74 lines
1.6 KiB
Go
74 lines
1.6 KiB
Go
//go:build cgo
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package filter
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import (
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"git.gammaspectra.live/S.O.N.G/Kirika/audio"
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"github.com/dh1tw/gosamplerate"
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"log"
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)
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const (
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QualityBest ResampleQuality = gosamplerate.SRC_SINC_BEST_QUALITY
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QualityGood ResampleQuality = gosamplerate.SRC_SINC_MEDIUM_QUALITY
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QualityFast ResampleQuality = gosamplerate.SRC_SINC_FASTEST
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QualityFastest ResampleQuality = gosamplerate.SRC_LINEAR
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)
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func (f ResampleFilter) Process(source audio.Source) audio.Source {
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if source.SampleRate == f.sampleRate { //no change
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return source
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}
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outBlocks := make(chan []float32)
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go func() {
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defer close(outBlocks)
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blockSize := f.blockSize * source.Channels
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samplerateConverter, err := gosamplerate.New(int(f.quality), source.Channels, blockSize)
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if err != nil {
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log.Panic(err)
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}
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defer gosamplerate.Delete(samplerateConverter)
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ratio := float64(f.sampleRate) / float64(source.SampleRate)
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for block := range source.Blocks {
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for len(block) >= blockSize {
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b, err := samplerateConverter.Process(block[0:blockSize], ratio, false)
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if err != nil {
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log.Panic(err)
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}
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if len(b) > 0 {
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outBlocks <- b
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}
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block = block[blockSize:]
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}
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if len(block) > 0 {
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b, err := samplerateConverter.Process(block, ratio, false)
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if err != nil {
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log.Panic(err)
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}
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if len(b) > 0 {
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outBlocks <- b
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}
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}
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}
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b, err := samplerateConverter.Process([]float32{}, ratio, true)
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if err != nil {
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log.Panic(err)
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}
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if len(b) > 0 {
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outBlocks <- b
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}
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}()
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return audio.Source{
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Channels: source.Channels,
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SampleRate: f.sampleRate,
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Blocks: outBlocks,
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}
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}
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