Class: Lolcommits::AnimatedGif

Inherits:
Object
  • Object
show all
Defined in:
lib/lolcommits/animated_gif.rb

Instance Method Summary collapse

Instance Method Details

#create(video_path:, output_path:) ⇒ Object 



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# File 'lib/lolcommits/animated_gif.rb', line 3

def create(video_path:, output_path:)
  unless File.exist?(video_path)
    debug "**warning** unable to create animated gif, no video at #{video_path}"
    return
  end

  debug "creating animated gif at #{output_path}"
  system_call "ffmpeg -nostats -v quiet -i \"#{video_path}\" \"#{frames_dir}/%09d.png\" > #{null_string}"

  # use fps to set delay and number of frames to skip (for lower filesized gifs)
  fps   = video_fps(video_path)
  skip  = frame_skip(fps)
  delay = frame_delay(fps, skip)
  debug "animated gif choosing every #{skip} frames with a frame delay of #{delay} (video fps: #{fps})"

  # create the looping animated gif from frames (delete frame files except every #{skip} frame)
  Dir["#{frames_dir}/*.png"].each do |frame_filename|
    basename = File.basename(frame_filename)
    frame_number = basename.split(".").first.to_i
    File.delete(frame_filename) if frame_number % skip != 0
  end

  # convert to animated gif with delay and transparency optimising
  MiniMagick.convert do |convert|
    convert << "#{frames_dir}/*.png"
    convert.layers "OptimizeTransparency"
    convert.delay delay
    convert.loop 0
    convert.coalesce
    convert << output_path
  end

  # remove tmp frames dir
  FileUtils.rm_rf(frames_dir)
end