From e45c67e15706066827504bda638046f1776d33d1 Mon Sep 17 00:00:00 2001
From: Trek H <trek.hopton@gmail.com>
Date: Thu, 28 Feb 2019 13:05:45 +1030
Subject: [PATCH] ADPCM: encoder now uses bytes.Buffer so that bytes and byte
 arrays can be written out

---
 stream/adpcm/adpcm.go | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/stream/adpcm/adpcm.go b/stream/adpcm/adpcm.go
index de123bf7..326f6758 100644
--- a/stream/adpcm/adpcm.go
+++ b/stream/adpcm/adpcm.go
@@ -33,26 +33,26 @@ LICENSE
 package adpcm
 
 import (
+	"bytes"
 	"encoding/binary"
 	"fmt"
-	"io"
 	"math"
 )
 
 // Encoder is used to encode to ADPCM from PCM data.
 // pred and index hold state that persists between calls to encodeSample and calcHead.
-// dest is the output, ie. where the encoded ADPCM data is written to.
+// dest is the output buffer that implements io.writer and io.bytewriter, ie. where the encoded ADPCM data is written to.
 type Encoder struct {
-	dest  io.ByteWriter
+	dest  *bytes.Buffer
 	pred  int16
 	index int16
 }
 
 // Decoder is used to decode from ADPCM to PCM data.
 // pred, index, and step hold state that persists between calls to decodeSample.
-// dest is the output, ie. where the decoded PCM data is written to.
+// dest is the output buffer that implements io.writer and io.bytewriter, ie. where the decoded PCM data is written to.
 type Decoder struct {
-	dest  io.ByteWriter
+	dest  *bytes.Buffer
 	pred  int16
 	index int16
 	step  int16
@@ -81,7 +81,7 @@ var stepTable = []int16{
 }
 
 // NewEncoder retuns a new ADPCM encoder.
-func NewEncoder(dst io.ByteWriter) *Encoder {
+func NewEncoder(dst *bytes.Buffer) *Encoder {
 	e := Encoder{
 		dest: dst,
 	}
@@ -89,7 +89,7 @@ func NewEncoder(dst io.ByteWriter) *Encoder {
 }
 
 // NewDecoder retuns a new ADPCM decoder.
-func NewDecoder(dst io.ByteWriter) *Decoder {
+func NewDecoder(dst *bytes.Buffer) *Decoder {
 	d := Decoder{
 		step: stepTable[0],
 		dest: dst,
@@ -213,8 +213,7 @@ func (e *Encoder) calcHead(sample []byte) error {
 	intSample := int16(binary.LittleEndian.Uint16(sample))
 	e.encodeSample(intSample)
 
-	e.dest.WriteByte(sample[0])
-	e.dest.WriteByte(sample[1])
+	e.dest.Write(sample)
 
 	e.dest.WriteByte(byte(uint16(e.index)))
 	e.dest.WriteByte(byte(0x00))