<div class="feed-task-info-block"> <div class="feed-task-info-label">Задача<div class="feed-task-info-label-icon"></div></div> <div class="feed-task-info-text"> <div class="feed-task-info-text-item"> <span class="feed-task-info-text-title">Сергей изменил статус задачи <a href="/company/personal/user/512/tasks/task/view/274664/" onclick="if (taskIFramePopup.isLeftClick(event)) {taskIFramePopup.view(274664); return false;}">test</a></span> </div><div class="feed-task-info-text-item"> <span class="feed-task-info-text-title">Задача закрыта</span> </div> <div class="feed-task-info-text-item"> <span class="feed-task-info-text-title">Ответственный:</span><span class="feed-task-info-text-cont"><a id="tasks-user-tooltip-5c17bd6526296" href="/company/personal/user/1433/">Сергей</a></span> </div> </div> <script> BX.tooltip(1433, 'tasks-user-tooltip-5c17bd6526296', ''); </script> </div>

preg_match('/href="watch?v=([^"]+)"/', $text, $out);
print_r($out);

Array
(
)