mirror of
https://github.com/pion/mediadevices.git
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25a1bf5a16
This follows image package from the standard library. By having a homogenous data type for storing the samples, it makes easier to manipulate the raw data in a generic way.
90 lines
2.1 KiB
Go
90 lines
2.1 KiB
Go
package audio
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import (
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"errors"
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"github.com/pion/mediadevices/pkg/wave"
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)
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var errUnsupported = errors.New("unsupported audio format")
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// NewBuffer creates audio transform to buffer signal to have exact nSample samples.
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func NewBuffer(nSamples int) TransformFunc {
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var inBuff wave.Audio
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return func(r Reader) Reader {
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return ReaderFunc(func() (wave.Audio, error) {
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for {
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if inBuff != nil && inBuff.ChunkInfo().Len >= nSamples {
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break
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}
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buff, err := r.Read()
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if err != nil {
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return nil, err
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}
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switch b := buff.(type) {
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case *wave.Float32Interleaved:
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ib, ok := inBuff.(*wave.Float32Interleaved)
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if !ok || ib.Size.Channels != b.Size.Channels {
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ib = wave.NewFloat32Interleaved(
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wave.ChunkInfo{
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SamplingRate: b.Size.SamplingRate,
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Channels: b.Size.Channels,
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Len: nSamples,
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},
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)
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ib.Data = ib.Data[:0]
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ib.Size.Len = 0
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inBuff = ib
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}
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ib.Data = append(ib.Data, b.Data...)
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ib.Size.Len += b.Size.Len
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case *wave.Int16Interleaved:
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ib, ok := inBuff.(*wave.Int16Interleaved)
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if !ok || ib.Size.Channels != b.Size.Channels {
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ib = wave.NewInt16Interleaved(
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wave.ChunkInfo{
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SamplingRate: b.Size.SamplingRate,
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Channels: b.Size.Channels,
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Len: nSamples,
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},
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)
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ib.Data = ib.Data[:0]
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ib.Size.Len = 0
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inBuff = ib
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}
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ib.Data = append(ib.Data, b.Data...)
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ib.Size.Len += b.Size.Len
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default:
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return nil, errUnsupported
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}
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}
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switch ib := inBuff.(type) {
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case *wave.Int16Interleaved:
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ibCopy := *ib
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ibCopy.Size.Len = nSamples
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n := nSamples * ib.Size.Channels * 2
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ibCopy.Data = make([]uint8, n)
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copy(ibCopy.Data, ib.Data)
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ib.Data = ib.Data[n:]
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ib.Size.Len -= nSamples
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return &ibCopy, nil
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case *wave.Float32Interleaved:
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ibCopy := *ib
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ibCopy.Size.Len = nSamples
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n := nSamples * ib.Size.Channels * 4
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ibCopy.Data = make([]uint8, n)
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copy(ibCopy.Data, ib.Data)
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ib.Data = ib.Data[n:]
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ib.Size.Len -= nSamples
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return &ibCopy, nil
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}
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return nil, errUnsupported
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})
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}
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}
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