Rocky
bf844caa7f
Mirror the personal dictionary through iCloud Key-Value Store with deterministic merge rules, main-app-only sync UI, and App Group as the keyboard runtime cache. Add cloud-engine ASR with dictionary bias and expand the bundled custom language model lexicon.
68 lines
2.3 KiB
Swift
68 lines
2.3 KiB
Swift
// PCMSampleWavEncoder.swift
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// OSGKeyboard · Shared
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//
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// Encodes mono Float32 PCM (@ 16 kHz) into a minimal WAV byte stream for
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// cloud ASR multipart / base64 uploads.
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import Foundation
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public enum PCMSampleWavEncoder {
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public static func encode(samples: [Float], sampleRate: Int = 16_000) -> Data {
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guard !samples.isEmpty else {
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return encode(pcm16: [], sampleRate: sampleRate)
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}
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var pcm16 = [Int16]()
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pcm16.reserveCapacity(samples.count)
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for sample in samples {
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let scaled = sample * 32_767.0
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let clipped = Swift.max(-32_768.0, Swift.min(32_767.0, scaled))
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pcm16.append(Int16(clipped.rounded()))
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}
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return encode(pcm16: pcm16, sampleRate: sampleRate)
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}
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public static func encode(pcm16: [Int16], sampleRate: Int) -> Data {
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let byteRate = sampleRate * 2
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let dataSize = pcm16.count * MemoryLayout<Int16>.size
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var data = Data()
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data.reserveCapacity(44 + dataSize)
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func appendASCII(_ string: String) {
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data.append(contentsOf: string.utf8)
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}
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func appendLE32(_ value: UInt32) {
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var le = value.littleEndian
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withUnsafeBytes(of: &le) { data.append(contentsOf: $0) }
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}
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func appendLE16(_ value: UInt16) {
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var le = value.littleEndian
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withUnsafeBytes(of: &le) { data.append(contentsOf: $0) }
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}
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appendASCII("RIFF")
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appendLE32(UInt32(36 + dataSize))
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appendASCII("WAVE")
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appendASCII("fmt ")
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appendLE32(16)
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appendLE16(1) // PCM
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appendLE16(1) // mono
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appendLE32(UInt32(sampleRate))
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appendLE32(UInt32(byteRate))
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appendLE16(2) // block align
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appendLE16(16) // bits per sample
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appendASCII("data")
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appendLE32(UInt32(dataSize))
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pcm16.withUnsafeBufferPointer { buffer in
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guard let base = buffer.baseAddress else { return }
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data.append(UnsafeBufferPointer(start: base, count: buffer.count))
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}
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return data
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}
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public static func dataURI(samples: [Float], sampleRate: Int = 16_000) -> String {
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let wav = encode(samples: samples, sampleRate: sampleRate)
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return "data:audio/wav;base64,\(wav.base64EncodedString())"
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}
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}
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