Flowplayer HTML5 supports multilingual subtitles but the plugin does not yet have an UI for it.
Till I am able to release an UI you can always the filter and manually add the subtitles according to the video id.
function unlambda_fp5_js_config( $js_config, $id ) {
if ( '5' == $id ) {
$js_config['clip'] = array(
'subtitles' => array(
array(
'kind' => 'subtitles',
'srclang' => 'en',
'label' => 'English',
'src' => '/standalone/basics/subtitles-en.vtt'
),
array(
'kind' => 'subtitles',
'srclang' => 'de',
'label' => 'Deutsch',
'src' => '/standalone/basics/subtitles-de.vtt'
)
)
);
}
return $js_config;
}
add_filter( 'fp5_js_config', 'unlambda_fp5_js_config', 10, 2 );