Slice & convert given video files to .gif format. GIF 짤방 제조용 스크립트. (Tested on OSX & ffmpeg built with 'brew install ffmpeg --with-libvpx --with-libvorbis')

2gif.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

# 2gif.rb
#
# https://gist.github.com/meinside/62c442900e6d73d5d3d9
#
# Convert video to gif.
# * referenced: http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html
#
# $ brew install ffmpeg --with-libvpx --with-libvorbis --with-faac
# $ brew install gifsicle
# $ gem install thor
#
# created on : 2014.11.27.
# last update: 2022.07.06.
#
# by [email protected]

# * how to encode video with subtitles:
#
# $ ffmpeg -i subtitle.smi subtitle.srt
#
# $ ffmpeg -i input.mp4 -vf "subtitles=subtitle.srt:force_style='FontName=맑은 고딕,Fontsize=30'" \
#          -c:V libx264 -c:a aac output.mp4

require 'bundler/setup'
require 'thor'

# ffmpeg module
module Ffmpeg
  # ToGif class
  class ToGif < Thor
    DEFAULT_FPS = 18
    PALETTE_STATS_MODE = 'full' # or 'diff'
    PALETTE_DITHERING = 'floyd_steinberg' # or 'bayer', 'heckbert', 'sierra2', 'sierra2_4a'
    SCALE_FILTER = 'lanczos'

    default_task :convert

    desc 'convert', 'convert a video file to .gif format'
    long_desc <<~CONVERT_DESC
      * Usage

      # will convert original.mp4 to original.mp4.gif

      $ #{__FILE__} -i original.mp4


      # will convert original.mp4 to converted.gif

      $ #{__FILE__} -i original.mp4 -o converted.gif


      # will convert original.mp4 into 320x240

      $ #{__FILE__} -i original.mp4 -w 320 -h 240


      # will slice & convert original.mp4 from 01:20:40.0 to 01:20:50.0 (for 10.0 seconds)

      $ #{__FILE__} -i original.mp4 -s 01:20:40.0 -d 10.0


      # will crop resulting gif

      $ #{__FILE__} -i original.mp4 -s 01:20:40.0 -d 10.0 -c 100,100+320x480
    CONVERT_DESC
    method_option :in_filepath, type: :string, aliases: '-i', desc: 'input video file\'s path', required: true
    method_option :out_filepath, type: :string, aliases: '-o', desc: 'output video file\'s path'
    method_option :start, type: :string, aliases: '-s', desc: 'start point of input video'
    method_option :duration, type: :string, aliases: '-d', desc: 'length of input video'
    method_option :width, type: :numeric, aliases: '-w', desc: 'width of output video'
    method_option :height, type: :numeric, aliases: '-h', desc: 'height of output video'
    method_option :fps, type: :numeric, aliases: '-f', desc: "number of frames per second (default: #{DEFAULT_FPS})"
    method_option :rotation, type: :numeric, aliases: '-r',
                             desc: 'rotate given video counter-clockwisely (90, 180, 270 degrees)'
    method_option :crop, type: :string, aliases: '-c',
                         desc: 'crop the resulting gif (X,Y+WxH format, eg. 100,100+320x480)'
    method_option :test, type: :boolean, aliases: '-t', desc: 'print ffmpeg command instead of running it'
    def convert
      # time
      start = options[:start] ? parse_time(options[:start]) : nil
      duration = options[:duration] ? parse_time(options[:duration]) : nil
      timing = "#{start ? "-ss #{start}" : ''} #{duration ? "-t #{duration}" : ''}".strip
      fps = options[:fps] ? options[:fps].to_i : DEFAULT_FPS

      # size
      width = options[:width]
      height = options[:height]

      # rotation
      rotation = case options[:rotation]
                 when 90
                   'transpose=1'
                 when 180
                   'transpose=1,transpose=1'
                 when 270
                   'transpose=2'
                 end

      # crop
      crop = options[:crop] || nil
      if crop && crop !~ /^(\d+),(\d+)\+(\d+)x(\d+)$/
        puts "crop parameter should be in 'x,y+widthxheight' format, but is: #{crop}"
        exit 1
      end

      # filepath
      in_filepath = File.expand_path(options[:in_filepath])
      palette_filepath = File.join('/tmp', "#{File.basename(in_filepath, '.*')}_palette.png")
      out_filepath = options[:out_filepath] ? File.expand_path(options[:out_filepath]) : "#{in_filepath}.gif"

      # filters
      filters = ["fps=#{fps}", "scale=#{width || -1}:#{height || -1}:flags=#{SCALE_FILTER}",
                 rotation].compact.join(',')

      # run ffmpeg
      cmd_ffmpeg = "ffmpeg #{timing} -i \"#{in_filepath}\" -vf \"#{filters},palettegen=stats_mode=#{PALETTE_STATS_MODE}\" -y \"#{palette_filepath}\" && ffmpeg #{timing} -i \"#{in_filepath}\" -i \"#{palette_filepath}\" -lavfi \"#{filters},paletteuse=dither=#{PALETTE_DITHERING} [x]; [x][1:v] paletteuse\" -r #{fps} \"#{out_filepath}\" -y"

      # run gifsicle
      cmd_gifsicle = "gifsicle --crop \"#{crop}\" \"#{out_filepath}\" --output \"#{out_filepath.gsub('.gif',
                                                                                                     '_cropped.gif')}\""

      # run or show command
      if options.test?
        puts '* will run ffmpeg command:'
        puts cmd_ffmpeg.to_s
        puts
        puts '* and gifsicle command:'
        puts cmd_gifsicle.to_s if crop
      elsif crop
        `#{cmd_ffmpeg} && #{cmd_gifsicle}`
      else
        `#{cmd_ffmpeg}`
      end
    end

    private

    def parse_time(time)
      separated = (time || '').split(':')

      seconds = (separated[-1] || 0).to_f
      minutes = (separated[-2] || 0).to_i
      hours = (separated[-3] || 0).to_i

      minutes += seconds / 60
      hours += minutes / 60
      seconds = seconds % 60.0
      minutes = minutes % 60
      format('%02d:%02d:%07.4f', hours, minutes, seconds)
    end
  end
end

trap('SIGINT') do
  puts
  exit 1
end
Ffmpeg::ToGif.start(ARGV)