diff --git a/extract-playlist.php b/extract-playlist.php
index ad2d05d..8d5f6e7 100644
--- a/extract-playlist.php
+++ b/extract-playlist.php
@@ -394,10 +394,203 @@ function extractFragmentedMP4( $filename ) {
     return $segments;
 }
 
-function consolidate( $target, $segments ) {
-    $out = [
-        'init' => $segments['init'],
+// http://www.mp3-tech.org/programmer/frame_header.html
+
+class MP3FrameHeader {
+    private $header;
+
+    public $valid = false;
+    public $size = 0;
+
+    public $sync;
+    public $mpeg;
+    public $layer;
+    public $protection;
+    public $bitrate;
+    public $sampleRate;
+    public $padding;
+
+    private static $bits = [
+        'sync'        => [ 21, 11 ],
+        'mpeg'        => [ 19,  2 ],
+        'layer'       => [ 17,  2 ],
+        'protection'  => [ 16,  1 ],
+        'bitrate'     => [ 12,  4 ],
+        'sampleRate'  => [ 10,  2 ],
+        'padding'     => [  9,  1 ],
+        'private'     => [  8,  1 ], // not needed below this
+        'channelMode' => [  6,  2 ],
+        'modeExt'     => [  4,  2 ],
+        'copyright'   => [  3,  1 ],
+        'original'    => [  2,  1 ],
+        'emphasis'    => [  0,  2 ],
     ];
+
+    private const SYNC_MASK = 0x7ff;
+
+    // 1s used for reserved slots to avoid exploding
+    // in case of invalid input
+    private static $sampleRates = [
+        // MPEG-2.5
+        [ 11025, 12000, 8000, 1 ],
+        // Reserved
+        [ 1, 1, 1, 1 ],
+        // MPEG-2
+        [ 22050, 24000, 16000, 1 ],
+        // MPEG-1
+        [ 44100, 48000, 32000, 1 ],
+    ];
+
+    private static $bitrates = [
+        [
+            // MPEG-2
+            // invalid
+            [ 0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, ],
+            // layer 3
+            [ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 ],
+            // layer 2
+            [ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 ],
+            // layer 1
+            [ 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 ],
+        ],
+        [
+            // MPEG-1
+            // invalid
+            [ 0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, ],
+            // layer 3
+            [ 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 192, 224, 256, 320, 0 ],
+            // layer 2
+            [ 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0 ],
+            // layer 1
+            [ 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 316, 448, 0 ],
+        ]
+    ];
+
+    private function field( $name ) {
+        [ $shift, $bits ] = self::$bits[$name];
+        $mask = ( 1 << $bits ) - 1;
+        return ( $this->header >> $shift ) & $mask;
+    }
+
+    public function __construct( $header ) {
+        $this->header = $header;
+
+        $this->sync = $this->field( 'sync' ) == self::SYNC_MASK;
+        if ( $this->sync ) {
+            $this->mpeg = $this->field( 'mpeg' );
+            $this->layer = $this->field( 'layer' );
+            $this->protection = $this->field( 'protection' );
+            $br = $this->field( 'bitrate' );
+            $this->bitrate = 1000 * self::$bitrates[$this->mpeg & 1][$this->layer][$br];
+            $sr = $this->field( 'sampleRate' );
+            $this->sampleRate = self::$sampleRates[$this->mpeg][$sr];
+            $this->padding = $this->field( 'padding' );
+
+            $this->valid = $this->sync;
+            if ( $this->bitrate == 0 ) {
+                var_dump( $this );
+                echo "br: $br\n";
+                //throw new Exception( "Invalid bitrate" );
+                $this->valid = false;
+            }
+            if ( $this->sampleRate == 1 ) {
+                var_dump( $this );
+                echo "sr: $sr\n";
+                //throw new Exception( "Invalid sample rate" );
+                $this->valid = false;
+            }
+            $this->size = intval( 144.0 * $this->bitrate / $this->sampleRate );
+            if ( $this->protection ) {
+                $this->size += 2;
+            }
+            if ( $this->padding ) {
+                $this->size++;
+            }
+        }
+    }
+}
+
+class MP3Reader {
+
+    private $file;
+
+    public function __construct( $file ) {
+        $this->file = $file;
+    }
+
+    public function pos() {
+        return ftell( $this->file );
+    }
+
+    public function readFrame() {
+        while ( true ) {
+            // Look for the sync pattern
+            $start = $this->pos();
+            $bytes = fread( $this->file, 4 );
+            if ( $bytes === false || strlen( $bytes ) < 4 ) {
+                // end of file
+                return false;
+            }
+
+            $data = unpack( "Nval", $bytes );
+            $header = new MP3FrameHeader( $data['val'] );
+            if ( $header->valid ) {
+                // Note we don't need the data at this time.
+                //fseek( $this->file, $start + $header->size, SEEK_SET );
+                var_dump ( $header );
+                fread( $this->file, $header->size - 4 );
+                return $header;
+            }
+
+            $x = hexdump( $bytes );
+            print "BACKUP $x\n";
+
+            if ( $header->sync && !$header->valid ) {
+                $x = hexdump( $bytes );
+                die('xxx ' . $x);
+            }
+
+            // back up 3 bytes and try again
+            fseek( $this->file, $start + 1, SEEK_SET );
+        }
+    }
+}
+
+function extractMP3( $filename ) {
+    $file = fopen( $filename, 'rb' );
+    if ( !$file ) {
+        throw new Exception( 'Error opening MP3 file' );
+    }
+    try {
+        $reader = new MP3Reader( $file );
+        $segments = [];
+        $timestamp = 0.0;
+        while ( true ) {
+            $start = $reader->pos();
+            $frame = $reader->readFrame();
+            if ( !$frame ) {
+                return $segments;
+            }
+            $duration = 144.0 / $frame->sampleRate;
+            $segments[] = [
+                'start' => $start,
+                'size' => $frame->size,
+                'timestamp' => $timestamp,
+                'duration' => $duration,
+            ];
+            $timestamp += $duration;
+        }
+    } finally {
+        fclose( $file );
+    }
+}
+
+function consolidate( $target, $segments ) {
+    $out = [];
+    if ( isset( $segments['init'] ) ) {
+        $out['init'] = $segments['init'];
+    }
+
     $n = count( $segments ) - 1;
     $start = $segments[0]['start'];
     $size = $segments[0]['size'];
@@ -492,8 +685,17 @@ function playlist( $filename, $segments ) {
 $argv = $_SERVER['argv'];
 $self = array_shift( $argv );
 $filename = array_shift( $argv );
-$segments = extractFragmentedMP4( $filename );
-$segments = consolidate( 10, $segments );
+$target = 10;
+
+$ext = substr( $filename, strrpos( $filename, '.' ) );
+if ( $ext === '.mp3' ) {
+    $segments = extractMP3( $filename );
+} elseif ( $ext === '.mp4' ) {
+    $segments = extractFragmentedMP4( $filename );
+} else {
+    die( "Unexpected file extension $ext\n" );
+}
+$segments = consolidate( $target, $segments );
 
 /*
 foreach ( $segments as $key => $segment ) {