popcorn.parserSRT.js

// PARSER: 0.3 SRT

(function (Popcorn) {
  /**
   * SRT popcorn parser plug-in 
   * Parses subtitle files in the SRT format.
   * Times are expected in HH:MM:SS,MIL format, though HH:MM:SS.MIL also supported
   * Ignore styling, which may occur after the end time or in-text
   * While not part of the "official" spec, majority of players support HTML and SSA styling tags
   * SSA-style tags are stripped, HTML style tags are left for the browser to handle:
   *    HTML: <font>, <b>, <i>, <u>, <s>
   *    SSA:  \N or \n, {\cmdArg1}, {\cmd(arg1, arg2, ...)}
   
   * Data parameter is given by Popcorn, will need a text.
   * Text is the file contents to be parsed
   * 
   * @param {Object} data
   * 
   * Example:
    1
    00:00:25,712 --> 00:00:30.399
    This text is <font color="red">RED</font> and has not been {\pos(142,120)} positioned.
    This takes \Nup three \nentire lines.
    This contains nested <b>bold, <i>italic, <u>underline</u> and <s>strike-through</s></u></i></b> HTML tags
    Unclosed but <b>supported tags are left in
    <ggg>Unsupported</ggg> HTML tags are left in, even if <hhh>not closed.
    SSA tags with {\i1} would open and close italicize {\i0}, but are stripped
    Multiple {\pos(142,120)\b1}SSA tags are stripped
   */
  Popcorn.parser( "parseSRT", function( data ) {

    // declare needed variables
    var retObj = {
          title: "",
          remote: "",
          data: []
        },
        subs = [],
        i = 0,
        len = 0,
        idx = 0,
        lines,
        time,
        text,
        sub;
    
    // Simple function to convert HH:MM:SS,MMM or HH:MM:SS.MMM to SS.MMM
    // Assume valid, returns 0 on error
    var toSeconds = function( t_in ) {
      var t = t_in.split( ':' );
      
      try {
        var s = t[2].split( ',' );
        
        // Just in case a . is decimal seperator
        if ( s.length === 1 ) {
          s = t[2].split( '.' );
        }
        
        return parseFloat( t[0], 10 )*3600 + parseFloat( t[1], 10 )*60 + parseFloat( s[0], 10 ) + parseFloat( s[1], 10 )/1000;
      } catch ( e ) {
        return 0;
      }
    };
    
    var createTrack = function( name, attributes ) {
      var track = {};
      track[name] = attributes;
      return track;
    };
  
    // Here is where the magic happens
    // Split on line breaks
    lines = data.text.split( /(?:\r\n|\r|\n)/gm );
    len = lines.length;
    
    for( i=0; i < len; i++ ) {
      sub = {};
      text = [];
      
      sub.id = parseInt( lines[i++], 10 );
      
      // Split on '-->' delimiter, trimming spaces as well
      time = lines[i++].split( /[\t ]*-->[\t ]*/ );
      
      sub.start = toSeconds( time[0] );
      
      // So as to trim positioning information from end
      idx = time[1].indexOf( " " );
      if ( idx !== -1) {
        time[1] = time[1].substr( 0, idx );
      }
      sub.end = toSeconds( time[1] );
      
      // Build single line of text from multi-line subtitle in file
      while ( i < len && lines[i] ) {
        text.push( lines[i++] );
      }
      
      // Join into 1 line, SSA-style linebreaks
      // Strip out other SSA-style tags
      sub.text = text.join( "\\N" ).replace( /\{(\\[\w]+\(?([\w\d]+,?)+\)?)+\}/gi, "" );
      
      // Escape HTML entities
      sub.text = sub.text.replace( /</g, "&lt;" ).replace( />/g, "&gt;" );
      
      // Unescape great than and less than when it makes a valid html tag of a supported style (font, b, u, s, i)
      // Modified version of regex from Phil Haack's blog: http://haacked.com/archive/2004/10/25/usingregularexpressionstomatchhtml.aspx
      // Later modified by kev: http://kevin.deldycke.com/2007/03/ultimate-regular-expression-for-html-tag-parsing-with-php/
      sub.text = sub.text.replace( /&lt;(\/?(font|b|u|i|s))((\s+(\w|\w[\w\-]*\w)(\s*=\s*(?:\".*?\"|'.*?'|[^'\">\s]+))?)+\s*|\s*)(\/?)&gt;/gi, "<$1$3$7>" );
      sub.text = sub.text.replace( /\\N/gi, "<br />" );
      subs.push( createTrack( "subtitle", sub ) );
    }
    
    retObj.data = subs;
    return retObj;
  });

})( Popcorn );