
function analyzeLoudness(audioBuffer) {
const channelData = audioBuffer.getChannelData(0);
const sampleRate = audioBuffer.sampleRate;
const segmentLength = 0.1 * sampleRate; // 100ms segments
const loudnessData = [];
for (let i = 0; i < channelData.length; i += segmentLength) {
const segment = channelData.slice(i, i + segmentLength);
const loudness = calculateLoudness(segment);
if (!isNaN(loudness)) {
loudnessData.push({ time: i / sampleRate, loudness });
}
}
return loudnessData;
}
function calculateLoudness(samples) {
if (samples.length === 0) return NaN;
const rms = Math.sqrt(samples.reduce((sum, sample) => sum + sample * sample, 0) / samples.length);
return 20 * Math.log10(Math.max(rms, 1e-10)); // Avoid log of 0
}
function determineSilenceThreshold(loudnessData) {
const sortedLoudness = loudnessData.map(d => d.loudness).sort((a, b) => a - b);
const medianIndex = Math.floor(sortedLoudness.length / 2);
const median = sortedLoudness[medianIndex];
// Assuming half of the audio should be silence, we'll use the median as our threshold
return median;
}
function identifyLoudnessTransitions(loudnessData, silenceThreshold, transitionThreshold, analysisWindowSize) {
const windowSamples = Math.floor(analysisWindowSize / 0.1); // Convert seconds to number of 100ms samples
let regions = [];
let currentRegion = null;
let prevAvgLoudness = null;
for (let i = 0; i < loudnessData.length - windowSamples; i += windowSamples) {
const window = loudnessData.slice(i, i + windowSamples);
const avgLoudness = average(window.map(d => d.loudness));
if (avgLoudness > silenceThreshold) {
if (!currentRegion) {
currentRegion = { start: window[0].time, avgLoudness };
} else if (prevAvgLoudness !== null && Math.abs(avgLoudness - prevAvgLoudness) > transitionThreshold) {
currentRegion.end = window[0].time;
regions.push(currentRegion);
currentRegion = { start: window[0].time, avgLoudness };
}
prevAvgLoudness = avgLoudness;
} else if (currentRegion) {
currentRegion.end = window[0].time;
regions.push(currentRegion);
currentRegion = null;
prevAvgLoudness = null;
}
}
if (currentRegion) {
currentRegion.end = loudnessData[loudnessData.length - 1].time;
regions.push(currentRegion);
}
return regions;
}
function average(arr) {
return arr.reduce((sum, val) => sum + val, 0) / arr.length;
}
function displayResults(regions, totalDuration, silenceThreshold) {
const resultsDiv = document.getElementById('results');
resultsDiv.innerHTML = '<h2>Analysis Results</h2>';
resultsDiv.innerHTML += `<p>Automatically determined silence threshold: ${silenceThreshold.toFixed(2)} dB</p>`;
if (regions.length === 0) {
resultsDiv.innerHTML += '<p>No significant loudness transitions identified. Try adjusting the parameters.</p>';
return;
}
regions.forEach((region, i) => {
const regionDuration = (region.end - region.start).toFixed(2);
const percentOfTotal = ((region.end - region.start) / totalDuration * 100).toFixed(1);
const loudnessDescription = describeLoudness(region.avgLoudness);
resultsDiv.innerHTML += `
<div class="region">
<span class="region-header">Region ${i + 1}:</span><br>
Start: ${formatTime(region.start)}<br>
End: ${formatTime(region.end)}<br>
Duration: ${regionDuration}s (${percentOfTotal}% of total)<br>
Avg Loudness: ${region.avgLoudness.toFixed(2)} dB (${loudnessDescription})
</div>
`;
});
}
function formatTime(seconds) {
const minutes = Math.floor(seconds / 60);
const remainingSeconds = (seconds % 60).toFixed(2);
return `${minutes}:${remainingSeconds.padStart(5, '0')}`;
}
function describeLoudness(loudness) {
if (loudness > -10) return "Very Loud";
if (loudness > -20) return "Loud";
if (loudness > -30) return "Moderate";
if (loudness > -40) return "Soft";
return "Very Soft";
}
</script>
</body>
</html>