From 408a952c9a7dd31b9898f05b0391e8181764f88d Mon Sep 17 00:00:00 2001
From: Trek H <trek.hopton@gmail.com>
Date: Wed, 13 Feb 2019 16:58:21 +1030
Subject: [PATCH] ADPCM: changed adpcm_test.go to use pre-allocation of byte
 slices

---
 stream/adpcm/adpcm_test.go | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/stream/adpcm/adpcm_test.go b/stream/adpcm/adpcm_test.go
index bbda1d31..a2c9c034 100644
--- a/stream/adpcm/adpcm_test.go
+++ b/stream/adpcm/adpcm_test.go
@@ -43,9 +43,11 @@ func TestEncodeBlock(t *testing.T) {
 	}
 
 	//encode adpcm
-	var comp []byte
-	bSize := 1010
-	for i, start := bSize-1, 0; i < len(pcm); i += bSize {
+	inBSize := 1010
+	numBlocks := int(len(pcm) / inBSize)
+	outBSize := int(float32(inBSize/4) + float32(3.5)) // compression is 4:1 and 3.5 bytes of info are added to each block
+	comp := make([]byte, 0, outBSize*numBlocks)
+	for i, start := inBSize-1, 0; i < len(pcm); i += inBSize {
 		block := pcm[start : i+1]
 
 		encBlock, err := EncodeBlock(block)
@@ -77,9 +79,11 @@ func TestDecodeBlock(t *testing.T) {
 	}
 
 	//decode adpcm
-	var decoded []byte
-	bSize := 256
-	for i, start := bSize-1, 0; i < len(comp); i += bSize {
+	inBSize := 256
+	numBlocks := int(len(comp) / inBSize)
+	outBSize := 2 + (inBSize-4)*4 // 2 bytes are copied, 2 are used as block header info, the remaining bytes are decompressed 1:4
+	decoded := make([]byte, 0, outBSize*numBlocks)
+	for i, start := inBSize-1, 0; i < len(comp); i += inBSize {
 		block := comp[start : i+1]
 		decBlock, err := DecodeBlock(block)
 		if err != nil {