353 lines
12 KiB
JavaScript
353 lines
12 KiB
JavaScript
/**
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* Demucs audio processor - Core separation logic
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*/
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import { CONSTANTS } from './constants.js';
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import { stft, istft, reflectPad } from './fft.js';
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const { SAMPLE_RATE, FFT_SIZE, HOP_SIZE, TRAINING_SAMPLES, MODEL_SPEC_BINS, MODEL_SPEC_FRAMES, SEGMENT_OVERLAP, TRACKS } = CONSTANTS;
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/**
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* Convert model frequency output to complex spectrogram per track
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*/
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export function standaloneMask(freqOutput) {
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const numTracks = 4;
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const numChannels = 4;
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const numBins = MODEL_SPEC_BINS;
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const numFrames = MODEL_SPEC_FRAMES;
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const result = [];
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for (let t = 0; t < numTracks; t++) {
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const trackSpec = {
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leftReal: new Float32Array(numBins * numFrames),
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leftImag: new Float32Array(numBins * numFrames),
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rightReal: new Float32Array(numBins * numFrames),
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rightImag: new Float32Array(numBins * numFrames)
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};
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for (let f = 0; f < numFrames; f++) {
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for (let b = 0; b < numBins; b++) {
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const baseIdx = t * numChannels * numBins * numFrames;
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const outIdx = b * numFrames + f;
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trackSpec.leftReal[outIdx] = freqOutput[baseIdx + 0 * numBins * numFrames + b * numFrames + f];
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trackSpec.leftImag[outIdx] = freqOutput[baseIdx + 1 * numBins * numFrames + b * numFrames + f];
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trackSpec.rightReal[outIdx] = freqOutput[baseIdx + 2 * numBins * numFrames + b * numFrames + f];
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trackSpec.rightImag[outIdx] = freqOutput[baseIdx + 3 * numBins * numFrames + b * numFrames + f];
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}
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}
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result.push(trackSpec);
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}
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return result;
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}
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/**
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* Convert complex spectrogram back to time domain (iSTFT with proper offsets)
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*/
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export function standaloneIspec(trackSpec, targetLength) {
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const numBins = MODEL_SPEC_BINS;
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const numFrames = MODEL_SPEC_FRAMES;
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const hopLength = HOP_SIZE;
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const paddedBins = numBins + 1;
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const paddedFrames = numFrames + 4;
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const padChannel = (real, imag) => {
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const paddedReal = new Float32Array(paddedFrames * paddedBins);
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const paddedImag = new Float32Array(paddedFrames * paddedBins);
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for (let f = 0; f < numFrames; f++) {
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for (let b = 0; b < numBins; b++) {
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const srcIdx = b * numFrames + f;
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const dstFrame = f + 2;
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const dstIdx = dstFrame * paddedBins + b;
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paddedReal[dstIdx] = real[srcIdx];
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paddedImag[dstIdx] = imag[srcIdx];
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}
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}
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return { real: paddedReal, imag: paddedImag };
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};
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const leftPadded = padChannel(trackSpec.leftReal, trackSpec.leftImag);
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const rightPadded = padChannel(trackSpec.rightReal, trackSpec.rightImag);
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const centerPad = FFT_SIZE / 2;
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const pad = Math.floor(hopLength / 2) * 3;
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const istftLength = (paddedFrames - 1) * hopLength + FFT_SIZE;
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const leftOut = istft(leftPadded.real, leftPadded.imag, paddedFrames, paddedBins, FFT_SIZE, hopLength, istftLength);
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const rightOut = istft(rightPadded.real, rightPadded.imag, paddedFrames, paddedBins, FFT_SIZE, hopLength, istftLength);
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const totalOffset = centerPad + pad;
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const left = leftOut.subarray(totalOffset, totalOffset + targetLength);
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const right = rightOut.subarray(totalOffset, totalOffset + targetLength);
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return { left: new Float32Array(left), right: new Float32Array(right) };
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}
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/**
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* Prepare model input from stereo audio
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*/
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export function prepareModelInput(leftChannel, rightChannel) {
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const inputLength = TRAINING_SAMPLES;
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const paddedLeft = new Float32Array(inputLength);
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const paddedRight = new Float32Array(inputLength);
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const copyLen = Math.min(leftChannel.length, inputLength);
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paddedLeft.set(leftChannel.subarray(0, copyLen));
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paddedRight.set(rightChannel.subarray(0, copyLen));
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const le = Math.ceil(inputLength / HOP_SIZE);
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const pad = Math.floor(HOP_SIZE / 2) * 3;
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const padRight = pad + le * HOP_SIZE - inputLength;
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const stftInputLeft = reflectPad(paddedLeft, pad, padRight);
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const stftInputRight = reflectPad(paddedRight, pad, padRight);
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const centerPad = FFT_SIZE / 2;
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const centeredLeft = reflectPad(stftInputLeft, centerPad, centerPad);
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const centeredRight = reflectPad(stftInputRight, centerPad, centerPad);
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const stftLeft = stft(centeredLeft, FFT_SIZE, HOP_SIZE);
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const stftRight = stft(centeredRight, FFT_SIZE, HOP_SIZE);
