SEE (actually, WATCH) https://www.youtube.com/watch?v=9SAUdx1FBis

git.demo.pub.ffmp.rb

|o|
video_output_options = {resolution: Ffmprb::HD_4K, fps: 60, encoder: 'huffyuv'}

class InputSlideCropper
  def initialize(inp, cols = 1, rows = 1)
    fail "not much of a slideshow"  unless
      rows > 0 && cols > 0 && rows + cols > 2
    @inp = inp
    @h1 = 1.0/(@rows = rows)
    @w1 = 1.0/(@cols = cols)
  end
  def slide(col = 1, row = 1)
    fail "hey, I don't have that many (#{col}, #{row}) cols/rows, just #{@cols}, #{@rows}"  unless
      row <= @rows && col <= @cols
    @inp.crop top: @h1 * (row - 1), bottom: @h1*(@rows - row), left: @w1 * (col - 1), right: @w1*(@cols - col)
  end
end

inp_screen =
  input('/media/2023/08/09/Screen Recording 2023-08-09 at 15.15.48.mov')
    .mute
inp_ols = InputSlideCropper.new(
  input('/media/2023/08/09/media_ 2023_08_09 proj_ ghlr_doc_presenting_git-demo - Page 1.png', loop: true),
  2, 6
)
inp_vo =
  input('/media/2023/08/12/Yehoshua Barzilay Street 2.m4a')
inp_bm =
  input('/media/wwardlaw.com/MellowDub23.aif')
    .volume(0.09)

output o, video: video_output_options do

  overlays = []
  curr_time = 0

  define_singleton_method :paste do |from, to, pace=1, inp=inp_screen|
    lay inp.cut(from: from, to: to).pace(pace)
    curr_time += (to - from)/pace.to_f
  end


  overlays << [inp_ols.slide(1, 1), curr_time+1, 4]
  paste 0, 8, 4
  paste 8, 24, 8
  paste 24, 56, 16
  overlays << [inp_ols.slide(1, 2), curr_time, 16]
  paste 56, 44*60, 512
  paste 45*60+57, 46*60+7, 32
  paste 46*60+42, 46*60+54, 32
  paste 47*60+11, 53*60+4, 64
  paste 73*60, 73*60+23, 8
  overlays << [inp_ols.slide(1, 3), curr_time+4, 8]
  paste 73*60+23, 74*60+34, 2
  paste 75*60+20, 76*60+7, 2
  paste 76*60+26, 76*60+37, 2
  paste 77*60+31, 77*60+32, 2
  paste 78*60+45, 78*60+53, 1
  paste 79*60+18, 79*60+26, 2
  paste 79*60+41, 80*60+17, 1
  paste 80*60+17, 80*60+31, 4
  overlays << [inp_ols.slide(1, 4), curr_time, 8]
  paste 80*60+41, 81*60+10, 2
  paste 81*60+10, 81*60+17, 1
  paste 81*60+30, 81*60+36, 1
  overlays << [inp_ols.slide(1, 5), curr_time, 16]
  paste 81*60+42, 82*60+10, 1
  paste 82*60+10, 82*60+12, 2
  paste 82*60+12, 82*60+16, 4
  paste 82*60+16, 82*60+24, 8
  paste 82*60+24, 82*60+40, 16
  paste 82*60+40, 127*60, 512
  paste 127*60, 127*60+8, 16
  paste 127*60+8, 127*60+12, 4
  paste 127*60+12, 127*60+14, 1
  paste 132*60+12, 132*60+24, 2
  overlays << [inp_ols.slide(1, 6), curr_time, 16]
  paste 132*60+43, 132*60+57, 1
  paste 133*60+24, 133*60+40, 1
  overlays << [inp_ols.slide(2, 2), curr_time+1, 16]
  paste 139*60+50, 140*60+39, 1
  overlays << [inp_ols.slide(2, 3), curr_time, 16]
  paste 141*60+4, 141*60+34, 2
  paste 141*60+42, 142*60+7, 1
  paste 146*60+6, 146*60+28, 1
  paste 147*60+43, 148*60+2, 1
  overlays << [inp_ols.slide(2, 4), curr_time, 16]
  paste 148*60+2, 148*60+46, 2
  paste 149*60+48, 149*60+52, 1
  paste 150*60+24, 151*60+15, 1
  overlays << [inp_ols.slide(2, 5), curr_time, 16]
  paste 151*60+53, 152*60+23, 1
  paste 152*60+30, 152*60+40, 2
  paste 153*60+4, 153*60+12, 1
  paste 153*60+14, 153*60+19, 1
  paste 153*60+23, 153*60+33, 1
  overlays << [inp_ols.slide(2, 6), curr_time, 16]
  paste 153*60+42, 154*60+21, 1
  paste 154*60+25, 154*60+38, 1


  # NOTE suppose the logo is at (2, 1),
  # the overlays are sequential and at least couple of seconds apart
  # and the logo comes up after the first overlay and disappears before the last
  inp_logo = inp_ols.slide(2, 1)
  before_at = 0
  overlays.each do |inp, at, len|
    unless before_at == 0 || (at - before_at) < 4
      overlay inp_logo.cut(to: at - before_at - 2), at: before_at + 1
    end
    overlay inp.cut(to: len), at: at
    before_at = at + len
  end

  overlay inp_bm.cut(to: curr_time - 6*2), at: 6
  overlay inp_vo
end