code to adjust SRT subtitle timing in emacs

srt-adjust.el

(defun incr-time (adjust-millis hour minute second milli)
  (message (format "test %d" adjust-millis))
  (let ((total-millis (+ milli (* second 1000) (* minute 60 1000) (* hour 60 60 1000))))
    (setq total-millis (+ total-millis adjust-millis))
    (format "%02d:%02d:%02d,%03d"
	    (/ total-millis 3600000)
	    (% (/ total-millis 60000) 60)
	    (% (/ total-millis 1000) 60)
	    (% total-millis 1000))))

(defun c5-replace (regexp to-string &optional delimited start end)
  (replace-regexp regexp 
		  (query-replace-compile-replacement to-string t)
		  delimited start end))

(defun fixup (millis)
  (interactive "nAdjust milliseconds: ")
  (c5-replace "\\([0-9]\\{2\\}\\):\\([0-9]\\{2\\}\\):\\([0-9]\\{2\\}\\),\\([0-9]\\{3\\}\\)"
	      (format "\\,(incr-time %d \\#1 \\#2 \\#3 \\#4)" millis)))