From b1d8c3888c2087d04b0cd78b5872c151fd124389 Mon Sep 17 00:00:00 2001
From: Trek H <trek.hopton@gmail.com>
Date: Wed, 23 Jan 2019 16:33:28 +1030
Subject: [PATCH] adpcm test working with wav files

---
 cmd/adpcm/main.go | 80 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 cmd/adpcm/main.go

diff --git a/cmd/adpcm/main.go b/cmd/adpcm/main.go
new file mode 100644
index 00000000..1c4b05bf
--- /dev/null
+++ b/cmd/adpcm/main.go
@@ -0,0 +1,80 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/bovarysme/adpcm"
+	"github.com/go-audio/audio"
+	"github.com/go-audio/wav"
+	"github.com/pkg/errors"
+)
+
+// This program is for compare data size of pcm and adpcm, it takes a wav file and compresses and encodes it to adpcm,
+// the adpcm byte array is stored as a file and then the adpcm is decoded and the result saved as final.wav
+
+func main() {
+	//open wav
+	wavPath := "out.wav"
+	f, err := os.Open(wavPath)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	//decode wav
+	dec := wav.NewDecoder(f)
+	if !dec.IsValidFile() {
+		panic(errors.Errorf("invalid WAV file %q", wavPath))
+	}
+	sampleRate, nchannels, bps := int(dec.SampleRate), int(dec.NumChans), int(dec.BitDepth)
+	buf, err := dec.FullPCMBuffer()
+	if err != nil {
+		panic(err)
+	}
+	//encode adpcm
+	var comp []byte
+	adpcm.Encode(buf.Data, &comp)
+	// save to file
+	pcmPath := "out.adpcm"
+	err = ioutil.WriteFile(pcmPath, comp, 0644)
+	if err != nil {
+		panic(err)
+	}
+	//decode adpcm
+	var decoded []int
+	deco := adpcm.NewDecoder(nchannels)
+	deco.Decode(comp, &decoded)
+
+	//encode wav and save to file
+	finalWavPath := "final.wav"
+	of, err := os.Create(finalWavPath)
+	if err != nil {
+		panic(err)
+	}
+	defer of.Close()
+
+	sampleBytes := bps / 8
+
+	// normal uncompressed WAV format
+	wavformat := 1
+
+	enc := wav.NewEncoder(of, sampleRate, bps, nchannels, wavformat)
+
+	format := &audio.Format{
+		NumChannels: nchannels,
+		SampleRate:  sampleRate,
+	}
+
+	intBuf := &audio.IntBuffer{Data: decoded, Format: format, SourceBitDepth: sampleBytes * 8}
+
+	if err := enc.Write(intBuf); err != nil {
+		panic(err)
+	}
+
+	if err := enc.Close(); err != nil {
+		panic(err)
+	}
+	fmt.Printf("Saved audio to %s\n", finalWavPath)
+
+}