Hi solosails,
You can mute videos with this filter like this:
function fp_mute_video_by_default( $config, $video_id ) {
if( $video_id == 5 ) {
$config['muted'] = true;
}
return $config;
}
add_filter( 'fp5_js_config', 'fp_mute_video_by_default', 10, 2 );
This will mute video with id 5, but if you want to mute all videos, you can just drop the if-condition.