Stream MP3 through a php file with audiojs

Question

I have the following code to get the contents of MP3 file and set the headers as required(?):

$file = fopen("test.mp3","r");
$content = fread($file,filesize("test.mp3"));

header("Content-Type: audio/");
header("Content-Length: " .(string)(filesize("test.mp3")) );

fclose($file);

echo $content;

For playing the file I use audiojs (http://kolber.github.io/audiojs/). My PHP file acts as the data source as a normal MP3 file would do.

audiojs is able to play this MP3 file, BUT You can visually see the player buffering, but you cannot jump to an already buffered position in the MP3 file. For real MP3 files this is possible.

Why not with PHP files which act as MP3 file? Is PHP or audiojs the reason?

I also tried the following code:

// Try and open the remote stream
  if (!$file = fopen("test.mp3","r")) {
    // If opening failed, inform the client we have no content
    header('HTTP/1.1 500 Internal Server Error');
    exit('Unable to open remote stream');
  }

  $stream = stream_get_contents($file);

  // It's probably an idea to remove the execution time limit - on Windows hosts
  // this could result in the audio stream cutting off mid-flow
  set_time_limit(0);

  // Inform the client we will be sending it some MPEG audio
  header("Content-type: audio");
  header("Content-Length: ".(string)(filesize("test.mp3")) );
  header("Content-transfer-encoding: binary");

  // Send the data
  fpassthru($stream);

Both not working :( Any chance? I really need this feature for permission topics. Or are there any other alternatives except .htaccess?

captan2