Trying to upload best quality to YouTube

[Sham 69]

No matter what you upload to YouTube, the site will further compress it based on pixel size. After using a Yadif deinterlace filter, I upscaled a DVD clip from 720:576 up to 2160:1620, changed the frame rate from 25 to 60, and changed the bit rate from 5000 to constant 20,000. I chose ultra fast mode.

Is there anything I change here to make the quality on YouTube identical to the original source?

[butterw]

Check the displayed Aspect Ratio is correct

Crop black bars if letterboxed.

I don't think increasing the frame rate to 60fps helps.

Try using single pass mode (ex: crf=18). I would use slow or slower x264 preset.

[alexstorm]

I believe Youtube might convert automatically to V9 codec.  It may be that unless you have that codec, they will encode a new copy.  They use to accept H.264 if the encoding rate did not exceed their maximum per video size.  If you are using variable bit rate, you might trigger their system to reencode.  A standard bit rate for Youtube videos should be listed on their site video encoding page somewhere.  Have you tried looking up their FAQ source for professional videographers?  I remember seeing some guidelines on their site.