diff --git a/extract-playlist.php b/extract-playlist.php
index 982a64e..241190a 100644
--- a/extract-playlist.php
+++ b/extract-playlist.php
@@ -115,26 +115,26 @@ class MP4Box {
     public $size;
     public $type;
 
-    function __construct( MP4Reader $reader, $start, $size, $type ) {
+    public function __construct( MP4Reader $reader, $start, $size, $type ) {
         $this->reader = $reader;
         $this->start = $start;
         $this->size = $size;
         $this->type = $type;
     }
 
-    private function pos() {
+    public function pos() {
         return $this->reader->pos();
     }
 
-    private function end() {
+    public function end() {
         return $this->start + $this->size;
     }
     
-    private function remaining() {
+    public function remaining() {
         return $this->end() - $this->pos();
     }
 
-    private function guard( $length ) {
+    public function guard( $length ) {
         $remaining = $this->remaining();
         if ( $remaining < $length ) {
             throw new Exception( "Reading beyond end of box; had $remaining bytes, wanted $length" );
@@ -199,16 +199,11 @@ function extractFragmentedMP4( $filename ) {
 
     $mp4 = new MP4Reader( $filename );
     $eof = false;
+    $moof = false;
     $init = false;
 
     while ( !$eof ) {
-        $eof = !$mp4->readBox( function ( $box ) use  ( &$segments, &$init ) {
-            $bytes = $box->readBytes( $box->size - 8 );
-            $bytes = substr( $bytes, 0, 16 );
-            $hex = hexdump( $bytes );
-            $safe = safestr( $bytes );
-            print "box: {$box->type} at {$box->start}, {$box->size} bytes {$hex} {$safe}\n";
-
+        $eof = !$mp4->readBox( function ( $box ) use  ( &$segments, &$moof, &$init ) {
             /*
             Need to:
             - find the end of the moov; everything up to that is the initialization segment
@@ -229,25 +224,34 @@ function extractFragmentedMP4( $filename ) {
 
 
             opus has timescale 48000 in moov.trak.mdia.mdhd
-
-            WARNING: opus is not dividing up fragments
-
             */
 
-            if ( $box->type === 'moof' ) {
-                if ( !$init ) {
-                    $init = [
-                        'start' => 0,
-                        'size' => $box->start + $box->size,
-                    ];
-                    $segments['init'] = $init;
-                }
-                array_push( $segments, [
-                    'start' => $box->start,
-                    'size' => $box->size,
-                    'timestamp' => 0.0,
-                    'duration' => 0.0,
-                ] );
+            switch ( $box->type ) {
+                case 'ftyp':
+                    break;
+                case 'moof':
+                    if ( !$init ) {
+                        $init = [
+                            'start' => 0,
+                            'size' => $box->end(),
+                            'timestamp' => 0.0,
+                            'duration' => 0.0,
+                        ];
+                        $segments['init'] = $init;
+                    }
+                    $moof = $box->start;
+                    break;
+                case 'mdat':
+                    // @todo use timestamp and duration data
+                    array_push( $segments, [
+                        'start' => $moof,
+                        'size' => $box->end() - $moof,
+                        'timestamp' => 0.0,
+                        'duration' => 0.0,
+                    ] );
+                    break;
+                default:
+                    // ignore
             }
 
             return true;
@@ -261,4 +265,12 @@ $argv = $_SERVER['argv'];
 $self = array_shift( $argv );
 $filename = array_shift( $argv );
 $segments = extractFragmentedMP4( $filename );
-var_dump( $segments );
+//var_dump( $segments );
+
+foreach ( $segments as $key => $segment ) {
+    if ( $key === 'init' ) {
+        print "$key {$segment['start']},{$segment['size']}\n";
+    } else {
+        print "$key {$segment['timestamp']},{$segment['duration']} @ {$segment['start']},{$segment['size']}\n";
+    }
+}