When spliting MP4s with ffmpeg how do I include metadata?
FFmpeg should carry over metadata automatically (so try it without -map_metadata and see if that works), but if it doesn't you should try using -map_metadata 0 rather than -map_metadata 0:0 - the :0 there refers to the first data stream (probably the video), and ffmpeg might be trying to copy over only the stream-specific metadata, rather than that of the whole file.