ffmpeg

ffmpeg -ss 00:00:00 -t 00:00:10 -i intro.webm -i main1.mp4 -i logo.png -filter_complex "[1]split[original][copy];[copy]scale=ih*16/9:-1,crop=h=iw*9/16,gblur=sigma=80,eq=saturation=0.9[background];[background][original]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2[m1];[0][m1]scale2ref=iw:ih[intro][main];[intro]drawbox=t=fill[intro-bg];[0][intro-bg]scale2ref=iw:ih:force_original_aspect_ratio=decrease:flags=spline[intro][intro-bg];[intro-bg][intro]overlay=x='(W-w)/2':y='(H-h)/2'[intro-resized];[main][2]overlay=main_w-overlay_w-10:10[omain];[intro-resized][0:a][omain][1:a]concat=n=2:v=1:a=1:unsafe=1[v][a]" -map '[v]' -map '[a]' -y -movflags +faststart -acodec aac -vcodec h264_nvenc -cbr true -b:v 1000k -bt 1000k -y -2pass true -threads 16 -profile:v high -r 30 -preset medium output.mp4