/*
NAME
  decode-pcm.go

DESCRIPTION
  See Readme.md

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
  along with revid in gpl.txt.  If not, see [GNU licenses](http://www.gnu.org/licenses).
*/

package main

import (
	"flag"
	"io/ioutil"

	"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 {
		panic(err)
	}

	//decode adpcm
	var decoded []byte
	start := 0
	for i := 0; i < len(comp); i++ {
		if i%256 == 255 {
			block := comp[start : i+1]
			decBlock, err := adpcm.DecodeBlock(block)
			if err != nil {
				panic(err)
			}
			decoded = append(decoded, decBlock...)
			start = i + 1
		}
	}

	// save pcm to file
	err = ioutil.WriteFile(outPath, decoded, 0644)
	if err != nil {
		panic(err)
	}
}