My kdenlive mp4 render settings for YouTube
f=mp4movflags=+faststartacodec=aacar=48000ab=384kvcodec=libx264progressive=1preset=fastthreads=0crf=23g=15bf=2meta.preset.extension=mp4meta.preset.note=H.264/AAC MP4 for YouTube
f=mp4movflags=+faststartacodec=aacar=48000ab=384kvcodec=libx264progressive=1preset=fastthreads=0crf=23g=15bf=2meta.preset.extension=mp4meta.preset.note=H.264/AAC MP4 for YouTube
ffmpeg -loop 1 -i images/img13.jpg -i audio.mp3 -c:v libx264 -c:a copy -shortest out.mp4