YouTube will accept just about anything you throw at it… but you won’t get what you expect if you go *over* their guidelines. If you stay within their guidelines, you will get exactly what you uploaded. What’s the difference? YouTube will re-encode anything over their guidelines — they use an open source (cheap) encoder and they probably use Single Pass (Faster Encode). It’s generally awful… and embarrassing.

Export from Motion or Final Cut Pro (neither one gives options to fine tune the export) as ProRes LT or better. Use Compressor (choke — I prefer Quicktime 7 Pro which will become obsolete and unusable in the next OS).

Set the Codec to H.264.

Set the Data Rate to be 8000 kbits/sec. [Macs do such a good job of compressing, you can probably start with a higher value — I typically start at 12,600, but if the end result goes one bit over 8000, you have to do it again at a lower bitrate. I’ll go down to 9600 next before going down to 8000.]

Set the frame rate to be the same as your project [Note: 29.97 is becoming obsolete – try to stay with whole frame rates in the future, like: 24, 25, 30, 48, 50, 60, etc.]

Set Key Frames to Automatic and make sure you turn OFF Frame Reordering.

Compressor Quality should be set to High (Best is only available with Automatic Data Rates) and

Encoding to Best Quality (Multi-pass).

Audio needs to be set to AAC 48kHz. You can get away with Render Settings: Normal and Variable Bit Rate, 128kbits/sec even though YT allows says they require 192kbits/sec Constant Bit Rate (I’ve never noticed that they re-encode for this variation and it gives the video an allowance for a little more data rate).

If you have Quicktime 7 Pro, make sure the dimensions are 1920 x 1080 HD and NOT HD 1920 x 1080 16:9 (they are not the same thing – one is actual pixels and the other has broadcast TV overscan calculated into it — it’s cropped.) There’s also a Setting for Preserve Aspect Ratio using — I have this always set to Letterbox. This may not be necessary anymore, but once upon a time it was.

If all you have is Compressor, then get some better advice from people who know how to get the best results. I’m not one of them. I used to try to use Compressor back with FCP7 and I just could never get the results as good as with QT7Pro. (Too many options to fiddle with… :P).

Export the video as a .MOV (lowercase is fine) file, not MP4. Google’s YouTube page is oriented more towards Windows users. YouTube handles MOV.

When you upload a correctly encoded file, when it finishes uploading, it only takes YouTube a minute or two to finish making things like the thumbnail and getting it ready for public viewing. If it takes any longer than that, say almost as long as it took you to transcode from ProRes to H.264, then YT is busy re-encoding your video an you failed to deliver the best possible file for uploading. Simple as that. I’ve been uploading videos to youtube for over 10 years now and actually performed experiments to figure out what was actually going on (and how I figured out the difference between HD and HD 16:9 designations because there would be an annoying line through the video for the broadcast versions…)

About h.264 compression:

I’ve had some files I’ve encoded that come in under 5Mbps (Mbits/sec) no matter how much Data Rate I give the encoder all the way up to Automatic. If you set the Data Rate to 12,600 and it comes in anywhere under 8000, take it unless for some rare reason you really need it more. In most cases, if your video needs higher bitrates to look good: there’s a lot of action in it or gradients or just a lot of screen area where there are a lot of frame to frame changes and nothing you can do is going to make it look perfect *under* 8000. (I have a Comic Book effect that cannot use anything less than a bitrate setting of 50000 — and that was for 720p!) Without “selling” you on the effect, here is a direct link to the video:

https://fcpxtemplates.com/storemedia/ComicBookDemoHD36-720.mov

It could not be played on YouTube OR Vimeo — both would turned it to mush. Here is the same video on YouTube — https://youtu.be/6FQimStoRAo (and Vimeo was worse).

Final Cut Pro and Motion export H.264 at its highest quality possible. FCPX generates something in the neighborhood, on average, of 40-50Mbits/sec. Super fine (archive) quality H.264. I do not know what difference there is if you upload directly to YouTube, if FCPX tries to come in under the YT requirement limits, but I’ve never gotten the quality I want doing so, in any format, so I have to guess that it doesn’t. “Professional” (Enterprise?) youtube accounts will accept any data rate and there are no other limitations to what you can upload if you have one of those accounts. I don’t. Most people don’t. (I’m not even sure they still offer the plan — I can’t find it anywhere but I remember it being offered to me a few years back.)

HTH