Changed let by expr
Changed let by expr

Fixes #1

--- a/HLS-Stream-Creator.sh
+++ b/HLS-Stream-Creator.sh
@@ -170,7 +170,7 @@
 DUR_X=$(echo "$DURATION" | cut -d ':' -f 3 | cut -d '.' -f 1)
 
 # Calculate the duration in seconds
-let "DURATION_S = ( DUR_H * 60 + DUR_M ) * 60 + DUR_X"
+DURATION_S=$(expr \( $DUR_H \* 60 + $DUR_M \) \* 60 + $DUR_X)
 
 
 # Check we've not got empty media

file:a/README.md -> file:b/README.md
--- a/README.md
+++ b/README.md
@@ -32,19 +32,20 @@
 
 As of version 1, the HLS resources will be output to the directory *output*. These will consist of video segments encoded in H.264 with MP3 audio (should be AAC really, but I'd compiled *ffmpeg* without) and an m3u8 file in the format
 
->#EXTM3U
->#EXT-X-MEDIA-SEQUENCE:0
->#EXT-X-VERSION:3
->#EXT-X-TARGETDURATION:10
->#EXTINF:10, no desc
->example_001.ts
->#EXTINF:10, no desc
->example_002.ts
->#EXTINF:10, no desc
->example_003.ts
->#EXTINF:5, no desc
->example_004.ts
->#EXT-X-ENDLIST
+>\#EXTM3U  
+>\#EXT-X-MEDIA-SEQUENCE:0  
+>\#EXT-X-VERSION:3  
+>\#EXT-X-TARGETDURATION:10  
+>\#EXTINF:10, no desc  
+>example_001.ts  
+>\#EXTINF:10, no desc  
+>example_002.ts  
+>\#EXTINF:10, no desc  
+>example_003.ts  
+>\#EXTINF:5, no desc  
+>example_004.ts  
+>\#EXT-X-ENDLIST
+