53 lines
1.2 KiB
Go
53 lines
1.2 KiB
Go
// ABOUTME: PCM audio encoder
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// ABOUTME: Encodes int32 samples to 16-bit or 24-bit PCM bytes
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package encode
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import (
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"encoding/binary"
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"fmt"
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"github.com/Sendspin/sendspin-go/pkg/audio"
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)
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type PCMEncoder struct {
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bitDepth int
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}
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func NewPCM(format audio.Format) (Encoder, error) {
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if format.Codec != "pcm" {
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return nil, fmt.Errorf("invalid codec for PCM encoder: %s", format.Codec)
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}
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if format.BitDepth != 16 && format.BitDepth != 24 {
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return nil, fmt.Errorf("unsupported bit depth: %d (supported: 16, 24)", format.BitDepth)
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}
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return &PCMEncoder{
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bitDepth: format.BitDepth,
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}, nil
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}
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func (e *PCMEncoder) Encode(samples []int32) ([]byte, error) {
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if e.bitDepth == 24 {
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output := make([]byte, len(samples)*3)
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for i, sample := range samples {
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bytes := audio.SampleTo24Bit(sample)
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output[i*3] = bytes[0]
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output[i*3+1] = bytes[1]
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output[i*3+2] = bytes[2]
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}
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return output, nil
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} else {
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output := make([]byte, len(samples)*2)
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for i, sample := range samples {
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sample16 := audio.SampleToInt16(sample)
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binary.LittleEndian.PutUint16(output[i*2:], uint16(sample16))
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}
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return output, nil
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}
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}
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func (e *PCMEncoder) Close() error {
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return nil
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}
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