mirror of https://bitbucket.org/ausocean/av.git
64 lines
1.4 KiB
Go
64 lines
1.4 KiB
Go
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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 string
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var outPath string
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var sf string
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flag.StringVar(&inPath, "in", "data.pcm", "file path of input data")
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flag.StringVar(&outPath, "out", "mono.pcm", "file path of output")
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flag.StringVar(&sf, "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: 2,
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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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// Convert audio.
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mono, err := pcm.StereoToMono(buf)
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if err != nil {
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log.Fatal(err)
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}
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// Save mono to file.
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err = ioutil.WriteFile(outPath, mono, 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(mono), "bytes to file", outPath)
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}
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