43 lines
1.3 KiB
Go
43 lines
1.3 KiB
Go
package transcriber
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import (
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"bytes"
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"encoding/binary"
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)
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// convertToWAV converts raw 16-bit PCM audio to WAV format
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func convertToWAV(rawAudio []byte) ([]byte, error) {
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var buf bytes.Buffer
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const sampleRate = 16000
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const channels = 1
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const bitsPerSample = 16
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const byteRate = sampleRate * channels * bitsPerSample / 8
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const blockAlign = channels * bitsPerSample / 8
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dataSize := len(rawAudio)
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fileSize := 36 + dataSize
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// WAV header
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buf.WriteString("RIFF")
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binary.Write(&buf, binary.LittleEndian, uint32(fileSize))
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buf.WriteString("WAVE")
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// fmt chunk
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buf.WriteString("fmt ")
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binary.Write(&buf, binary.LittleEndian, uint32(16)) // fmt chunk size
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binary.Write(&buf, binary.LittleEndian, uint16(1)) // PCM format
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binary.Write(&buf, binary.LittleEndian, uint16(channels)) // number of channels
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binary.Write(&buf, binary.LittleEndian, uint32(sampleRate)) // sample rate
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binary.Write(&buf, binary.LittleEndian, uint32(byteRate)) // byte rate
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binary.Write(&buf, binary.LittleEndian, uint16(blockAlign)) // block align
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binary.Write(&buf, binary.LittleEndian, uint16(bitsPerSample)) // bits per sample
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// data chunk
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buf.WriteString("data")
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binary.Write(&buf, binary.LittleEndian, uint32(dataSize))
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buf.Write(rawAudio)
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return buf.Bytes(), nil
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}
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