ffmpegで適当なmp4ファイルを作る

アップデートにちょうどいいサンプル動画を探すのめんどくさい

ffmpeg -f lavfi -i color=black:1280x720:rate=30:duration=5 -c:v libx264 -pix_fmt yuv420p black.mp4

ffmpeg \
  -f lavfi -i color=white:1280x720:rate=30:duration=1 \
  -f lavfi -i color=black:1280x720:rate=30:duration=1 \
  -f lavfi -i color=white:1280x720:rate=30:duration=1 \
  -f lavfi -i color=black:1280x720:rate=30:duration=1 \
  -f lavfi -i color=white:1280x720:rate=30:duration=1 \
  -filter_complex "[0:v][1:v][2:v][3:v][4:v]concat=n=5:v=1:a=0[out]" \
  -map "[out]" -c:v libx264 -pix_fmt yuv420p alternating.mp4