mirror of https://bitbucket.org/ausocean/av.git
91 lines
2.4 KiB
Go
91 lines
2.4 KiB
Go
/*
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NAME
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resample.go
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DESCRIPTION
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resample.go is a program for resampling a pcm file.
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AUTHOR
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Trek Hopton <trek@ausocean.org>
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LICENSE
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resample.go is Copyright (C) 2018 the Australian Ocean Lab (AusOcean)
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It is free software: you can redistribute it and/or modify them
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under the terms of the GNU General Public License as published by the
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Free Software Foundation, either version 3 of the License, or (at your
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option) any later version.
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It is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License in gpl.txt.
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If not, see [GNU licenses](http://www.gnu.org/licenses).
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*/
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package main
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import (
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"flag"
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"fmt"
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"io/ioutil"
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"log"
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"bitbucket.org/ausocean/av/audio/pcm"
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"github.com/yobert/alsa"
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)
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// This program accepts an input pcm file and outputs a resampled pcm file.
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// Input and output file names, to and from sample rates, channels and sample format can be specified as arguments.
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func main() {
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var inPath = *flag.String("in", "data.pcm", "file path of input data")
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var outPath = *flag.String("out", "resampled.pcm", "file path of output")
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var from = *flag.Int("from", 48000, "sample rate of input file")
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var to = *flag.Int("to", 8000, "sample rate of output file")
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var channels = *flag.Int("ch", 1, "number of channels in input file")
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var sf = *flag.String("sf", "S16_LE", "sample format of input audio, eg. S16_LE")
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flag.Parse()
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// Read pcm.
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inPcm, err := ioutil.ReadFile(inPath)
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if err != nil {
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log.Fatal(err)
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}
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fmt.Println("Read", len(inPcm), "bytes from file", inPath)
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var sampleFormat alsa.FormatType
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switch sf {
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case "S32_LE":
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sampleFormat = alsa.S32_LE
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case "S16_LE":
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sampleFormat = alsa.S16_LE
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default:
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log.Fatalf("Unhandled ALSA format: %v", sf)
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}
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format := alsa.BufferFormat{
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Channels: channels,
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Rate: from,
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SampleFormat: sampleFormat,
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}
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buf := alsa.Buffer{
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Format: format,
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Data: inPcm,
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}
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// Resample audio.
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resampled, err := pcm.Resample(buf, to)
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if err != nil {
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log.Fatal(err)
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}
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// Save resampled to file.
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err = ioutil.WriteFile(outPath, resampled, 0644)
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if err != nil {
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log.Fatal(err)
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}
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fmt.Println("Encoded and wrote", len(resampled), "bytes to file", outPath)
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}
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