The encoding of your source media failed as encoding from H.264 to ProRes 4444 is not supported.

[Todd Kopriva]

It’s a restriction that Apple puts on the use of their codecs.

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Todd Kopriva, Adobe Systems Incorporated
After Effects product manager and curmudgeon
After Effects team blog
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[Justin Crowell]

Oh wow, that’s really bizarre…I wish the error handling was a bit more clear.

Thanks, though, Todd.

Editor, Motion Graphics Designer, Director
JustinCrowell.com

[Ryan Holmes]

You should be able to transcode to ProRes422 or (HQ) from h.264.

Out of curiosity why would want to go from h.264 to ProRes 4×4? Obviously, you’re not gaining quality. I’m just curious what the reason for that codec is versus a standard ProRes or (HQ) (both of which are still over kill for footage originating in h.264, imho).

Ryan Holmes
http://www.ryanholmes.me
@CutColorPost

[Justin Crowell]

Understood. I’m testing some Gh4 footage upon which there will be a ton of roto and green-screen work. So, just seeing if the keys we can pull are better done when there is some increased interpolated chrominance data. If it were a simple cut and color, I’d be in full agreement. Just want to see how AE/Nuke handle things.

Most likely I’ll just end up going with HQ.

Editor, Motion Graphics Designer, Director
JustinCrowell.com

[Jan Vork]

Today I came across the very same limitation.

My arguments to convert H.264 to ProRes4444:
I am working on a montage with 1920×1080 ProRes4444 footage, where some shots are filmed with a drone-camera that outputs 4K H.264.
I want my footage to all have the same codec and resolution for the rest of the process – I have to convert anyway, so I prefer to go to the best workable codec, while losing as less data as possible. I gues the 4444 codec qualifies better for this than 422.
For grading 4444 adds more room ‘in between’ the restricted H.264 colors.
I like to think about color depth as if it where spatial resolution: converting a lo-res image to a higer res does not improve quality, but it allows to add detail.

Now I am going to render it via After Effects.

http://www.jaydude.nl