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const numBins = MODEL_SPEC_BINS;
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const numFrames = MODEL_SPEC_FRAMES;
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const frameOffset = 2;
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const magSpec = new Float32Array(4 * numBins * numFrames);
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for (let f = 0; f < numFrames; f++) {
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const srcFrame = f + frameOffset;
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for (let b = 0; b < numBins; b++) {
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const srcIdx = srcFrame * stftLeft.numBins + b;
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magSpec[0 * numBins * numFrames + b * numFrames + f] = stftLeft.real[srcIdx];
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magSpec[1 * numBins * numFrames + b * numFrames + f] = stftLeft.imag[srcIdx];
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magSpec[2 * numBins * numFrames + b * numFrames + f] = stftRight.real[srcIdx];
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magSpec[3 * numBins * numFrames + b * numFrames + f] = stftRight.imag[srcIdx];
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}
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}
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const waveform = new Float32Array(2 * inputLength);
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waveform.set(paddedLeft, 0);
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waveform.set(paddedRight, inputLength);
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return { waveform, magSpec, numBins, numFrames, originalLength: leftChannel.length };
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}
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/**
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* Main Demucs processor class
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*/
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export class DemucsProcessor {
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constructor(options = {}) {
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this.ort = options.ort || null;
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this.session = null;
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this.modelPath = options.modelPath || './htdemucs_embedded.onnx';
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this.sessionOptions = options.sessionOptions || {};
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this.onProgress = options.onProgress || (() => {});
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this.onLog = options.onLog || (() => {});
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this.onDownloadProgress = options.onDownloadProgress || (() => {});
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}
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async loadModel(modelPathOrBuffer) {
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if (!this.ort) {
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throw new Error('ONNX Runtime not provided. Pass ort in constructor options.');
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}
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this.onLog('model', 'Loading model...');
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let modelBuffer;
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if (modelPathOrBuffer instanceof ArrayBuffer) {
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modelBuffer = modelPathOrBuffer;
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} else {
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const response = await fetch(modelPathOrBuffer || this.modelPath);
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// Check if we can track progress
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const contentLength = response.headers.get('Content-Length');
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if (contentLength && response.body) {
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const totalSize = parseInt(contentLength, 10);
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const reader = response.body.getReader();
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const chunks = [];
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let loadedSize = 0;
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while (true) {
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const { done, value } = await reader.read();
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if (done) break;
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chunks.push(value);
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loadedSize += value.length;
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this.onDownloadProgress(loadedSize, totalSize);
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}
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// Combine chunks into single ArrayBuffer
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const combined = new Uint8Array(loadedSize);
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let offset = 0;
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for (const chunk of chunks) {
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combined.set(chunk, offset);
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offset += chunk.length;
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}
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modelBuffer = combined.buffer;
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} else {
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// Fallback: no progress tracking
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modelBuffer = await response.arrayBuffer();
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}
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}
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const defaultSessionOptions = {
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executionProviders: ['webgpu', 'wasm'],
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graphOptimizationLevel: 'basic'
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};
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this.session = await this.ort.InferenceSession.create(modelBuffer, {
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...defaultSessionOptions,
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...this.sessionOptions
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});
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this.onLog('model', 'Model loaded successfully');
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return this.session;
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}
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async separate(leftChannel, rightChannel) {
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if (!this.session) {
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throw new Error('Model not loaded. Call loadModel() first.');
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}
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const totalSamples = leftChannel.length;
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const stride = Math.floor(TRAINING_SAMPLES * (1 - SEGMENT_OVERLAP));
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const numSegments = Math.ceil((totalSamples - TRAINING_SAMPLES) / stride) + 1;
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const outputs = TRACKS.map(() => ({
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left: new Float32Array(totalSamples),
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right: new Float32Array(totalSamples)
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}));
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const weights = new Float32Array(totalSamples);
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let segmentIdx = 0;
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for (let start = 0; start < totalSamples; start += stride) {
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const end = Math.min(start + TRAINING_SAMPLES, totalSamples);
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const segmentLength = end - start;
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const segLeft = new Float32Array(TRAINING_SAMPLES);
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const segRight = new Float32Array(TRAINING_SAMPLES);
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for (let i = 0; i < segmentLength; i++) {
