$re = '/^(?!.*10[Bb]it)(.*[x|h]\.?(265|HEVC).*)$/m';
$str = 'Thor The Dark World 2013 Bluray 2160p x265 10Bit HDR TrueHD Atmos 7.1 mUHD -iCandy
something.without.8bit.whoknows
Something.just.with.h265.hvec in.it
Thor.The.Dark.World.2013.PROPER.1080p.UHD.BluRay.DD+7.1.x264-LoRD
Thor.The.Dark.World.2013.2160p.UHD.HDR10.BluRay.Multi.TrueHD.7.1.x265-4K4U
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php