54 lines
2.2 KiB
TypeScript
54 lines
2.2 KiB
TypeScript
const sampleRate = 16000
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export const soundCheckWav = Buffer.alloc(44 + sampleRate * 2)
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soundCheckWav.write('RIFF', 0)
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soundCheckWav.writeUInt32LE(soundCheckWav.length - 8, 4)
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soundCheckWav.write('WAVEfmt ', 8)
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soundCheckWav.writeUInt32LE(16, 16)
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soundCheckWav.writeUInt16LE(1, 20)
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soundCheckWav.writeUInt16LE(1, 22)
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soundCheckWav.writeUInt32LE(sampleRate, 24)
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soundCheckWav.writeUInt32LE(sampleRate * 2, 28)
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soundCheckWav.writeUInt16LE(2, 32)
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soundCheckWav.writeUInt16LE(16, 34)
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soundCheckWav.write('data', 36)
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soundCheckWav.writeUInt32LE(sampleRate * 2, 40)
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for (let sample = 0; sample < sampleRate; sample++) {
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const time = sample / sampleRate
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const start = time < 0.5 ? 0.05 : 0.55
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const elapsed = time - start
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if (elapsed < 0 || elapsed >= 0.4) continue
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const envelope = Math.min(1, elapsed / 0.02, (0.4 - elapsed) / 0.02)
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const frequency = time < 0.5 ? 440 : 660
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soundCheckWav.writeInt16LE(Math.round(6553 * envelope * Math.sin(2 * Math.PI * frequency * elapsed)), 44 + sample * 2)
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}
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// Runs in the audio devices renderer; keep this function independent of module imports.
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export function playSoundCheck(): Promise<void> {
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const media = document.querySelector('audio')
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if (!media) return Promise.reject(new Error('Проверка звука недоступна'))
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return new Promise<void>((resolve, reject) => {
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let finished = false
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const finish = (error?: Error) => {
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if (finished) return
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finished = true
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clearTimeout(timeout)
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media.removeEventListener('ended', ended)
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media.removeEventListener('error', failed)
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media.pause()
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media.removeAttribute('src')
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media.load()
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if (error) reject(error)
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else resolve()
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}
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const ended = () => finish()
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const failed = () => finish(new Error('Не удалось воспроизвести проверочный сигнал'))
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const timeout = setTimeout(() => finish(new Error('Превышено время проверки звука')), 3000)
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media.addEventListener('ended', ended)
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media.addEventListener('error', failed)
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media.muted = false
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media.volume = 1
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media.src = 'screen-app://app/sound-check.wav'
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void media.play().catch(failed)
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})
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}
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