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segLeft[i] = leftChannel[start + i];
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segRight[i] = rightChannel[start + i];
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}
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const input = prepareModelInput(segLeft, segRight);
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const waveformTensor = new this.ort.Tensor('float32', input.waveform, [1, 2, TRAINING_SAMPLES]);
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const magSpecTensor = new this.ort.Tensor('float32', input.magSpec, [1, 4, MODEL_SPEC_BINS, MODEL_SPEC_FRAMES]);
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const feeds = {};
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feeds[this.session.inputNames[0]] = waveformTensor;
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if (this.session.inputNames.length > 1) {
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feeds[this.session.inputNames[1]] = magSpecTensor;
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}
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const inferResults = await this.session.run(feeds);
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let timeData = null, timeShape = null;
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let freqData = null;
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for (const name of this.session.outputNames) {
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const tensor = inferResults[name];
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if (tensor.dims.length === 4 && tensor.dims[2] === 2) {
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timeData = tensor.data;
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timeShape = tensor.dims;
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} else if (tensor.dims.length === 5 && tensor.dims[2] === 4) {
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freqData = tensor.data;
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}
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}
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if (!timeData) {
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throw new Error('Could not find time-domain output tensor');
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}
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let combinedOutputs = null;
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if (freqData) {
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const trackSpecs = standaloneMask(freqData);
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combinedOutputs = [];
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for (let t = 0; t < 4; t++) {
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const freqOutput = standaloneIspec(trackSpecs[t], TRAINING_SAMPLES);
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const numChannels = timeShape[2];
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const samples = timeShape[3];
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const timeLeft = new Float32Array(samples);
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const timeRight = new Float32Array(samples);
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for (let i = 0; i < samples; i++) {
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timeLeft[i] = timeData[t * numChannels * samples + 0 * samples + i];
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timeRight[i] = timeData[t * numChannels * samples + 1 * samples + i];
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}
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const combined = {
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left: new Float32Array(samples),
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right: new Float32Array(samples)
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};
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for (let i = 0; i < samples; i++) {
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combined.left[i] = timeLeft[i] + (freqOutput.left[i] || 0);
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combined.right[i] = timeRight[i] + (freqOutput.right[i] || 0);
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}
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combinedOutputs.push(combined);
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}
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}
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const numTracks = timeShape[1];
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const numChannels = timeShape[2];
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const samples = timeShape[3];
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const overlapWindow = new Float32Array(segmentLength);
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for (let i = 0; i < segmentLength; i++) {
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const fadeIn = Math.min(i / (stride * 0.5), 1);
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const fadeOut = Math.min((segmentLength - i) / (stride * 0.5), 1);
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overlapWindow[i] = Math.min(fadeIn, fadeOut);
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}
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for (let t = 0; t < numTracks; t++) {
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for (let i = 0; i < segmentLength && start + i < totalSamples; i++) {
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let leftVal, rightVal;
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if (combinedOutputs) {
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leftVal = combinedOutputs[t].left[i];
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rightVal = combinedOutputs[t].right[i];
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} else {
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const leftIdx = t * numChannels * samples + 0 * samples + i;
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const rightIdx = t * numChannels * samples + 1 * samples + i;
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leftVal = timeData[leftIdx];
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rightVal = timeData[rightIdx];
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}
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outputs[t].left[start + i] += leftVal * overlapWindow[i];
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outputs[t].right[start + i] += rightVal * overlapWindow[i];
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}
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}
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for (let i = 0; i < segmentLength && start + i < totalSamples; i++) {
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weights[start + i] += overlapWindow[i];
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}
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segmentIdx++;
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this.onProgress({
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progress: segmentIdx / numSegments,
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currentSegment: segmentIdx,
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totalSegments: numSegments
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});
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}
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for (let t = 0; t < TRACKS.length; t++) {
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for (let i = 0; i < totalSamples; i++) {
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if (weights[i] > 0) {
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outputs[t].left[i] /= weights[i];
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outputs[t].right[i] /= weights[i];
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}
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}
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}
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return {
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drums: outputs[0],
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bass: outputs[1],
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other: outputs[2],
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vocals: outputs[3]
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};
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}
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}
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