Emacs News Highlights

    (defun my/emms-insert-timestamp ()
      (interactive)
      (when (looking-at "[0-9]:[0-9][0-9]:[0-9][0-9] ")
        (replace-match ""))
      (insert
       (format "%d:%02d:%02d "
               (/ emms-playing-time 3600)
               (% (/ emms-playing-time 60) 60)
               (% emms-playing-time 60)))
      (forward-line)
      (beginning-of-line)
      (skip-chars-forward "| "))
  ;; (progn (require 'emms-setup) (emms-all) (emms-default-players))
  ;; (global-set-key (kbd "<f5>") 'my/emms-insert-timestamp)
  ;; (global-set-key (kbd "<f6>") 'emms-pause)
    (defun my/get-timestamp-lines ()
      (save-excursion
        (goto-char (point-min))
        (let (temp result)
          (while (re-search-forward "^ *|? *\\(\\([0-9]\\):\\([0-9][0-9]\\):\\([0-9][0-9]\\)\\) *|? *\\(.*?\\) *|?$" nil t)
            (setq temp (cons (list :time
                                   (+
                                    (* 60 60 (string-to-number (match-string 2)))
                                    (* 60 (string-to-number (match-string 3)))
                                    (string-to-number (match-string 4)))
                                   :start-ts (match-string 1)
                                   :raw (match-string 5)
                                   :text (replace-regexp-in-string
                                          "\\[\\|\\]\\| (<.*?>)" ""
                                          (save-match-data (org-export-string-as (save-match-data (match-string 5)) 'ascii t))))
                             temp)))
          (reverse temp))))
  (defun my/calculate-duration-and-end-ts (temp)
    (loop for i below (1- (length temp)) do
          (plist-put (elt temp i) :end-ts (plist-get (elt temp (1+ i)) :start-ts))
          (plist-put (elt temp i) :duration (- (plist-get (elt temp (1+ i)) :time) (plist-get (elt temp i) :time))))
    temp)

    (defun my/generate-subtitles (lines)
      (interactive (list (my/get-timestamp-lines)))
      (save-excursion
        (goto-char (point-min))
        (let ((temp
               (my/calculate-duration-and-end-ts
                (seq-remove (lambda (o) (string-match "file:" (plist-get o :raw)))
                            lines))))
          (with-current-buffer (find-file "subtitles.srt")
            (erase-buffer)
            (insert
             (s-join ""
                     (loop for i below (1- (length temp)) collect
                           (format "%d\n%s,000 --> %s,000\n%s\n\n"
                                   (1+ i)
                                   (plist-get (elt temp i) :start-ts)
                                   (plist-get (elt temp i) :end-ts)
                                   (plist-get (elt temp i) :text)))))
            (save-buffer)))))
(my/generate-subtitles (my/get-timestamp-lines))

(defun my/include-subtitles ()
  (interactive)
  "ffmpeg -y -i with-audio.webm -i subtitles.srt -c:v copy -c:a copy emacs-conf-2020-emacs-news-highlights-sacha-chua.webm")

(defun my/generate-video (lines audio)
  (interactive (list (my/get-timestamp-lines) "run"))
  (let ((result (my/calculate-duration-and-end-ts
                 (seq-filter (lambda (o) (string-match "file:" (plist-get o :raw)))
                             lines)))
        output)
    ;;      (setq result (seq-take result 5))
    (setq output (format "ffmpeg -y %s -i %s -filter_complex \"%s;%sconcat=n=%d:v=1[v]\" -map '[v]' -map %d:a -shortest -vsync 1 -c:a copy -c:v vp8 with-audio.webm"
                         (mapconcat (lambda (o)
                                      (if (string-match "file:\\([^]]+*\\)" (plist-get o :raw))
                                          (format "-loop 1 -t %d -framerate 5 -i '%s'"
                                                  (or (plist-get o :duration) 0)
                                                  (match-string 1 (plist-get o :raw))))) result " \\\n")
                         audio
                         (s-join ";"
                                 (loop for i below (1- (length result)) collect
                                       (format "[%d:v]scale=1280:720:force_original_aspect_ratio=decrease,setsar=sar=1,pad=1280:720:(ow-iw)/2:(oh-ih)/2[r%d]" i i)))
                         (s-join ""
                                 (loop for i below (1- (length result)) collect 
                                       (format "[r%d]" i)))
                         (1- (length result))
                         (length result)))
    output))
(let ((lines (my/get-timestamp-lines)))
  ;(my/generate-subtitles lines)
  (funcall
     (cdr (assoc run '(("copy" . kill-new) ("show" . identity) ("run" . shell-command))))
     (concat (my/generate-video lines audio)
             ";" (my/include-subtitles))))