Screencasting + Gif = Gifcasting :: using ffcast + ffmpeg in emacs

gifcast.el

(defun sha/screencast (&optional output-file)
  (let ((output-file
         (or output-file
             (concat "/tmp/"
                     (format "%S" (abs (random)))
                     ".mp4"))))
    (message  "screen-cast started")
    (start-process "screencasting" 
                   (get-buffer-create "*screencast-buffer*")
                   "ffcast"
                   "rec"
                   output-file)
    output-file))

(defun sha/screencast-handler ()
  (interactive)
  (if (process-status "screencasting")
      (progn
        (process-send-string "screencasting" "q")
        (message "screen-cast stopped"))
    (sha/screencast)))

(global-set-key (kbd "s--") 'sha/screencast-handler )

(defun sha/gif-encode (input-file &optional scale frames)
  (setq sha/gif/frames (or frames "15"))
        (setq sha/gif/scale (or scale "720"))
        (setq sha/gif/palette "/tmp/palette.png")
        (setq sha/gif/filters
         (concat "fps=" sha/gif/frames
                 ",scale=" sha/gif/scale
                 ":-1:flags=lanczos"))
    (set-process-sentinel
     (start-process "gifcasting" 
                    (get-buffer-create "*gifcast-buffer*")
                    "ffmpeg" "-i" input-file
                    "-vf" (concat sha/gif/filters ",palettegen")
                    "-y" sha/gif/palette)
     (lambda (process event)
       (when (= 0 (process-exit-status process))
         (set-process-sentinel
          (start-process "gifcasting"
                         (get-buffer-create "*gifcast-buffer*")
                         "ffmpeg" "-i" input-file
                         "-i" sha/gif/palette
                         "-lavfi" (concat sha/gif/filters
                                          "[x]; [x][1:v] paletteuse")
                         "-y" (concat input-file ".gif"))
          (lambda (process event)
            (when (= 0 (process-exit-status process))
              (message "gif-casting done"))))))))

(defun sha/screencast-to-gif (&optional scale frames)
  (interactive)
  (sha/gif-encode (read-file-name "Enter .mp4 path : " "/tmp/")
                  scale frames)
  (message "Gif-casting started" ))