SHELL

ffmpeg convert mp4 to gif

ffmpeg -ss 30 -t 3 -i input.mp4 -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 output.gif

merge gif with mp4 using ffmpeg

ffmpeg -i input.mp4 -i eq.gif -filter_complex "[1]format=rgba,colorchannelmixer=aa=0.5[front];[0][front]overlay=x=(W-w)/2:y=H-h,format=yuv420p" output.mp4

Convert mpg / mp4 to gif with ffmpeg

ffmpeg -ss 30 -t 3 -i input.mp4 -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 output.gif