Don't consider the guidelines as strict requirements. General recommendation is to provide the highest quality that is practical for you to upload. It's that simple; whatever you upload is going to be re-encoded anyway and YouTube will almost always accept whatever you give them. That means you either upload the original content, or if the original is too big you can re-encode it using a high quality. Example using ffmpeg:
ffmpeg -i input -c:v libx264 -crf 18 -preset slow -c:a copy output.mkv See FFmpeg Wiki: H.264 for more details–specifically the -crf and -preset options. Notice that I simply copied the audio, but you may choose to re-encode it if the source contains uncompressed audio.
Your player may not be able to play the output for various reasons, but YouTube certainly will.