Add progress bar for transcoding status

To make it so PHP doesn't exhaust its memory on large files, here's a better while loop:

<?php

        stream_set_blocking($pipes[2], 0);
        while (! feof($pipes[2])) {
          $current = fgets($pipes[2]);
  
          if (empty($current) || $current == $last) {
            continue;
          }
  
          $stderr .= $current;
  
          $duration = ($duration) ? $duration : $this->parse_duration($stderr);
  
          preg_match_all("/time=(.*?) bitrate/", $stderr, $matches); 
          
          $current_time = floatval($matches[1][count($matches[1])-1]);
          
          $progress = round($current_time / $duration * 100);
   
          if ($progress > 0 && $progress <= 100) {
            cache_set('ffmpeg_wrapper_transcoding_progress_' . $this->file->fid, $progress);
          }
          
          $last = $current;
        }
?>

Glad you like it. :) The only thing I can see that could be changed would be to remove:

<?php
  $progress['message'] = 'HERE :' . $cache->data;
?>

Which sometimes flashes across the screen briefly before transcoding a file for the first time.