I am trying to convert a series of pngs into an mp4 video. I am using ffmpeg, and want to encode the video with the x264 codec. Using the command ffmpeg -y -r 30 -b 1800k -i _tmp%04d.png -vcodec libx264 out.mp4 I get the following warning message Incompatible pixel format 'bgra' for codec 'libx264', auto-selecting format 'yuv420p' My…