- array_map: documentation ( source)
- print_r: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$re = '/^(?:\d+\n)?.*\h+-->\h+[0-5]{2}:.*$/m';
$str = '1
00:00:04,019 --> 00:00:07,299
line1
line2
2
00:00:07,414 --> 00:00:09,155
line1
00:00:09,276 --> 00:00:11,429
line1
00:00:11,549 --> 00:00:14,874
line1
line2
';
preg_match_all($re, $str, $matches);
$matches = array_map("trim" , $matches[0]);
print_r($matches);