FV Player Bridge for HTML video tags

fv-player-handle-video-tags.php

<?php

/*
Plugin Name: FV Player - Handle video tags
Description: Changes any <video> tag to FV Player
Author: Foliovision
Version: 0.2
Author URI: https://foliovision.com
*/

// Work in front-end only
add_action( 'wp_head', function() {
  ob_start();
  
  // Check the output in wp_footer to ensure it's not too late to output CSS and JS
  add_action( 'wp_footer', function() {
    $html = ob_get_clean();
    
    $replacements = 0;
    
    // Match all <video> tags
    preg_match_all( '/(?:<video[^>]*)(?:(?:\/>)|(?:>.*?<\/video>))/', $html, $videos, PREG_SET_ORDER );
		foreach ( (array) $videos as $video_html ) {
			if ( empty( $video_html ) ) {
				continue;
			}
      
      // parse the <video> tag and its <source> tags
      $dom = new \DOMDocument();
      $dom->loadHTML( $video_html[0] );
      $video_tag = $dom->getElementsByTagName( 'video' )->item( 0 );
      $sources = $video_tag->getElementsByTagName( 'source' );
      if( empty($sources) ) {
        continue;
      }
      
      // Create FV Player shortcode
      $shortcode_args = array();
      foreach( array(
        'poster' => 'splash',
        //'width' => 'width',
        //'height' => 'height',
      ) AS $old => $new ) {
        if( $value = $video_tag->getAttribute($old) ) {
          $shortcode_args[$new] = $value;
        }
      }
      
      $count = 0;
      foreach( $sources as $source ) {
        $shortcode_args['src'.( $count > 0 ? $count : '' )] = $source->getAttribute( 'src' );
        $count++;
      }
      
      // Did it find any video sources?
      if( $count > 0 ) {
        $shortcode = '[fvplayer';
        foreach( $shortcode_args AS $k => $v ) {
          $shortcode .= ' '.$k.'="'.esc_attr($v).'"';
        }
        $shortcode .= ']';
        
        // create the FV Player
        $fv_player = do_shortcode($shortcode);
        if( isset($_GET['fv_player_debug']) ) {
          $fv_player .= "\n<!--debug video ".var_export( str_replace( '<video', '', $video_html[0] ),true)."-->\n";
          $fv_player .="\n<!--debug shortcode ".$shortcode."-->\n";
        }
        
        $replacements++;
        
        // Put it into page HTML
			  $html = str_replace( $video_html[0], $fv_player, $html );
      }
		}

    $html .= "<!-- FV Player - Handle video tags did ".$replacements." replacements -->\n";
    echo $html;
  }, -1 /* Magic number - ensure FV Player Pro didn't try to init the scripts yet */ );
} );