av/exp/adpcm/decode-pcm/decode-pcm.go

77 lines
2.1 KiB
Go

/*
NAME
decode-pcm.go
DESCRIPTION
decode-pcm.go is a program for decoding/decompressing an adpcm file to a pcm file.
AUTHOR
Trek Hopton <trek@ausocean.org>
LICENSE
decode-pcm.go is Copyright (C) 2018 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
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.
It 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 in gpl.txt.
If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
package main
import (
"bytes"
"flag"
"fmt"
"io/ioutil"
"log"
"bitbucket.org/ausocean/av/stream/adpcm"
)
// This program accepts an input file encoded in adpcm and outputs a decoded pcm file.
// Input and output file names can be specified as arguments.
func main() {
var inPath string
var outPath string
flag.StringVar(&inPath, "in", "encoded.adpcm", "file path of input")
flag.StringVar(&outPath, "out", "decoded.pcm", "file path of output data")
flag.Parse()
// Read adpcm.
comp, err := ioutil.ReadFile(inPath)
if err != nil {
log.Fatal(err)
}
fmt.Println("Read", len(comp), "bytes from file", inPath)
// Decode adpcm.
inBSize := 256
numBlocks := len(comp) / inBSize
outBSize := 2 + (inBSize-4)*4 // 2 bytes are copied, 2 are used as block header info, the remaining bytes are decompressed 1:4
decoded := bytes.NewBuffer(make([]byte, 0, outBSize*numBlocks))
dec := adpcm.NewDecoder(decoded)
for i := 0; i < numBlocks; i++ {
block := comp[inBSize*i : inBSize*(i+1)]
err := dec.DecodeBlock(block)
if err != nil {
log.Fatal(err)
}
}
// Save pcm to file.
err = ioutil.WriteFile(outPath, decoded.Bytes(), 0644)
if err != nil {
log.Fatal(err)
}
fmt.Println("Decoded and wrote", len(decoded.Bytes()), "bytes to file", outPath)
}