$re = '/\d+[\r\n](\d+:\d+:\d+,\d+ --> \d+:\d+:\d+,\d+)[\r\n]((.+\r?\n)+(?=(\r?\n)?))/';
$str = '1
00:02:17,440 --> 00:02:20,375
Senator, we\'re making
our final approach into Coruscant.
2
00:02:20,476 --> 00:02:22,501
Very good, Lieutenant.
3
00:03:20,476 --> 00:03:22,501
こんにちは
';
preg_match_all($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