mirror of https://bitbucket.org/ausocean/av.git
76 lines
2.0 KiB
Go
76 lines
2.0 KiB
Go
/*
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NAME
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encode-pcm.go
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DESCRIPTION
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encode-pcm.go is a program for encoding/compressing a pcm file to an adpcm file.
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AUTHOR
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Trek Hopton <trek@ausocean.org>
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LICENSE
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encode-pcm.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
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along with revid in gpl.txt. 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/stream/adpcm"
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)
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// This program accepts an input pcm file and outputs an encoded adpcm file.
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// Input and output file names can be specified as arguments.
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func main() {
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var inPath string
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var adpcmPath string
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flag.StringVar(&inPath, "in", "data.pcm", "file path of input data")
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flag.StringVar(&adpcmPath, "out", "encoded.adpcm", "file path of output")
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flag.Parse()
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//read pcm
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pcm, 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(pcm), "bytes from file", inPath)
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//encode adpcm
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inBSize := 1010
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numBlocks := int(len(pcm) / inBSize)
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outBSize := int(float32(inBSize/4) + float32(3.5)) // compression is 4:1 and 3.5 bytes of info are added to each block
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comp := make([]byte, 0, outBSize*numBlocks)
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for i := 0; i < numBlocks; i++ {
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block := pcm[inBSize*i : inBSize*(i+1)]
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encBlock, err := adpcm.EncodeBlock(block)
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if err != nil {
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log.Fatal(err)
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}
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comp = append(comp, encBlock...)
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}
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// save adpcm to file
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err = ioutil.WriteFile(adpcmPath, comp, 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(comp), "bytes to file", adpcmPath)
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}
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