63 lines
2.8 KiB
TypeScript
63 lines
2.8 KiB
TypeScript
// Helper function for distortion curve generation
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function createDistortionCurve(amount: number): Float32Array<ArrayBuffer> {
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const k = typeof amount === "number" ? amount : 50;
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const nSamples = 44100;
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const curve = new Float32Array(nSamples);
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const deg = Math.PI / 180;
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for (let i = 1; i < nSamples; i += 1) {
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const x = (i * 2) / nSamples - 1;
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curve[i] = ((3 + k) * x * 20 * deg) / (Math.PI + k * Math.abs(x));
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}
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return curve;
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}
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export const getRadioStream = (stream: MediaStream, volume: number): MediaStream | null => {
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try {
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const audioContext = new window.AudioContext();
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const sourceNode = audioContext.createMediaStreamSource(stream);
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const destinationNode = audioContext.createMediaStreamDestination();
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const gainNode = audioContext.createGain();
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gainNode.gain.setValueAtTime(volume, audioContext.currentTime); // Lower gain for reduced volume
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// Create distortion node to simulate radio-like audio
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const distortionNode = audioContext.createWaveShaper();
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distortionNode.curve = createDistortionCurve(15);
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distortionNode.oversample = "none";
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// Compressor node for dynamic range compression
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const compressorNode = audioContext.createDynamicsCompressor();
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compressorNode.threshold.setValueAtTime(-60, audioContext.currentTime); // Lower threshold for more compression
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compressorNode.knee.setValueAtTime(30, audioContext.currentTime); // Slightly softer knee for smoother compression
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compressorNode.ratio.setValueAtTime(15, audioContext.currentTime); // Higher ratio for stronger compression
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compressorNode.attack.setValueAtTime(0.002, audioContext.currentTime); // Faster attack for more aggressive compression
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compressorNode.release.setValueAtTime(0.15, audioContext.currentTime); // Faster release for a "snappier" sound
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// Low-pass filter to simulate reduced fidelity
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const lowPassFilterNode = audioContext.createBiquadFilter();
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lowPassFilterNode.type = "lowpass";
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lowPassFilterNode.frequency.setValueAtTime(2800, audioContext.currentTime);
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// High-pass filter to reduce low-end noise
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const highPassFilterNode = audioContext.createBiquadFilter();
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highPassFilterNode.type = "highpass";
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highPassFilterNode.frequency.setValueAtTime(400, audioContext.currentTime);
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// Chain the nodes
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sourceNode
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.connect(distortionNode) // Apply distortion first
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.connect(highPassFilterNode) // Remove low-end noise
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.connect(lowPassFilterNode) // Simulate reduced fidelity
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.connect(compressorNode) // Apply compression
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.connect(gainNode) // Connect to gain node
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.connect(destinationNode); // Connect to output
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// Return the modified stream
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return destinationNode.stream;
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} catch (error) {
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console.error("Error processing audio stream:", error);
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return null; // In case of error, return null so that the page doesn’t hang
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}
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};
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