86 lines
1.7 KiB
JavaScript
86 lines
1.7 KiB
JavaScript
import wavefile from 'wavefile';
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let WaveFile = wavefile.WaveFile;
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import {
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readFileSync,
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writeFileSync
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} from 'fs';
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function byte2byte(arr) {
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let lines = [];
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for (let i=0; i < arr.length; i++) {
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lines.push(`.byte ${arr[i]}`);
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}
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return lines.join('\n');
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}
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class Dither {
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constructor() {
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this.err = 0;
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}
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to4bit(val8) {
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let val = (val8 / 255) + this.err;
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if (val < 0) {
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val = 0;
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}
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if (val > 1) {
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val = 1;
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}
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let val4 = Math.round(val * 15);
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let dithered = (val4 / 15);
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this.err = (val - dithered);
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return val4;
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}
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}
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function pack(audio) {
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let packed = [];
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let dither = new Dither();
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for (let i = 0; i < audio.length; i += 2) {
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// little-endian 4-bit samples
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let low = dither.to4bit(audio[i]);
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let high = dither.to4bit(audio[i + 1]);
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let byte = low | (high << 4);
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packed.push(byte);
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}
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/*
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// raw push bytes
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for (let i = 0; i < audio.length; i += 2) {
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let val = to4bit(audio[i]);
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let byte = val | 0x10;
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packed.push(byte);
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}
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*/
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return packed;
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}
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function audio2assembly(audio) {
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return `
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.segment "AUDIO"
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.export audio_samples
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.export audio_samples_end
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audio_samples:
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${byte2byte(pack(audio))}
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audio_samples_end:
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.byte 24
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`;
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}
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function wav2assembly(buffer) {
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let wav = new WaveFile(buffer);
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let samples = wav.getSamples();
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let n = samples.length - (samples.length % 131);
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return audio2assembly(samples.slice(0, n));
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}
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let infile = process.argv[2];
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let outfile = process.argv[3];
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let buffer = readFileSync(infile);
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let asm = wav2assembly(buffer);
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writeFileSync(outfile, asm, 'utf-8');
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