URL Rewriting in WordPress

functions.php

<?php

/* Custom Rewrite rules for video embedding */
function flush_player_rules(){
  global $wp_rewrite;
	$wp_rewrite->flush_rules();
}
add_filter("wp_loaded","flush_player_rules");

function add_player_rewrite($rules){
	$newrule = array();
	$newrule['(video-embed)/(\d*)$']  = 'index.php?pagename=$matches[1]&vid_id=$matches[2]';
	return $newrule + $rules;
}
add_filter("rewrite_rules_array","add_player_rewrite");

function add_player_vars($vars){
	array_push($vars,"vid_id");
	return $vars;
}
add_filter("query_vars","add_player_vars");

template.php

<?php 

// Getting the value, you should be able to use $wp_query->query_vars property 
// http://codex.wordpress.org/Class_Reference/WP_Query
if( isset($wp_query->query_vars['vid_id']) ) {
      $id = $wp_query->query_vars['vid_id'];
  // ...do things with the $id
}

// OR http://codex.wordpress.org/Function_Reference/get_query_var

$id = get_query_var( "vid_id" );
if( $id ) {
  // ...do things with the $id
}