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Diffstat (limited to 'autoart/autoaudio.go')
| -rw-r--r-- | autoart/autoaudio.go | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/autoart/autoaudio.go b/autoart/autoaudio.go new file mode 100644 index 0000000..05a91d4 --- /dev/null +++ b/autoart/autoaudio.go @@ -0,0 +1,56 @@ +/* +Copyright (C) 2019 Leo Tenenbaum + +This file is part of AutoArt. + +AutoArt is free software: you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 3 of the License, or +(at your option) any later version. + +AutoArt is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with AutoArt. If not, see <https://www.gnu.org/licenses/>. +*/ + +package autoart + +import ( + "github.com/pommicket/autoart/autoutils" + "io" +) + +func GenerateAudio(output io.Writer, duration float64, sampleRate int32, + functionLength int, rectifier int) error { + samples := int64(duration * float64(sampleRate)) + err := autoutils.WriteAudioHeader(output, samples, 1, sampleRate) + if err != nil { return err } + + vars := make([]float64, 1) + const sampleBufferSize = 4096 + sampleBuffer := make([]uint8, sampleBufferSize) + sampleBufferIndex := 0 + + var function autoutils.Function + function.Generate(1, functionLength) + + for s := int64(0); s < samples; s++ { + t := float64(s) / float64(sampleRate) + vars[0] = t + value := rectify(function.Evaluate(vars), rectifier) + sampleBuffer[sampleBufferIndex] = uint8(255 * value) + sampleBufferIndex++ + if sampleBufferIndex == sampleBufferSize { + err = autoutils.WriteAudioSamples(output, sampleBuffer) + if err != nil { + return err + } + sampleBufferIndex = 0 + } + } + return autoutils.WriteAudioSamples(output, sampleBuffer[:sampleBufferIndex]) +}
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