package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"log"

	"bitbucket.org/ausocean/av/audio/pcm"
)

// This program accepts an input pcm file and outputs a resampled pcm file.
// Input and output file names, to and from sample rates, channels and bit-depth can be specified as arguments.
func main() {
	var inPath string
	var outPath string
	var from int
	var to int
	var channels int
	var bitDepth int
	flag.StringVar(&inPath, "in", "data.pcm", "file path of input data")
	flag.StringVar(&outPath, "out", "resampled.pcm", "file path of output")
	flag.IntVar(&from, "from", 48000, "sample rate of input file")
	flag.IntVar(&to, "to", 8000, "sample rate of output file")
	flag.IntVar(&channels, "ch", 1, "number of channels in input file")
	flag.IntVar(&bitDepth, "bd", 16, "bit depth of input file")
	flag.Parse()

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

	// Resample pcm.
	resampled, err := pcm.Resample(inPcm, from, to, channels, bitDepth)
	if err != nil {
		log.Fatal(err)
	}

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