make_gif.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import cv2\n",
    "import os"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "infile = '/Users/misterbrainley/Movies/clucky.mov'\n",
    "outfile = 'clucky.gif'\n",
    "prefix = 'tmp_makegif'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "shrink = 6\n",
    "frame_rate = 7\n",
    "start_frame = 3\n",
    "stop_frame = 57"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "# get file dimensions\n",
    "vf = cv2.VideoCapture(infile)\n",
    "h = vf.get(cv2.CAP_PROP_FRAME_HEIGHT)\n",
    "w = vf.get(cv2.CAP_PROP_FRAME_WIDTH)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create an image stack using ffmpeg\n",
    "cmd = 'ffmpeg -i %s -s %dx%d -r %d -f image2 %s_%%04d.png'\n",
    "os.system(cmd % (infile, w//shrink, h//shrink, frame_rate, prefix))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "# determine number of output images\n",
    "files = os.listdir('.')\n",
    "n_files = len(list(filter(lambda s: prefix in s, files))) + 1\n",
    "if stop_frame is None:\n",
    "    stop_frame = n_files"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
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      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "# create gif using image magick\n",
    "cmd = 'convert -delay 1x%d `seq -f %s_%%04g.png %d 1 %d` -coalesce -layers OptimizeTransparency %s'\n",
    "os.system(cmd % (frame_rate, prefix, start_frame, stop_frame, outfile))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "# cleanup png files\n",
    "files = os.listdir('.')\n",
    "for f in filter(lambda s: prefix in s, files):\n",
    "    os.remove(f)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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