/*
NAME
  encode-pcm.go

DESCRIPTION
  encode-pcm.go is a program for encoding/compressing a pcm file to an adpcm file.

AUTHOR
  Trek Hopton <trek@ausocean.org>

LICENSE
  encode-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/audio/adpcm"
)

// This program accepts an input pcm file and outputs an encoded adpcm file.
// Input and output file names can be specified as arguments.
func main() {
	var inPath string
	var adpcmPath string
	flag.StringVar(&inPath, "in", "data.pcm", "file path of input data")
	flag.StringVar(&adpcmPath, "out", "encoded.adpcm", "file path of output")
	flag.Parse()

	// Read pcm.
	pcm, err := ioutil.ReadFile(inPath)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println("Read", len(pcm), "bytes from file", inPath)

	// Encode adpcm.
	numBlocks := len(pcm) / adpcm.PcmBS
	comp := bytes.NewBuffer(make([]byte, 0, adpcm.AdpcmBS*numBlocks))
	enc := adpcm.NewEncoder(comp)
	_, err = enc.Write(pcm)
	if err != nil {
		log.Fatal(err)
	}

	// Save adpcm to file.
	err = ioutil.WriteFile(adpcmPath, comp.Bytes(), 0644)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println("Encoded and wrote", len(comp.Bytes()), "bytes to file", adpcmPath)
}