From 6beefc536b62d89b2a56962e0a7e12d3b743354c Mon Sep 17 00:00:00 2001
From: Trek <trek@ausocean.org>
Date: Fri, 1 Feb 2019 01:07:24 +1030
Subject: [PATCH] adpcm: saving raw pcm before conversion

---
 cmd/adpcm/main.go | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/cmd/adpcm/main.go b/cmd/adpcm/main.go
index 1c4b05bf..e3b852b0 100644
--- a/cmd/adpcm/main.go
+++ b/cmd/adpcm/main.go
@@ -1,6 +1,8 @@
 package main
 
 import (
+	"encoding/binary"
+	"flag"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -16,7 +18,9 @@ import (
 
 func main() {
 	//open wav
-	wavPath := "out.wav"
+	var wavPath string
+	flag.StringVar(&wavPath, "path", "before_compression.wav", "file path of input data")
+	flag.Parse()
 	f, err := os.Open(wavPath)
 	if err != nil {
 		panic(err)
@@ -32,12 +36,34 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
+	fmt.Println("Decoded wav. First 8 samples: ")
+	for i := 0; i < len(buf.Data) && i < 8; i++ {
+		fmt.Print(buf.Data[i], ", ")
+	}
+	fmt.Println()
+	// save pcm to file
+	var pcmBytes []byte
+	for _, sample := range buf.Data {
+		bs := make([]byte, 2)
+		binary.LittleEndian.PutUint16(bs, uint16(sample))
+		pcmBytes = append(pcmBytes, bs[0], bs[1])
+	}
+	pcmPath := "out.pcm"
+	err = ioutil.WriteFile(pcmPath, pcmBytes, 0644)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println("Saved raw PCM to " + pcmPath + ". First 8 bytes: ")
+	for i := 0; i < len(pcmBytes) && i < 8; i++ {
+		fmt.Print(pcmBytes[i], ", ")
+	}
+	fmt.Println()
 	//encode adpcm
 	var comp []byte
 	adpcm.Encode(buf.Data, &comp)
-	// save to file
-	pcmPath := "out.adpcm"
-	err = ioutil.WriteFile(pcmPath, comp, 0644)
+	// save adpcm to file
+	adpcmPath := "out.adpcm"
+	err = ioutil.WriteFile(adpcmPath, comp, 0644)
 	if err != nil {
 		panic(err)
 	}